Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
DSpace
UBCV
Manco, Julián David
Master of Science - MSc
University of British Columbia
The El Alacrán Deposit is located in the San Matías District (SMD) in the Northern Western Cordillera of Colombia and is associated with a Late Cretaceous pre-accretional island arc environment of the Calima Terrane. The El Alacrán Deposit comprises a replacement style of mineralization that trends northerly for about 1 km and has a vertical extent of >200 m. Ore is primarily hosted within a calcareous volcanoclastic sequence (Unit 2), which was intruded by a series of andesitic sills and tonalites (e.g. the El Alacrán Oeste Tonalite). The El Alacrán Deposit contains total resources of 82.15 Mt of 0.73-0.49% CuEq which represents ~ 87% of the total mineral resources of the SMD (94.9 Mt@ 0.71% Eq. Cu, Cordoba Minerals Corp., 2019b). The genesis and evolution of the El Alacrán Deposit had not been properly established, thus making it challenging to explore for similar deposits in the SMD. This thesis presents the results of petrographic, geochronologic (U-Pb, Ar-Ar, Re-Os), and isotopic (Pb, S) characterization of the El Alacrán Deposit ores and related representative units and prospects of the SMD. The hydrothermal alteration assemblages of the El Alacrán Deposit are zoned from early high-temperature calc-silicate alteration to a subsequent calc-potassic, sericitic, and carbonate base metal (CBM) alteration. The mineral paragenesis indicates at least three different gold precipitation events: 1) associated with pyrite – mushketovite in the calc-silicate alteration; 2) precipitation of Au electrum with chalcopyrite, traces of the pyrrhotite and molybdenite in the calc-potassic and sericitic alteration; and 3) as visible grains in the carbonate base metal-related alteration. The mineral paragenesis, Ar-Ar dates, Pb and S isotopic composition (δ34S ~ 11‰) from the El Alacrán Deposit can be explained by two different magmatic fluids with a marked interaction with seawater. The magmatic fluids might have been sourced from the El Alacrán Oeste Tonalite and a concealed intrusion (Px2) that is possibly associated with the Montiel E porphyry event (~68-70 Ma). The results suggest a hybrid model between iron oxide copper gold (IOCG)-style and a carbonate replacement deposit (CRD) that is associated with a porphyry source can best explain the El Alacrán Deposit mineralizations.
GEOLOGY, GEOCHRONOLOGY AND GEOCHEMISTRY OF THE EL ALACRÁN DEPOSIT, SAN MATÍAS DISTRICT, CORDOBA-COLOMBIA by Julián David Manco B.Sc., Universidad Nacional de Colombia-Medellín, 2010 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Geological Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2020 © Julián David Manco, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis/dissertation entitled: GEOLOGY, GEOCHRONOLOGY AND GEOCHEMISTRY OF THE EL ALACRÁN DEPOSIT, SAN MATÍAS DISTRICT, CORDOBA-COLOMBIA submitted by Julian David Manco in partial fulfillment of the requirements for the degree of Master of Science in Geological Sciences Examining Committee: Dr. Craig Hart Supervisor. Mineral Desposit Research Unit (MDRU) Director; EOAS department professor, UBC. Dr. Hildebrando Leal Mejía Co-supervisor, Mineral Desposit Research Unit (MDRU) research associate. Dr. Greg Dipple Supervisory Committee Member, Bradshaw Research Initiative for Minerals and Mining (BRIMM) Director; EOAS department professor, UBC. Dr. Lori Kennedy Additional Examiner, EOAS Department professor. Additional Supervisory Committee Members: Supervisory Committee Member Supervisory Committee Member iii Abstract The El Alacrán Deposit is located in the San Matías District (SMD) in the Northern Western Cordillera of Colombia and is associated with a Late Cretaceous pre-accretional island arc environment of the Calima Terrane. The El Alacrán Deposit comprises a replacement style of mineralization that trends northerly for about 1 km and has a vertical extent of >200 m. Ore is primarily hosted within a calcareous volcanoclastic sequence (Unit 2), which was intruded by a series of andesitic sills and tonalites (e.g. the El Alacrán Oeste Tonalite). The El Alacrán Deposit contains total resources of 82.15 Mt of 0.73-0.49% CuEq which represents ~ 87% of the total mineral resources of the SMD (94.9 Mt@ 0.71% Eq. Cu, Cordoba Minerals Corp., 2019b). The genesis and evolution of the El Alacrán Deposit had not been properly established, thus making it challenging to explore for similar deposits in the SMD. This thesis presents the results of petrographic, geochronologic (U-Pb, Ar-Ar, Re-Os), and isotopic (Pb, S) characterization of the El Alacrán Deposit ores and related representative units and prospects of the SMD. The hydrothermal alteration assemblages of the El Alacrán Deposit are zoned from early high-temperature calc-silicate alteration to a subsequent calc-potassic, sericitic, and carbonate base metal (CBM) alteration. The mineral paragenesis indicates at least three different gold precipitation events: 1) associated with pyrite – mushketovite in the calc-silicate alteration; 2) precipitation of Au electrum with chalcopyrite, traces of the pyrrhotite and molybdenite in the calc-potassic and sericitic alteration; and 3) as visible grains in the carbonate base metal-related alteration. The mineral paragenesis, Ar-Ar dates, Pb and S isotopic composition (e.g. heavy δ34S ~ 11‰) from the El Alacrán Deposit can be explained by two different magmatic fluids with a marked iv interaction with seawater. The magmatic fluids might have been sourced from the El Alacrán Oeste Tonalite and a concealed intrusion (Px2) that is possibly associated with the Montiel E porphyry event (~68-70 Ma). The results suggest a hybrid model between iron oxide copper gold (IOCG)-style and a carbonate replacement deposit (CRD) that is associated with a porphyry source can best explain the El Alacrán Deposit mineralizations. v Lay Summary Global consumption of copper and gold is anticipated to increase significantly in the future. Copper and gold are formed in a range of mineral deposit types (e.g. porphyry Au-Cu, volcanogenic massive sulfide and skarn) in various regions of the planet. In northern Colombia, the El Alacrán copper- gold deposit was discovered in the San Matías District (SMD) which is a mineral district that lacked previous detailed studies. The El Alacrán Deposit exhibits an unusual set of mixed characteristics that cannot be completely associated to a single mineral deposit model type. This thesis research applies scientific tools to understand the physical and chemical conditions under which the El Alacrán Deposit was formed. This characterization can contribute to improved mineral exploration success and increase the chances of discoverying more deposits of this type in this part of Colombia, and potentially other regions of the world with similar geology. vi Preface The thesis objectives and research strategy presented herein were jointly established between the author, Cordoba Minerals Corp., High Power Exploration (HPX), and the Mineral Deposit Research Unit (MDRU) at The University of British Columbia (UBC). The author participated in the core logging in the El Alacrán Deposit and other prospects of the SMD. The author conducted the sampling during three sampling campaigns: 1) in April-May, 2017; 2) September 2017; and 3) January 2018. Cordoba Minerals Corp. provided information and datasets to the research effort, including: multi-element geochemistry of drill holes and the lithological model for the El Alacrán Deposit. All the sample preparation, analytical work and interpretation of results were conducted by the author at The University of British Columbia, except for the U-Pb, Ar-Ar and Re-Os geochronology, lithogeochemistry, and Pb and S isotopic analysis. Samples for sulphur isotopic analysis were sent to the Queen’s Facility for Isotopic Analysis (QFIR) at Queen’s University in Kingston, Ontario. Lithogeochemical analyses were carried out by Bureau Veritas Minerals Ltd., in Vancouver, BC, Canada. Short-wave infrared spectroscopy (SWIR) was completed with a desktop TerraSpec at the Mineral Deposit Research Unit of The University of British Columbia. Scanning Electron Microscopy (SEM), Electron Probe Micro-Analysis (EPMA), Cathodoluminescence (CL), petrography, rock imaging and scanning, zircon separation, and fluid inclusion petrography were also undertaken in various facilities of UBC’s Earth, Ocean and Atmospheric Sciences Department (EOAS) and the Mineral Deposit Research Unit (MDRU) by the author supported by MDRU staff. LA-ICP-MS U-Pb zircon and 40Ar-39Ar geochronology analysis were carried out by Dr. Robert G. Lee and Dr. Janet Gabites at the Pacific Centre for Isotopic and Geochemical Research (PCIGR) of UBC. Re-Os molybdenite geochronology vii analyses were carried out by Dr. Robert Creaser at the Canadian Centre for Isotopic Microanalysis (CCIM) of the University of Alberta. Thesis supervision was provided by Dr. Craig J.R. Hart, MDRU Director, with considerable support from Dr. Hildebrando Leal-Mejía (MDRU Research Associate), and Committee members including Dr. Gregory Dipple (UBC Professor) and Dr. Peter Winterburn† (MDRU-UBC NSERC/Acme Labs/Bureau Veritas Minerals Executive Industrial Research Chair in Exploration Geochemistry). HPX’s Charles Foster (VP of exploration), Graham Boyd (Principal Geologist), Mark Gibson (COO), and Eric Finlayson (President and Cordoba Minerals Corp. Director), provided key company support and guidance. The Cordoba Minerals Corp., exploration team in Colombia also provided significant support and feedback during fieldwork activities. viii Table of Contents Abstract ......................................................................................................................................... iii Lay Summary .................................................................................................................................v Preface ........................................................................................................................................... vi Table of Contents ....................................................................................................................... viii List of Tables ............................................................................................................................ xviii List of Figures ...............................................................................................................................xx List of Abbreviations ................................................................................................................. xlii Acknowledgements ................................................................................................................... xliv Dedication ................................................................................................................................... xlv Chapter 1: Introduction ................................................................................................................1 1.1 Introduction ..................................................................................................................... 1 1.2 Location and Exploration History in San Matías District ............................................... 2 1.3 Mineral Prospects in the San Matías District .................................................................. 5 1.4 Thesis Objectives and Organization ............................................................................... 8 1.5 Approach and Methods ................................................................................................. 10 1.5.1 Company Geochemistry Database ............................................................................ 10 1.5.2 Fieldwork and Sampling ........................................................................................... 11 1.5.3 Petrography ............................................................................................................... 12 1.5.4 K-feldspar Staining ................................................................................................... 13 1.5.5 Fluid Inclusions Petrography .................................................................................... 13 1.5.6 Whole Rock Geochemistry ....................................................................................... 13 ix 1.5.7 Short Wave Infrared (SWIR) Spectral Analysis ....................................................... 14 1.5.8 SEM-EDS-BSE and EMPA ...................................................................................... 15 1.5.9 Geochronology .......................................................................................................... 15 1.5.10 S and Pb Isotope Chemistry .................................................................................. 17 1.6 Project Support.............................................................................................................. 19 1.7 Colombia Geo-tectonic Framework Review ................................................................ 19 1.8 Cretaceous to Eocene Granitoid Magmatism of Colombia .......................................... 23 1.9 Remarks of the Tectonic Framework Review .............................................................. 26 1.10 Mineral Deposits Review .............................................................................................. 28 1.10.1 Iron Oxide Copper-Gold (IOCG) deposits ........................................................... 28 1.10.1.1 IOCGs Characteristic Features ..................................................................... 32 1.10.1.2 IOCGs Tectonic Setting ................................................................................ 33 1.10.1.3 IOCGs Hydrothermal Alteration................................................................... 33 1.10.1.4 IOCGs Genetic Model .................................................................................. 34 1.10.1.5 IOCGs Occurrences in the Andean Chain .................................................... 37 1.10.2 Porphyry Copper Deposits (PCDs) ....................................................................... 38 1.10.2.1 PCDs Characteristic Features ....................................................................... 38 1.10.2.2 PCDs Tectonic Setting .................................................................................. 39 1.10.2.3 PCDs Hydrothermal Alteration..................................................................... 40 1.10.2.4 PCDs Genetic Model .................................................................................... 40 1.10.2.4.1 PCDs in Colombia ..................................................................................... 42 1.10.2.5 PCDs and IOCGs relationships ..................................................................... 48 1.10.3 Skarn Cu (Au) Deposits ........................................................................................ 49 x 1.10.3.1 Skarns Characteristic Features and Tectonic Setting .................................... 49 1.10.3.2 Skarns Hydrothermal Alteration ................................................................... 50 1.10.3.3 Skarns Genetic Model ................................................................................... 51 1.10.4 Carbonate Replacement Deposits (CRD) ............................................................. 52 1.10.4.1 CRDs Characteristic Features ....................................................................... 52 1.10.4.2 CRDs Tectonic Setting ................................................................................. 52 1.10.4.3 CRDs Hydrothermal Alteration .................................................................... 53 1.10.4.4 CRDs Genetic Model .................................................................................... 53 1.10.5 Volcanogenic Massive Sulfide (VMS) Deposit .................................................... 54 1.10.5.1 VMS Deposits Characteristic Features ......................................................... 54 1.10.5.2 VMS Deposits Tectonic Setting.................................................................... 54 1.10.5.3 VMS Deposits Hydrothermal Alteration ...................................................... 56 1.10.5.4 VMS Deposits Genetic Model ...................................................................... 56 1.11 Remarks of the Deposit Models Review ...................................................................... 57 1.12 Conclusions ................................................................................................................... 59 Chapter 2: Geology of the El Alacrán Deposit ..........................................................................61 2.1 Introduction ................................................................................................................... 61 2.2 Regional Geology Review ............................................................................................ 62 2.2.1 Permo-Triassic Units ................................................................................................ 63 2.2.1.1 The Cajamarca Complex................................................................................... 63 2.2.2 Cretaceous Units ....................................................................................................... 63 2.2.2.1 Mafic to Ultramafic Complex ........................................................................... 63 2.2.2.2 Barroso Formation ............................................................................................ 63 xi 2.2.2.3 Penderisco Formation ....................................................................................... 64 2.2.3 Paleogene Units ........................................................................................................ 64 2.2.3.1 San Cayetano Formation ................................................................................... 64 2.2.4 Neogene Units ........................................................................................................... 66 2.2.4.1 Ciénaga de Oro Formation ................................................................................ 66 2.2.4.2 Cerrito Formation.............................................................................................. 66 2.2.4.3 Sincelejo Group ................................................................................................ 66 2.3 Regional Structures Review .......................................................................................... 67 2.4 San Matías District Local Geology ............................................................................... 68 2.5 The El Alacrán Deposit Volcaniclastic Rocks .............................................................. 70 2.5.1 Unit 3: Mafic Volcanoclastic Rock Sequence .......................................................... 73 2.5.1.1 TufF+TufL: Lithic Tuff lithofacies ................................................................... 73 2.5.1.2 TufM: Mafic Tuff lithofacies ............................................................................ 74 2.5.1.3 TufA + TufP: Amygdalar Tuff lithofacies ........................................................ 74 2.5.2 Unit 2: Calcareous Volcanoclastic Rock Sequence .................................................. 74 2.5.2.1 TufF+TufC: Fine to coarse crystal tuff lithofacies ........................................... 75 2.5.2.2 TufL: Lithic Tuff lithofacies ............................................................................. 75 2.5.2.3 TufL: Lithic Tuff lithofacies ............................................................................. 77 2.5.2.4 TufD: Fiamme Tuff lithofacies ......................................................................... 77 2.5.2.5 Lim: Massive Fossiliferous Limestone lithofacies ........................................... 78 2.5.2.6 Mudsil: Laminated Limestone lithofacies ........................................................ 78 2.5.3 Unit 1: Felsic Volcanoclastic Rock Sequence .......................................................... 79 2.5.3.1 ABx: Andesitic Breccia lithofacies ................................................................... 79 xii 2.5.3.2 TufR: Rhyolite Tuff lithofacies ........................................................................ 81 2.5.3.3 RBx: Dacite Breccia lithofacies ........................................................................ 81 2.6 Intrusive rocks of the San Matías District..................................................................... 82 2.6.1 San Matías - La Jagua Magmatic Suite..................................................................... 83 2.6.1.1 The Montiel E Porphyry ................................................................................... 85 2.6.1.2 Costa Azul Porphyry ......................................................................................... 94 2.6.1.3 La Jagua Tonalite .............................................................................................. 95 2.6.2 San Jorge Magmatic Suite ........................................................................................ 97 2.6.2.1 San Jorge Quartz Diorite ................................................................................... 97 2.6.2.2 Bucaramanga Quartz Diorite .......................................................................... 100 2.6.3 Betesta-Mina Escondida Magmatic Suite ............................................................... 100 2.6.3.1 Betesta Quartz Diorite..................................................................................... 101 2.6.3.2 Mina Escondida Tonalite ................................................................................ 102 2.6.3.3 El Alacrán Oeste Tonalite ............................................................................... 103 2.6.3.4 Mafic-poor diorite sills (Sill 2) ....................................................................... 105 2.6.4 El Alacrán Norte Magmatic Suite ........................................................................... 105 2.6.4.1 El Alacrán Norte Tonalite ............................................................................... 106 2.6.4.2 Mafic-rich diorite sills (Sill 1) ........................................................................ 107 2.6.5 San Pedro - Costa Rica Magmatic Suite ................................................................. 108 2.6.5.1 Alto San Pedro Diorite .................................................................................... 108 2.6.5.2 Costa Rica Tonalite ......................................................................................... 109 2.6.6 Relationship of the volcanic rocks and intrusions of the San Matías District. ....... 110 xiii 2.6.7 Volcanic rocks of the SMD Compared to Other Volcanic Units of Western Colombia ............................................................................................................................. 112 2.6.7.1 The Barroso Formation ................................................................................... 112 2.6.7.2 Buriticá Dacite ................................................................................................ 114 2.6.7.3 Remolinos-1 Andesite ..................................................................................... 114 2.6.7.4 Planeta Rica Vulcanite .................................................................................... 115 2.6.8 Magmatism of the SMD in Comparison to Other Intrusive Units .......................... 115 2.6.8.1 The Santa Fé Batholith.................................................................................... 115 2.6.8.2 The Buriticá Tonalite ...................................................................................... 118 2.6.8.3 The Buga Batholith ......................................................................................... 118 2.6.8.4 The Cicuco-22 Pluton ..................................................................................... 119 2.7 The Structural Geology of the San Matias Distric ...................................................... 120 2.7.1 District Scale Structures .......................................................................................... 120 2.7.1.1 NS-NNE Faults Set ......................................................................................... 120 2.7.1.2 NW Faults Set ................................................................................................. 121 2.7.1.3 NEE-EW Faults .............................................................................................. 123 2.7.2 Structures of the El Alacrán Deposit ...................................................................... 124 2.8 Conclusions ................................................................................................................. 124 Chapter 3: The Hydrothermal Fluid Evolution of the El Alacrán Deposit, San Matías District, Colombia. .....................................................................................................................127 3.1 Introduction ................................................................................................................. 127 3.2 Previous works ............................................................................................................ 128 3.3 Hydrothermal Alteration of the El Alacrán Deposit. .................................................. 131 xiv 3.3.1 Group I: Barren Calc-Silicate ................................................................................. 132 3.3.1.1 Calc-sodic assemblage: quartz - Mg-rich chlorite - albite ± apatite ± rutile-anatase (± pyrite) ............................................................................................................. 132 3.3.1.2 Propylitic assemblage: chlorite + carbonate + epidote ................................... 136 3.3.1.3 Sodic assemblage: albite + titanite + carbonate .............................................. 136 3.3.2 Group II: Calc-Silicate ............................................................................................ 136 3.3.2.1 Magnetite - quartz assemblage: magnetite - quartz - apatite ± Fe-rich chlorite (± pyrite). 138 3.3.2.2 Mushketovite - pyrite assemblage: mushketovite - quartz - apatite - Fe-rich chlorite – carbonate ± REE mineral (pyrite > chalcopyrite). .......................................... 140 3.3.2.3 Chlorite assemblage: Fe-rich chlorite - carbonate - quartz (pyrite > chalcopyrite) ................................................................................................................... 141 3.3.3 Group III: Calc-Potassic ......................................................................................... 143 3.3.3.1 Actinolite-vanadium mica assemblage: actinolite - vanadium mica - quartz - carbonate (chalcopyrite - pyrite ± pyrrhotite ± illmenite)............................................... 143 3.3.3.2 Pyrrhotite - actinolite assemblage: pyrrhotite - quartz - actinolite ± chlorite ± clay 144 3.3.4 Group IV: Sericitic .................................................................................................. 144 3.3.4.1 Carbonate – illite assemblage: carbonate - illite - chlorite - titanite/rutile (chalcopyrite + pyrite ± molybdenite ± pyrrhotite ± ilmenite) ....................................... 144 3.3.5 Group V: Carbonate Base Metal (CBM) ................................................................ 148 3.3.5.1 CBM – apatite assemblage: carbonate + quartz + apatite + chlorite (chalcopyrite ± sphalerite ± pyrite ± molybdenite) ......................................................... 148 xv 3.3.5.2 CBM veins: carbonate (chalcopyrite + sphalerite + arsenopyrite + pyrite ± molybdenite) ................................................................................................................... 149 3.3.6 Group VI: Zeolite-Calcite ....................................................................................... 149 3.3.6.1 Late calcite veins assemblage ......................................................................... 150 3.3.6.2 Fe-staining assemblage ................................................................................... 150 3.4 Mineralization of the El Alacrán Deposit. .................................................................. 151 3.4.1 Metal distribution .................................................................................................... 151 3.4.2 Deposit Au Fineness and Precipitation ................................................................... 155 3.5 The Timing of the El Alacrán Deposit Ore Related Processes. .................................. 157 3.5.1 Re-Os in molybdenite age dating of the El Alacrán Deposit and San Matías District porphyry Cu-Au prospects .................................................................................................. 158 3.5.2 Ar-Ar geochronology of alteration minerals from the El Alacrán Deposit and La Jagua (Mina Cocos) vein-type mineralization in the San Matías District .......................... 159 3.5.3 Conclusions and Remarks of the San Matias District Geochronology Data .......... 164 3.6 Deciphering the Ore Forming Processes at El Alacrán Deposit: Mineralogy and Fluid Inclusion Analysis ................................................................................................................... 165 3.6.1 Fluid Inclusions of the El Alacrán Deposit and the Montiel E porphyry prospect of the San Matias District ........................................................................................................ 165 3.6.2 Paleo-Temperature, Acidity and Fluid Paths of the El Alacrán Deposit Ore-Forming Fluids 168 3.6.3 Sulfidation State of the El Alacrán Deposit Ore-Forming Fluids ........................... 173 3.6.4 Redox conditions during Au and Cu mineralization at El Alacrán Deposit ........... 175 xvi 3.7 The Source of Metals Responsible For El Alacrán Deposit Mineralization: Lead and Sulfur Isotope Analysis ........................................................................................................... 177 3.7.1 Pb Isotopic composition .......................................................................................... 177 3.7.1.1 Introduction ..................................................................................................... 177 3.7.1.2 Methodology ................................................................................................... 178 3.7.1.3 Results and Discussion ................................................................................... 179 3.7.2 S Isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizations of the San Matias District .......................................................................... 186 3.7.2.1 Introduction ..................................................................................................... 186 3.7.2.2 Methodology ................................................................................................... 188 3.7.2.3 Results and Discussion ................................................................................... 188 3.7.3 Re content in molybdenite as an indication of the ore-forming fluid conditions ... 192 3.8 Conclusions ................................................................................................................. 194 Chapter 4: Genetic Model for the El Alacrán Deposit ...........................................................197 4.1 Introduction ................................................................................................................. 197 4.2 Tectonic Setting and Magmatic Evolution of the San Matias District ....................... 198 4.2.1 Pre-Deformation, Extensional Tectonic Setting ..................................................... 199 4.2.1.1 Early Volcanism and Plutonism in the San Matías District ............................ 199 4.2.1.2 Brecciation Stage in the El Alacrán Deposit ................................................... 199 4.2.1.3 Main Mineralization Stage at El Alacrán Deposit .......................................... 201 4.2.2 Syn-Deformation, Compressional Setting .............................................................. 201 4.2.2.1 Deformation and Orogenesis in the San Matías District ................................ 201 4.2.3 Post-Deformation Setting........................................................................................ 203 xvii 4.2.3.1 Erosion in the San Matías District .................................................................. 203 4.3 The Evolution of the Hydrothermal Fluid in the El Alacrán Deposit ......................... 205 4.3.1 Pre-Mineralization Stage ........................................................................................ 205 4.3.2 Mineralizating Stage .............................................................................................. 207 4.3.2.1 Mineralizing Model I ...................................................................................... 208 4.3.2.2 Mineralizing Model II ..................................................................................... 209 4.4 Comparison of the El Alacrán Deposit with other deposits ........................................ 210 4.5 El Alacrán Deposit Classification Model ................................................................... 216 4.5.1 Features Consistent with CRD mineralization (Porphyry Cu-Au -related) ............ 217 4.5.2 Features Consistent with an IOCG Model .............................................................. 218 4.5.3 Genetic Model Summary ........................................................................................ 219 Chapter 5: Conclusions, Exploration Implications and Future Research in the San Matías District, Colombia ......................................................................................................................221 5.1 Conclusions ................................................................................................................. 221 5.2 Exploration Implications ............................................................................................. 225 5.2.1 Deposit Scale .......................................................................................................... 225 5.2.2 District Scale ........................................................................................................... 226 5.2.3 Regional Scale ........................................................................................................ 227 5.3 Future Research .......................................................................................................... 228 5.3.1 Deposit Scale .......................................................................................................... 228 5.3.2 District Scale ........................................................................................................... 229 5.3.3 Regional Scale ........................................................................................................ 229 References ...................................................................................................................................231 xviii List of Tables Table 1-1 Sampling Campaigns executed in the San Matías District. .......................................... 12 Table 1-2 Geological Characteristics of the reviewed deposit models ......................................... 30 Table 1-3 Fluid Physico-chemical Characteristics of the reviewed deposit models ................... 31 Table 2-1 Summary of the lithogeochemistry ratios of the San Matías District magmatic suites and basement rocks. ...................................................................................................................... 87 Table 2-2 Existent U-Pb geochronology data in zircon from San Matías District. ...................... 92 Table 2-3 Summary of characteristics of the zircon crystals from selected intrusions of the San Matías District dated by U-Pb LA-ICP-MS in zircon .................................................................. 92 Table 3-1 Historic Geochronology Data of the San Matías District ........................................... 131 Table 3-2 Gold mineralizing events, characteristics and fineness for samples of the El Alacrán Deposit in the San Matías District. Gold fineness calculated after semi-quantitative normalized weight percent (wt. %) values obtained with EDS (Au/Au+Ag X 1000, Corbett and Leach, 1993)..................................................................................................................................................... 156 Table 3-3 New Re-Os ages for molybdenite samples from the El Alacrán Deposit and the Costa Azul and Montiel E porphyry Cu-Au prospects in the San Matías District ............................... 159 Table 3-4 Summary of the El Alacrán Deposit alteration groups and mineral assemblages and inferred paleo-temperature and acidity. The alteration porphyry analogy after Gustafson and Hunt (1975) is also indicated for comparison. ............................................................................ 170 Table 3-5 Pb isotopic composition of the sulfides from the El Alacrán Deposit and other selected mineralization in the San Matias District.................................................................................... 182 xix Table 3-6 Weighted Average Pb isotopic composition of individual feldspars crystals from selected intrusions and volcano-sedimentary units from El Alacrán Deposit and the San Matias District......................................................................................................................................... 182 Table 3-7 δ34S ‰ isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizaitons of the San Matías District. ................................................................... 189 xx List of Figures Figure 1-1 Location, access and mineral deposits and prospects of the San Matías District (SMD) in NW Colombia. A. Digital Elevation Model (DEM), roads and access to the SMD and El Alacrán Deposit. B. Detailed map showing El Alacrán Deposit and other prospects within the San Matías District. Lidar image provided by the Cordoba Minerals Corp. .................................. 4 Figure 1-2. Changes in plate configuration in the Caribbean and Central America between the Cretaceous and Miocene. A. Diagram shows the dominat NE-oriented stress-field in the Cretaceous (125 – 120 Ma). B. Diagram shows the dominat SE-oriented stress-field during the Miocene (~10 Ma). Modified from Kennan and Pindell (2009). ................................................ 20 Figure 1-3. Location of the San Matías District in the context of different tectonic models proposed for Colombia. A. Etayo-Serna et al. (1983). B. Restrepo and Toussaint (1988). C. Cediel et al. (2003), and D. Kennan and Pindell (2009). The red square corresponds to the San Matías District area. ...................................................................................................................... 22 Figure 1-4 Distribution of the Cretaceous to Eocene magmatism in Colombia and the El Alacrán Deposit location. The dots in the upper part show the location of oil and gas wells extracted from Mora et al., (2017). The dots are colored according to intercepted basement lithology. Purple dots correspond to metamorphic basement intercepts, pink dots are granitic rock intercepts, and green dots corresponds to mafic to intermediate volcanic basement intercepts. The ages are extracted from Leal-Mejía, 2011; Rodriguez and Arango, 2013; Zapata-Villada et al., 2013; Weber et al., 2015; Villagómez et al., 2011, and Nivia et al., 2017. ............................................ 25 Figure 1-5. Schematic tectono-magmatic sections of the possible environment of formation for the ~70 Ma magmatism from San Matías District and the distribution of the Cretaceous xxi magmatism defined by Leal-Mejía (2011) and Leal-Mejía et al. (2019). The graph shows the features relevant to the discussion and tectonic model revision of this chapter. A. The pre-accretional setting is consistent with the tectonic interpretations of Cediel et al., (2003); Bayona et al., (2012); Cardona et al., (2003, 2012). B. Syn-accretional setting with the tectonic interpretations of Restrepo and Toussaint, (1988), Villagómez et al., (2011), and Spikings et al., (2010). C. A post-accretional setting. This includes the interpretations of Rodriguez and Arango, (2013) and Mora et al., (2017). It is important to indicate that the genetic relation of the Central Cordillera magmatism (Eastern Group Granitoids) and the intrusions of the Magangue arc (e.g. Bonga pluton) have not been demonstrated in the literature. ....................................................... 27 Figure 1-6 Global Distribution of IOCG provinces showing ages, representative abundances of sodic (- calcic), potasic alteration, and economic copper (-gold). The red polygon corresponds to the SMD area and El Alacrán Deposit location. Taken from Barton, 2013. ................................ 29 Figure 1-7 Alternative hydrothermal origins and architectures for IOCG systems illustrating possible fluid sources, paths, and distribution of the alteration and the ores. Multiple fluid sources are possible in all cases. A. Magmatic source implies distinctive composition and proximity to source; regional Na (-Ca) is coincidental. B. Evaporitic source implies coeval or older brine source, necessary but indifferent to type of heat source, and available upper crustal plumbing. C. Metamorphic source implies meta-evaporitic (or conceivably mantle) Cl source with regional plumbing. Taken from Barton, 2013. ..................................................................... 35 Figure 1-8 Schematized styles of IOCGs in the Coastal Cordillera of the central Andes proposed by Sillitoe (2003). Note the fundamental control exerted by the faults, commonly shared with pre-ore mafic (basaltic andesite/diorite) dykes. Vein breccias (and breccia mantos and pipes) tend to occur at relatively shallow palaeodepths and, hence, are typically confined to xxii volcanogenic wall rocks. There is an upward change in the predominant hydrothermal iron oxide from magnetite to specular hematite. ............................................................................................ 37 Figure 1-9 Worldwide locations of porphyry Cu systems. The principal deposit type(s), contained metals, and age are also indicated. Taken from Sillitoe (2010) and cited references. The red polygon corresponds to the SMD area and El Alacrán Deposit location. ....................... 39 Figure 1-10 Anatomy of a telescoped Cu-porphyry System. A. The diagram shows spatial relationships of a centrally located porphyry Cu ± Au ± Mo deposit in a multiphase porphyry stock and its immediate host rocks; peripheral proximal and distal skarn, carbonate- replacement (CRD), and sediment-hosted (distal-disseminated) deposits in a carbonate unit and sub-epithermal veins in non-carbonate rocks; and overlying high- and intermediate-sulfidation epithermal deposits in and alongside the lithocap environment. B. Generalized alteration-mineralization zoning pattern for telescoped porphyry Cu deposits, based on the geologic and deposit-type. Taken from Sillitoe, 2010. The Red boxes are used to highlight some mineralization styles (e.g., Carbonate-replacement, proximal Cu-Au skarn). .............................. 41 Figure 1-11 Location of the SMD and El Alacrán Deposit relative to the VMS, IOCGs, and PCDs documented in Western Colombia. The porphyry and VMS prospects location were extracted from Leal-Mejia, 2011; Leal-Mejía et al., 2019 and Shaw et al., 2019. An IOCG prospect (IOA type) was taken from Garzón, 2017. In the background, the Colombia DEM overlaid by the Romeral Fault System taken from the Colombia Geological Map (Gomez-Tapias, 2015). ............................................................................................................................................ 44 Figure 1-12 Model of the skarn-related mineralogy distribution in relation to the protolith host rock (Meinert, 1997). The diagram indicates how fluid-controlled metasomatic skarn typically is coarse-grained and does not closely reflect the composition or texture of the protolith. ............. 50 xxiii Figure 1-13 Evolution of a caldera-related submarine magmatic-hydrothermal system in VMSs formation A. Conceptual model showing the evolution of a caldera-related submarine magmatic-hydrothermal system responsible for the formation of Volcanogenic Massive Sulfide (VMS) deposits (Stix et al., 2003). The diagram shows how cold seawater flows downward along outer inward-dipping faults, while hot mineralizing fluids move up along a series of outward-dipping faults resulting from piecemeal caldera collapse. As a result, massive sulfide deposits can form in a number of locations and possible water depths within the caldera. B. (detail a) displays the distribution of the alteration mineral assemblages in a classic mound-shaped VMS (e.g. Hellyer Deposit; Large, 1992). C. (detail b) displays the distribution of the alteration mineral assemblages in a layered-shaped VMS (e.g. Scuddles Deposit; Large, 1992). ............................ 55 Figure 2-1 Regional Geology of NW Colombia around the SMD A. Regional Geology of the northwestern Colombia after Gomez et al. (2015). Morphological units, including Sinú Deformed Belt, San Jacinto Deformed Belt (SJDB) and the Lower Magdalena Valley (LMV) (Mora et al.,2017) are also indicated. The Romeral Fault System trace is shown in red. B. Detail of the San Matías District (white polygon) and surrounding areas. ............................................. 62 Figure 2-2 Chronostratigraphic diagram of the Cordoba Department showing the relative position and correlation between the regional geological units (Gómez et al., 2015) and ten detailed stratigraphic sequences for the Sinú, San Jacinto Folded Belts, and the Lower Magdalena Valley (SJFB, SFB, LMV, respectively) compiled by Mora et al. (2017) in the stratigraphic record (modified from Mora et al., 2017). Known late Cretaceous ages for magmatism in the San Matías District (ca. 70 Ma U-Pb (zircon); Leal-Mejía and Hart, 2017) are indicated. ....................................................................................................................................... 65 xxiv Figure 2-3 Geology map of the San Matías District A. mapped lithologies, intrusions and structures from different sources (field mapping, GroundMag and Lidar lineaments) in the San Matías District surroundings (source: Cordoba Minerals Corp). Note that metamorphic rocks of the Cajamarca Complex do not occur in the proximity of the SDM. B. Detail of the San Matías District area showing the location of the El Alacrán Deposit with respect to other mineral prospects in the district and spatially related intrusions. .............................................................. 69 Figure 2-4 El Alacrán Deposit Geology. A. Surface geology map displaying the location of the studied cross-sections. (a) 85570m N, (b) 855540m N, and (c) 855050m N. B. Generalized stratigraphic column of the El Alacrán Deposit Units indicating the distribution of the defined volcano-clastic lithofacies. ............................................................................................................ 71 Figure 2-5 El Alacrán Deposit local geology along the studied three sections. A. Section 85570m N (Northern El Alacrán Deposit). B. Section 855540m N (Central part of the El Alacrán Deposit). C. Section 855050m N (Southern El Alacrán Deposit). The sections display the drill holes used for the lithology interpretation and correlation (Provided by Cordoba Mineral Corp.)........................................................................................................................................................ 72 Figure 2-6 El Alacrán Deposit volcanoclastic lithofacies from Unit 2 and Unit 3. A. Core-scale sample of the TufF+TufL lithofacies (banded interbedding of fine-grained tuff and lithic tuffs). B. Core-scale sample of the TufA+TufM lithofacies (coherent lavas with amygdaloidal facies). C. Photomicrograph (10x, XPL) of the TufP lithofacies (peperites in the contact of TufM) note the contact zone between a basaltic rock and a fine-grained lapilli tuff. D. Core-scale sample of the TufF-TufC lithofacies (fine-grained to coarse-grained tuff). E. Core-scale sample of the TufL lithofacies (lithic tuff). E1. Photomicrophotograph (2x, PL) of photo E, showing the breccia texture in the rock. Note the clasts composition dominated by vitroclasts and recrystallized xxv quartz. F. Core-scale sample of the TufD lithofacies (fiamme tuff). G. Core-scale sample of the Lim lithofacies (Marlstone). H. Core-scale sample of the MudSil lithofacies (laminated limestone). H1. Photomicrograph (10x, XPL) showing some occurrences of welded (?) vitriclasts and some dissemination of sphalerite. .......................................................................................... 76 Figure 2-7 El Alacrán Deposit volcano-clastic lithofacies from Unit 1. A. Photo of drill core from the Andesite Breccia (ABx) (drill hole ACD075 @ 210 – 213 m). B. Detailed of photo A. Photomicrograph (10X, XPL) showing a coherent facies composition of the ABx lithofacies. Note the glassy groundmass in the dark-grey facies. C. Drill core sample of some quartz-rich porphyritic facies associated with the RBx lithofacies. D. Quartz stockwork in porphyry clast embedded in a quartz-rich groundmass volcanic/magmatic? breccia from the TufR lithofacies. E. Detail of TufR lithofacies. F. Photo of drill core from the Dacite Breccia (RBx) in transitional contact with the TufR lithofacies (drill hole ACD003 @ 84.2 – 86.5 m). G. Photomicrograph (10X, XPL) of photo F showing a fine-grained breccia texture composed of quartz, plagioclase and K-feldspar. .............................................................................................................................. 80 Figure 2-8 Trace element and REE element pattern of the San Matías District magmatic suites. A. Diagram displays the normalized values from the San Matías-La Jagua magmatic suite. In red the REE element pattern from the TufR lithofacies of the El Alacrán Deposit Unit 1. B. Diagrama displays the normalized values from San Jorge magmatic suite and contrasts with the El Alacrán Norte magmatic suite. C. Diagram displays the normalized values from the Betesta-Mina Escondida magmatic suites. D. Diagram displays the normalized values from the San Pedro-Costa Rica magmatic suite. The trace elements values are normalized to Chondrite (Thompson, 1982), and the REE values are normalized to NMORB (Sun and McDonough 1989)........................................................................................................................................................ 84 xxvi Figure 2-9 Immobile element analysis in San Matías District samples and their indicated fertility for porphyry Cu. A. Sr/Y vs Y diagram showing large Y values displayed by the San Pedro-Costa Rica magmatic suite relative to the rest of the magmatic suites. B. Europium Anomaly (Eu*) vs SiO2% diagram indicating (grey zone) the field of adakite-like rocks (Richards et al., 2012). C. Sr/Y vs SiO2%, indicating in grey the field of adakite-like rocks. D. La/Yb vs Yb diagram showing the correlation between Unit 2 and Unit 3 rocks with the San Pedro-Costa Rica magmatic suite. E. La/Sm vs Dy/Yb diagram showing the largest fractionation of the Light Rare Earth Elements (LREE) indicated by the San Matías-La Jagua magmatic suite. F. TiO2 vs Zr diagram showing the elevated TiO2 and Zr content in Unit 2, Unit 3 and San Pedro-Costa Rica magmatic suite. ............................................................................................................................. 86 Figure 2-10 Ti-in-zircon temperatures of the San Matías District magmatic suites. Temperatures are calculated using the equation proposed by Ferry and Watson (2007); the activities of SiO2 and Ti are set to 1 and 0.70, respectively (see in the text). ........................................................... 87 Figure 2-11 Macroscopic and microscopic aspects of selected San Matías District intrusions. A. Photo of drill core from the Montiel E porphyry suite showing a chilled contact between the tonalite porphyry (PxH) and the leucocratic quartz-feldspar porphyry (QFPx) (drill hole SMDDH012 @ 163.4–166.16 m). B. Detail of photo A., showing the main mineralizing porphyry phase from Montiel E Porphyry (PxHe). C. Photomicrograph (2x, XPL) of the quartz-feldspar porphyry (QFPx) from photo A. D. Photomicrograph (2x, XPL) of the Costa Azul Porphyry. Note the crowded porphyry texture and the marked plagioclase zonation. E. Photo of drill core from the San Jorge quartz diorite (drill hole SJDDH001 @ 226.3–229.10 m). F. Detail of photo E. G. Photomicrograph (2x, PPL) of the San Jorge quartz diorite. H. Photomicrograph xxvii (2x, XPL) of the Las Claritas quartz diorite showing a poikilitic texture of hornblende with inclusions of plagioclase and quartz. ............................................................................................ 88 Figure 2-12 Modal classification of samples from the San Matías District intrusions based on 200-300 point-counting on the QAP diagram of Streckeisen (1967). .......................................... 89 Figure 2-13 Major oxides vs. SiO2 Harker variation diagrams for the least altered samples of the San Matías District intrusions ....................................................................................................... 91 Figure 2-14 U-Pb LA-ICP-MS zircon geochronological results from tonalite and tonalite porphyries of Montiel E Porphyry suite and La Jagua Tonalite. A. Concordia plot and weighted average age estimation based on four LA-ICP-MS analysis of the SMA_ME_1705_JM_061 sample. The lower part shows a CL image of a representative equant zircon of this sample. B. Concordia plot and weighted average age estimation based on six-teen LA-ICP-MS analysis of the SMA_ME_1705_JM_060 sample. The lower part shows a CL image of a representative equant and pyramidal crystals found in this sample. C. Concordia plot and weighted average age estimation based on twenty-seven LA-ICP-MS analysis of the SMA_JA_1704_JM_057 sample. The bars in blue indicate the rejected analysis. The lower part shows a CL image of the zircon morphologies found in this sample. .............................................................................................. 93 Figure 2-15 U-Pb LA-ICP-MS zircon geochronological results for the San Jorge and the Betesta quartz diorite intrusions of the San Matías District A. Concordia and weighted average age plots based on twenty-eight LA-ICP-MS analysis of the San Jorge Quartz Diorite (sample SMA_SJ_1709_JM_066). CL image of a representative prismatic zircon of this sample is also shown. The blue bars indicate the rejected analysis. B. Concordia and weighted average age plots based on twenty-four LA-ICP-MS analysis of the Betesta Quartz Diorite (sample xxviii SMA_BT_1801_JM_122). CL image of a representative pyramidal zircon of this sample is also shown. ........................................................................................................................................... 99 Figure 2-16 Macroscopic and microscopic aspects of selected San Matías District intrusions. A. Photo of drill core from the El Alacrán Oeste Tonalite (drill hole ACD042 @ 152.2–157.7 m). B. Detailed of photo A. C. Photomicrograph (4x, PPL) of the El Alacrán Norte Tonalite. D. Photomicrograph (4x, PPL) of the El Alacrán Oeste Tonalite. Note the selective alteration of chlorite after hornblende. E. Drill core photo of the Sill 1a unit. F. Drill core photo of the Sill 1b unit. G. Drill core photo of the Sill 2 unit with pervasive albite + chlorite alteration. H. Drill core photo of the stained off-cut of the Alto San Pedro Diorite sample. The positive reaction to etching by HF sodium cobaltinitrite (yellow) stain coincides with a clay - illite alteration. I. Photomicrograph (4x, PPL) of the Alto San Pedro Diorite. Note the two generations of clinopyroxene (ClPx 1 and ClPx2). ............................................................................................ 104 Figure 2-17 Trace Elements and REE pattern of the San Matías District volcanic rocks A. Chondrite Normalized Trace Elements pattern (Thompson, 1982). B. Normalized REE NMORB pattern (Sun & McDonough 1989). The background in grey indicates the pattern obtained for the San Matías District intrusive rocks. ............................................................................................ 111 Figure 2-18 Trace elements and REE patterns of the El Alacrán Deposit volcanics in comparison with other regional volcanic units. A. Trace element pattern of El Alacrán Deposit basement rocks in comparison to the whole rock geochemistry from the Arc group of the Barroso Formation (Rodriguez and Arango, 2013); whole rock geochemistry of the Plateau Group of the Barroso Formation (Villagómez et al., 2011). B. Trace element pattern of El Alacrán Deposit basement rocks in comparison to the whole rock geochemistry from the Buriticá Dacite (Weber et al., 2015); the Remolinos-1 Andesite and the Planeta Rica Vulcanite (Silva et al., 2016). .... 113 xxix Figure 2-19 Tectonic Environment for El Alacrán Deposit Rocks. The diagrams include the whole rock geochemistry from the Plateau and Barroso Fm., Arc groups (Villagómez et al., 2011; Rodriguez and Arango, 2013, respectively). The diagrams also include whole rock geochemistry data from the Buriticá Dacite (Weber et al., 2015); the Remolinos-1 Andesite and the Planeta Rica Vulcanite (Silva et al., 2016). A. Tectonic classification of mafic igneous rocks (Cabanis, and Lecolle, 1989). B. Basalt Th-Hf-Ta (Wood, 1980). C. Th-Co Discrimination Diagram (Hastie et al., 2007). ..................................................................................................... 116 Figure 2-20 Trace elements and REE patterns of the San Matías District intrusions. Trace element pattern uses the normalized to Chondrite (Thompson, 1982) and the REE pattern uses the normalization to NMORB (Sun and McDonough 1989). A. The background in red corresponds to the bulk of the San Matías District intrusions, which is contrasted with whole rock geochemistry data from the Santa Fe Batholith (Tonalite I; Weber et al., 2015) and the Cicuco-22 Pluton (Silva et al., 2016). B. The background in red corresponds to the bulk of the San Matías District intrusions, which is contrasted with whole rock geochemistry data from the Buga Batholith (Villagómez et al., 2011) and the Buriticá Tonalite (Weber; et al., 2015). ....... 117 Figure 2-21 Nb/Yb vs Th/Yb plot (Pearce, 2008) for the San Matías District intrusions. The San Matías District intrusions are compared with whole rock geochemistry data from the Santa Fe Batholith (Tonalite I) and Buriticá Tonalite (Weber et al., 2015). The diagram also includes data from the Aruba and Buga Batholiths (White et al., 1999; Villagómez et al., 2011) and the Pujilí Granite and the Cicuco-22 pluton (Vallejo et al., 2006; Silva et al., 2016). Also shown the fields from oceanic and continental arcs, and ophiolite felsics after Condie and Kroner (2013). Note the marked low Th content in rocks from the San Jorge and El Alacrán Norte magmatic suite rocks...................................................................................................................................................... 119 xxx Figure 2-22 Interpreted structural evolution for the SMD areas. A. The diagram includes a pre-mineral stage associated with the formation of the major structures. The scheme in diagram A is interpreted based on the regional NE relative motion of the Caribbean Plate with the South American Plate documented for the Early Cretaceous (ca. 125 - 120 Ma Kennan and Pindell, 2009). The NS-NNE structures are arc-parallel; therefore, either compressional or extensional dynamics are expected in the front- and intra-arc location, respectively. B. The diagram indicates a structural framework for the SMD areas that resolve the syn-mineral (~ 70 Ma, Leal-Mejía and Hart, 2017) fault kinetics and spatial orientation of the veins associated with the SMD prospects Montiel E = quartz stockwork, Mina Ra = mesothermal sulfide + quartz vein, and Mina Pirita = quartz fault-fill vein. During this stage, the major structures might have undergone a clockwise rotation for the structures formed in A. Symbols in red indicate the change in the fault dynamics en relation to the previous stage. C. The diagram shows the structural framework that resolves the post-mineral kinetics observed in the SMD areas (e.g. Manco and Davila, 2012; Starling, 2012), as well as the neo-tectonic in northwestern Colombia, which is highly influenced by the SE relative movement of the Caribbean Plate (Taboada et al., 2000). Symbols in red indicate the change in the fault dynamics en relation to the previous stage D. Stereonet-Equal Angle (Wulff net) using 390 Dip/Dip directions measurements from El Alacrán Deposit. The diagram indicates the two major structural trends observed in the Deposit. E. Plan and section view of the 3D modelled structures of the El Alacrán Deposit. The diagram shows the distribution of the ABx Breccia in relation to the measured faults. ........................................... 122 Figure 3-1 El Alacrán Deposit Alteration Map. Surface geology map displaying the location of the studied cross-sections. (a) 85570m N, (b) 855540m N, and (c) 855050m N. The distribution of the alteration assemblages was constructed using drill hole data and surface mapping. The El xxxi Alacrán Deposit major intrusions are displayed for reference. Cordoba Minerals Corp., provided the > 0.3% equivalent Cu (eCu) resource shell of the deposit. ................................................... 129 Figure 3-2 Mineral paragenesis diagram for the El Alacrán Deposit. The relationship between drill core -scale precipitation stages and groups and .................................................................. 133 Figure 3-3 Studied cross-sections from El Alacrán Deposit. From north to south Section 855750m N, Section 855540m N, and Section 855050m N. The sections display the distribution and type of the alteration mineral assemblages. The background corresponds to the volcanoclastic lithofacies and intrusions of the host rock. ......................................................... 134 Figure 3-4 Calc-sodic and propylitic alteration assemblages of the El Alacrán Deposit in the San Matías District. A. Drill core interval showing pervasive replacement of the calc-sodic alteration assemblage affecting the Sill 2 lithofacies (Drill hole ACD035@115.20m to 117.50m). B. Photomicrograph (50x, PL) of the quartz and chlorite association from photo A. C. Drill core interval showing selective replacement of propylitic alteration in TufM lithofacies (Unit 3, drill hole ACD002@300.91m to 303.48m). D. Detail of photo C. E-F. Microphotographs (2x, XPL) of photo D. Note the fine-grained plagioclase rock and the distribution of the vesicles filled with chlorite and epidote. Ab: Albite, Qtz: Quartz, Chl: Chlorite, Ep: Epidote, Car: Carbonate, Plag: Plagioclase. ................................................................................................................................. 135 Figure 3-5 Sodic and FeOx staining alteration assemblages from the El Alacrán Deposit in the San Matías District. A. Drill core interval showing patchy and selective replacement of Fe-staining alteration overprinting sodic alteration in the TufF lithofacies (Unit 2, drill hole ACD001@155.0m to 157.8m). B. Detailed core photo showing the Fe-staining overprinting calc-sodic alteration assemblage. C. Photomicrograph (50x, PPL) of the Fe stained chlorite areas (Photo B). D. Scanning Electron Microscope (SEM) image of the Fe-staining alteration after the xxxii calc-sodic alteration assemblage (albite - chlorite - quartz). E-F. Detailed drill core photographs of samples with albite alteration assemblage in the TufD and TufF lithofacies, respectively. Ab: Albite, Qtz: Quartz, chl: Chlorite, Car: Carbonate, Plag: Plagioclase, Ser: Sericite, Rut: Rutile...................................................................................................................................................... 137 Figure 3-6. Magnetite-rich mineral assemblages of the El Alacrán Deposit. A. Core sample of the magnetite - quartz alteration assemblage in the MudSil lithofacies. B. Photomicrograph (2x,XPL, TL) of photo A. Note quartz - magnetite + carbonate (left side) vs the apatite bands with semi-massive magnetite + carbonate (right side). C. Drill core photograph showing the transition between Mushketovite + Pyrite assemblages and the Magnetite + Quartz (Drill hole ACD081@ 51.95m to 54.65m). D. Detail of photo C showing selective silica replacement after clasts of the ABx breccia. E. Photomicrograph (20x, PPL, TL+RL) showing the alteration of specularite to magnetite (Mushketovite). F. Photomicrograph (5x, PPL, TL+RL) showing the intergrowth of mushketovite and magnetite and traces of chlorite and carbonate. Chalcopyrite is the latest phase in this association. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Mag: Magnetite, Ap:Apatite, Musk: Mushketovite, Ccp:Chalcopyrite, Py:Pyrite. ............................................... 139 Figure 3-7 Chlorite and actinolite-vanadium mica alteration assemblages of the El Alacrán Deposit A. Drill core showing the chlorite alteration assemblage in the ABx lithofacies (Unit 1 Hole ASA037@58.9m to 76.48m). B. Detail of the Chlorite alteration assemblage in TufL lithofacies. C. Polished-thin section photo showing the occurrence of radiated V-rich mica occurrence intergrowing with carbonate and quartz. D. Photomicrograph (5x, XPL) of polished thin section in photo C. E. Relict acicular/bladed shapes (possible earlier mushketovite) replaced by quartz and pyrite. F. Photomicrograph (10x, PPL, TL+RL) showing the occurrence of sphalerite accompanied by chalcopyrite and the striated V-rich Mica in the actinolite - vanadium xxxiii mica alteration assemblage. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Ep: Epidote, Act: Actinolite, Ccp: Chalcopyrite, Py: Pyrite, Ilm: Ilmenite. Sph: Sphalerite. ................................. 142 Figure 3-8 Sericitic and Carbonate Base Metal (CBM) alteration assemblages in the El Alacrán Deposit of the San Matías District. A. Photo of drill core showing pervasive carbonate-sericite alteration assemblage in the ABx lithofacies (Unit 1, drill hole ACD036@57.33m to 59.85m). B. Detail of Photo A. C. Photomicrograph (10x, XPL) showing the occurrence of carbonate with euhedral titanite accompanied by sericite and chlorite. D. Scanning Electron Microscope (SEM) image of the sericite + carbonate + quartz paragenesis of the carbonate-sericite alteration assemblage. E. Short-wave infrared (SWIR) spectrum of the sericite in sample SMA_AL_1808_JM_133 consistent with Illite spectral response. F. Photomicrograph (2x, XPL) showing the open-space filling texture with prismatic quartz in the center and anhedral quartz in the host rock. Note a late carbonate vein event. G. Drill core photo of sphalerite + carbonate + sulfide veins of the CBM alteration assemblage. H. Oval-shaped, infill plugs with CBM alteration assemblage. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Ccp: Chalcopyrite, Py: Pyrite, Sph: Sphalerite, Ser: Sericite, Tita: Titanite, Ap: Apatite. .......................................................... 146 Figure 3-9 Short-wave infra-red (SWIR) analyses for samples from different alteration assemblages and lithofacies from the El Alacrán Deposit, San Matías District. A. White mica spectral value of the 2200 nm feature (W2200) respect to the dominant alteration assemblage. Note that the analyzed sericite samples from the carbonate-illite alteration assemblage coincide with the illite (s.s.) spectral values (2200-2210, Graham et al., 2018). B. Schematic diagram illustrating the relationship between equivalent Cu concentration (eCu, Kulla and Oshust, 2018), alteration assemblage, and hosting volcanoclastic lithofacies of the El Alacrán Deposit for xxxiv samples along the selected cross-sections. Cu concentration values provided by Cordoba Minerals Corp. ............................................................................................................................ 147 Figure 3-10 Leapfrog Geo model of sulfide shells along the selected cross-sections of the El Alacrán Deposit in the San Matías District. A-B. Pyrite, pyrrhotite, and chalcopyrite shells in the northern 855750m N section. C-D. Pyrite and chalcopyrite shells in the central 855540m N section. E-F. Pyrite and chalcopyrite shells in the southern 855050m N section. Sulfide distribution was modelled using Leapfrog Geo version 4.1.0 (spheroidal interpolant; global trend with dip 55°, dip azimuth 270°, pitch 52.5; ellipsoid ratios maximum 8, intermediate 6, minimum 1; resolution 25; March 2019, Appendix D.3). Sulfide distribution and relative concentrations based on the core-logging database provided by Cordoba Minerals Corp. ................................ 152 Figure 3-11 Leapfrog modelled Cu (%) and Au (ppm) shells along the selected cross-sections of the El Alacrán Deposit in the San Matías District. Volcanoclastic lithofacies and alteration assemblages of Figure 3-2 are shown in the background. Cu and Au values distribution was modelled using Leapfrog Geo version 4.1.0 (spheroidal interpolant; global trend with dip 55°, dip azimuth 270°, pitch 52.5; ellipsoid ratios maximum 8, intermediate 6, minimum 1; resolution 25; March 2019, Appendix D.3) Cu and Au values from database provided by Cordoba Minerals Corp............................................................................................................................................. 154 Figure 3-12. Cu (%) and Au (ppm) value distribution for selected altered samples from different alteration assemblages along the selected cross-sections of the El Alacrán Deposit in the San Matías District. A. and B. Tukey box plots showing the Cu (%) and Au (ppm) value distribution. Mean = black dot, median = black horizontal line. C. and D. Probability plot for Cu (%) and Au (ppm) values. Note the bulk of the carbonate-illite along with the mushketovite-pyrite alteration xxxv assemblages coincide with higher Cu % grades. Cu and Au values provided by Cordoba Minerals Corp. Alteration assemblages, according to the legend of Figure 3-2. ........................ 155 Figure 3-13 Gold events of the El Alacrán Deposit in the San Matías District. A. Event Au1: Gold inclusion in pyrite from the mushketovite-pyrite alteration assemblage (Group II) (sample SMA_AL_1709_JM_077). B. Events Au1 and Au2: Back-Scattered Electron (BSE) Ag map showing the differences in the Ag content in gold particles from events Au1 and Au2 (sample SMA_AL_1709_JM_077). C. Event Au2: Fracture infill gold mineralization occurring in the contact of pyrite and chalcopyrite from the calc-potassic and sericitic alterations. D) Event Au3: Back-Scattered Electron (BSE) image visible gold (VG) intergrown with sphalerite from the CBM Vein alteration assemblage. .............................................................................................. 157 Figure 3-14 40Ar/39Ar age spectra, normal and inverse isochrons for alteration minerals of the El Alacrán Deposit and the Mina Cocos (La Jagua) vein-type mineralization of the San Matías District. A. Actinolite associated with the actinolite-vanadium mica assemblage (sample SMA-AL-1709-JM-043). B. Sericite of the carbonate-illite alteration assemblage (sample SMA-AL-1709-JM-073). C. Sericite from La Jagua Mineralization (sample SMA-JA-1704-JM-048). ... 160 Figure 3-15 Summary of geochronology data compilation for magmatism and mineralization in the San Matías District. The age of mineralization/hydrothermal alteration at the El Alacrán Deposit is constrained at ca.75.8 - 68.31 Ma (dark red zone). The vertical coloured boxes indicate the age intervals constrained for Costa Azul and Montiel E porphyry Cu-Au events in the San Matías District. Compiled ages from other authors include (1) Leal-Mejía and Hart (2017), (2) Sernageomin (2018), (3) Sernageomin (2012) and (4) Anglo American, pers. comm., 2014............................................................................................................................................. 163 xxxvi Figure 3-16 Fluid Inclusions Assemblages (FIA) identified in samples of the El Alacrán Deposit in the San Matias District. A. FIAII in apatite from the magnetite-quartz alteration assemblage. B. FIAIII in carbonate from the actinolite-vanadium mica alteration assemblage. C. FIAIIHC (Hydrocarbon FI) in quartz from the CBM alteration assemblages. D. FIAIII in quartz vein from the Montiel E porphyry prospect. E. FIAII in quartz vein from the Costa Azul porphyry prospect. F. FIAII in quartz clast from the TufR lithofacies in Unit 1, at El Alacrán Deposit. G. Probability plot of the distribution of the FI length size. The largest fluid inclusions correspond to FIAIIHC of the CBM assemblages. H. Frequency histogram of the vapour-liquid ratio (V/V+L) in the fluid inclusions identified. ................................................................................. 167 Figure 3-17 Common temperature stability ranges in geothermal systems for hydrothermal minerals observed at the El Alacrán Deposit (modified from Escolme, 2017). Minerals arranged by their stability with respect to pH. Sulfide and magnetite formation temperatures from experimental studies (Simon et al., 2000). .................................................................................. 168 Figure 3-18 Fluids paths for the El Alacrán Deposit in the context of the pH vs temperature conditions for the formation of hydrothermal alteration minerals and standard alteration types in hydrothermal systems (modified after Corbett and Leach, 1998). Apatite (Ap) added based on petrographic observations in samples from the El Alacrán Deposit. Path A shows the possible fluid evolution of barren calc-silicate and zeolite-calcite alterations. Path B shows the proposed fluid evolution of the calc-silicate alteration. Path C shows the proposed fluid evolution of calc-potassic and sericitic alteration assemblages. The CBM-veins (in question marks) may represent continued cooling from the CBM-apatite assemblages or may represent another event associated with a late epithermal stage. ........................................................................................................ 169 xxxvii Figure 3-19 LogfS2-1,000T diagram illustrating the mineralizing fluid evolution for the fluid paths proposed for the El Alacrán Deposit in the San Matias District (modified after Einaudi et al., 2003). Path B (green arrow) indicates the trajectory of a possible cooling or heating fluid associated with the calc-silicate alteration. Path C (orange arrow) represents the trajectory of a cooling fluid associated with the calc-potassic and sericitic alterations. An additional path (light blue arrow) represents the late CBM veins epithermal fluids associated with the sphalerite ± arsenopyrite occurrence. ............................................................................................................. 174 Figure 3-20 Fluid cooling paths proposed for the El Alacrán Deposit in the fO2-pH stability fields for Fe-oxides and sulfides (Huston et al. 1993) constructed at 350°C, calculated from mΣS = 10-2.5, mΣCl = 3.5, mΣNa = 3.0, mΣK = 0.30, mΣCa = 0.10 (e.g. Productora Deposit, Chile Escolme, 2017). Gold solubility as AuCl2- and Cu solubility as CuCl0. Path B arrow indicates the evolution of the calc-silicate alteration in the El Alacrán Deposit that precipitated pyrite and gold and minor chalcopyrite in the transition from hematite to mushketovite (magnetite). In contrast, Path C arrow is used to indicate a possible trajectory in the calc-potassic and sericitic alterations that precipitated both gold and chalcopyrite from an initial fluid stable with pyrrhotite and later pyrite. Path C arrow, however, does not represent the real stability fields defined in the diagram. ...................................................................................................................................... 176 Figure 3-21 208Pb/206Pb vs 207Pb/206Pb diagram for Pb isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralization of the San Matias District. The plumbotectonics Pb evolution curves (Orogen curve) from Zartman and Doe (1981) are included for reference. ............................................................................................................................... 181 Figure 3-22 207Pb/206Pb (A) and 208Pb/206Pb (B) isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralization in the San Matias District (SMD) and feldspar xxxviii grains from intrusions of the San Matias District. The bars in the SMD intrusions include the weighted average of the individual feldspars and their ±2σ error. ............................................. 184 Figure 3-23 207Pb/206Pb vs 208Pb/206Pb diagram for sulfides from the El Alacrán Deposit and other selected mineralizations in the San Matias District, and feldspar crystals from the El Alacrán Deposit and other intrusions in the San Matias District. The error lines correspond to ±2σ error. Note the proximity of the average isotopic composition of the El Alacrán Oeste Tonalite feldspars with the El Alacrán Deposit sulfide. ............................................................. 185 Figure 3-24 δ34S ‰ isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizations in the San Matias District, with respect to alteration assemblages (A) and host rock lithofacies or intrusions (B). Values for the magmatic (0 ± 5 ‰; Ohmoto and Goldharber, 1997) and seawater sulfate for Late Cretaceous times (+19 ± 0.2‰; Paytan et al., 2004), are indicated in orange and blue, respectively, for comparison purposes. The distribution pattern for δ34S ‰ values of H2S and sulfide minerals when sulfate of δ34S = +20‰ is reduced by Inorganic Reduction at T >250°C (Ohmoto and Rye, 1979) is displayed for comparison purposes. The labelled numbers correspond to the sample suffixes. Abbreviations include ABx=Andesite Breccia; TufL= Lithic tuff; TufF-TufC= fine-grained to coarse-grained tuff; MudSil=Laminated limestone; Lim=Massive fossiliferous limestone. ...................................... 190 Figure 4-1 Pre-deformational evolution of the San Matías District (SMD). A. Schematic diagram indicating the pre-accretional setting of the Calima Terrane and location of the B, C and D diagrams. B., C. and D. diagrams show the tectono-magmatic evolution for the SMD under an extensional tectonic setting at > 77Ma, ~77 Ma, ~75 Ma, respectively. .................................... 200 Figure 4-2 Syn-deformational evolution of the San Matías District (SMD) between ~75 – 69 Ma. A. diagram shows a syn-accretional regional setting for the Calima Terrane and the location of B xxxix and C diagrams. B-C diagrams show the deformational evolution of the SMD areas under a regional NEE-SWW-oriented stress-field. This district-scale stress-field is interpreted based on field evidence documented by Manco and Davila (2012) and Starling (2012). Abbreviations: Ca = Calima Terrane, Ta = Tahamí Terrane, Ch = Chibcha Terrane adopted from the tectonic model proposed by Restrepo and Toussaint (1988). .............................................................................. 202 Figure 4-3. Post- accretional and post-deformation evolution of the San Matías District under an NW-SE-oriented stress-field (Taboada et al., 2000). A. diagram shows the accretion and orogenesis of the Calima Terrane to the continental margin (Tahami Terrane) and the location of the B diagram. B. The diagram displays the current configuration of the San Matías District, where the NW faults (Las Claritas, Montiel, and Teheran Faults) exhibit a transtensional kinematics. Numbers highlight the field evidence that includes: 1. Spread hematization alteration in the west-dipping volcanics sequences west of the Valdes Fault. 2. Non-faulted San Pedro River Lineament. 3. Dextral, transtensive reactivation evidence in the Las Claritas Fault (Cordoba Minerals Corp., pers. comm., 2016). 4. The La Loma de San Juan quarry, where magnetite replacement in east-dipping volcanoclastics is observed. 5. Outcrops in the Betesta area, where west-dipping mineralized volcanoclastics similar to El Alacrán Deposit Unit 2, have been identified. C. The diagram represents the post-accretional arc erosion and formation of the San Jacinto Deformed Belt (SJDB) (Cardona et al., 2012). Abbreviations: Ca = Calima Terrane, Ta = Tahamí Terrane, Ch = Chibcha Terrane. The nomenclature adopted from the tectonic model proposal from Restrepo and Toussaint (1988). ........................................................................... 204 Figure 4-4. Fluid evolution of the El Alacrán Deposit. A. West-looking schematic diagram of the initial configuration of the El Alacrán Deposit. The schematic diagram shows the El Alacrán Deposit sequence units (Unit 1, Unit 2, and Unit 3), the pre-mineral location of the El Alacrán xl Norte Tonalite magmatism, and the beginning of the Sill 2 magmatism that led to the formation of the cooling Path A alteration assemblages (Section 3.6.2.2). B. Model I explains the mineralizations and alteration assemblages under a single long-lived fluid as a product of the seawater interaction with the El Alacrán Oeste Tonalite. The lines in the top indicate the relative abundances on Zn-Ag, Au, and Cu in the deposit. C. Modell II explains the mineralizations and alteration assemblages formed from seawater interaction with at least two magmatic fluids; one fluid sourced from the El Alacrán Oeste Tonalite (in Path B) and other sourced from a possibly concealed porphyry source (Px2) consistent with the cooling Path C defined in Section 3.6.2.2...................................................................................................................................................... 207 Figure 4-5. Pb isotopes from non-galena sulfides of the El Alacrán Deposit mineralizations. The isotopic data are compared with sulfides and rocks from other deposits and provinces in Colombia, Ecuador, Peru, and Chile that formed under a tectonic environment or age similar to the San Matías District. A. Uranogenic diagram (207Pb/204Pb vs 206Pb/204Pb) displaying the El Alacrán Deposit sulfides in black. B. Thorogenic diagram (208Pb/204Pb vs 206Pb/204Pb) displaying the El Alacrán Deposit sulfides in black. Diagrams include the plumbotectonics modelled curves Version II from Zartman and Doe (1981). The displayed isotopic data in Colombia comes from Sillitoe and Hart 1984; Dupre and Echavarria, 1984; and Leal-Mejia, 2011. In Perú comes from De Haller et al., 2006; in Chile from Marschik et al., 2003; and in Ecuador from Chiaradia et al.,2004. ....................................................................................................................................... 212 Figure 4-6 S isotopic comparison from the El Alacrán Deposit and other Andean deposits. A. Ranges of δ34S values determined for sulfide and sulphate minerals associated with Porphyry Cu-Au deposits. Modified from Escolme (2017). B. Compilation of δ34S values for sulfide minerals, mostly pyrite and chalcopyrite, from selected IOCG, manto-Cu, vein, skarn and magnetite-xli apatite deposits in northern Chile and southern Perú. Figure modified from Escolme (2017) and includes data from Sillitoe (2003), Ripley and Ohmoto (1977), De Haller and Fontbote (2009). Values are centred close to zero ‰, indicating a predominantly magmatic sulphur source (Barton, 2013). Large deviations at Raul-Condestable are interpreted to indicate a reduction of evaporitic or seawater sulphate (Ripley and Ohmoto, 1977; de Haller et al., 2002) and biogenic sulphur (de Haller et al., 2002). The light blue is the range found in the El Alacrán Deposit sulfides, whereas the darker blue represents the δ34S values obtained in the San Matías District Cu-Au porphyries........................................................................................................................ 213 xlii List of Abbreviations BC = British Columbia BSE = Backscattered electron BV = Bureau Veritas Labs CDT = Canon Diablo Troilite CL = Cathodoluminescence EPMA = Electron probe micro-analysis MDRU = Mineral Deposit Research Unit PCIGR = Pacific Centre for Isotopic and Geochemical Research PPL = plane polarized light (petrographic images) QFIR = Queen’s Facility for Isotope Research RFL = Reflected light (petrographic images) SEM = Scanning electron microscope SWIR = Short-wave infrared UBC = University of British Columbia XPL = Crossed polarized light (petrographic images) eCu = Equivalent Cu LA-ICP-MS = Laser Ablation Inductively Coupled Plasma Mass Spectrometer Mineral, rock, and constituent abbreviations used in figures Ab = Albite Amp = Amphibole Amyg = Amygdule Aug = Augite Bn = Bornite Bt = Biotite Car = Carbonate Chl = Chlorite xliii Ccp = Chalcopyrite Ep = Epidote Ap= Apatite Hb = Hornblende He = Hematite FK = K-feldspar Kao = Kaolinite Mag = Magnetite Mo = Molybdenite Plag = Plagioclase Po = Pyrrhotite Py = Pyrite Qtz = Quartz Ser = Sericite Sph = Sphalerite V-Mica = Vanadium Mica Tita = Titanite Rut = Rutile Act = Actinolite Ab = Albite Law = Lawmontite Mushk = Mushketovite Sp = Specularite Aspy = Arsenopyrite Ill = Ilmenite Mainly based on mineral abbreviations are obtained from Whitney and Evans, 2010. xliv Acknowledgements The support received throughout this project from the MDRU-UBC, and Cordoba Minerals Corp. - High Power Exploration is gratefully acknowledged and was crucial to the success of this project. Specifically, I want to thank Dr. Craig Hart and Dr. Hildebrando Leal Mejía, who believed in the project as an essential asset no only for the sponsoring companies but also as a contribution to Colombian Metallogeny understanding. Special thanks to the High Power Exploration staff (Charlie Foster, Graham Boyd, and Cathy Fitzgerald), for the deep-technical discussions, mainly thanks to Mark Gibson, who believed in my potential and for his mentorship and guidance. I would also like to thank Dr. Farhad Bouzari, Dr. Greg Dipple, Dr. Robert Lee, Dr. Kenneth Hickey, and Thomas Bissig for the support and willingness to share their knowledge answering endless questions. I would like to thank to Dr. Peter Winterburn† for triggering a passion for geochemistry. Many thanks to Dr. Lori Kennedy for her appreciated support during the thesis defense. Thank you to all my Cordoba Minerals colleagues in Colombia (Oscar E. Pinilla, Jaime Aroca, Mario Castaño, and Henry Ramirez), especially to Javier Pinilla, who helped to log kilometres of drilling-core required for this project. Also thanks to Chris Grainger, the big boss. Finally, thanks to my colleagues at MDRU and BRIMM who helped me a lot with the chapters review, my accent, and making this journey a meaningful experience. xlv Dedication to my family, specially to my nephews Samuel, Sebastian and my niece Valeria, who I want to inspire to dream big 1 Chapter 1: Introduction 1.1 Introduction Colombia was the largest gold producer in South America before Brazil and Peru took over in the 1980s and had produced close to 100 Moz Au (Kiri, 2019). Recent discoveries of new mineral deposit in Colombia, such as La Colosa (>28 Moz Au; AngloGold Ashanti, 2015), Nuevo Chaquiro (>5.6 Moz Au; >3.6 million tonnes (Mton) Cu; Bartos, 2017), and Buriticá (~10 Moz Au; Continental Gold, 2019) demonstrate the tremendous geological potential of the country to host world-class Au-Cu deposits. These discoveries increased mineral exploration throughout the country and opened research opportunities to further understand the evolution of the mineral systems in Colombia. The restricted access to certain areas of Colombia during past-armed conflicts have prevented the opportunity to develop an improved understanding of the magmatism and mineralization in some regions of Colombia. One of these regions is the San Matías District (SMD) in the Western Cordillera, where Cordoba Minerals Corp. identified porphyry Cu-Au-style mineralization (Cordoba Minerals Corp., 2013) of Late Cretaceous age (~ 75 - 70 Ma , Leal-Mejía and Hart (2017). Intrusive rocks and related mineralization of these Late Cretaceous ages had not been previously recognized in this part of Colombia and their recognition offered an opportunity to establish a new metallogenic foundation to better understand the endowment and to consider where new mineral deposits can be discovered. In the SMD area, artisanal workings and historical exploration were previously developed in the El Alacrán Deposit. The El Alacrán Deposit is currently the most advanced prospect of the district and has significant geochemistry data accumulated from historic and recent drill hole exploration. Although at a 2 district-scale, this deposit has a spatial relationship with the nearby porphyry Cu-Au prospects, a genetic assertion lacks unambiguous evidence to supports a porphyry Cu-Au source. Instead, the El Alacrán Deposit exhibits characteristics that are more commonly described in other deposit models such as iron oxide copper-gold (IOCG), skarn, and volcanogenic massive sulfide (VMS), all of which adds more complexity to the understanding of the genesis of the deposit within the context of the SMD metallogeny. This study focuses on the El Alacrán Deposit; however, it also characterizes the major intrusive units and mineral occurrences within the San Matías District. The detailed characterization of the mineralization, host rocks, hydrothermal fluid chemistry, and age of the El Alacrán Deposit help to understand the relationship of this deposit with the SMD magmatism and metallogeny. Understanding the SMD throughout the El Alacrán Deposit provides an opportunity to document a new metallogenic belt with unprecedented deposits within the Colombian geotectonic framework. This study uses petrography, whole rock geochemistry, U-Pb, Ar-Ar, and Re-Os geochronology data, that combined with S and Pb isotopic analysis to develop a genetic model for the El Alacrán Deposit, to contribute to the understand the metallogenic evolution of the SMD area, and to provide guidelines for future exploration in this increasingly significant district. 1.2 Location and Exploration History in San Matías District The San Matías District is located in the municipality of Puerto Libertador, Department of Córdoba, in the northern foothills of the Western Cordillera and the southern side of the Caribbean lowlands (Figure 1-1). Initial exploration in the San Matías District was made on the El Alacrán Deposit by Dual 3 Resources Inc. between 1987 and 1989. Their work included pits, trenches, rock sampling, underground sampling, geological mapping and a ground magnetic survey, followed by 15 diamond drill holes totalling 2,408m. The El Alacrán Deposit has been mined by artisanal miners who founded a settlement named El Alacrán. In the El Alacrán area, a concession agreement was granted in 2009 to Sociedad Ordinaria de Minas Omni S.O.M. (Omni), and subsequently optioned to Ashmont Resources Corp., in 2010. Ashmont completed geological mapping, underground mapping and sampling, a ground magnetic survey, and 52 diamond drill holes totalling 13,429.45 m. The predecessor to the Cordoba Minerals Corp., the Minatura Group company, undertook a Joint Venture with the Canadian company Wesgold Resources to create the company Minerales Cordoba S.A.S and started surface geology exploration in the San Matías area in 2010. This exploration mostly focused on the Montiel Prospect (Montiel W) with > 1 km of trenches and mapping. Extended regional mapping, soil and stream sediment samples were collected to the south of Montiel W prospect and concluded with the identification of additional porphyry Cu-Au prospects (e.g., Costa Azul, Buenos Aires, Mina Ra and Mina Escondida; Figure 1-1). In 2011, Sabre Metals Corp. part of the de Bullet Group started exploration in the San Matías District, focused on the surroundings of the Teheran Mine (Montiel E) prospect, Betesta and La Concepción areas. In 2013, Minerales Cordoba S.A.S. and Sabre Metals Corp. merged into Cordoba Minerals Corp. Under this new company, 575 m were initially drilled in four diamond drill holes on the Montiel E target. 4 Figure 1-1 Location, access and mineral deposits and prospects of the San Matías District (SMD) in NW Colombia. A. Digital Elevation Model (DEM), roads and access to the SMD and El Alacrán Deposit. B. Detailed map showing El Alacrán Deposit and other prospects within the San Matías District. Lidar image provided by the Cordoba Minerals Corp. In 2014, 21 diamond drill holes (6,135m) close to the San Matías village and 7,047 m of Rotary Air Blast (RAB) drilling in Montiel E, Montiel W and Costa Azul prospects were completed. In 2015, High Power Exploration Inc. formed a strategic partnership to explore the district. Cordoba Minerals Corp. acquired the El Alacrán property from the Sociedad Ordinaria de Minas Omni S.O.M. and completed three diamond drill holes in 2015, 41 diamond drill holes in 2016, and 40 diamond drill holes in 2017. 5 To date, the diamond drilling exploration has been accompanied by the collection of 6,900 soil, 1,980 stream sediments, and 1,890 rock and saprolite samples. Diamond drilling at El Alacrán Deposit comprises a total of 38,462 m in 136 HQ and NQ-diameter holes completed between 1987 and 2017 (52 holes drilled by Ashmont and 84 holes drilled by Cordoba Minerals Corp. 1.3 Mineral Prospects in the San Matías District Exploration in the San Matías District led to the identification of multiple prospects with different mineralization styles, including Cu-Au porphyry-related, replacement and veins. In the following paragraphs, brief descriptions of the most important prospects are presented: El Alacrán Cu-Au Deposit: The El Alacrán Deposit is located in the western margin of the San Pedro River, near the El Alacrán village (Figure 1-1C). The Cu-Au mineralization is hosted by a 550 m thick west-dipping mafic volcanic and metasedimentary-volcaniclastic sequence, capped by intermediate intrusions and felsic sub-volcanic bodies. Copper-gold mineralization occurs throughout the whole metasedimentary-volcaniclastic package, except for the lower mafic rocks preferentially developed in the mid to upper part of this calcareous affinity package. Copper-gold mineralization comprises replacement and disseminations of chalcopyrite + pyrite ± pyrrhotite with quartz and carbonate and locally produce massive sulfides zones (>70% pervasive replacement). The current total resource (indicated + inferred) at El Alacrán Deposit is 82.15 Mt grading 0.54-0.39% Cu, 0.28-0.13 g/t gold (0.73-0.49% CuEq; Cordoba Minerals Corp., 2019b). Apatite is commonly associated with the mineralization. The copper and gold sulfide mineralization partially to completely replace a previous magnetite-stage alteration. Pyrrhotite dominates early copper-gold mineralization. A pyritic assemblage commonly overprints pyrrhotite, and much of the chalcopyrite 6 formed at this stage, associated with chlorite-carbonate ± sericite and albite alteration. Sphalerite-carbonate-Au veins (CBM veins) crosscut the sequence and are interpreted to have beenformed at the last stage. Several different deposit models have been proposed for El Alacrán Deposit, including volcanogenic massive sulfide (VMS), skarn, and Iron Oxide Copper-Gold (IOCG). Based on one field visit and core logging data, Sillitoe (2018) concluded that the El Alacrán Deposit is a strata-bound replacement body of IOCG-type. Montiel East (Montiel E): The Montiel E Cu-Au Porphyry prospect occurs in the eastern margin of the San Pedro River lineament in the San Matías village, 2 km northeast of the El Alacrán Deposit (Figure 1-1C). This prospect has been mined by artisanal miners since the early exploration of El Alacrán Deposit began. The porphyry contacts are intrusive and display local breccias with fragments of the andesite host rocks. Outcrops are usually scarce and small (<1 Ha). The Montiel E porphyry suite comprises at least four different intrusive phases: PxHe, PxHL, Pxto, and QfPx that occur in an N-E oriented cluster of 600 m length. The PxHe is an early phase that hosts the main Cu-Au mineralization. Three sets of veins are recognized within this phase: 1) Tardy-magmatic quartz veins, 2) magnetite-chalcopyrite±bornite quartz veins, and 3) chalcopyrite-only veinlets. Hydrothermal alteration is mostly associated with actinolite, quartz, and early magnetite veinlets. The PxTo is an intermineral-late, low-grade phase with variable amounts of chalcopyrite, pyrite and pyrrhotite. It shows a marked hydrothermal biotite occurrence with chlorite retrogradation. The PxHL is a late, low-grade to barren, tonalitic phase with propylitic alteration and pyrite occurrence. The QFPx is a silica altered, low-grade to barren late quartz-feldspar phase that crosscut the entire porphyry suite. Drill hole intercepts and grades include 123 m@ 0.74% Cu and 0.60 g/ton Au (e.g. SMDDH009; Cordoba Minerals Corp., 2014). Although initial interpretations of the Montiel E porphyry Cu-Au mineralization by Sillitoe (2008) 7 suggested a possible temporal relationship with the late Miocene Middle Cauca Au-Cu Belt (ca. 9 - 5.6 Ma; Leal-Mejía et al., 2017), recent geochronological data demonstrate a Late Cretaceous age for the magmatism and mineralization (Leal-Mejía and Hart, 2017). Costa Azul (CA): The Costa Azul Porphyry Cu-Au prospect is also located in the eastern side of the San Pedro River Lineament, 2.5 km east of the El Alacrán Deposit (Figure 1-1C). This prospect comprises a series of equigranular to porphyritic intrusions similar to those described in the Montiel E Porphyry Cu-Au prospect. A barren porphyry phase is exposed along the Costa Azul creek, whereas the mineralizing phase is not exposed. The CA porphyry contacts are dominantly intrusive with respect to the andesitic volcanic basement. The Porphyry Cu-Au mineralization is associated with sheeted quartz-magnetite-chalcopyrite-pyrite-bornite veinlets, which are hosted in an altered tonalite porphyry and volcanic wall rock. The sill-shaped morphology and the selective distribution of the quartz + magnetite + chalcopyrite stockwork mineralization of the Costa Azul Cu-Au Porphyry (developed only in the intrusion hanging-wall) suggest this prospect formed sub-horizontally. The Costa Azul porphyry suite comprises intrusive phases equivalent to the ones described at Montiel E Porphyry (e.g. PxHe, PxHL). Consequently, the veining paragenesis resembles the one observed at Montiel E Porphyry (e.g. chalcopyrite veinlets crosscut the early quartz-bearing veins). Crosscutting relationship of quartz-molybdenite-chlorite veins after chalcopyrite veinlets suggests that molybdenite occurrence in this porphyry is related to a late mineralizing stage. Drill hole intercepts and grades include 111 m @ 0.32% Cu and 0.36 g/ton Au (e.g. CADDH001; Cordoba Minerals Corp., 2014). Montiel West (Montiel W): The Montiel W prospect is located on the eastern side of the San Pedro River Lineament, 800 m west of Montiel E prospect (Figure 1-1C). This prospect extends 200m E-W and up to 500m N-S. Preliminary, diamond drilling at the Montiel W target has intersected zones of 8 multi-directional sheeted quartz-magnetite-chalcopyrite-bornite veins that are hosted in both mafic and intermediate volcanic rocks. This style of copper-gold mineralization is interpreted to be porphyry-related, as seen at both the Montiel E and Costa Azul prospects, where it occurs immediately adjacent to the mineralized porphyry intrusions. Drilling, however, has yet to locate the associated porphyry intrusion. Drill hole intercepts include 52@ 0.43% Cu and 0.35 g/ton Au (e.g. MWDDH001; Cordoba Minerals Corp., 2014). Other small Cu-Au mineralizations. Additional minor Cu-Au mineralizations include porphyry-style mineralization ~ 3.5 km southeast El Alacrán Deposit at Caño Pepo prospect and Au-bearing fault-fill vein at Mina Cocos ~ 4 km southeast El Alacrán Deposit (Figure 1-1C). Artisanal works of pyrrhotite-chalcopyrite-pyrite±gold veins occur at Mina Ra, Mina Escondida and Mina Guapa mines (5.7 km south El Alacrán) (Figure 1-1C). These veins correspond to ~1 m thick quartz-sulfides veins with limited carbonate-sericite alteration observed in the wall rock, possibly of a mesothermal origin. Magnetite replacement mineralization occurs at the Buenos Aires area in the eastern margin of the San Pedro River (Figure 1-1C), where replacement and in-fracture infill magnetite-tourmaline-pyrite-carbonate mineralization is hosted in a porphyritic andesite rock. Local artisanal miners have mined this prospect since 2012. An auriferous paleo-placer is mined at a small scale by artisanal miners at la Mecedora locality, close to La Rica Village, north of SMD (Figure 1-1B). The paleo-placer deposit shows evidence of lithification and deformation possibly associated with the San Jacinto Fold Belt (SJFB). 1.4 Thesis Objectives and Organization The following four objectives are proposed to explain the origin of the El Alacrán Deposit. The objectives are approached in the thesis through five chapters. 9 Objective 1: Establish the geological framework for the El Alacrán Deposit. This objective determines the tectonic setting of the San Matías District magmatism to define if the SMD was favorable to form some of the deposit models that have been proposed to explain the El Alacrán Deposit mineralization (i.e. IOCG, VMS, Skarn, and CRD). Objective 1 is addressed in Chapter 1, which introduces the reader to Colombian tectonic models, magmatic epochs, and discusses the genetic considerations of the potential mineral deposit models. Objective 2: Evaluate the petrography, lithogeochemical, and geochronological characteristics of the intrusions at the El Alacrán Deposit and other SMD prospects. This helps to classify and compare key intrusive units, and to determine their metallogenic fertility. This objective is addressed in Chapter 2, which explains the regional and local geology of the San Matías District and provides the detailed lithostratigraphy of the El Alacrán Deposit. Chapter 2 also presents the whole rock geochemical characterization and U-Pb geochronology, along with trace element zircon geochemistry from key San Matías District intrusions. Objective 3: Characterize the mineralization and alteration types of the El Alacrán Deposit and determine their relative and absolute timing constraints in a paragenetic framework. This allows the recognition of temperature and chemistry conditions of the ore-forming fluids and its temporal relationships with host-rock, dikes, and sills, which are fundamental to constrain the deposit genetic evolution. This information is also critical to identify the potential fluid source(s), and controls on high-grade zones of the deposit. This objective is aimed at Chapter 3. The ore formation timing discussion focuses on the Re-Os and Ar-Ar geochronology data, whereas, physicochemical conditions are inferred 10 from the observed mineralogy and stable S and radiogenic Pb isotopes. 2D modelling of the distribution of mineralization and alteration along the three selected cross-sections is presented. Objective 4: Integrate available data to propose a genetic model for the El Alacrán Deposit and establish an exploration model for the San Matías District. This aims to contribute to improved decision-making, thereby increasing exploration success both at a deposit and regional scale. Objective 4 is aimed at chapters 4 and 5. Chapter 4 discusses the San Matías District tectono-magmatic evolution and proposes a genetic model for the El Alacrán Deposit. Chapter 5 summarizes the main conclusions of the thesis research and discuss the exploration implications from the proposed genetic model for the El Alacrán Deposit. Additionally, this chapter proposes future work to improve the thesis results. 1.5 Approach and Methods The objectives outlined in section 1.5 have been achieved through a combination of literature review, fieldwork, and laboratory analyses. 1.5.1 Company Geochemistry Database Cordoba Minerals Corp., allowed the use of their multi-element geochemistry database acquired from the drilling campaigns. The geochemistry analyses were done at ALS Minerals laboratories in Chile, Perú and Canada. Gold was analyzed by fire assay on a 50 g aliquot with an AAS finish (method Au-AA24, Appendix A.1). Multi-elements were analyzed by 4-acid digestion of a 0.25 g sample with ICP emission spectrometry finish for 33 elements (method ME-ICP61, Appendix A.1). Samples above the upper detection limit of 10,000 ppm Cu were reanalyzed by 4-acid digestion with ICP-AES finish (method Cu-OG62, Appendix A.1). 11 1.5.2 Fieldwork and Sampling A total of 86 outcrop and diamond drill core rock samples were used in the current research. The samples were collected during three campaigns: April - May 2017, September 2017, and January 2018 (Ref. 1704 - 1705, 1709, and 1801, respectively, Appendix A.2). The April - May 2017 campaign was executed either at a deposit scale (e.g. El Alacrán Deposit, Montiel E, and Costa Azul prospects) and at a regional scale (e.g. Rio Verde, Betesta, Mina Escondida, San Jorge, and La Jagua localities). At a deposit scale the sampling methodology consisted of collecting a representative samples of the different mineral alteration associations and focus on sampling actinolite, sericite and molybdenite for age dating purposes. A total of 34 samples from 26 drill holes were revised during this campaign (Table 1-1). The geochemistry database was used to identify high concentrations of Mo in the drill cores, which allowed identifying molybdenite. At the regional scale, 12 samples from outcrops the San Matías District regional intrusive units (including dikes and sills) were collected for petrographic, lithogeochemical, and geochronological characterization. The general methodology consisted in obtaining at least 10 kg sample of each intrusive unit. The evaluation of the Zr content in the drill cores from prospects with available drill core and geochemistry data (e.g. El Alacrán Deposit, Montiel E and Costa Azul, and the San Jorge Intrusion) allowed selection of materials likely to host zircons. The September 2017 campaign (Appendix A.2) focused on the El Alacrán Deposit. Representative samples of the different oxide and sulfide mineralization styles recognized were selected and characterized petrographically and chemically. Thirteen samples from 11 drill holes were sampled during this campaign (Table 1-1). 12 Table 1-1 Sampling Campaigns executed in the San Matías District. The January 2018 campaign (Appendix A.2) focussed on the El Alacrán Deposit and the Buenos Aires prospect. Representative samples of the various host rock lithofacies were mostly from the drill hole ACD075, which is located beyond the principal mineralization/alteration zone of the El Alacrán Deposit. This allowed obtaining unaltered material for petrography and lithogeochemistry characterization. The purpose of sampling the Buenos Aires prospect was to characterize petrography and geochemistry of the iron-oxide mineralization given its similarities with the El Alacrán Deposit mineralization. Twenty-seven samples from drill holes and outcrops were collected during this sampling campaign (Table 1-1). 1.5.3 Petrography A total of 112 polished thin sections were examined in transmitted and reflected light microscopy to identify ore/alteration minerals, mineral assemblages, and their cross-cutting relationships (Appendix B.1, B.2). The analyzed material included: 72 polished thin sections collected for this research and 20 polished thin sections selected for a previous petrography study by Dunne (2016) and 20 polished thin sections provided by Cordoba Minerals Corp. Petrographic descriptions were performed with a NIKON ECLIPSE E600 POL polarizing microscope, coupled with a CANON REBEL EOS T21 camera for 13 photomicrographs. Systematic point-counting methodology (200-300 points) was applied for intrusion specimens to determine modal classification for the rocks. 1.5.4 K-feldspar Staining Twenty-three samples were etched with HF and exposed to sodium cobaltinitrite to identify the presence of primary K-feldspar in the intrusion samples and improve their modal classification. The etching and staining preparation was conducted at Precision Petrographics Ltd. Lab, in Langley, BC, Canada, on selected thin section offcuts (Appendix B.1). 1.5.5 Fluid Inclusions Petrography Fluid Inclusion petrography was carried out in eight 200 μm-thick sections prepared at Precision Petrographics Labs, in Langley, BC, Canada. The fluid inclusion petrography focussed on quartz and apatite samples from the El Alacrán Deposit and quartz veins from the San Matías District Porphyry Cu-Au prospects. The objective was to compare the fluids involved in the porphyry prospects and the El Alacrán Deposit and make some inferences for the physical and chemical conditions of the ore-forming fluids as described by Nash (1976). The fluid inclusion petrography was conducted at the Fluid Inclusion Laboratory of MDRU at the Earth, Ocean and Atmospheric Department of The University of British Columbia (UBC), in Vancouver, BC, Canada, using an Olympus BX60 petrographic microscope coupled with a Retiga 2000R camera for photomicrographs, with transmitted and reflected light capabilities and 20X, 40X and 100X objectives with maximum magnification of up to 200X. 1.5.6 Whole Rock Geochemistry Thirty representative samples of the and El Alacrán Deposit lithofacies and San Matías District intrusions were analyzed by Bureau Veritas Minerals Ltd. laboratories using a customized research lithogeochemical package “MDRU-Lith17” (a combination of the BV standard LF702-EXT and LF100-EXT analytical packages with additional selected elements from the AQ200). The sample preparation 14 and analyses included: sample preparation in a ceramic bowl pulveriser; extra wash of sand followed by acetone cleaning of ceramic mill; and whole rock and traces by XRF including Loss On Ignition (LOI) and SO3 plus full set of trace element and REE by fusion ICP-MS. Major element oxides were normalized to 100%, and selected plots were generated with the REFLEX ioGAS software (Appendix C.1). For QAQC, at least two control samples were submitted in each lab shipment. To evaluate the reproducibility, one duplicate control was inserted in every shipment. The control consisted of a pulp sample with a known chemical composition from previous lab analysis. The QAQC procedure for standards consisted of defining warning (2*SD) and failure limits (3*SD) over elements with accepted values (Appendix C.2). Using ioGAS software, four different alteration criteria were used to define the degree of alteration of the analyzed samples and estimate the cations (e.g. Na, K, Ca, and Mg) losses or gains. The alteration screening included the use of the (Na/Al vs K/Al) ratio diagram from Davied and Whitehead (2006); the Alteration Box plot (Chlorite Carbonate Pyrite (CCPI) vs Ishakawa Alteration Index (AI)) from Large et al. (2001); the Molar Element Ratio (K/Al vs (2Ca+Na+K)/Al) from Warren et al. (2007), and the Loss On Ignition (LOI) criteria from Lecher and Desilets (1987) (Appendix C.2). After the alteration assessment made in ioGAS, the normative mineralogy from the least altered samples of the San Matías District intrusions were calculated using the CIPW Norms from Kelsey (1965) (Appendix C.3). 1.5.7 Short Wave Infrared (SWIR) Spectral Analysis A total of 101 short-wave infrared (SWIR) spectra were measured using the ASD Terraspec instrument at the SWIR facilities of MDRU. The objective was to characterize the chemical variations of the white mica (sericite) and chlorite associated with different paragenetic assemblages of the El Alacrán Deposit. The spectra were interpreted using The Spectral Geologist Professional© (TSG) version 5.03.002 and 15 Specwin software by comparison to a reference database (e.g., USGS spectral library, Kokaly et al., 2017). SWIR data are presented in Appendix D.1. 1.5.8 SEM-EDS-BSE and EMPA Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) data were collected using the Hitachi SU-70 field emission SEM fitted with an Oxford AZtec XMax80 EDS system at EOAS. Fourteen polished thin sections were analyzed under SEM-EDS to identify small mineral species, including rare earth element (REE) minerals. In addition, 44 feldspar grains were analyzed to verify their composition and spot selection for Pb isotopes LA-ICP-MS analysis. Backscattered electron (BSE) imaging was carried out on four polished thin sections with gold mineralization to determine the texture and distribution of the gold particles (Appendix D.2). 1.5.9 Geochronology Geochronology analyses were undertaken to constrain the absolute ages of magmatism/volcanism and mineralization/alteration at the El Alacrán Deposit and the most important prospects of the San Matías District (Appendix E.1). Zircon crystal separation from 13 samples was conducted at MDRU-UBC mineral separation facilities following standard procedures for sample crushing and milling, gravimetric and magnetic techniques. Zircon crystals were recovered and hand-picked under the binocular microscope. Just five out of 13 samples yielded recoverable zircons. The individual zircon grains were mounted in epoxy resin and imaged by Cathodoluminescence (CL) prior to analysis. LA-ICP-MS analyses were carried out on an ArF excimer laser ablation system (193nm; Resolution M-50LR, ASI Australia) connected to a Quadrupole ICP-MS (Agilent 7700x) at the Pacific Centre for Isotopic and Geochemical Research (PCIGR) at UBC. Laser spots were set in the central (core) and external (rim) parts of the zircon crystals. 16 Measurements were performed at a repetition rate of 5 Hz and spot sizes of 34µm. The energy density on the sample was 1.8 J/cm2. Helium served as carrier gas and was admixed with N2 for signal enhancement. The mass spectrometer was tuned for sensitivity, ThO/Th < 0.3% and a mass bias with 238/232<110%. Data reduction was performed with the Iolite 3.4 software (Paton et al., 2011). The size and internal morphology of individual zircon crystals were determined following the morphology characterization by Corfu et al. (2003). The zircon QAQC process included a visual inspection under reflected light and CL to verify the presence or absence of inclusions and cracks within the crystals and the review and comparison of trace element geochemistry on cores and rims Appendix E.1. The comparison of the trace element geochemistry within individual zircon crystals helped to identify inconsistencies and to exclude some results of the data integration. The data integration, final ages and uncertainties were calculated using the Isoplot 3.7 Excel macro (Ludwig, 2003). Calibration for trace element analyses was carried out using the silicate glass standard SRM NIST612 as an external standard and [Zr] = 49.7 %m/m as an internal standard. G_NIST612, Z_Plesovice and the basaltic BCR-2G were cross-checked for quality control. For age dating, the zircon reference materials Temora, Plesovice, NIST612, NIST610, and 91500 were analyzed along with the samples. Standard samples were calibrated using the methodologies defined by Lee and Amini (2019). For 40Ar-39Ar geochronology, two samples were irradiated at the McMaster Nuclear Reactor in Hamilton, Ontario, Canada. 40Ar-39Ar geochronological analyses were performed at the Noble Gas Laboratory of the Pacific Centre for Isotopic and Geochemical Research (PCIGR) of the EOAS Department at The University of British Columbia, Vancouver, BC, Canada. Samples were step-heated and analyzed with a VG5400 mass spectrometer equipped with an ion-counting electron multiplier. Plateau spectrum and isochron ages were calculated using Isoplot v. 3.09 (Ludwig, 2003). Further analytical information is summarized in Appendix E.2. 17 For Re-Os geochronology, three samples with molybdenite mineralization from the El Alacrán Deposit drill cores were submitted to Dr. Robert Creaser for mineral separation and Re-Os dating at the Canadian Centre for Isotopic Microanalysis (CCIM) of the University of Alberta. For each sample, a molybdenite mineral separate was made by metal-free crushing, followed by gravity and magnetic concentration methods described in detail by Selby and Creaser (2004). The 87Re and 187Os concentrations in molybdenite were determined by isotope dilution mass spectrometry using Carius-tube, solvent extraction, anion chromatography and negative thermal ionization mass spectrometry techniques. For this work, a mixed double spike containing known amounts of isotopically enriched 185Re, 190Os, and 188Os analysis was used (Markey et al., 2007). Isotopic analysis used a Thermo Scientific Triton mass spectrometer by Faraday collector. Total procedural blanks for Re and Os are less than <3 picograms and 2 picograms, respectively, which are insignificant in comparison to the Re and Os concentrations in molybdenite. The Reference Material 8599 Henderson molybdenite (Markey et al., 2007) is routinely analyzed as a standard, and during the past year returned an average Re-Os date of 27.76 ± 0.08 Ma (n=8), indistinguishable from the reference age value of 27.66 ± 0.1 Ma (Wise and Watters, 2011) (Appendix E.3). 1.5.10 S and Pb Isotope Chemistry Stable sulfur and radiogenic lead isotopes for sulfide minerals from El Alacrán Deposit and the San Matías District mineral prospects were analyzed to characterize their isotopic composition and compare their potential sources. Representative and paragenetically constrained sulfide separates of pyrite, chalcopyrite, sphalerite and arsenopyrite were extracted from crushed and washed fraction of samples. Each grain was carefully examined under binocular microscope to avoid mixed aggregates and inclusions. Only pure separates of each sulfide were selected for analysis. For S isotopes, a suite of 18 mineral separates were submitted to the Queen’s Facility for Isotope Research (QFIR) of the Queen’s 18 University in Kingston, ON, Canada, whereas aliquotes of the same samples for Pb isotopes were submitted to the PCIGR at UBC (Appendix F.1). For Pb isotope composition of the San Matías District, sulfide separates (pyrite and sphalerite) were analyzed using a Thermal Ionization Mass Spectrometer (TIMS) at the PCIGR Geochronology Laboratory at The University of British Columbia. The results were normalized using a fractionation factor of 0.12% based on multiple analyses of NBS981 standard lead, and the values in Thirlwall (2000). Errors were reported at the 2-sigma level. The total procedural blank was 88pg, with composition 206Pb/204Pb = 17.71, 207Pb/204Pb = 15.22, 208Pb/204Pb = 36.54. In addition, Pb isotope analyses for forty-one feldspar grains from ten samples from San Matías District intrusions and volcanics were used for comparison with the Pb isotopic composition of the El Alacrán Deposit ore sulfides (Appendix H.2). Trace element composition of the analyzed feldspars were obtained by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) at the PCIGR. Lead isotope ratios were analyzed by connecting the Resolution laser system to the HR-SF-ICP-MS NuAttom (Nu Instruments, Wrexham, UK). The laser spots varied between 60 and 80µm. The data reduction was carried out using a customized data reduction scheme of the Iolite v.3, under the methodology defined by Lee and Amini (2019). The data integration and uncertainties were calculated using the Isoplot 3.7 Excel macro (Ludwig, 2003). G_NIST612, G_BCR2G, G_NIST610Z, and KL2_G standard samples were cross-checked for quality control. The standard values are described in Lee and Amini (2019). For QAQC purposes, significant variations in the trace element composition of the analyzed feldspars and standards were used to identify contamination, alteration or the presence of micro-inclusion. Therefore, it was used as a criterion to exclude some analysis results for the current study. For S isotope composition, the samples were weighed into tin capsules, and the sulfur isotopic composition measured using a MAT 253 Stable Isotope Ratio Mass Spectrometer coupled to a Costech 19 ECS 4010 Elemental Analyzer. δ34S values were calculated by normalizing the 34S/32S ratios in the sample to that of the Vienna Canyon Diablo Troilite (VCDT) international standard, values are reported using the delta (δ) notation in permil (‰) units and are reproducible to 0.2 permil (Appendix E.3). The Queen's Facility for Isotope Research (QFIR) protocols ensured both QA and QC generating 10% analyses each of the following: 1) certified reference materials and secondary standards, 2) random duplication of unknown samples, and 3) blanks. 1.6 Project Support This project is a collaboration between the Mineral Deposit Research Unit (MDRU) at The University of British Columbia (UBC), Cordoba Minerals Corp., and High Power Exploration Inc. (HPX). Logistics and field support, including the technical insights and discussions with project geologists on site was facilitated by Cordoba Minerals Corp. 1.7 Colombia Geo-tectonic Framework Review The tectonic evolution of Colombia is recognized to be highly complex in response to an “atypical” subduction-driven tectono-magmatic and metallogenic protracted history of back-arc basin and passive margin formation followed by the accretion of oceanic plateau basalts with large magnitudes of dextral shear (Villagómez et al., 2010, 2011; Leal-Mejía et al., 2019). The tectonic framework in western Colombia from the Cretaceous to the Miocene was controlled by the northeast passage of the Caribbean Plate and associated oceanic terranes relative to the South American Plate (Figure 1-2A-B). During the displacement of the Caribbean Plate form the Galapagos hot spot paleo-latitude to its current location, the stress field shifted from a NE-oriented to a SE-oriented (Figure 1-2, Kennan and Pindell 2009). 20 Figure 1-2. Changes in plate configuration in the Caribbean and Central America between the Cretaceous and Miocene. A. Diagram shows the dominat NE-oriented stress-field in the Cretaceous (125 – 120 Ma). B. Diagram shows the dominat SE-oriented stress-field during the Miocene (~10 Ma). Modified from Kennan and Pindell (2009). In the literature, there are marked differences in the definition of the western terranes of Colombia between different authors. These differences are related to the origin, limits, ages, and timing of accretion of the proposed terranes. At least four different tectonic models have been proposed by different authors for Colombia and the Northern Andes. These tectonic models include the proposals by Etayo-Serna et al. (1983), Restrepo and Toussaint (1988), Cediel et al. (2003), and Kennan and Pindell (2009) Figure 1-3. An extended review of these models is presented in Appendix I. The implications for the San Matías District magmatism and mineralization are discussed considering the proposed terrane extension and limits. Under the model proposal from Etayo-Serna et al. (1983), the San Matías District is located in the Buriticá Terrane (Figure 1-3A). The accretion of the Buriticá Terrane is uncertain Middle Albian to 21 Upper Cretaceous in age (Etayo-Serna et al., 1983). The geological framework for the Buriticá Terrane (e.g. calc-alkaline intrusions interacting with calcareous marine volcano-sediments) suggests that this terrane may host mineral occurrences similar to the El Alacrán Deposit. Hence, under this terrane delimitation, the San Matías District magmatism and associated metallogeny would potentially be extended from the Dabeiba Fault (south of San Matías District) to the Montelibano Fault (North of San Matías District) (Figure 1-3A, Appendix I). Similarly, under the model proposed by Restrepo and Toussaint (1988), the San Matías District is included in the Calima Terrane (Figure 1-3B). The Calima Terrane may be amalgamated to the western Colombia margin during Late Cretaceous along the San Jerónimo Fault that constitutes the easternmost fault of the Romeral Fault System (Maya and Gozalez, 1995) (Appendix I). However, Rodriguez and Arango (2013), suggested that the acreecion might be occurred earlier than the age of the Sabanalarga Batholith (ca. 83 Ma). The cretaceous magmatism along the Calima Terrane is pre-accretional and is traced from the north of Ecuador (e.g. the Tangula Batholith, Villagómez et al., 2011) till the Caribbean Great Antilles (e.g. the Aruba Batholith, Villagómez et al., 2011) Figure 1-3B. Under this terrane model, the San Matías District magmatism and metallogeny might 22 Figure 1-3. Location of the San Matías District in the context of different tectonic models proposed for Colombia. A. Etayo-Serna et al. (1983). B. Restrepo and Toussaint (1988). C. Cediel et al. (2003), and D. Kennan and Pindell (2009). The red square corresponds to the San Matías District area. 23 potentially be extended from south Colombia, close to the border with Ecuador until the Caribbean coast (Figure 1-3B). According to Cediel et al. (2003) tectonic model, the San Matías District is located within the allochthonous San Jacinto Terrane (Figure 1-3C). The San Jacinto Terrane accreted to the continental margin along the San Jacinto Fault and its arrival may be recorded by the deposition of Paleocene turbidite sequences of continental affinity and erosion surfaces of early Eocene in this terrane (Cediel et al., 2003). Based on the San Jacinto terrane definition proposed by Cediel et al. (2003, 2019), the San Matías District magmatism and associated metallogeny may extend from the Dabeiba Fault (south of San Matías District ) to the Santa Marta – Bucaramanga Fault (North of San Matías District) (Figure 1-3C, Appendix I). Finally, under the model from Kennan and Pindell (2009), the San Matías District lies within the T4 Terrane (T4b Block, Figure 1-3D). These authors suggested a Late Cretaceous through Cenozoic accretion of the T4 Terrane that involved under-thrusting of the Western Cordillera rocks beneath the Central Cordillera rocks. Under this model proposal, the magmatism and mineral occurrences similar to those in the San Matías District would be restricted to the T4b block that extends from Ecuador (e.g. Guaranda Terrane) to the Caribbean Floodplains in Northern Colombia (Figure 1-3D, Appendix I). The T4b block broadly coincides with the Calima Terrrane proposed by Restrepo and Toussaint (1988). 1.8 Cretaceous to Eocene Granitoid Magmatism of Colombia The distribution, nature, and temporal-spatial evolution of Colombian granitoids were recently reviewed by Leal-Mejía et al. (2019). These authors defined four major magmatic epochs for Colombia: 1) Paleozoic-mid-Triassic, 2) latest Triassic-Jurassic, 3) Cretaceous-Eocene, and 4) latest Oligocene-Mio-Pliocene (Appendix I). The available ages for the San Matías District magmatism (ca. 70 Ma, Leal-24 Mejía and Hart, 2017) indicate a relationship with the Cretaceous-Eocene magmatic epoch. Leal-Mejía (2011) separated the Cretaceous to Eocene magmatism of Colombia into two groups based on their geographic location relative to Romeral Fault System (Figure 1-4), and chemistry: 1) the Eastern Group Granitoids (EGG) and 2) the Western Group Granitoids (WGG) (Figure 1-4) The WGG displays a low-K character (K2O content <1%), a mixed magnesian-ferroan nature, and a distinctly calcic tendency relative to the EGG (Leal-Mejía, 2011). Given the structural location of the San Matías District magmatism, it is more likely to be related to the WGG (Figure 1-4). The WGG includes ca. 100 - 84 Ma Cretaceous age intrusions (Leal-Mejía et al., 2019), including: the Buriticá Tonalite (ca. 100 Ma, U-Pb; Weber et al., 2015), the Santa Fé Batholith (tonalite I, Weber et al., 2015) (ca 89 Ma, Zapata-Villada et al., 2013),the Buga Batholith (ca. 88 - 69 Ma, U-Pb; Nivia et al., 2017), and the Jejenes Stock (ca 85 Ma; Leal-Mejía, 2011). In addition, the WGG includes Paleocene-Eocene intrusions (ca. 62–42 Ma), such as the Mandé-Acandí batoliths (Leal-Mejía et al., 2019) (Figure 1-4). The Cretaceous age WGG is considered to be a component of the Colombian-Caribbean Oceanic Plateau (CCOP) (Kerr et al., 1997; Leal-Mejía et al., 2019) that formed in a west-dipping island arc setting upon the Caribbean Plateau (Villagómez et al., 2011, Weber et al., 2015). The WGG magmatism evolved from tholeiitic affinity (e.g. Altamira Gabro, ca. 88 Ma; Zapata-Villada et al., 2013) to calc-alkaline (e.g. the Buriticá Tonalite, Weber et al., 2015). This island arc may have collided with the continental margin around ca. 75 - 70 Ma along the Cauca–Almaguer Fault (Van der Lelij et al., 2010; Villagómez et al., 2011) causing the cessation of the Cretaceous magmatism associated to the Eastern Grup Granitoids (e.g. Antioquia Batholith, ca. 96 - 58, Leal-Mejía, et al., 2019, Figure 1-4). Similarly, the Eocene age WGG formed in an intra-oceanic arc setting upon a late Cretaceous oceanic basement of the Chocó Arc (Montes et al., 2012).25 Figure 1-4 Distribution of the Cretaceous to Eocene magmatism in Colombia and the El Alacrán Deposit location. The dots in the upper part show the location of oil and gas wells extracted from Mora et al., (2017). The dots are colored according to intercepted basement lithology. Purple dots correspond to metamorphic basement intercepts, pink dots are granitic rock intercepts, and green dots corresponds to mafic to intermediate volcanic basement intercepts. The ages are extracted from Leal-Mejía, 2011; Rodriguez and Arango, 2013; Zapata-Villada et al., 2013; Weber et al., 2015; Villagómez et al., 2011, and Nivia et al., 2017. 26 1.9 Remarks of the Tectonic Framework Review Based on preliminary ages obtained for the San Matías District intrusive rocks (i.e., 70.6 ± 1.4 Ma U-Pb (zircon) at Montiel E; Leal-Mejía and Hart, 2017) at least three hypotheses can be proposed for the magmatism and related metallogeny of the San Matías District: Pre-, Syn- and, Post-accretional magmatism. These possible scenarios are shown in Figure 1-5. 1. Pre-Accretional: This scenario implies that the San Matías District magmatism formed in an allochthonous oceanic arc within the San Jacinto terrane (cf. Cediel et al., 2003; Bayona et al., 2012; Cardona et al., 2003, 2012) and does not correlate neither with the Magangue Arc (e.g. the Bonga Pluton, Mora et al., 2017) nor with the Central Cordillera magmatism (Eastern Group Granitoids, Leal-Mejía et al., 2019) Figure 1-5A. 2. Syn-Accretional: This alternative scenario implies that the San Matías District magmatism formed in an allochthonous oceanic arc of the Calima terrane (cf. Toussaint and Restrepo, 1988; Villagómez et al., 2011; Spikings et al., 2010). Thus, this does not correlate either with the Magangue and Central Cordillera arcs, but with the Western Group Granitoids of the Western Cordillera (e.g. the Buga Batholith and the Buriticá and Jejénes stocks; Leal-Mejía et al., 2019) (Figure 1-5B). 3. Post-Accretional: Finally, this scenario implies that the San Matías District magmatism was formed in a continental margin (e.g. the Barroso Arc; Rodriguez and Arango, 2013), consistent with the Magangue Arc (e.g. the Bonga Pluton, Mora et al., 2017) (Figure 1-5C). 27 Figure 1-5. Schematic tectono-magmatic sections of the possible environment of formation for the ~70 Ma magmatism from San Matías District and the distribution of the Cretaceous magmatism defined by Leal-Mejía (2011) and Leal-Mejía et al. (2019). The graph shows the features relevant to the discussion and tectonic model revision of this chapter. A. The pre-accretional setting is consistent with the tectonic interpretations of Cediel et al., (2003); Bayona et al., (2012); Cardona et al., (2003, 2012). B. Syn-accretional setting with the tectonic interpretations of Restrepo and Toussaint, (1988), Villagómez et al., (2011), and Spikings et al., (2010). C. A post-accretional setting. This includes the interpretations of Rodriguez and Arango, (2013) and Mora et al., (2017). It is important to indicate that the genetic relation of the Central Cordillera magmatism (Eastern Group Granitoids) and the intrusions of the Magangue arc (e.g. Bonga pluton) have not been demonstrated in the literature. 28 1.10 Mineral Deposits Review During the exploration of the San Matías District and particularly at the El Alacrán Deposit, various authors have proposed different mineral deposit models to explain the field observations and the ambiguous characteristics of the mineralization, including: iron oxide copper-gold (IOCG), volcanogenic massive sulfide (VMS), and replacement mineralization such as skarn and carbonate replacement deposit (CRD) (e.g. Mosher G.Z, 2011; Rey G., 2016; Dunne, 2016b; and Sillitoe, 2018). The review presented in the following paragraphs provides a brief introduction of the geological and physico-chemical characteristics of these deposit models (Table 1-2, Table 1-3), highlighting key genetic features for each of them. 1.10.1 Iron Oxide Copper-Gold (IOCG) deposits Globally, IOCG deposits are an important source of iron and copper. Nearly all continents have both Cu-poor and Cu-rich IOCG deposits, although the proportions vary greatly (Figure 1-6). IOCGs ores typically contain 25 - 55 wt% Fe, <1 wt% Ti, 0.01 - 2 wt% P, and 0 - 2 wt% S (William et al., 2015). Ore bodies range in size from a few million to > 1 billion tons. Fe concentrations vary from trace to about 1.5 wt%, whereas Cu contents vary from a trace to about 1.5 wt% (Barton, 2013). 29 Figure 1-6 Global Distribution of IOCG provinces showing ages, representative abundances of sodic (- calcic), potasic alteration, and economic copper (-gold). The red polygon corresponds to the SMD area and El Alacrán Deposit location. Taken from Barton, 2013. The IOCG provinces span in time from the Precambrian to the Phanerozoic (Groves et al., 2010) (Figure 1-6). IOCG districts in the world have produced Fe and (or) Cu with or without other commodities (Barton, 2013). Economically, the most important IOCG regions ordered by age, from younger to older, are: the Mesozoic Central Andes (Cu + Fe), the Mesozoic Lower Yangtze (Fe ± Cu), the Paleozoic southern Urals (Fe), the Mesoproterozoic South Australia (Cu + U + Au), the Paleo to Mesoproterozoic North-Central Australia (Cu + Au), the Paleoproterozoic N-Baltic (Fe ± Cu), and the Late Archean Carajas (Cu + Au) (Sillitoe 2003; Williams et al., 2005, Barton, 2013). 30 Table 1-2 Geological Characteristics of the reviewed deposit models 31 Table 1-3 Fluid Physico-chemical Characteristics of the reviewed deposit models 32 1.10.1.1 IOCGs Characteristic Features The high diversity of deposits considered as IOCG in the literature obscured the fundamental definitions of fluid source and tectonic setting for this deposit type. To overcome this challenge Groves (2010) used the term iron oxide-associated deposits and subdivide them into five categories: 1) iron oxide Cu-Au deposits (these represent IOCG deposits sensu stricto), 2) P-rich iron oxide deposits (Iron Oxide Apatite - IOA), 3) carbonatite-iron oxide lithophile element (F- and REE-rich) deposits, 4) Cu-Au porphyry and Fe skarn deposits, and 5) high-grade magnetite-replacement Au ± Cu magnetite deposits. Subgroups 2 and 3 do not generally have economic copper or gold grades (Groves, 2010). Skarns with abundant magnetite are distinguished from the other subgroups based on their definitive skarn mineralogy (summarized in Meinert et al., 2005). Under the Groves (2010) proposal, the following six characteristics define a deposit as IOCG sensu stricto: 1) Cu + Au as economic metals; 2) hydrothermal characteristics and structural controls, commonly with breccias; 3) abundant low-Ti Fe oxides (magnetite, hematite) and/ or Fe silicates (grunerite, Fe actinolite, fayalite); 4) LREE enrichment and low-S sulfides, including chalcopyrite-bornite-chalcocite and pyrrhotite; 5) lack of abundant syn-sulfide quartz veins and alteration that commonly includes a decreased SiO2 content of wall rocks, and 6) a temporal relationship with magmatism, yet no close spatial association with causative intrusions (cf. Cu-porphyry, skarn Cu-Au, intrusion-related gold, and Sn-W systems). This review prioritizes the geological and chemical characteristics of deposits considered as IOCG sensu stricto (Groves, 2010) and focuses on the documented IOCG occurrences along the Andean chain where the El Alacrán Deposit is located. 33 1.10.1.2 IOCGs Tectonic Setting The IOCG deposits s.s. have a large range in depth of formation from the deep crust (>10 km; e.g., Ernest Henry, Salobo) to the paleosurface (e.g., Olympic Dam) (Groves et al., 2010). Thus, they contrast with Cu-porphyry and skarn Cu-Au systems, typically restricted to the upper 5 km of the crust (Meinert et al., 2005; Seedorff et al., 2005, Table 1-2). Haywood (2008) suggests that IOCG tectonic settings consist of reactivated back-arc settings, in which domains of metasomatized Sub Continental Lithospheric Mantle (SCLM) below the back-arc has anomalous volatile components (Bindeman and Bailey, 1999), gold contents (Moss et al., 2001), and are the source of the local partial melts ultimately responsible for IOCG mineralization. This has been widely used as an explanation for the highly fractionated, mantle-derived intrusions ranging from gabbronorite to granodiorite (Dallmeyer et al., 1996), with alkaline to sub-alkaline affinity rocks that accompany IOCG systems (Pollard, 2006). 1.10.1.3 IOCGs Hydrothermal Alteration Regarding hydrothermal alteration assemblages in IOCGs systems, the alteration mineralogy varies from camp to camp, however widespread early sodic or sodic-calcic alteration occurs as the dominant alteration in some Andean IOCG districts (Escolme, 2017). The sodic-calcic alteration includes albite principally with or without actinolite (e.g. Candelaria- Punta del Cobre; Marschik and Fontbote 1996, 2001). However, some Andean IOCG Deposits do not display this alteration (e.g. Mantoverde; Vila et al. 1996; Cornejo et al. 2000), where pervasive potassic alteration (biotite – quartz – magnetite - ±K-feldspar) seems to dominate the Cu introduction (e.g. Candelaria-Punta del Cobre, Marschik and Fontbote 2001). The hydrolytic alteration has been documented in the upper and proximal portion of many IOCG systems, accompanied by a mixture of hematite-magnetite (Hitzman et al., 1992). The acid alteration consists of sericite and 34 chlorite; however, advanced argillic alteration has been also documented in some IOCGs systems (Barton and Johnson, 1996, 2000). A distinctive feature of the hydrolytic alteration in IOCGs is that it is considerably less voluminous than the Na - Ca – K (Fe) alteration in comparison with other deposit types (Escolme, 2017). Sericitic/Chloritic alteration in IOCG systems contrasts with other settings, like Cu-porphyry and seafloor systems that are typically pyrite-rich. However, in favourable circumstances, sulfide could be generated by the reduction of sulphate through the oxidation of magnetite to hematite (Gow et al., 1994). 1.10.1.4 IOCGs Genetic Model Three main genetic models have been proposed for IOCG deposit formation, reflecting alternative fluid sources, which continue to be debated: 1) metal-bearing magmatic brine (Hitzman et al., 1992; Ullrich and Clark, 1999; Pollard, 2001, 2006)(Figure 1-7A); 2) external ‘basinal’ brine heated by intrusions (Haynes et al., 1995; Barton and Johnson, 1996; Williams et al., 2005) (Figure 1-7A); and 3) Metamorphic Fluids from meta-evaporite sources and channelled along plumbing structures (Figure 1-7C).The later is partially related to the second one, where external brines play an important role. The magmatic model is favored for the extensive zones of high-temperature alteration, attributed to the proximity to a causative batholith, which creates higher thermal gradients (Hitzman, 2000), and produce crustally derived lithophile elements such as Fe, K, Ca, U, and REE which are incorporated in the fluid (Richards and Mumin, 2013). Formation temperatures range from >500°C in magnetite-apatite-actinolite (or clinopyroxene) associations down to 200 - 300°C for hematite-dominated mineralization (Barton, 2013,Table 1-3). 35 Figure 1-7 Alternative hydrothermal origins and architectures for IOCG systems illustrating possible fluid sources, paths, and distribution of the alteration and the ores. Multiple fluid sources are possible in all cases. A. Magmatic source implies distinctive composition and proximity to source; regional Na (-Ca) is coincidental. B. Evaporitic source implies coeval or older brine source, necessary but indifferent to type of heat source, and available upper crustal plumbing. C. Metamorphic source implies meta-evaporitic (or conceivably mantle) Cl source with regional plumbing. Taken from Barton, 2013. The spatial and temporal relationship of Mesozoic Cu - (Au) porphyry deposits with Andean IOCGs is argued by Sillitoe, (2003) as evidence to favor the magmatic origin. He proposes the mineralizing fluids are exsolved from deeper, more primitive portions of cooling plutons during the final consolidation. Mafic dyke magmas may have also be derived from this source (Sillitoe, 2003). Metalliferous fluids and mafic magmas ascend to ore-forming levels, and are guided by second and lower order fault splays (Sillitoe, 2003) (Figure 1-8). An alternative genetic model for IOCG deposits involves chloride-rich basinal-brines from evaporite and meta-evaporites dissolution (Barton and Johnson, 1996; Barton, 2013). High 36 salinities observed in IOCG deposits (>80 wt.% NaCl eq., av. 10-50 wt.% NaCl eq. Table 1-3) are indicated by Barton (2013) as evidence for external sources of salinity (e.g. evaporite deposits), required to have these high salinity values. In addition, a high-saline fluid is required for effective transport of large quantities of iron and other metals in solution, as well as to incorporate chalcophile elements that trigger the precipitation of Cu minerals accompanying the Au ores (Haynes et al., 1995). However, the evaporitic brine model is debated by Sillitoe (2003), who argued that the occurrence of deposits within large plutonic complexes, evidence a fluid ascent as opposed to descent. This suggests that the basinal brine model alone is not enough to explain the final fluids observed in IOCGs deposits, and magmas must have been involved as a heat ± fluid source. Overall, there is an agreement in the literature that IOCG deposits formed from fluids on a cooling path, that magmatic heat is the typical driver, and that various fluids permeated deep into large intrusive complexes. Moreover, the mineral assemblages and temperatures in IOCG systems require that mineralization occurs under relatively oxidized (SO4 H2S) and low total sulfur conditions. Finally, although early studies suggested that high-CO2 content might be characteristic of IOCG deposits (Pollard, 2000), Barton (2013) argued that many systems lack CO2-rich inclusions what is not an exclusive feature of IOCGs. 37 Figure 1-8 Schematized styles of IOCGs in the Coastal Cordillera of the central Andes proposed by Sillitoe (2003). Note the fundamental control exerted by the faults, commonly shared with pre-ore mafic (basaltic andesite/diorite) dykes. Vein breccias (and breccia mantos and pipes) tend to occur at relatively shallow palaeodepths and, hence, are typically confined to volcanogenic wall rocks. There is an upward change in the predominant hydrothermal iron oxide from magnetite to specular hematite. 1.10.1.5 IOCGs Occurrences in the Andean Chain The Mesozoic IOCG deposits of the Coastal Cordillera of Chile and Peru are the youngest known IOCG province globally (Escolme, 2017). Economic Cu deposits include the Mesozoic Candelaria - Punta del Cobre District and Manto Verde (Maksaev et al., 2007). The district is characterized by an anomalous mafic composition of the mantle-derived intrusion suites (e.g. the Copiapo Batholith, Marschik et al., 2003). Back-arc extensional tectonics in the middle Cretaceous has been used to explain the occurrence of relatively S-poor asthenospheric magma formed by the partial melting of a subduction-38 modified lithospheric source (e.g. Metasomatized Precambrian SCLM) (Groves et al., 2010). This crustal extension and thinning may have facilitated the greater involvement of primitive, mildly alkaline magmas involved with the IOCG formation in Peru and Chile (Richards et al., 2016). Despite the generalized extensional setting for IOCG deposits formation, the Mesozoic IOCGs have been divided into two sub-belts based on their age and dominant tectonic setting (Sillitoe, 2003): 1) A middle to late Jurassic sub-belt formed in a predominantly extensional environment, and 2) Early Cretaceous Cu-rich deposits formed under a transtensional to compressional regime. 1.10.2 Porphyry Copper Deposits (PCDs) In 2010, porphyry copper deposits (PCDs) supplied nearly three-quarters of the Cu, half the Mo, one-fifth of the Au, most of the Re, and minor amounts of other metals (Ag, Pd, Te, Se, Bi, Zn, and Pb) world production (Sillitoe, 2010). The major resources of these metals and the majority of the exploitable Cu, Mo, Au are hosted in PCDs (e.g. 203 Mt Cu: Los Bronces-Río Blanco, central Chile; 2.5 Mt Mo: El Teniente, central Chile); and the second-largest Au deposit by 2010 (129 Moz: Grasberg, including contiguous skarn, Indonesia) (Figure 1-9) (Sillitoe, 2010 and references therein). 1.10.2.1 PCDs Characteristic Features Porphyry Cu systems host some of the most widely distributed mineralization types, including porphyry deposits centred on intrusions, proximal skarn and carbonate-replacement, high-sulfidation epithermal, and distal sediment-hosted Au deposits and intermediate-sulfidation epithermal in increasingly peripheral locations (Sillitoe, 2010) (Figure 1-10A). PCDs are sulfur-rich and predominate in the Phanerozoic and are also a source for Sn and W associated with chalcopyrite, bornite, molybdenite, magnetite, and abundant pyrite (Richards and Mumin, 2013). 39 Figure 1-9 Worldwide locations of porphyry Cu systems. The principal deposit type(s), contained metals, and age are also indicated. Taken from Sillitoe (2010) and cited references. The red polygon corresponds to the SMD area and El Alacrán Deposit location. 1.10.2.2 PCDs Tectonic Setting PCDs typically form along convergent plate margins associated with subduction-related island and continental arcs or less commonly in extensional back-arc or post-subduction settings (John et al., 2010; Richards, 2009; Table 1-2). Deposits are associated with calc-alkaline to alkaline, oxidized, and multiphase intrusive complexes. Magmas associated with these deposits typically are hydrous, oxidized, sulfur-rich, and has likely undergone complex processes of differentiation and evolution at the crust-mantle boundary (Richards, 2003; John et al., 2010). 40 1.10.2.3 PCDs Hydrothermal Alteration Alteration and mineralization in PCDs are zoned upward from barren, early sodic-calcic through potentially ore-grade potassic, chlorite-sericite, and sericitic, to advanced argillic, the last of these constituting the lithocaps (Figure 1-10A, Table 1-2). Low sulfidation-state chalcopyrite ± bornite assemblages are characteristic of potassic alteration zones, whereas higher sulfidation-state sulfides are generated progressively upward associated with temperature decrease and greater degrees of hydrolytic alteration, culminating in pyrite ± enargite ± covellite in the shallow parts of the lithocaps (Sillitoe, 2010). Overprinting of late, shallow, epithermal precious and base metal mineralization over early, deep porphyry-type mineralization is a common characteristic of porphyry copper systems (Figure 1-10) widely known as telescoping (Sillitoe, 1994). Crosscutting relationships, including offset veins, provide definitive evidence for the relative timing of hydrothermal events at a particular location (Seedorff et al., 2005). Hydrothermal activity lasts between 50,000 and 500,000 yr, but several large porphyry Cu deposits include multiple events span several million years (Seedorff et al., 2005). 1.10.2.4 PCDs Genetic Model The upper mantle, subducting slab, lower to mid-crust, as well as the upper crust, are contributing components to the magmas involved in PCDs. The varying proportions of these sources likely lead to the observed compositional diversity of ore-forming magmas. For example, Cu, Au, and Platinum-Group Elements (PGE) may have predominantly mantle sources, whereas Mo and Pb may be contributed by subducting slab or crust (Seedorf et al., 2005). Certain magmatic components, such as sulfur, likely have diverse sources that vary between deposits (Ohmoto and Rye, 1979), with proposals for both, mafic magma (Hattori and Keith, 2001) and crustal assimilation sources (Field et al., 2005). The evolution of porphyry systems begins with 41 Figure 1-10 Anatomy of a telescoped Cu-porphyry System. A. The diagram shows spatial relationships of a centrally located porphyry Cu ± Au ± Mo deposit in a multiphase porphyry stock and its immediate host rocks; peripheral proximal and distal skarn, carbonate- replacement (CRD), and sediment-hosted (distal-disseminated) deposits in a carbonate unit and sub-epithermal veins in non-carbonate rocks; and overlying high- and intermediate-sulfidation epithermal deposits in and alongside the lithocap environment. B. Generalized alteration-mineralization zoning pattern for telescoped porphyry Cu deposits, based on the geologic and deposit-type. Taken from Sillitoe, 2010. The Red boxes are used to highlight some mineralization styles (e.g., Carbonate-replacement, proximal Cu-Au skarn). the development of an intermediate silicic magmatic chamber of variable composition, as a product of mantle-sourced mafic magmas generated by the influx of subduction-derived fluids or asthenospheric rise (Seedorf et al., 2005). The mafic magmas rise into the crust, where they evolve, fractionate, mix and hybridize with partial melts of crustal origin. The magma chamber is considered to evolve as an open system during a part of the life of the magmatic center. Processes include degassing, erupting, recharging, crystallizing, assimilating and commingling of magmas of different compositions (Eichelberger et al., 2000). 42 The formation of large porphyry deposits requires different processes to occur within an upper crustal magma chamber. These processes include the separation of an aqueous phase capable of carrying and scavenging metals (Candela and Piccoli, 2005). The fluid is thought to accumulate in a magmatic cupola prior to its ascent to the site of ore deposition (Seedorf et al., 2005). Multiple porphyry stocks are generally observed to be emplaced into the ore zone over a relatively short period (<300.000 years; Seedorf et al., 2005). The relative position of early mineralized intrusions with respect to the inter-mineral or post-mineral ones defines the geometry of the potentially resulting ore body, and the distribution of contained ore minerals. Magmatic-hydrothermal fluids are dominant during magma emplacement, when fluid over-pressuring and hydraulic fracturing can produce hydrostatic conditions for the entrance of external fluids, such as cooled early magmatic hydrothermal fluids, formation waters of variable salinity, meteoric water, seawater, or mixtures of these different fluid types. The PCDs ore fluid is characterized by an oxidized, neutral to acidic fluid with a H2O-NaCl-KCl composition (Richards and Mumin, 2013). Formation temperature range between 250 – 700 °C with an average of ~350 °C and fluid inclusions studies demonstrate salinities varying from (12 - 50 wt% NaCl Eq.) (Nash, 1976) (See summary in Table 1-3). 1.10.2.4.1 PCDs in Colombia This review draws attention to the poorly documented PCDs occurrences of Cretaceous age in Colombia, where the San Matías Project porphyry occurrences (e.g. Montiel E and Costa Azul porphyries) are the first documented of this age along the Western Cordillera. The oldest documented porphyry deposits in Colombia corresponds to Jurassic deposits formed in a continental domain (e.g.; the Rovira-Chaparral, Infierno Cilli, Dolores porphyries, ca. 146 – 43 131 Ma, Sillitoe, 1982; and the Mocoa Porphyry, 170.2 ± 2.7 Ma. Leal-Mejía, 2011; Figure 1-11). These deposits are associated with minor hypabyssal porphyry suites of Jurassic age (160 – 149 Ma), associated with the Mocoa, Norosí, and northern Ibagué batholiths (Leal-Mejía et al., 2019;Figure 1-11). In the Western Cordillera, porphyry-related mineralization of suspected Cretaceous-age is documented in the Ginebra-El Retiro District possibly associated with the Buga Batholith (ca. 92 – 90 Ma, Villagómez et al., 2011, Shaw et al., 2019). In the Colombia Central Cordillera, Shaw et al. (2019) documented some late Cretaceous – early Paleocene porphyry-related Au-Ag mineralization at El Rayo porphyry prospect. This porphyry yielded a U-Pb (zircon) age of 59.9 ± 0.9 Ma (Leal-Mejia, 2011; Figure 1-11). Finally, hydrothermally altered porphyry dike (55.9 ± 2.0 Ma, K-Ar in sericite) associated with vein-type Au-Ag mineralization is documented by Leal-Mejía (2011) in the El Vapor Deposit (Figure 1-11). Cenozoic Porphyry Copper Deposits in Colombia occur within the Mandé-Acandí Cu (Au, Mo) porphyry trend (Shaw et al., 2019) (Figure 1-11). This trend is associated with the youngest ages observed in the Western Group Granitoids (Leal-Mejía et al., 2019; section 1.8) and includes the porphyry prospects of Murindó (54.7 ± 1.3 Ma, K-Ar/Hornblende), Acandí (48.1 ± 1.0 Ma, K-Ar/Sericite), and Pantanos-Pegadorcito (42.7 ± 0.9 Ma, K-Ar/Sericite) (Sillitoe, 1982). Pre-mineral porphyritic tonalite in the Porphyry-style Cu (Au, Mo) Pantanos-Pegadorcito yielded U-Pb (zircon) crystallization ages of 45.3 ± 1.2 Ma and 44.6 ± 0.9 Ma (Leal-Mejía, 2011). These ages are consistent with additional later U-Pb (zircon) crystallization ages obtained for the Mandé-Acandí Batholith (ca. 59 - 43 Ma; Montes et al., 2015). 44 Figure 1-11 Location of the SMD and El Alacrán Deposit relative to the VMS, IOCGs, and PCDs documented in Western Colombia. The porphyry and VMS prospects location were extracted from Leal-Mejia, 2011; Leal-Mejía et al., 2019 and Shaw et al., 2019. An IOCG prospect (IOA type) was taken from Garzón, 2017. In the background, the Colombia DEM overlaid by the Romeral Fault System taken from the Colombia Geological Map (Gomez-Tapias, 2015). The bulk of porphyry copper deposits occurrences in Colombia are associated with Miocene-Pliocene magmatism. This magmatism is located along the “Patía-Upper Cauca trend” and the "Middle Cauca Trend” (Shaw et al., 2019). Within the Patía-Upper Cauca trend, Shaw et al. (2019) defined two porphyry clusters: (1) Piedrasentada-La Vega-Berruecos Porphyry Au (Ag, Cu) Cluster (ca. 17.5 to 9 Ma), where the most distinct porphyry occurrences include the Piedrasentada porphyry (17.4 ± 0.4 Ma K-Ar; Sillitoe et al., 1982) and the Dominical porphyry 45 (17.0 ± 0.4 Ma U-Pb (zircon); Leal-Mejía et al., 2019) (Figure 1-11); (2) Buenos Aires-Suárez Porphyry Au (Cu) Cluster (ca. 17 Ma) where porphyry occurrences are documented at La Toma (17.7 ± 0.5 Ma, Leal-Mejía et al., 2019) and El Molino (Sillitoe, 2000) (Figure 1-11). Conversely, the Middle Cauca Trend (former Middle Cauca Porphyry Belt from Sillitoe, 2008; ca. 9 to 4 Ma), is perhaps the best documented and most explored of the Colombian precious metals provinces. This belt host historic deposits such as the Marmato Ag-Au District (ca. 5.6 - 6.5 Ma, Shaw et al., 2019), the Titiribí porphyry Suite (7.6 ± 0.3 Ma U-Pb (zircon); Leal-Mejía, 2011), the La Mina porphyry (7.6 ± 0.3 Ma U-Pb (zircon); Leal-Mejía, 2011), and Nuevo Chaquiro porphyry (7.6 ± 0.2 Ma U-Pb (zircon); Bartos et al., 2017). The southern Middle Cauca belt is characterized by multiple and overprinting alteration assemblages typical of Au-rich porphyries worldwide (e.g. Maricunga Belt in Chile, Sillitoe, 2000). Based on geographic location, basement composition and mineralogical evidence, Shaw et al. (2019) defined the Cajamarca-Salento Porphyry Au Cluster (ca. 8.3 to 7.3 Ma, Leal-Mejia, 2011) and separate it from the Middle Cauca Porphyry Belt definition from Sillitoe (2008) (Figure 1-11). Within the Cajamarca-Salento Porphyry Au Cluster, the most important porphyry deposit in terms of Au mineral resources (>28M oz Au, AngloGold Ashanti, 2015) is La Colosa Au porphyry (Lodder et al., 2010). In addition, ca. 10 - 8.5 Ma and ca. 2.6 - 1.3 Ma porphyry occurrences are documented by Shaw et al. (2019) along the Vetas-California Porphyry Cu-Mo (Au) and Au-Ag trend (Figure 1-11). These intrusions are spatially and genetically related to the mineralization at three semi-contiguous deposits: Angostura, La Bodega, and La Mascota, totalling >7M oz Au, 19 M oz Ag, and 84M lbs Cu (Rodríguez et al., 2017; Shaw et al., 2019). Finally, recent work by Leal-Mejía et al. (2019) defined the Plio-Pleistocene Río Dulce porphyry cluster. This cluster includes hypabyssal porphyritic granitoids and associated epithermal Au-Ag 46 occurrences and represents the youngest expression of hypabyssal porphyry magmatism in western Colombia (Shaw et al., 2019). The Plio-Pleistocene Río Dulce porphyry cluster includes the ca. 1.1 Ma Espíritu Santo- Santa Rita Porphyry and Diatreme Breccias (Leal-Mejía et al., 2019) (Figure 1-11). Finally, hydrothermally altered porphyry dike (55.9 ± 2.0 Ma, K-Ar in sericite) associated with vein-type Au-Ag mineralization is documented by Leal-Mejía (2011) in the El Vapor Deposit (Figure 1-11). Cenozoic Porphyry Copper Deposits in Colombia occur within the Mandé-Acandí Cu (Au, Mo) porphyry trend (Shaw et al., 2019) (Figure 1-11). This trend is associated with the youngest ages observed in the Western Group Granitoids (Leal-Mejía et al., 2019; section 1.8) and includes the porphyry prospects of Murindó (54.7 ± 1.3 Ma, K-Ar/Hornblende), Acandí (48.1 ± 1.0 Ma, K-Ar/Sericite), and Pantanos-Pegadorcito (42.7 ± 0.9 Ma, K-Ar/Sericite) (Sillitoe, 1982). Pre-mineral porphyritic tonalite in the Porphyry-style Cu (Au, Mo) Pantanos-Pegadorcito yielded U-Pb (zircon) crystallization ages of 45.3 ± 1.2 Ma and 44.6 ± 0.9 Ma (Leal-Mejía, 2011). These ages are consistent with additional later U-Pb (zircon) crystallization ages obtained for the Mandé-Acandí Batholith (ca. 59 - 43 Ma; Montes et al., 2015). The bulk of porphyry copper deposits occurrences in Colombia are associated with Miocene-Pliocene magmatism. This magmatism is located along the “Patía-Upper Cauca trend” and the "Middle Cauca Trend” (Shaw et al., 2019). Within the Patía-Upper Cauca trend, Shaw et al. (2019) defined two porphyry clusters: (1) Piedrasentada-La Vega-Berruecos Porphyry Au (Ag, Cu) Cluster (ca. 17.5 to 9 Ma), where the most distinct porphyry occurrences include the Piedrasentada porphyry (17.4 ± 0.4 Ma K-Ar; Sillitoe et al., 1982) and the Dominical porphyry (17.0 ± 0.4 Ma U-Pb (zircon); Leal-Mejía et al., 2019) (Figure 1-11); (2) Buenos Aires-Suárez 47 Porphyry Au (Cu) Cluster (ca. 17 Ma) where porphyry occurrences are documented at La Toma (17.7 ± 0.5 Ma, Leal-Mejía et al., 2019) and El Molino (Sillitoe, 2000) (Figure 1-11). Conversely, the Middle Cauca Trend (former Middle Cauca Porphyry Belt from Sillitoe, 2008; ca. 9 to 4 Ma), is perhaps the best documented and most explored of the Colombian precious metals provinces. This belt host historic deposits such as the Marmato Ag-Au District (ca. 5.6 - 6.5 Ma, Shaw et al., 2019), the Titiribí porphyry Suite (7.6 ± 0.3 Ma U-Pb (zircon); Leal-Mejía, 2011), the La Mina porphyry (7.6 ± 0.3 Ma U-Pb (zircon); Leal-Mejía, 2011), and Nuevo Chaquiro porphyry (7.6 ± 0.2 Ma U-Pb (zircon); Bartos et al., 2017). The southern Middle Cauca belt is characterized by multiple and overprinting alteration assemblages typical of Au-rich porphyries worldwide (e.g. Maricunga Belt in Chile, Sillitoe, 2000). Based on geographic location, basement composition and mineralogical evidence, Shaw et al. (2019) defined the Cajamarca-Salento Porphyry Au Cluster (ca. 8.3 to 7.3 Ma, Leal-Mejia, 2011) and separate it from the Middle Cauca Porphyry Belt definition from Sillitoe (2008) (Figure 1-11). Within the Cajamarca-Salento Porphyry Au Cluster, the most important porphyry deposit in terms of Au mineral resources (>28M oz Au, AngloGold Ashanti, 2015) is La Colosa Au porphyry (Lodder et al., 2010). In addition, ca. 10 - 8.5 Ma and ca. 2.6 - 1.3 Ma porphyry occurrences are documented by Shaw et al. (2019) along the Vetas-California Porphyry Cu-Mo (Au) and Au-Ag trend (Figure 1-11). These intrusions are spatially and genetically related to the mineralization at three semi-contiguous deposits: Angostura, La Bodega, and La Mascota, totalling >7M oz Au, 19 M oz Ag, and 84M lbs Cu (Rodríguez et al., 2017; Shaw et al., 2019). Finally, recent work by Leal-Mejía et al. (2019) defined the Plio-Pleistocene Río Dulce porphyry cluster. This cluster includes hypabyssal porphyritic granitoids and associated epithermal Au-Ag occurrences and represents the youngest expression of hypabyssal porphyry magmatism in 48 western Colombia (Shaw et al., 2019). The Plio-Pleistocene Río Dulce porphyry cluster includes the ca. 1.1 Ma Espíritu Santo- Santa Rita Porphyry and Diatreme Breccias (Leal-Mejía et al., 2019) (Figure 1-11). 1.10.2.5 PCDs and IOCGs relationships There are remarkable similarities between IOCGs and PCDs, including the presence of hydrothermal magnetite/hematite and potassic, potassic-calcic, and sodic-calcic alteration assemblages (Hitzman, 1992; Sillitoe, 2003). Similarly, there is no clear difference in oxidation state between coetaneous groups of PCD and IOCG deposits, which all appear to be similarly oxidized (e.g. Coastal Cordillera of Chile and Peru, Richards et al., 2017). The sodic and sodic-calcic alteration that has been widely recognized in deep IOCG systems (Williams et al., 2005) is not exclusive of these deposits. In PCDs, sodic-calcic alteration has been interpreted to be the product of the interaction between non-magmatic fluids and evaporite wall rocks (e.g. Yerington-Ajo, Nevada; Dilles et al., 1995; Groves et al., 2010). Similarly, magnetite, apatite and REE mineralogy that are documented in IOCG systems (Groves et al., 2010) are also observed in PCDs: Au-rich PCDs display a strong sodic alteration (albitization), have associated REE-enriched Cu-Au-magnetite skarns and can be spatially associated with both, diorite intrusions and magnetite-apatite deposits (Meinert, 1984; Sillitoe, 1997; Williams et al., 2005). There is an intimate and clear association of PCDs with contemporaneous igneous intrusions, whereas IOCGs have no clear spatial and temporal association with causative intrusions (Williams et al., 2005). PCDs are major sources of Cu, Mo, Au and Ag and locally Pb and Zn, whereas IOCGs are rich in Fe with subordinate Cu ± Au (Hitzman, 1992). In PCDs, abundant sulfide minerals and sulphates (e.g. anhydrite) indicate an excess of sulphur in the hydrothermal fluids. In opposition, 49 typically, IOCGs have lower sulphur abundances and are more oxidized; thus, iron oxides dominate the mineral paragenesis (Williams et al., 2005). In the Andes, the PCDs and IOCGs in the Coastal Cordillera in Chile and Peru are readily distinguishable because the potassic alteration and copper-(gold) mineralization in the former are centred on, and largely confined to, porphyry stocks, which are absent from the latter (Sillitoe, 2010). Additionally, the IOCG deposits lack the characteristic sulfide-bearing quartz veinlets and D-type veinlets that characterize the typical PCDs, whereas the iron oxides (the most important mineral in IOCGs) are sparsely represented in the PCDs (Sillitoe, 2010). Preservation also plays an important role in the distribution of PCDs and IOCGs. This is evident in metallogenic belts along the Coastal Cordillera in Chile and Peru. There, PCDs tend to be preserved in less deeply eroded conditions (Escolme, 2017). This preservation degree may be directly associated with the marked formation depth defined in the literature (Groves et al., 2010, Meinert et al., 2005; Seedorff et al., 2005; Table 1-3). This characteristic raises the question of whether shallower-formed porphyries in the Coastal Cordillera have been eroded away and whether the IOCGs and magnetite-apatite deposits could, in fact, represent the root zones of such systems (Escolme, 2017). 1.10.3 Skarn Cu (Au) Deposits 1.10.3.1 Skarns Characteristic Features and Tectonic Setting Skarns are part of the cluster of deposits that can be formed peripheral to Cu-porphyry deposits within carbonate-rich lithologies (Sillitoe, 2010; Figure 1-12). 50 Figure 1-12 Model of the skarn-related mineralogy distribution in relation to the protolith host rock (Meinert, 1997). The diagram indicates how fluid-controlled metasomatic skarn typically is coarse-grained and does not closely reflect the composition or texture of the protolith. However, skarns are not associated to a particular geologic setting; rather, they are the product of a combination of temperature, pressure, fluid and host rock composition within the stability range of the identified skarn minerals (Meinert, 1992). Thus, skarns not only may form adjacent to plutons but also along faults, shallow geothermal systems, on the seafloor and at lower crustal depths in deeply buried metamorphic terranes. Similarly, neither a pluton nor limestone is necessarily required to form skarn (Meinert, 1992; Meinert et al., 2005). 1.10.3.2 Skarns Hydrothermal Alteration Skarn ore deposits are typically characterized by two distinct alteration styles: 1) an early prograde stage with anhydrous minerals, such as garnet and pyroxene, and 2) a later retrograde stage, which consists of hydrous minerals, such as epidote, amphibole, and chlorite (Kwak, 1986; Figure 1-12, Table 1-2). Copper skarn mineralogy is dominated by andradite garnet with 51 hematite-magnetite lodes commonly present on dolomitic wall rocks (Meinert, 1992; Meinert et al., 2005). Intense retrograde alteration is common in Cu-skarns and may destroy most of the prograde garnet and pyroxene in some Cu-porphyry-related deposits (e.g. Ely in Nevada; James, 1976). Sulfide mineralogy can also be zoned relative to the causative pluton. In general, pyrite and chalcopyrite are the most abundant near the pluton, with chalcopyrite increasing away from the pluton and bornite finally occurring with wollastonite near the marble contact (Meinert, 1992). 1.10.3.3 Skarns Genetic Model The widely accepted model for skarn formation involves early magmatic fluids and late meteoric water (Einaudi et al., 1981). However, Meinert et al. (2003) proposed an alternative model developed in two steps: First, a magmatic fluid with bulk salinity of 7 wt.% NaCl eq., intersects its solvus and separates into a 50 wt.% NaCl eq., hypersaline liquid in equilibrium with vapor containing ~1 wt.% NaCl eq. (Table 1-3). This high-temperature, hypersaline liquid with high-base metal solubilities and relatively low-sulfur content may inhibit sulfide deposition during the formation of the prograde skarn mineralogy. Conversely, the vapour phase produces cavernous porosity in carbonate rocks, which is eventually overrun by the high-salinity, skarn-forming fluid as the system expands. Breccia occurrences in the early-stage hydrothermal evolution of the skarn systems are used as evidence to support this process (Einaudi, 1982). Second, a later stage fluid reaches the previously formed skarn in progressive cooling accompanied by only a slight increase in salinity (~7 to 10 wt.% NaCl eq. Table 1-3). This later low-temperature, low-salinity fluid allows the sulfide mineralization to precipitate and the formation of the retrograde alteration assemblage. Under this model, Meinert et al. (2003) suggested that the fluid 52 responsible for prograde and retrograde alteration as well as for ore formation was dominantly magmatic in origin without significant participation of meteoric water. 1.10.4 Carbonate Replacement Deposits (CRD) 1.10.4.1 CRDs Characteristic Features Only few examples of CRDs are described in the literature; however, it is comparable to the “Polymetallic Vein and Replacement Deposits” that seem to be more widely studied (USGS MODELS 19a and 22c; Morris and Cox, 1986) and summarized by Plumlee et al. (1995). According to the USGS mineral deposit model, these deposits show elevated abundances of Pb + Zn ± Cu ± Au ± Ag ± Mo ± As ± Bi ± Sb and exhibit a metal zonation with copper-gold ore proximal to intrusions, whereas Pb - Zn - Ag ore is laterally and vertically distal to intrusions (Plumlee et al.,1995). Minerals listed in approximate decreasing order of abundance are: pyrite + sphalerite + galena + siderite + quartz + marcasite + rhodochrosite + dolomite + chalcopyrite + pyrrhotite + tetrahedrite + digenite + argentite + electrum, ± enargite, ± bornite, ± arsenopyrite, ± Bi-Te-Hg-Au-Ag minerals (e.g., hessite, petzite, pyrargyrite, etc.), ± barite, ± fluorite. Most deposits are pyrite-rich, but few deposits are pyrite-poor and are dominated by sphalerite and galena (Plumlee et al., 1995). 1.10.4.2 CRDs Tectonic Setting Carbonate-replacement deposits (CRD) have also been described as part of a cluster of wall rock-hosted orebodies alongside Cu-porphyry deposits, in a compressional arc and post-collision tectonic setting where receptive carbonate rocks are present (Sillitoe, 2010, Figure 1-10). Mineralization styles include: carbonate-replacement (chimney-manto), massive sulfide bodies dominated by either Cu (e.g., Superior district, Arizona and Sepon district, Laos; Paul and 53 Knight, 1995; Loader, 1999) or, more commonly, Zn, Pb, Ag ± Au (e.g., Recsk, Hungary; Kisvarsanyi, 1988) that usually occur beyond the skarn front (Figure 1-10). 1.10.4.3 CRDs Hydrothermal Alteration When mineralization occurs in carbonate rocks, the rock units are commonly recrystallized, dolomitized, bleached, and sanded. This later consists of a process whereby carbonate cement is removed from sedimentary rocks. Silica-rich jasperoid is also commonly observed (e.g. The Great Basin CRDs in the U.S; Megaw et al.,1998). Conversely, when mineralization is hosted in volcanic igneous units, rocks are altered to quartz-sericite-pyrite and quartz-clay (argillic) assemblages that grade into distal propylitic (epidote, chlorite, pyrite, carbonate) alteration assemblages. 1.10.4.4 CRDs Genetic Model The genetic model for CRD includes ore-fluid migration away from a heat source along structurally-controlled permeability networks until they find carbonate rocks favourable for mineralization. In some cases, this happens immediately adjacent to the intrusive body, whereas other occurrences show that fluids migrate significant distances before sulfide precipitation occurs (Titley and Megaw, 1985; Megaw et al., 1988). This travel distance allows ore fluids to mix with meteoric and connate waters or basin brines and to acquire exotic elements, sulfur, and isotopic contents which tend to mask the original magmatic signatures of the system (Megaw et al., 1988). The CRD model implies a link with more distal fluids than those that occur in skarn environments. Therefore, the fluids are consistent with the monophase liquid with low salinity and low temperature formed in the temperature declining process from which the retrograde skarn Cu ± Au ± Zn, carbonate-replacement Cu or Zn-Pb-Ag-(Au), and sediment-hosted Au- 54 (As-Sb) deposits are formed (Meinert et al., 1997, 2003; Heinrich, 2005) (See Skarn Deposits review, section 1.10.3). CRD ore fluids are hot (250 - >500 °C), reduced, acidic and saline (>15 wt.% NaCl eq.). They also exhibit H2S stability, chloride and bisulfide complexing, and a significant magmatic component (Howd and Barnes, 1975; Megaw et al., 1988; Megaw, 1990; Beaty et al., 1990; Barton et al. 1995; Table 1-3). 1.10.5 Volcanogenic Massive Sulfide (VMS) Deposit 1.10.5.1 VMS Deposits Characteristic Features Volcanogenic Massive Sulfide (VMS) deposits are strata-bound accumulations of sulfide minerals that precipitated at or near the seafloor in spatial, temporal and genetic association with contemporaneous volcanism (Franklin et al., 2005; Figure 1-13). VMS deposits are currently classified, based on their lithostratigraphic scheme, into six types: 1) bimodal-mafic, 2) mafic, 3) pelitic-mafic, 4) bimodal-felsic, 5) siliciclastic-felsic, and 6) hybrid bimodal-felsic (Franklin et al., 2005). The lithostratigraphic scheme influences the final morphology (e.g. pods, lenses, replacement) and the composition of proximal footwall alteration (Gibson et al., 1999; Doyle and Allen, 2003; Franklin et al., 2005; Ross and Mercier-Langevin, 2014). The mafic-dominated, bimodal-mafic, and bimodal-felsic host rocks are dominated by effusive volcanic successions and accompanying large-scale hypabyssal intrusions that support higher temperature (>350°C) hydrothermal systems associated with Cu VMS and variable Au and Ag contents (Galley et al., 2007). 1.10.5.2 VMS Deposits Tectonic Setting VMS deposits form in extensional tectonic settings (Franklin et al., 2005). Approximately 300 sites with accumulations of Massive Seafloor Sulfides (MSS) are known on the modern ocean floor (Shanks and Thurston, 2012). Of these, 65% are located on mid-ocean ridges, 22% are 55 Figure 1-13 Evolution of a caldera-related submarine magmatic-hydrothermal system in VMSs formation A. Conceptual model showing the evolution of a caldera-related submarine magmatic-hydrothermal system responsible for the formation of Volcanogenic Massive Sulfide (VMS) deposits (Stix et al., 2003). The diagram shows how cold seawater flows downward along outer inward-dipping faults, while hot mineralizing fluids move up along a series of outward-dipping faults resulting from piecemeal caldera collapse. As a result, massive sulfide deposits can form in a number of locations and possible water depths within the caldera. B. (detail a) displays the distribution of the alteration mineral assemblages in a classic mound-shaped VMS (e.g. Hellyer Deposit; Large, 1992). C. (detail b) displays the distribution of the alteration mineral assemblages in a layered-shaped VMS (e.g. Scuddles Deposit; Large, 1992). found in back-arc basins, and 12% are located in submarine arcs (Hannington et al., 2005). VMS deposits can develop into strike-slip basins generated along plate boundaries in older arc assemblages (Ziegler, 1992). These basins may also be an important setting for mineralized Cu-porphyry systems (Richards, 2003; Table 1-2). 56 1.10.5.3 VMS Deposits Hydrothermal Alteration Metal zonation within the massive sulfide body from Fe + Cu at the base to Zn + Fe ± Pb ± Ba at the top and margins characterize many deposits (Galley et al., 2007). In many cases, VMS deposits occur along or near brecciated rhyolite domes (e.g. Hokoruko and Noranda districts; Ohmoto and Takahashi, 1983; Gibson and Galley, 2007). Magnetite in VMS systems is reported as exhalite deposits that consist of a combination of fine volcaniclastic material that formed when shallowly circulating seawater stripped Fe, Si, and some base metals before precipitating them on the seafloor in low-temperature (<250°C) hydrothermal venting (Spry et al., 2000; Peter, 2003). The diagnostic minerals of hydrothermal alteration in VMS comprise five major assemblages; 1) Advanced argillic: Kaolinite, alunite, opal, smectite; 2) Argillic: Sericite-illite-smectite-pyrophyllite-opal; 3) Sericitic: Sericite-illite-opal; 4) Chloritic: Chlorite-opal-quartz-sericite; and 5) Carbonate-propylitic: Carbonate (Fe-Mg)-epidote-chlorite-sericite-white mica (Bonnet and Corriveau, 2007). 1.10.5.4 VMS Deposits Genetic Model There is continued debate about the fluids that form economic VMS ore deposits. The most accepted model is the water/rock interaction model, where connate seawater in the porous crust is first heated, causing it to become buoyant, and as it rises through syn-volcanic fault structures, cold seawater is drawn in above the cooling intrusion. The originally cold, near-neutral pH fluids are progressively heated during their downward migration, interacting with the surrounding rocks at progressively higher temperatures and lower pH, extracting or leaching the sulfides and iron from the mafic host rocks at temperatures close to 250°C (Seyfried and Shanks, 2004). An alternative model involves pulses of magmatic fluids injected into seawater convective systems and are maybe the major metal contributors (Yang and Scott, 2002). This is supported 57 by the well-established fact that magmatic degassing adds He (helium), CO2, CH4, and H2S or SO2 to convective hydrothermal systems that can be associated with main ore stages (Lilley et al., 1982; Kadko et al., 1995; Glasby et al., 2008). An alternative model suggest a partial magmatic enrolment where magmatic volatile-rich fluids contribute acidic components to convective hydrothermal systems, resulting in very acidic fluids (pH <1) that can leach additional metals (Craddock et al., 2007). In VMS fluids, the salinities are generally less than 5-10 wt.% NaCl eq. and contain low (mostly undetectable) concentrations of CO2 or other gases. The presence of Ca2+ in VMS inclusions has been confirmed using crush/leach analysis of fluid inclusions (e.g., Graupner et al., 2001). The fluid can be interpreted using the H2O–NaCl–CaCl2 system (Steele-MacInnis et al., 2011; Vanko et al., 1988; Table 1-3). 1.11 Remarks of the Deposit Models Review • The highest formation temperatures among the reviewed deposit models have been reported for IOCGs and porphyry Cu-Au deposits (>600°C), prograde alteration stage in skarn deposits (<700°C) and CRD deposits (<500°C), whereas lower formation temperatures are documented for VMS (<250°C) and retrograde alteration stage associated with skarn deposits (>100°C). • The documented formation depth in IOCGs presents is widely variable range (from 0 to 10km), whereas the other reviewed deposit models are consistently formed more shallowly (<5 km). The shallowest (<2 km) formation depth documented occurs in VMS deposits. 58 • Extensional settings are dominant in IOCG and VMS environments, whereas the compressional settings appear to be prevalent in Cu-porphyry and CRD formation. In contrast, skarn deposits can be formed in either compressional or extensional settings. • The magmatic fluids in the IOCG model are widely accepted to have been derived from a back-arc extensional setting that allowed the partial melting of subduction-modified lithospheric sources (e.g. Precambrian Metasomatized Subcontinental lithospheric mantle (SCLM)). This is used to explain the occurrence of relatively S-poor magmatic fluids and the old and thick continental crustal involved in the formation of IOCG deposits. • In terms of mineralogy, apatite is widely documented in IOCG systems; however, has also been documented in high-temperature porphyries. Sericite is mostly found in Cu-porphyry, CRD, and VMS deposits, but is generally absent in IOCG and skarn deposits. • The fluid types in the reviewed deposit models show the consistent occurrence of the H2O-NaCl-KCl system in Cu-porphyry, skarn and CRD deposits, while VMS fluids show a KCl depletion relative to CaCl2 (This is explained in the literature by a major interaction of sedimentary fluids). Conversely, IOCG fluids have been reported with a higher CO2 content compared to other reviewed deposit models. • The magnetite formation in the reviewed deposit models shows multiple origins. Magnetite occurrences are explained as high-temperature leaching and magmatic in IOCG systems, magmatic-hydrothermal fluids in Porphyry-Skarn deposits and low-temperature leaching in VMS deposits. In contrast, magnetite in CRD deposits is not documented in the reviewed literature. In skarn deposits, magnetite+hematite occurrence seems to be restricted to dolomite-hosted skarns but is overall unusual. 59 • In contrast with IOCGs, the magnetite + Cu-sulfides in calc-alkaline Cu-Au porphyry related systems commonly form early, and their later acidic alteration (e.g. phyllic and argillic) tends to be Cu-poor. • Regarding the IOCG genetic model, an unequivocal association with a distinctive range of sulfur-poor, high-salinity fluids, and magmatic heat sources are indicated. 1.12 Conclusions • The SMD magmatism and related metallogeny can be associated with three arc-related tectono-magmatic scenarios: 1) Pre-accretionary setting that implies that SMD magmatism was generated in an allochthonous intra-oceanic arc that collided in the Paleocene (~56 Ma). 2) A syn-accretional setting where the available SMD ages (~70 Ma) are close to the ages (~75 Ma) proposed by some authors as the collision age of the intra-oceanic arc with the continental margin. 3) Post-accretionary setting where the SMD magmatism and metallogeny formed in a continental margin setting after the accretion of oceanic terranes. • The SMD tectonic setting does not offer the potential to form magmatic-derivated IOCGs deposits similar to the ones described in the central Andes. The SMD tectonic framework is directly related to the Caribbean Large Igneous Province (CLIP) oceanic plateau basalts and associated intra-oceanic island arcs. This island arc setting does not offer the conditions to host magmatism derived from a pre-metasomatized mantle wedge melting responsible for S-poor fluids accepted for in this model. • The geochemical characteristics of the reviewed deposit models do not present discrete limits to separate one deposit model from another clearly. Similarly, there is no 60 consensus in the literature, and open debates about the fluid nature involved in some deposits systems remain (e.g. magmatic vs. basinal fluids for IOCG, skarn and VMS). • The geological and mineralogical evidence remains as a key identifier and should prevail over the analytical data. However, some reviewed geochemical and fluid characteristics may be useful to classify the El Alacrán Deposit, including fluid temperature, fluid solutes composition, acidity and salinity. 61 Chapter 2: Geology of the El Alacrán Deposit 2.1 Introduction The El Alacrán Deposit in the Western Cordillera of Colombia has been the focus of geological and metallogenic controversy since the beginning of the San Matías District (SMD) exploration. Multiple hypotheses for the possible deposit model have been proposed, including: 1) a skarn-style replacement after calcareous rocks (Ray G., 2016); 2) syn-volcanic origin (e.g. volcanogenic massive sulfide; Dunne, 2016b); and 3) an iron oxide copper-gold (IOCG) deposit (Sillitoe, 2018). The controversy remains unsolved because some aspects such as the age, chemistry, and lithological classification of the El Alacrán Deposit host rocks have not been properly constrained or characterized. In adittion, the SMD basement rocks and intrusions remained poorly understood in a regional context, this offered an opportunity to stablish a regional correlation with other geological units that occur in the Western Cordillera of Colombia. This chapter summarises the lithological and structural characteristics of the El Alacrán Deposit based on three W-E cross-sections across the deposit: 1) 855570m N, 2) 855450m N, and 3) 855050m N (Figure 2-1). Detailed petrography of the El Alacrán Deposit volcanoclastic lithofacies, along with U-Pb geochronology and whole rock lithogeochemistry of the El Alacrán Deposit and additional representative intrusions within the SMD are further compared with coeval magmatic units of the Western Cordillera of Colombia. By comparing the age and chemistry of the SMD magmatism with other geological units in a similar tectonic context, it is possible to establish a temporal and genetic relationships and to constrain the evolution of the SMD in a regional context to delineate new prospective areas to explore similar mineral deposits. 62 Figure 2-1 Regional Geology of NW Colombia around the SMD A. Regional Geology of the northwestern Colombia after Gomez et al. (2015). Morphological units, including Sinú Deformed Belt, San Jacinto Deformed Belt (SJDB) and the Lower Magdalena Valley (LMV) (Mora et al.,2017) are also indicated. The Romeral Fault System trace is shown in red. B. Detail of the San Matías District (white polygon) and surrounding areas. 2.2 Regional Geology Review According to the latest version of the Geological Map of Colombia (Gómez et al., 2015), the geology of the SMD is broadly dominated by rocks with oceanic affinity (i.e. the Barroso Formation) to the west and metamorphic rocks with continental affinity (i.e. the Cajamarca Complex) to the east (Figure 2-1). In the northern and northwestern SMD areas, these basement 63 rocks are covered by Paleocene to Neogene sequences of the San Jacinto (SJFB) and Sinú (SFB) Fold Belts (e.g. the Sincelejo Group, and the Cerrito, Cienaga de Oro, and San Cayetano formations) (Figure 2-1). In the following paragraphs, these geological units are described from oldest to youngest and complemented with the detailed stratigraphy for the Cordoba Department presented by Mora et al. (2017; Figure 2-2). 2.2.1 Permo-Triassic Units 2.2.1.1 The Cajamarca Complex The Cajamarca Complex comprises aluminum-rich, graphite, quartz-muscovite, chlorite and amphibole schists, phyllites, quartzites, marbles and serpentines. This unit is separated from Precambrian metamorphic rocks by the Otú-Pericos Fault to the east and from oceanic basement units by the San Jerónimo Fault (eastern most fault of the Romeral Fault System) to the west (Maya and Gonzalez, 1995, Figure 2-1). 2.2.2 Cretaceous Units 2.2.2.1 Mafic to Ultramafic Complex The Mafic to Ultramafic Complex includes the Lower Cretaceous banded gabbros, diorites, and serpentinized peridotites intruded by rodingites dikes (e.g. Ure, Cerro Matoso, and Planeta Rica ultramafic complexes; Gómez et al., 2015; Figure 2-1). These ultramafic bodies are members of an ophiolite suite whose contacts are not properly understood given the strong tectonic deformation (Coleman, 1977). 2.2.2.2 Barroso Formation The Barroso Formation (K2-Vm7, Gómez et al., 2015; Figure 2-1) correspond to the lower Sequence # 1 proposed by Mora et al. (2017; Figure 2-2), and comprises porphyritic basalts, amygdalar basalts, agglomerates and tuffs successions with sub alkaline-tholeiitic to arc affinity 64 and calc-alkaline pyroclastic rocks. The minimum relative age for the Barroso Fm. have been established between Campanian and Maastrichtian based on its fossil record (Pchidyscus sp., Moreno and Pardo, 2003; and bivalves, Pardo-Trujillo, 2015). Buchs et al. (2018) documented Late Cretaceous (ca. 90 Ma) evidence (e.g. accretionary lapillies) of subaerial volcanic activity for the Barroso Formation. Recently, diabases and pillow basalts originally included in the Barroso Formation with a tholeiitic to transitional MORB affinity of Jurassic age (155.1 ± 11.2 Ma 40Ar-39Ar whole rock), are now referred as the San Juan de Urama Diabases, and separated from the Barroso Formation sensu stricto (Rodriguez and Arango, 2013). 2.2.2.3 Penderisco Formation The Penderisco Formation (k2k6-Sm7, Turonian to Maastrichtian; Gómez et al., 2015; Figure 2-1) corresponds to the upper Sequence # 1 proposed by Mora et al. (2017; Figure 2-2), and comprises mudstones, lithic sandstones, cherts, limestones, tuffs, and agglomerates. In the northern San Matías District this unit has been described as the Cansona Formation (Aleman, 1983; Clavijo and Barrera, 2001; Guzmán, 2007). 2.2.3 Paleogene Units 2.2.3.1 San Cayetano Formation The Upper Paleocene to Lower Eocene San Cayetano Formation (e3e4-Sm, Gómez et al., 2015; Figure 2-1), corresponds to the sequences # 2 proposed by Mora et al. (2017; Figure 2-2), and represents the bulk of the San Jacinto Fold Belt (SJFB). It is composed of a fining upward succession of polymictic conglomerates and litharenites at the base and gray siltstones to mudstones with minor chert and interbedded limestones at the top (Guzmán et al., 2004; Guzman, 2007). 65 Figure 2-2 Chronostratigraphic diagram of the Cordoba Department showing the relative position and correlation between the regional geological units (Gómez et al., 2015) and ten detailed stratigraphic sequences for the Sinú, San Jacinto Folded Belts, and the Lower Magdalena Valley (SJFB, SFB, LMV, respectively) compiled by Mora et al. (2017) in the stratigraphic record (modified from Mora et al., 2017). Known late Cretaceous ages for magmatism in the San Matías District (ca. 70 Ma U-Pb (zircon); Leal-Mejía and Hart, 2017) are indicated. Interpretations of its depositional environment range from deep marine turbiditic fans to turbiditic to distal deltaic, and fan deltas (Duque-Caro, 1972; Aleman, 1983; Guzmán, 2007). The clasts in the conglomerates of the lower part include abundant granodiorite to granite fragments and intermediate volcanics with porphyritic texture (Cardona et al., 2012) suggesting a proximal setting with respect to the source areas (Silva-Arias et al., 2016). 66 2.2.4 Neogene Units 2.2.4.1 Ciénaga de Oro Formation The Oligocene to Miocene Ciénaga de Oro Formation (e8n2-St, Gómez et al., 2015; Figure 2-1) corresponds to the Sequences # 5-6 proposed by Mora et al. (2017; Figure 2-2), and comprises fine-grained to conglomeratic, iron-rich sandstones interbedded with highly bioturbated siltstones that fines upwards to very fine-grained calcareous shales, siltstones, and coal (Dueñas, 1986). The measured thickness of this unit reaches 800 m (Clavijo and Barrera, 2001). The lower contact is discordant with the San Cayetano formation and the upper contact is transitional to the Cerrito Formation (Guzman et al., 2004). The depositional environment is transitional deltaic to continental platform (Dueñas, 1986). 2.2.4.2 Cerrito Formation The Middle to Upper Miocene Cerrito Formation (n3n5-St, Gómez et al., 2015; Figure 2-1) corresponds to the sequences # 7-8-9 proposed by Mora et al. (2017; Figure 2-2) and comprises sandstones and limestones interbedded with shales. The whole Cerrito Formation is highly fossiliferous, containing abundant Lamellibranchiates and marine Gastropods (Werenfels, 1926). The lower contact is transitional with rocks of the Ciénaga de Oro Formation (Cáceres and De Porta, 1972). 2.2.4.3 Sincelejo Group The Middle Pliocene – Pleistocene Sincelejo Group (N2-Sc, Gómez et al., 2015; Figure 2-1) corresponds to the sequence # 10 proposed by Mora et al. (2017; Figure 2-2), and comprises interbedded facies of sandy, clayey siltstones with lesser amounts of muddy and sandy conglomerates formed in flood plains, marshes and canals (Bermudez et al., 2012). It has been 67 divided into three members: 1) the Sincelejo Formation at the base, 2) the Morroa Formation at the middle, and 3) the Betulia Formation on top. This later is characterized by poorly consolidated sandstones (Lazala and Parra, 2010). 2.3 Regional Structures Review The Romeral Fault System (RFS) runs nearly parallel to the paleo continental margin at the northwestern corner of the South American craton. In central and south Colombia, the easternmost fault of the RFS is the San Jerónimo Fault (Maya and Gonzalez, 1995), whereas in the northern Colombia is denominated the San Jacinto Fault (Cediel et al., 2003). The San Jerónimo Fault is widely accepted to be the structural contact between oceanic and continental crusts along the entire western Colombia (Duque-Caro, 1972; Gonzalez, 1977; Maya and Gonzalez, 1995). However, to the north, the role and evolution are more complex as the San Jacinto Fault cuts a block of continental crust (Ruiz et al., 2000). The southern faults of the Romeral Fault System (e.g. San Jerónimo Fault and Peltetec Fault in Ecuador) display a marked melange zone and an orthogonal convergence kinematics, whereas the northern faults (e.g. San Jacinto Fault) lack an evident tectonic melange, and subduction-related magmatism Cediel et al. (2003). However, isolated bodies of ultramafic rocks of the Mafic to Ultramafic Complex (e.g. Uré, Figure 2-1) have been interpreted by Mejía and Durango (1982) to represent scraped-off material of the upper part of a subducting slab in a tectonic melange zone associated with the San Jacinto Fault. The San Jacinto Fault has been interpreted as the early-middle Eocene tectonic boundary or suture between the continental crust to the east and the accreted oceanic San Jacinto Terrane to the west (ESRI-ILEX, 1995, Laverde, 2000). Thus, the San Jacinto Fault and its NNE related 68 structures are dextral-oblique and document the passage of the Caribbean plate along the northern margin of the South American continental margin during the Cretaceous-Cenozoic (Cediel et al., 2003) Figure 1-2. Based on the combined analysis of the seismic, gravity and magnetic data, Mantilla-Pimiento (2007) suggested the existence of a Continental Tectonic Wedge (CTW) beneath the oceanic “basement complex” of the San Jacinto Fold Belt (to the west of the San Jacinto Fault), challenging the idea that the San Jacinto Fault represents a paleo-suture or tectonic boundary. The author suggest that the San Jacinto Fault and its associated structures formed under an intra-continental dextral transpressive setting developed as a result of the oblique convergence between the Caribbean and South American plates. 2.4 San Matías District Local Geology Although the available regional geology indicates that the San Matias District basement is composed of oceanic-affinity rocks from the Barroso Formation and by metamorphic rocks from the Cajamarca Complex (section 2.20, Figure 2-1), only rocks from the Barroso Formation are present in the San Matias District. Metamorphic rocks of the Cajamarca Complex were only reported during exploration activities ~ 9 km east of San José de Uré (Figure 2-3). The Barroso Formation rocks in the San Matías District comprise two end members: 1) The volcanic and 2) The volcanoclastic-end member. The volcanic end-member occurs preferentially to the east of the San Pedro River Lineament and comprises aphyric to porphyritic basalts and andesites with variable amounts of plagioclase, hornblende, and augite (Figure 2-3). Conversely, the volcanoclastic end-member is better exposed in the El Alacrán Deposit area and occurs mostly as a tight package limited to the east by the San Pedro River Lineament and to the west by the 69 Figure 2-3 Geology map of the San Matías District A. mapped lithologies, intrusions and structures from different sources (field mapping, GroundMag and Lidar lineaments) in the San Matías District surroundings (source: Cordoba Minerals Corp). Note that metamorphic rocks of the Cajamarca Complex do not occur in the proximity of the SDM. B. Detail of the San Matías District area showing the location of the El Alacrán Deposit with respect to other mineral prospects in the district and spatially related intrusions. Valdés Fault (Figure 2-3). Volcanoclastic rocks also occur to the east of the San Pedro River Lineament as discontinuous “roof pendants,” overlying the volcanic rocks (Figure 2-3). The volcanoclastic-end member rocks comprise a succession of volcanic breccias, crystal tuffs, and mafic to intermediate tuffs interbedded with limestones and mudstones (Figure 2-3). The 70 occurrence acid breccias and tuffs is only reported in the El Alacrán Deposit area; however, these rocks seem to have a different origin and will discussed further in this chapter. This work approaches the San Matías District basement study through the detailed characterization of the volcanoclastic sequence hosting the Cu-Au mineralization at the El Alacrán Deposit. A series of tonalite, quartz diorite, and diorite bodies intrude the San Matías District basement rocks. The bulk of those intrusions outcrops to the east of the San Pedro River Lineament, whereas to the west of this lineament, intrusions have been just reported in the El Alacrán Deposit area (Figure 2-3). For the purpose of this work, informal names have been assigned to these bodies based on their geographic area of occurrence and composition (e.g. Alto San Pedro Diorite, El Alacrán Oeste Tonalite; Figure 2-3) 2.5 The El Alacrán Deposit Volcaniclastic Rocks Detailed mapping and core logging at the El Alacrán Deposit show that the Cu-Au mineralization is hosted in a 550 m thick sequence intruded in the western and northern parts by the El Alacrán Oeste Tonalite and the El Alacrán Norte Tonalite, respectively, and it is also cut by a series of sills (e.g. Sill 1a, Sill 1b, and Sill 2; Figure 2-4). From bottom to top, the El Alacrán Deposit sequence can be separated into three major lithological units (Unit 3, Unit 2, and Unit 1, respectively; Figure 2-4). Based on the interpretation of surface mapping and core logging data, three detailed geological W-E cross-sections (855750m N, 855540m N, and 855050m N) are presented to show variations on the spatial distrinution of the different lithologies across the El Alacrán Deposit (Figure 2-5). 71 Figure 2-4 El Alacrán Deposit Geology. A. Surface geology map displaying the location of the studied cross-sections. (a) 85570m N, (b) 855540m N, and (c) 855050m N. B. Generalized stratigraphic column of the El Alacrán Deposit Units indicating the distribution of the defined volcano-clastic lithofacies. 72 Figure 2-5 El Alacrán Deposit local geology along the studied three sections. A. Section 85570m N (Northern El Alacrán Deposit). B. Section 855540m N (Central part of the El Alacrán Deposit). C. Section 855050m N (Southern El Alacrán Deposit). The sections display the drill holes used for the lithology interpretation and correlation (Provided by Cordoba Mineral Corp.). 73 2.5.1 Unit 3: Mafic Volcanoclastic Rock Sequence The Unit 3 comprises coherent mafic lavas interlayered with mafic to intermediate volcanoclastic rocks. Locally, remnants of vitroclastic and lesser epiclastic silty tuffaceous materials are observed. The thickness of this unit exceeds 300 m and is the oldest unit unit of the El Alacrán Deposit stratigraphy delineated by drilling (Figure 2-4, Figure 2-5). At surface, Unit 3 outcrops along the San Pedro River margins and typically exhibits gradational depositional contact with the base of Unit 2. Unit 3 locally exhibit propylitic alteration assemblages comprising chlorite, epidote, and calcite. Also, the very fine-grained primary magnetite of this unit is altered to secondary hematite producing local reddish-staining. Minor albite is also present in some Unit 3 rocks preferentially distributed in the northern part of the deposit. Based on textural, composition, geometry, and volcanic structure criteria (McPhie et al., 1993), three major lithofacies have been defined within this unit (i.e. TufF + TufL, TufM, and TufA + TufP; Figures 2-4 and 2-5). 2.5.1.1 TufF+TufL: Lithic Tuff lithofacies This lithofacies comprises a 40 - 60 m thick interbedded succession of poorly sorted lithic tuffs and fine-grained laminated tuffs that are the bulk of Unit 3 (Figure 2-5). Under the microscope, the TufF + TufL lithofacies displays a series of fine- to very fine-grained, banded hypocrystalline layers that contain glass, crystals (plagioclase and augite), and well-sorted basaltic rocks fragments (Figure 2-6A). 74 2.5.1.2 TufM: Mafic Tuff lithofacies This lithofacies comprises a series of 8 - 16 m thick coherent plagioclase-rich, porphyritic andesitic to basaltic lavas that occur preferentially at the base of Unit 3. (Section 855750m N, Figure 2-5). Petrographically, the TufM lithofacies displays plagioclase and hornblende phenocrysts in a fine- to very fine-grained (<0.3 mm) plagioclase amphibole and magnetite groundmass (80%) (Figure 2-6B). 2.5.1.3 TufA + TufP: Amygdalar Tuff lithofacies This lithofacies comprises 8 - 25 m thick coherent amygdaloidal andesitic lavas that occur interbedded with fine-grained volcanoclastics in Unit 3 (Figure 2-5). The andesite lava displays highly-irregular peperite texture in contact with very fine-grained (<0.1 mm) ash tuffs (Figure 2-6C). Petrographically, this lithofacies has a fine-grained (<1 mm), phaneritic plagioclase-rich groundmass (~25%) with plagioclase phenocrysts and rock fragments (~15%). Immobile and trace element geochemistry in the least altered samples of this lithofacies yielded the following concentrations: SiO2 = 48.1%, Al2O3% = 16.1, TiO2 = 1.09%, and Zr = 65.6 ppm (Figures 2-9 and 2-13). 2.5.2 Unit 2: Calcareous Volcanoclastic Rock Sequence Unit 2 crops out by >800 m N-S along the El Alacrán Deposit sequence and ranges from 160 to 208 m in thickness (Figure 2-4, Figure 2-5). Unit 2 exhibits gradational contacts with underlying Unit 3 and is overlaid and locally intruded by Unit 1 rocks, (Figure 2-4, Figure 2-5). Unit 2 hosts the bulk of the mineralization of the El Alacrán Deposit. Five different volcanic lithofacies are defined within this unit (i.e. TufF-TufC, TufL, TufD, Lim, and, MudSil; Figures 2-4 and 2-5). 75 Unit 2 displays various types and alteration degrees ranging from magnetite + quartz in the MudSil lithofacies to weak and pervasive sericite + carbonate alteration in the other lithofacies. The distribution and alteration intensity in Unit 2 is highly controlled by the host rock lithology and will better be discussed in Chapter 3. 2.5.2.1 TufF+TufC: Fine to coarse crystal tuff lithofacies The TufF+TufC lithofacies comprises several coarse- to fine-laminated (<1 cm-thick) tuff packages with thickness from few meters in the shallow levels to 50 m thick at depth. The base of this lithofacies conformably overlies Unit 3, and it corresponds to the largest lithofacies in Unit 2 (Figure 2-5). In drill core, the TufF+TufC lithofacies is not easily distinguishable from the TufF+TufL lithofacies of Unit 3. However, in thin section, the TufF+TufC lithofacies displays a fine-grained (<1 mm) andesite tuff composition with relictic pyroxenes (2%) occurrence that is not observed in Unit 2 tuffs (Figure 2-6D). Immobile and trace element geochemistry in the least altered sample of this lithofacies shows: SiO2 = 51.2%, Al2O3 = 18.1%, TiO2 = 1.18%, and Zr = 94.6ppm (Appendix C.2). 2.5.2.2 TufL: Lithic Tuff lithofacies The TufL lithofacies comprises several medium-grained (>1 mm), poorly sorted, monomictic breccias, interbedded with fossiliferous mudstones (Figure 2-6E). This lithofacies range in thickness from 5 - 16 m and occurs preferentially in the upper Unit 2 (Figure 2-5). In thin section, the TufL lithofacies shows a microcrystalline groundmass (~20%) composed of very fine-grained (<0.1 mm) aggregates of quartz and plagioclase. The fragments are medium- to coarse-grained (>5 mm), glassy shards with incipient welding evidence. 76 Figure 2-6 El Alacrán Deposit volcanoclastic lithofacies from Unit 2 and Unit 3. A. Core-scale sample of the TufF+TufL lithofacies (banded interbedding of fine-grained tuff and lithic tuffs). B. Core-scale sample of the TufA+TufM lithofacies (coherent lavas with amygdaloidal facies). C. Photomicrograph (10x, XPL) of the TufP lithofacies (peperites in the contact of TufM) note the contact zone between a basaltic rock and a fine-grained lapilli tuff. D. Core-scale sample of the TufF-TufC lithofacies (fine-grained to coarse-grained tuff). E. Core-scale sample of 77 the TufL lithofacies (lithic tuff). E1. Photomicrophotograph (2x, PL) of photo E, showing the breccia texture in the rock. Note the clasts composition dominated by vitroclasts and recrystallized quartz. F. Core-scale sample of the TufD lithofacies (fiamme tuff). G. Core-scale sample of the Lim lithofacies (Marlstone). H. Core-scale sample of the MudSil lithofacies (laminated limestone). H1. Photomicrograph (10x, XPL) showing some occurrences of welded (?) vitriclasts and some dissemination of sphalerite. Perlite textures are commonly observed overprinting primary flow banding, while observed vitriclasts exhibit incipient devitrification to quartz (Figure 2-6E1). Immobile and trace element geochemistry in the least altered sample of this lithofacies shows concentrations of SiO2 = 52.3%, Al2O3 = 14.9%, TiO2 = 0.91%, and Zr = 92ppm (Appendix C.2). 2.5.2.3 TufL: Lithic Tuff lithofacies The TufL lithofacies comprises several medium-grained (>1 mm), poorly sorted, monomictic breccias, interbedded with fossiliferous mudstones (Figure 2-6E). This lithofacies range in thickness from 5 - 16 m and occurs preferentially in the upper Unit 2 (Figure 2-5). In thin section, the TufL lithofacies shows a microcrystalline groundmass (~20%) composed of very fine-grained (<0.1 mm) aggregates of quartz and plagioclase. The fragments are medium- to coarse-grained (>5 mm), glassy shards with incipient welding evidence. Perlite textures are commonly observed overprinting primary flow banding, while observed vitriclasts exhibit incipient devitrification to quartz (Figure 2-6E1). Immobile and trace element geochemistry in the least altered sample of this lithofacies shows concentrations of SiO2 = 52.3%, Al2O3 = 14.9%, TiO2 = 0.91%, and Zr = 92ppm (Appendix C.2). 2.5.2.4 TufD: Fiamme Tuff lithofacies The TufD lithofacies comprises a series of fine-grained, poorly sorted and matrix-supported lapilli tuffs, exhibiting massive flow banding and welding (Figure 2-6F). The TufD lithofacies 78 occurs in 5 - 20 m thick discontinuous packages in the middle to upper Unit 2. Petrographically, this lithofacies displays a monomictic cryptocrystalline (<0.05 mm) matrix (~55%) composed of recrystallized glass with a subtle flow banded textures. The clasts in the sample correspond to coarse-grained (>5 mm) elongated, juvenile volcanic clasts (fiammes) (~15%), indicative of a welding process during rock compaction. Also, clasts include fine-grained (<0.4 mm) plagioclase and quartz (1%), which occur as free crystals. Immobile and trace elements geochemistry in the least altered sample of this lithofacies contains SiO2 = 56.95, Al2O3 = 14.25, TiO2 = 0.87%, and Zr = 78.3ppm (Appendix B.2). 2.5.2.5 Lim: Massive Fossiliferous Limestone lithofacies The Lim lithofacies comprises a series of discontinuous, non-graded, bioclasts-bearing limy mudstones packages (marlstones) with thickness ranging from 5 - 8 m. These packages are located approximately 80 - 100 m below the contact between Unit 1 and Unit 2 (Figure 2-5). Petrographically, the Lim lithofacies displays a matrix-supported, poorly transported, hybrid composition between microcrystalline matrix and bioclasts (Figure 2-6G). The matrix contains fine-grained (~0.1mm), anhedral carbonate (~40%), and vitriclasts (~20%). The bioclasts (~15%) correspond to coarse-grained (>10 mm) bivalve shells made of fine-grained (0.3 mm) carbonate crystals. Plagioclase (5%) also occurs in the matrix as free crystals accompanied by traces of quartz (Appendix B.2). 2.5.2.6 Mudsil: Laminated Limestone lithofacies The Mudsil lithofacies comprises a well-sorted, fine- to coarse-layered (<6 mm), chemical sedimentary rock (Figure 2-6A). Stratigraphically, the MudSil lithofacies ranges in thickness from 10 m in the central sector of the deposit to 35 m in the southern area, (Figure 2-5B,C), whereas it seems to be absent in the northern part of the deposit (Figure 2-5A). Petrographically, 79 MudSil lithofacies consists of fine (<1 mm) to very fine-grained (<0.1 mm) laminations of euhedral carbonate (~97%) with primary granoblastic textures. Fine-grained (<0.1 mm), elongate glassy shards are observed interlayered within the carbonate sequence (Figure 2-6H-H1, Appendix B.2). 2.5.3 Unit 1: Felsic Volcanoclastic Rock Sequence Unit 1 extends >1500 m N-S in the El Alacrán Deposit sequence and range 120 m thick in the north to few meters in the south where it is completely obliterated by the El Alacrán Oeste Tonalite. Unit 1 comprises andesitic to rhyolitic tuffs grouped into three dominant lithofacies (TufR; RBx; and Abx; Figure 2-4 and Figure 2-5). Unit 1 is weakly to pervasively mineralized and constitutes the youngest unit of the El Alacrán Deposit sequence. The persistent presence of quartz phenocrysts in drill core is a diagnostic feature for Unit 1. The Unit 1 lithofacies show various degrees of hydrothermal alteration ranging from weak to destructive sericitic alteration (carbonate + sericite + chlorite ± titanite) overprinted by FeOx staining producing a patchy brownish colorin the rocks. In the southern part of the deposit, however, the dominant hydrothermal alteration is dark-green chlorite. 2.5.3.1 ABx: Andesitic Breccia lithofacies The ABx lithofacies comprises a poorly sorted, monomictic to polymictic, clast-supported intrusive breccia (Figure 2-7). This breccia unit displays near-vertical, locally discordant contacts producing pipe-like shaped bodies. This lithofacies range in thickness from 3 - 40 m and outcrops in a 350 m N-S, preferentially in the central part of the deposit (Figure 2-5B). Textures in the ABx breccia including high-angularity fragments of the Unit 2 lithofacies, indicates a peripheral location relative to a causative intrusion. 80 Figure 2-7 El Alacrán Deposit volcano-clastic lithofacies from Unit 1. A. Photo of drill core from the Andesite Breccia (ABx) (drill hole ACD075 @ 210 – 213 m). B. Detailed of photo A. Photomicrograph (10X, XPL) showing a coherent facies composition of the ABx lithofacies. Note the glassy groundmass in the dark-grey facies. C. Drill core sample of some quartz-rich porphyritic facies associated with the RBx lithofacies. D. Quartz stockwork in porphyry clast embedded in a quartz-rich groundmass volcanic/magmatic? breccia from the TufR lithofacies. E. Detail of TufR lithofacies. F. Photo of drill core from the Dacite Breccia (RBx) in transitional contact with the TufR lithofacies (drill hole ACD003 @ 84.2 – 86.5 m). G. Photomicrograph (10X, XPL) of photo F showing a fine-grained breccia texture composed of quartz, plagioclase and K-feldspar. In thin section, the ABx lithofacies exhibits two different clast-supported (70%) breccia facies with similar phenocrysts mineralogy and marked variations in the matrix crystallinity. One of the breccia facies is glassy, whereas the other comprises very fine-grained (<0.1mm) plagioclase and quartz. Both breccia facies have fine-grained (~0.4 mm) tabular plagioclase (~70%) and K-feldspar phenocrysts (Figure 2-7B). 81 Quartz fragments (3%) occur in both breccia facies as fine-grained, sub-rounded fragments. Some quartz + carbonate + sulfides fragments from Unit 2 (e.g. MudSil and TufF) are reported to occur within these lithofacies (Cordoba Minerals Corp., pers. comm., 2019) indicating a syn- to a post-volcanic origin of this breccia lithofacies. However, the heterogeneous distribution of the alteration and mineralization within the ABx breccia is interpreted as evidence for a pre-mineral origin. 2.5.3.2 TufR: Rhyolite Tuff lithofacies The TufR lithofacies consists of poorly sorted, flow-banded rhyolite to andesite breccias that extends from near surface to > 200 m depth downhole (Figure 2-5, Figure 2-7D). The TufR lithofacies displays gradational contact with the RBx lithofacies and exhibits some local <10 m-thick massive, porphyritic textural changes (Figure 2-7C). This lithofacies constitutes the bulk of the Unit 1 rocks and its lowercontact present evidence of an intrusion/emplacement in the volcanoclastic Unit 2. In thin section, this unit comprises fine-grained (<1 mm), quartz (5-20%) and plagioclase microphenocrysts in a matrix (30%) composed of plagioclase, K-feldspar and quartz (Figure 2-7D). Immobile and trace element geochemistry in the least altered sample of this lithofacies shows: SiO2 = 58.3%, Al2O3 = 16.4%, TiO2 = 0.25%, and Zr = 23.7ppm (Figure 2-9, Appendix B.2). 2.5.3.3 RBx: Dacite Breccia lithofacies The RBx lithofacies comprises a matrix-supported, monomictic to polymictic intrusive dacitic to rhyolitic breccia (Figure 2-7F). This breccia contains quartz and rocks fragments bigger than ten cm-length, occasionally with porphyritic textures and quartz stockwork veining (Figure 2-7D). This lithofacies extends for up to 450 m N-S and occurs in the northwestern part of the El Alacrán Deposit as a series of 8 to 28 m thick concordant packages. Textures in the RBx breccia 82 including rounded milling fragments and quartz stockwork porphyry clasts (Figure 2-7F), indicate an intrusion-centred formation. In thin section, this unit displays aplite (?) clasts of fine-grained (<0.1 mm) k-feldspar (25%), quartz (10%) and plagioclase (7%) set in a fine-grained (<0.5 mm) rhyodacite groundmass (Figure 2-7F). The breccia groundmass contains k-feldspar (5%), quartz (5%), and plagioclase (25%), indicating a dominant coherent composition between rock clasts and their matrix (auto breccia facies) (Figure 2-7G). The presence of abundant primary K-feldspar, quartz and high-viscosity textures such as autobrecciation is evidence for possible volcanic depositional settings such as a lava dome or cryptodome (McPhie, et al., 1993). Like the ABx breccia, the heterogeneous distribution of the alteration and mineralization within the RBx breccia is interpreted as an evidence of a pre-mineral origin. 2.6 Intrusive rocks of the San Matías District This study group the San Matías District intrusions into five major magmatic suites: 1) San Matías-La Jagua, 2) San Jorge, 3) Betesta-Mina Escondida, 4) San Pedro-Costa Rica, and 5) El Alacrán Norte, based on the NMORB-normalized (Sun and McDonough 1989) REE patterns and Chondrite-normalized (Thompson, 1982) trace element spider-diagrams (Figure 2-8). From a geochemical point of view, all the magmatic suites are calc-alkaline and display a low- to medium-K content (Appendix C.2). In addition, most of the San Matías District magmatic suites have trace element patterns show negative Nb-Ta anomalies, indicating subduction-related affinities, except for the San Pedro-Costa Rica magmatic suite, which lacks that particular feature (Figure 2-8). Rock and drillcore samples of representative intrusions from each magmatic suite were selected for U-Pb zircon geochronology to establish the age and temporal relationships between the different magmatic suites. 83 2.6.1 San Matías - La Jagua Magmatic Suite The San Matias – La Jagua magmatic suite includes the Montiel E porphyry suite, the Costa Azul porphyry suite, and the La Jagua Tonalite, distributed preferentially along a N-S trend to the east of the San Pedro River Lineament (Figure 2-3). The rocks associated with this suite are characterized by negative Ti anomalies relative to the Chondrite values (Figure 2-8), Sr/Y > 20 (26.2 - 58.8) and Eu*= 0.8 - 1.7, fulfilling the adakite-like composition criteria (Figure 2-9A-B-C; Table 2-1). Moreover, (La/Sm)N = 1.9 - 5.3, and (La/Yb)N = 3.5 - 4.7, are the highest ratios within the San Matías District intrusive rocks and indicate significant fractionation between the Heavy Rare Earth Elements (HREE) and the Light Rare Earth Elements (LREE) (Figure 2-9D). (Dy/Yb)N = 0.9 - 0.8, are the lowest in the San Matías District intrusions also suggesting a remarkable differentiation between the Middle Rare Earth Elements (e.g. Ho, Dy) and the HREE, consistent with hornblende fractionation in the magma (Richards et al., 2012; Figure 2-9E). Rocks from the San Matías - La Jagua magmatic suite are also distinguished by the lowest TiO2 (0.1 - 0.32%) and Zr (32.1 - 72.1 ppm) concentrations (Figure 2-9). The average Ti-in-zircon temperature of the San Matías-La Jagua Suite varies from 703.91 ± 30.21 °C in the Montiel E early phase (PxHe, n=4), through 728.30 ± 30.21 °C in the Montiel E late phase (QFPx, n=15), and 753.54 ± 74.96 °C in la Jagua Tonalite (n= 27). The average temperature for the suite is 740.99 ± 68.27 °C (Figure 2-10). 84 Figure 2-8 Trace element and REE element pattern of the San Matías District magmatic suites. A. Diagram displays the normalized values from the San Matías-La Jagua magmatic suite. In red the REE element pattern from the TufR lithofacies of the El Alacrán Deposit Unit 1. B. Diagrama displays the normalized values from San Jorge magmatic suite and contrasts with the El Alacrán Norte magmatic suite. C. Diagram displays the normalized values from the Betesta-Mina Escondida magmatic suites. D. Diagram displays the normalized values from the San Pedro-Costa Rica magmatic suite. The trace elements values are normalized to Chondrite (Thompson, 1982), and the REE values are normalized to NMORB (Sun and McDonough 1989). 85 2.6.1.1 The Montiel E Porphyry The Montiel E porphyry occurs to the east of the San Pedro River Lineament in the San Matías Village, 2 km northeast of the El Alacrán Deposit (Figure 2-3). This intrusive body comprises at least four different intrusive phases (PxHe, PxHL, Pxto, QFPx) that occur in a cluster of 600 m length with limited outcrops (~1 Ha). The contacts of the body with the andesite host rock are intrusive and locally develop breccias. The Montiel E intrusion has associated important Cu-Au mineralization, and is the most explored porphyry Cu-Au prospect within the San Matías District. Petrographically, the PxHe, PxHL and PxTo phases of Montiel E comprise a series of holocrystalline rocks with a dominant crowded, porphyritic texture (Figure 2-11A-B). The groundmass (30%) is composed of very fine-grained (up to 0.05 mm) quartz, whereas the phenocrysts corresponds to fine- to medium-grained (up to 2 mm) plagioclase (40%), hornblende (5%), and fine- to very fine-grained (up to 0.1mm) biotite (2.5%) (Figure 2-12, Appendix B.1). Primary magnetite occurs as fine-grained (up to 0.7mm), subhedral aggregates selectively replaced to chlorite. The QFPx phase occurs as an intermineral-late phase as evidenced by the low-ore mineralization and clear cross-cutting relationship to the early formed porphyry phase (PxHe). The QFPx phase corresponds to an inequigranular medium-grained (0.5 to 2mm) leucocratic phase composed of anhedral K-feldspar (14%), euhedral plagioclase (10%), and fine-grained (<1 mm) quartz (40%) (Figure 2-11C). 86 Figure 2-9 Immobile element analysis in San Matías District samples and their indicated fertility for porphyry Cu. A. Sr/Y vs Y diagram showing large Y values displayed by the San Pedro-Costa Rica magmatic suite relative to the rest of the magmatic suites. B. Europium Anomaly (Eu*) vs SiO2% diagram indicating (grey zone) the field of adakite-like rocks (Richards et al., 2012). C. Sr/Y vs SiO2%, indicating in grey the field of adakite-like rocks. D. La/Yb vs Yb diagram showing the correlation between Unit 2 and Unit 3 rocks with the San Pedro-Costa Rica magmatic suite. E. La/Sm vs Dy/Yb diagram showing the largest fractionation of the Light Rare Earth Elements (LREE) indicated by the San Matías-La Jagua magmatic suite. F. TiO2 vs Zr diagram showing the elevated TiO2 and Zr content in Unit 2, Unit 3 and San Pedro-Costa Rica magmatic suite. 87 Table 2-1 Summary of the lithogeochemistry ratios of the San Matías District magmatic suites and basement rocks. Figure 2-10 Ti-in-zircon temperatures of the San Matías District magmatic suites. Temperatures are calculated using the equation proposed by Ferry and Watson (2007); the activities of SiO2 and Ti are set to 1 and 0.70, respectively (see in the text). 88 Figure 2-11 Macroscopic and microscopic aspects of selected San Matías District intrusions. A. Photo of drill core from the Montiel E porphyry suite showing a chilled contact between the tonalite porphyry (PxH) and the leucocratic quartz-feldspar porphyry (QFPx) (drill hole SMDDH012 @ 163.4–166.16 m). B. Detail of photo A., showing the main mineralizing porphyry phase from Montiel E Porphyry (PxHe). C. Photomicrograph (2x, XPL) of the quartz-feldspar porphyry (QFPx) from photo A. D. Photomicrograph (2x, XPL) of the Costa Azul Porphyry. Note the crowded porphyry texture and the marked plagioclase zonation. E. Photo of drill core from the San Jorge quartz diorite (drill hole SJDDH001 @ 226.3–229.10 m). F. Detail of photo E. G. Photomicrograph (2x, PPL) of the San Jorge quartz diorite. H. Photomicrograph (2x, XPL) of the Las Claritas quartz diorite showing a poikilitic texture of hornblende with inclusions of plagioclase and quartz. 89 Figure 2-12 Modal classification of samples from the San Matías District intrusions based on 200-300 point-counting on the QAP diagram of Streckeisen (1967). Hydrothermal alteration of Montiel E porphyry suite varies depending on each intrusive phase: The most hydrothermally altered phase (PxHe) exhibits a fine-grained (~0.2 - 0.4 mm) silicification (23%), secondary biotite (8%), chlorite (2%), and traces of actinolite, whereas in the later phases (QFPx and PxHL) alteration minerals are dominated by very fine-grained (<0.1 mm) sericite, carbonate, and clay (3 - 15%) after plagioclase and by chlorite (4%) after biotite, hornblende and actinolite. Mineralization in the PxHe phase is dominated by fine-grained (~0.3 mm) chalcopyrite in A-type (quartz ± magnetite), B-type (quartz + magnetite + chalcopyrite and actinolite), and C-type (chalcopyrite-rich) veinlets (Sillitoe, 2010). Disseminated chalcopyrite and bornite mineralization is also common (Figure 2-11B - D). 90 Major oxide geochemistry for samples from different phases of this porphyry suite (n=4) shows: SiO2 = 61.8 - 73.8%, Al2O3 = 13.6 - 16.6%, CaO = 2.06 - 6.83%, MgO = 0.8 - 3.04%, and TiO2 = 0.1 - 0.32%, indicating the highest fractionation degree within the SMD intrusions (Figure 2-13). An LA-ICP-MS U-Pb zircon age for the Montiel E Porphyry was presented by Leal-Mejía and Hart (2017) from a tonalitic porphyry rock with minor chlorite and pyrite alteration (sample NCB-SM-JM-05, PxHL), provided by Cordoba Minerals Corp. According to the exploration team observations (e.g. the lack of the alteration and mineralization) the PxHL phase formed late within the Montiel E Porphyry suite. In this sample, the authors recognized two different groups of zircon grains based on their external/internal morphology: 1) euhedral equant crystals with a weighted average age of 70.0 ± 2.0 Ma, and 2) elongated prismatic crystals that yielded a weighted average age of 72.3 ± 1.8 Ma. These authors interpreted such a difference of ca. 2 Ma, as evidence of separated magmatic crystallization events within the cooling history of the Montiel E Porphyry suite. The ages obtained by these authors compare well with previous unpublished U-Pb zircon age dating conducted by Anglo American PCL from an outcrop of the Montiel E Porphyry Cu-Au prospect (71.5 ± 0.5 Ma, Anglo American, pers. comm., 2014) (Table 2-2). New LA-ICP-MS U-Pb zircon ages obtained in this study from the Montiel E Porphyry suite include samples of the earliest PxHe and late QFPx phases. From the early PxHe phase (sample SMA_ME_1705_JM_061), only two zircon crystals were recovered, whereas ten zircon crystals were recovered from the late QFPx phase (sample SMA_ME_1705_JM_060) (Appendix E.1a-b). The zircon characteristics are summarized in Table 2-3. 91 Figure 2-13 Major oxides vs. SiO2 Harker variation diagrams for the least altered samples of the San Matías District intrusions 92 Table 2-2 Existent U-Pb geochronology data in zircon from San Matías District. Table 2-3 Summary of characteristics of the zircon crystals from selected intrusions of the San Matías District dated by U-Pb LA-ICP-MS in zircon The PxHe zircons display equant external morphologies with sizes close to 200 μm. In the QFPx phase, the pyramidal and equant zircon shapes dominate with lengths between 100 – 250 μm. CL images in both phases exhibit sector zoning in the equant zircons and oscillatory growth zoning parallel to C-axis with minor reabsorbed borders and xenocrystic cores in the pyramidal zircons (Figure 2-14A – D, Appendix E.1b). 93 Figure 2-14 U-Pb LA-ICP-MS zircon geochronological results from tonalite and tonalite porphyries of Montiel E Porphyry suite and La Jagua Tonalite. A. Concordia plot and weighted average age estimation based on four LA-ICP-MS analysis of the SMA_ME_1705_JM_061 sample. The lower part shows a CL image of a representative equant zircon of this sample. B. Concordia plot and weighted average age estimation based on six-teen LA-ICP-MS analysis of the SMA_ME_1705_JM_060 sample. The lower part shows a CL image of a representative equant and pyramidal crystals found in this sample. C. Concordia plot and weighted average age estimation based on twenty-seven LA-ICP-MS analysis of the SMA_JA_1704_JM_057 sample. The bars in blue indicate the rejected analysis. The lower part shows a CL image of the zircon morphologies found in this sample. 94 Uranium concentrations range between 32.7 and 68.5 ppm in PxHe, whereas reach up to 262 ppm in the QFPx phase. In both phases, the U/Th ratios are consistently magmatic and span a range from 1.79 to 4.25. The U/Th ratios found in the Montiel E Porphyry are the highest among of the analyzed samples of the San Matías District intrusions, where the U/Th ratio average is 1.9 ( Table 2-3). U-Pb LA-ICP-MS analyses of the PxHe phase was conducted in four spots (core and rim of the two recovered zircons). The individual LA-ICP-MS analyses yielded Pb/U ages between 68.5 ± 7.5 and 78.0 ± 10.0 Ma (Appendix E.1c), with a weighted average U-Pb age of 72.4 ± 4.3 Ma (Figure 2-14A,B). Similarly, U-Pb LA-ICP-MS analyses in the QFPx phase was conducted in 18 spots within the recovered zircons and yielded individual Pb/U ages between 66.0 ± 13 and 79.3 ± 7.3 Ma (Appendix E.1c). After QAQC processes (Appendix E.1b) two analyses were excluded for the data integration, and the obtained weighted average yielded an U-Pb age of 73.4 ± 1.9 Ma. (Figure 2-14C, D). Both obtained ages for the Montiel E porphyry suite are consistent within error ( Table 2-3). 2.6.1.2 Costa Azul Porphyry The Costa Azul porphyry suite is also located to the east of the San Pedro River Lineament, 2.5 km to the east of the El Alacrán Deposit, and comprises a series of equigranular to porphyritic intrusive phases with Porphyry Cu-Au mineralization similar to those described in the Montiel E Porphyry suite. The porphyritic suite in Costa Azul outcrops ~1 km along the Costa Azul Creek, and the contacts are dominantly intrusive with respect to the andesitic volcanic basement (Figure 2-3). 95 The mineralizing phase of the Costa Azul Porphyry (PxHe) is a holocrystalline, porphyritic tonalite dominated by phenocrysts (~70%). The phenocrysts are medium-grained (up to 2 mm), euhedral plagioclase (21%) and anhedral to subhedral hornblende (6%) intergrown with primary magnetite and biotite. Quartz (27%) occurs either as fine-grained (up to 0.5 mm), anhedral phenocrysts, or as very fine-grained (<0.05 mm) granoblastic aggregates in the groundmass (Figure 2-12, Appendix B.1). Hydrothermal alteration intensity is weak to moderate silicification (29%), fine-grained (<0.5 mm) chlorite (3%), and traces of actinolite. Chalcopyrite is the dominant sulfide and occurs in two different stages: 1) Very fine- to fine-grained (<0.3 mm) anhedral aggregates intergrown with bornite ± pyrite in quartz-rich B-type veins, and 2) chalcopyrite-rich veinlets (0.2 mm-wide) that crosscut the B-type veins. Major oxide geochemistry in samples (n=2) of this unit shows: SiO2 = 61.6 - 63.7%, Al2O3 = 15.9 - 16.5%, CaO = 6.3 - 6.45% , MgO = 2.57 - 2.65% and TiO2 = 0.3 - 0.32%, consistent with the concentrations obtained for the Montiel E Porphyry suite samples. 2.6.1.3 La Jagua Tonalite The La Jagua Tonalite crops out in 25 ha in the western margin of the La Jagua creek, 5 km southeast of the El Alacrán Deposit. The contacts of the La Jagua Tonalite with the host rock are not clearly defined; however, the eastern contact with the Betesta intrusion is interpreted to be faulted. The La Jagua Tonalite hosts vein-type mineralization exploited by artisanal miners at the Mina Cocos mine (i.e. La Jagua vein) (Figure 2-3). The La Jagua Tonalite corresponds to a holocrystalline, hypidiomorphic intrusion dominated by medium-grained (1.5 mm) euhedral plagioclase + K-feldspar (43%), and fine- to medium-grained (up to 1.5 mm) anhedral quartz (24%). The mafic minerals are medium-grained (<3.5 mm) anhedral to subhedral hornblende (7%), and fine-grained (~0.5 mm) biotite (3%) (Figure 96 2-12, Appendix B.1). Primary magnetite was not observed under the microscope. The hydrothermal alteration intensity in this intrusion is weak to moderate and comprises very fine-grained aggregates of sericite ± illite as a selective replacement after plagioclase and fine-grained (<0.8 mm) anhedral chlorite after hornblende and biotite. Mineralization occurs as fine-grained (<0.5 mm), anhedral to subhedral selective replacement of pyrite and chalcopyrite after magnetite and hornblende. Major oxide geochemistry of one sampleshows: SiO2 = 62.0%, Al2O3 = 16.5%, CaO = 6.3%, MgO = 5.76%, and TiO2 = 0.32%, similar to the values obtained in both, the Montiel E and Costa Azul Porphyry suites (Figure 2-13). The LA-ICP-MS U-Pb zircon age for the La Jagua Tonalite intrusion was obtained based on sixteen analyses (core and rim) on eight recovered zircon crystals (sample SMA_JA_1704_JM_057, Appendix E.1a-b). The zircon crystals characteristics are summarized in Table 2-3. The external morphology of zircons from La Jagua Tonalite intrusion are dominated by subhedral pyramidal and euhedral prismatic shapes. There is not an evident relationship between zircon sizes and their external morphologies. Zircon sizes vary from 100 – 200 μm in length and 30 – 100 in width. CL images exhibit a dominant oscillatory zoning parallel to c-axis. Unzoned zircon crystals are also observed in the sample (Figure 2-14C). Uranium concentrations vary from 137 to 318 ppm (251.2 ppm on average) in the prismatic zircons, whereas the pyramidal zircons display higher values (163 to 1580 ppm; 519.5 ppm on average). U/Th ratios are magmatic in both cases and span a range between 1.62 and 2.2 ( Table 2-3). 97 U-Pb LA-ICP-MS analyses yielded individual 206Pb/238U ages between 71.2 and 113 Ma (Appendix E.1c). Two analyses were excluded for the data integration and the weighted average 206Pb/238U age is 74.4 ± 1.2 Ma. (Figure 2-14C). 2.6.2 San Jorge Magmatic Suite This suite includes the San Jorge and Bucaramanga Quartz Diorite units. The rocks from this suite show a marked negative Th anomaly, a positive to flat Ti anomaly and the LREE plot below the Chondrite values (Figure 2-8B). Sr/Y = 32.3 - 45.9, and Eu* > 1 values (Table 2-1) fulfill the adakite-like composition criteria for oxidized magmas (Figure 2-9 A-B-C). (La/Sm)N = 1.2 - 1.8 and (La/Yb)N = 2.1 - 3.0 suggest a marked fractionation between the LREE and HREE groups (Figure 2-9). This fractionation degree, however, is lower than that indicated by the San Matías-La Jagua suite rocks. The San Jorge magmatic suite display: TiO2 = 0.32 - 0.47% and Zr = 32.1 - 72.1 ppm (Figure 2-9 F, Table 2-1). The average Ti-in-Zircon temperature calculated for the samples of the San Jorge Quartz Diorite (n=25) is 731.75 ± 47.7 °C (Table 2-1). These temperatures approximate the obtained Ti-in-Zircon temperatures of the Betesta-Mina Escondida Suite samples (Figure 2-10). 2.6.2.1 San Jorge Quartz Diorite The San Jorge Quartz Diorite intrusion crops out in approximately 400 ha in the area of La Bonga and San Luis Creeks, 4.5 km northeast of the El Alacrán Deposit. Similar intrusions are mapped at the Las Claritas and Rio Verde localities. The San Jorge intrusion has clear intrusive contacts within the volcanic basement and is easily recognized in the field because it defines dome-like morphologies and topographic highs (Figure 2-3). 98 The San Jorge Quartz Diorite is a medium-grained (<2 mm), holocrystalline, phaneritic equigranular intrusion (Figure 2-11E,F) with poikilitic texture variations (e.g. Las Claritas, Figure 2-11H). This intrusion is composed of euhedral to subhedral crystals of plagioclase (58 - 61%), hornblende (15 - 22%), fine-grained (<0.2 mm) anhedral quartz (13 - 16%), and biotite (3 - 9%) (Figure 2-11G, Appendix B.1). Primary magnetite occurs as very fine-grained (~25 μm) subhedral aggregates intergrown with hornblende. Hydrothermal alteration comprises weak propylitic assemblage dominated by fine-grained (0.8 mm) anhedral silica veinlets, fine-grained (<0.1 mm) chlorite after hornblende and biotite, very fine-grained (<0.05 mm) sericite after plagioclase and minor occurrence of fine-grained (<0.5 mm) epidote. Mineralization is observed as fine-grained (<1 mm), anhedral traces of disseminated pyrite and chalcopyrite. Major oxide geochemistry in samples of the San Jorge intrusion(n=3) shows: SiO2 = 52.8 - 58.2%, Al2O3 = 17.1 - 20.9%, CaO = 7.58 - 10.7%, MgO = 3.8 - 5.0% and TiO2 = 0.32 - 0.42%, indicating less fractionation of the magma compared to the samples from the San Matías-La Jagua magmatic suite (Figure 2-13). LA-ICP-MS U-Pb zircon age for the San Jorge Quartz Diorite was based on sixteen recovered zircon crystals (sample SMA_SJ_1709_JM_066, Appendix E.1a-b). The zircon crystals characteristics are summarized in Table 2-3. The external morphology of the recovered zircons exhibits prismatic shapes with sizes varying from 150 – 400 μm in length and 50 – 80 μm in width. CL images exhibit oscillatory zoning parallel to c-axis and un-zoned crystals (Figure 2-15A). Uranium concentrations vary from 383 to 1371 ppm (766.12 ppm in average) and correspond to the highest U contents among the analyzed zircons from the San Matías District intrusions. U/Th ratios are consistently magmatic and span from 1.0 to 4.0 (Table 2-3). 99 Figure 2-15 U-Pb LA-ICP-MS zircon geochronological results for the San Jorge and the Betesta quartz diorite intrusions of the San Matías District A. Concordia and weighted average age plots based on twenty-eight LA-ICP-MS analysis of the San Jorge Quartz Diorite (sample SMA_SJ_1709_JM_066). CL image of a representative prismatic zircon of this sample is also shown. The blue bars indicate the rejected analysis. B. Concordia and weighted average age plots based on twenty-four LA-ICP-MS analysis of the Betesta Quartz Diorite (sample SMA_BT_1801_JM_122). CL image of a representative pyramidal zircon of this sample is also shown. LA-ICP-MS U-Pb zircon analyses for cores and rims of individual zircons (twenty-eight spots in total) yielded 206Pb/238U ages between 69.9 and 82.1 Ma (Appendix E.1c). Two analyses were rejected during the data integration. The weighted average yielded an U-Pb age of 74.47 ± 0.74 Ma (Figure 2-15A). 100 2.6.2.2 Bucaramanga Quartz Diorite The Bucaramanga Quartz Diorite intrusion occurs to the eastern of the San Pedro River Lineament, 5 km southeast of the the El Alacrán Deposit. This intrusion has limited outcrop dimensions (about 200 m-length) along the Bucaramanga Creek. The contacts with the Betesta quartz diorite and basement host rocks are not well defined (Figure 2-3). Petrographically, the Bucaramanga Quartz Diorite corresponds to a holocrystalline, sub-hypidiomorphic rock composed of medium-grained (~1.5 mm) euhedral plagioclase (42%), medium-grained subhedral hornblende (23%), and fine-grained (<0.2 mm) anhedral quartz (10%) (Figure 2-12, Appendix B.1). Primary magnetite (2%) occurs as very fine-grained (~50 μm) exolutions along the hornblende cleavages. The lack of primary biotite in this intrusion suggests differences with respect to the magma associated with the neighbouring Betesta Quartz Diorite. Hydrothermal alteration intensity in this intrusion is moderate to strong fine-grained (up to 0.5 mm) actinolite, chlorite, and silica (10%). Minor mineralization (~1%) occurs as fine-grained (<0.25 mm) disseminated pyrite. Major oxide geochemistry in one sample of this unit shows: SiO2 = 50.6%, Al2O3 = 18.5%, CaO = 10.5%, MgO = 0.18% and TiO2 = 0.47%, which are consistent with a very low-fractionation state relative to the fractionation observed in rocks of the Betesta-Mina Escondida magmatic suite (Figure 2-13). 2.6.3 Betesta-Mina Escondida Magmatic Suite This suite includes the rocks from the Betesta Quartz Diorite, the Mina Escondida Tonalite, the El Alacrán Oeste Tonalite, and the sills 1b and 2 from the El Alacrán Deposit. The Betesta-Mina Escondida magmatic suite displays a weak negative Ti anomaly and the LREE values plot below the Chondrite values (Figure 2-8B). Sr/Y = 17.6 - 21.4 and Eu* ≈ 1 inadequately fulfill the 101 adakite-like criteria (Figure 2-9 A-B-C). The (La/Sm)N = 1.2 - 1.52 and (Dy/Yb)N > 1 values (Figure 2-9 D) suggest a poor differentiation between the LREE and HREE, respectively, which can be interpreted as plagioclase fractionation conditions from intermediate to low-hydrous magma (Richards et al., 2012). TiO2 = 0.4 - 0.5% is similar to those found at the San Jorge magmatic suite, however, Zr = 26.2 - 35.4 ppm are higher than the San Jorge magmatic suite values (Figure 2-9 F, Table 2-1). The Ti-in-Zircon average temperature for samples of the Betesta Quartz Diorite intrusion was calculated in 737.87 ± 55.02 °C (n=20) (Table 2-1, Figure 2-10). 2.6.3.1 Betesta Quartz Diorite The Betesta Quartz Diorite intrusion occurs to the east of the San Pedro River Lineament, 4.5 km southeast of the El Alacrán Deposit, at the eastern margin of the Betesta Creek. It displays a significant topographic high in the Betesta area and outcrops in 150 ha approximately. The southern contact with the volcano-sedimentary basement is faulted, whereas the northern contact is intrusive (Figure 2-3). The Betesta Quartz Diorite is a holocrystalline, sub-hypidiomorphic rock composed of medium-grained (up to 2 mm) euhedral plagioclase (42%), subhedral hornblende (31%), fine-grained (up to 0.2 mm) anhedral quartz (14%), and anhedral biotite (1%). Primary magnetite occurs as very fine-grained (~0.05 mm), subhedral, disseminated aggregates. Hydrothermal alteration intensity is weak and corresponds to silicification (6%), clinozoisite (4%), and chlorite (2%) after hornblende, also sericite and carbonate occur replacing plagioclase (Appendix B.1). Mineralization occurs as a very fine-grained (<0.1 mm) traces of disseminated chalcopyrite and pyrite associated with carbonate and sericite. Major oxide geochemistry of one sample shows: SiO2 = 54.8%, Al2O3 = 18.1%, CaO = 9.18%, MgO = 4.9%, and TiO2 = 0.39%, which is similar 102 to those in the San Jorge magmatic suite and consistent with a low degree of fractionation of the parental magma relative to the San Matías-La Jagua magmatic suite Figure 2-13). LA-ICP-MS U-Pb zircon age for the Betesta Quartz Diorite is based on seventeen zircons crystals (sample SMA_BT_1801_JM_122, Appendix E.1a). The zircon characteristics are summarized in Table 2-3. Pyramidal shapes dominate the external morphology of the recovered zircons (Figure 2-15B). Zircon sizes vary from 120 – 260 μm in length and 40 – 180 in width. CL images exhibit a dominant oscillatory zoning parallel to c-axis and sector zoning. Mineral inclusions of apatite were observed in some of the zircons (Appendix E.1b). Uranium concentrations exhibit a large variation (116.2 to 1314 ppm) without an evident relationship with zircon morphologies. U/Th ratios are magmatic and span a range between 0.8 and 2.1 (Table 2-3). LA-ICP-MS U-Pb analyses were conducted on twenty-seven spots; however, after QAQC inspection, three of the analyses were excluded. Individual 206Pb/238U ages vary between 68.4 and 84.2 Ma (Appendix E.1c). One additional analysis was rejected during data integration and the weighted average 206U/238Pb age is 72.9 ± 1.2 Ma (Figure 2-15B). 2.6.3.2 Mina Escondida Tonalite The Mina Escondida tonalite intrusion occurs to the east of the San Pedro River Lineament, 7 km southeast of the El Alacrán Deposit. This intrusion has dimensions up to 400 ha along the Sabaletas Creek, and intrusive contacts with the volcano-sedimentary basement. This intrusion is spatially related to the pyrite and pyrrhotite-bearing mesothermal (?) veins of the Mina Escondida prospect (Figure 2-3). The Mina Escondida Tonalite is holocrystalline, sub-hypidiomorphic, composed of fine- to medium-grained (0.5 - 2 mm) euhedral plagioclase (50%), anhedral hornblende (29%), and 103 subhedral quartz (14%). Primary magnetite occurs as fine-grained (>0.1 mm) disseminated aggregates intergrown with hornblende (Figure 2-12, Appendix B.1). Hydrothermal alteration intensity is moderate to strong and includes fine- to fine-grained (~0.1mm) anhedral silica (10%), very fine-grained (<0.1mm) chlorite, and medium-grained (~1.2mm) clinozoisite after hornblende. Mineralization occurs as very fine-grained (up to 0.06mm) traces of pyrite and chalcopyrite replacement after hornblende. Major oxide geochemistry of the Mina Escondida tonalite intrusion shows: SiO2 = 52.8%, Al2O3 = 17.7%, CaO = 10.5%, MgO = 9.56%, and TiO2 = 0.5%. These values are consistent with those obtained in rocks from San Jorge and the Betesta quartz diorite intrusions (Figure 2-13). 2.6.3.3 El Alacrán Oeste Tonalite The El Alacrán Oeste Tonalite intrudes the El Alacrán volcanoclastic succession in a broadly 1.5 km north-south contact. The intrusion contacts dip moderately to steeply west and are broadly concordant to locally discordant with respect to the stratigraphy. Petrographically, the tonalite is holocrystalline, sub-hypidiomorphic, composed of medium-grained (~2 mm) euhedral plagioclase (50%), clinopyroxene (7%), fine-grained (~0.5 mm) anhedral quartz (13%), and euhedral hornblende (16%). Magnetite (~2%) is widespread in this unit and occurs as fine-grained (<0.25 mm), euhedral aggregates intergrown with plagioclase (Figure 2-16D, Appendix B.1). The El Alacrán Oeste Tonalite intrusion presents weak to moderate intensity of hydrothermal alteration, including silicification (11%), chloritization (15%) after mafic minerals, and sericite-carbonate (~2%) after plagioclase. It is non-mineralized but displays very fine-grained (<0.04 mm) disseminated pyrite. Major oxide geochemistry 104 Figure 2-16 Macroscopic and microscopic aspects of selected San Matías District intrusions. A. Photo of drill core from the El Alacrán Oeste Tonalite (drill hole ACD042 @ 152.2–157.7 m). B. Detailed of photo A. C. Photomicrograph (4x, PPL) of the El Alacrán Norte Tonalite. D. Photomicrograph (4x, PPL) of the El Alacrán Oeste Tonalite. Note the selective alteration of chlorite after hornblende. E. Drill core photo of the Sill 1a unit. F. Drill core photo of the Sill 1b unit. G. Drill core photo of the Sill 2 unit with pervasive albite + chlorite alteration. H. Drill core photo of the stained off-cut of the Alto San Pedro Diorite sample. The positive reaction to etching by HF sodium cobaltinitrite (yellow) stain coincides with a clay - illite alteration. I. Photomicrograph (4x, PPL) of the Alto San Pedro Diorite. Note the two generations of clinopyroxene (ClPx 1 and ClPx2). 105 displays: SiO2 = 55.9%, Al2O3 = 17.3%, CaO = 7.88%, MgO = 4.38%, and TiO2 = 0.45%, indicating a low fractionating state of the parental magma, similar to the San Jorge Quartz Diorite, but, slightly higher with respect to the El Alacrán Norte Tonalite intrusion (Figure 2-13). 2.6.3.4 Mafic-poor diorite sills (Sill 2) Sill 2 comprises a discontinuous N-S oriented sill body, divided into two segments: The northern segment extends 380 m northwards, whereas the southern segment extends 300 m southwards until it merges with Sill1b. Both segments are separated from one another by approximately 300 m. Sill 2 is 10 - 33 m wide (e.g. drill hole ACD079) and intrudes concordantly and locally discordantly the lower stratigraphy of the El Alacrán Unit 2 (e.g. drill hole ACD036). Petrographically, Sill 2 corresponds to a fine-grained, holocrystalline, strongly altered, mafic-poor, porphyritic diorite rock (Figure 2-16G). The groundmass constitutes about 70% of the sample, and the relict phenocrysts correspond to fine-grained (up to 1mm) euhedral to subhedral plagioclase (~5%) (Figure 2-16G, Appendix B.1). Intense sodic-calcic alteration is a distinct feature of this unit, comprising fine-grained albite (45%), chlorite (30%), and quartz (5%) with traces of titanite and anhedral apatite. Mineralization occurs as fine-grained (<0.1 mm) traces of anhedral pyrite accompanying chlorite. This unit presents a geochemical affinity with the El Alacrán Oeste Tonalite and Sill 1b (e.g. SiO2 = 55.1%, TiO2 = 0.37%, and (Al/Zr)/103=9.9) (Figure 2-13). 2.6.4 El Alacrán Norte Magmatic Suite The El Alacrán Norte Magmatic Suite includes rocks from the El Alacrán Norte Tonalite and the Sill 1a from the El Alacrán Deposit. The trace element patterns of these rocks are similar to those observed in the San Jorge Suite (Figure 2-8B) where the Sr/Y = 23.2 - 49.4 and Eu* = 0.9 - 1.3, 106 inadequately fulfill the adakite-like composition criteria (Figure 2-9 A-B-C). The REE patterns show low (La/Sm)N = 0.5 - 1.0 and (La/Yb)N = 0.8 - 1.1 values (Figure 2-9 E), suggesting a lack of differentiation of the LREE relative to the HREE and the formation from a primitive and anhydrous magma. Zr (12.9 - 31.1 ppm) and Ti (0.2 - 0.3%) content is similar to those found at the San Matías-La Jagua suite (Figure 2-9 F, Table 2-1). Due to the lack of zircons in samples of this suite, the Ti-in-Zircon temperature was not obtained. 2.6.4.1 El Alacrán Norte Tonalite The El Alacrán Norte tonalite intrusion occurs in the northernmost part of the El Alacrán Deposit, where it intrudes and is possibly faulted against the volcano-clastic sequence (Figure 2-3). In the field, this unit has been mapped along 1 km northerly by 0.5 km to the east and constitutes the topographic high observed in the Northern El Alacrán Deposit (Mina Norte Hill). Field relationships suggest this unit is post-mineral with respect to the El Alacrán Deposit mineralization. Petrographically, the El Alacrán Norte Tonalite comprises medium-grained (up to 2 mm) holocrystalline rocks with inequigranular texture. The phenocrysts are dominated by plagioclase (~56%), hornblende + pyroxene (~31%) and fine-grained (~0.5 mm) anhedral quartz (~13%). Primary magnetite (~1%) occurs as fine-grained, euhedral to sub-rounded isolated crystals (Figure 2-16C, Appendix B.1). Although the El Alacrán Norte Tonalite is generally fresh, it is locally silicified (18%), and the mafic minerals are altered to fine- to very fine-grained (~0.12 mm) chlorite (4%). This intrusion is non-mineralized and barely exhibit pyrite traces (~0.5%) after the mafic mineralogy. Major oxide geochemistry from two samples shows: SiO2 = 54 - 54.7%, Al2O3 = 18.5 - 18.8%, CaO = 6.54 - 7.34%, MgO = 4.4 - 4.7%, and TiO2 = 0.33%, 107 which indicate a low-fractionating state of the parental magma, similar other San Matías District intrusions (e.g. San Jorge Quartz Diorite) (Figure 2-13). 2.6.4.2 Mafic-rich diorite sills (Sill 1) The Sill 1 concordantly intrudes the El Alacrán Unit 2 sequence along a >1 km N-S contact. This sill unit comprises two different bodies (i.e. Sill 1a and Sill 1b) separated 40m from each other and with thickness ranging between 5 and 10 m. These sills occur within the first 100 m-depth below the contact between Unit 1 and 2. Sill1a has been intercepted in the artisanal mining tunnels in the northern part of the El Alacrán Deposit, lying adjacent to mineralized ore shoots exploited by local miners. In addition, boulders of >1 m-length of this sill are found in the El Alacrán artisanal works. Petrographically, Sill 1a and Sill 1b are similar: fine- to medium-grained holocrystalline rocks with porphyritic texture, in a groundmass (58 - 60%) dominated by plagioclase and mafic minerals. The phenocrysts comprise medium-grained (<2 mm) plagioclase (33 - 59%), pyroxene (3 - 4%), and hornblende (25 - 28%). Primary magnetite occurs as fine-grained euhedral to sub-rounded free crystals (Figure 2-16E-F). Sill 1 exhibits variable weak to strong hydrothermal alteration. When strongly altered, this unit presents a calc-sodic assemblage (albite + chlorite + epidote + carbonate ± actinolite) that selectively replaces the mafic mineralogy. Major oxide geochemistry of Sill 1a and Sill 1b is also similar: SiO2 = 53.2 - 55.1%, Al2O3 = 15.4 - 17.4%, CaO = 5.1 - 6.2%, MgO = 5.6 - 6.0%, and TiO2 = 0.2-0.4% (Figure 2-13). However, Sill1a displays (Al/Zr)/103 = 20.6 - 24.1 and Sill1b displays (Al/Zr)/103 = 8.9 suggesting differences in their parental magmatic source. 108 2.6.5 San Pedro - Costa Rica Magmatic Suite The San Pedro – Costa Rica magmatic suite includes the Alto San Pedro Diorite and Costa Rica Tonalite intrusions. Weak to absent negative Nb-Ta and Ti anomaly differentiate this suite from other San Matías District magmatic suites (Figure 2-8D). Sr/Y = 10.8 - 11.4, do not fulfill the adakite-like composition criteria and are the lowest values for the San Matías District intrusions (Figure 2-9 A-B-C). (Dy/Yb)N = 1.1 and (La/Yb)N = 3.1 - 3.7, are the largest values obtained among San Matías District samples (Figure 2-9 D, E) (Table 2-1). Rocks from this suite do not exhibit REE patterns consistent with hornblende fractionation, suggesting that they may have been formed from a fractionated anhydrous magma (Richards et al., 2012). Rocks from this magmatic suite are also distinguished by their high Ti (TiO2 = 0.9 - 1.0%) and Zr (78.2 - 85.4 ppm) contents (Figure 2-9 F, Table 2-1). Due to the lack of zircons in samples of this suite, the Ti-in-Zircon temperature was not obtained. 2.6.5.1 Alto San Pedro Diorite The Alto San Pedro Diorite intrusion occurs to the east of the San Pedro River Lineament, 4.2 km southeast of El Alacrán Deposit and between the Betesta and Mina Ra mine hills (Figure 2-3). This intrusion crops out approximately 70 ha along the San Pedro River riverbed and exhibits intrusive contacts with the volcanic host rock. Petrographically, the Alto San Pedro Diorite comprises holocrystalline, hypidiomorphic rocks, composed of medium-grained (<4 mm) euhedral plagioclase (57%) and two stages of clinopyroxene (~27%, ClPx1 and ClPx2) (Figure 2-16H-I). ClPx1: Corresponds to coarse-grained (<5 mm) phase altered to chlorite-zoisite. ClPx2: Consists of coarse- to medium-grained phase that overgrowth around ClPx1. Primary quartz (1%) occurs as fine-grained (~0.5 mm), anhedral crystals intergrown with plagioclase. Primary magnetite (~5%) occurs as fine-grained 109 (~0.4 mm) subhedral disseminations and as inclusions in plagioclase (Figure 2-12, Appendix B.1). Clay alteration (9%) (weathering) and very fine-grained (<0.05 mm) illite and carbonate affected the plagioclase grains. Mineralization occurs as patchy traces of very fine-grained (<57 μm) chalcopyrite, bornite + chalcocite. Major oxide geochemistry for one sample of this intrusion shows: SiO2 = 53.2%, Al2O3 = 14.3%, CaO = 8.81%, MgO = 6.34% and TiO2= 1.8%, consistent with a low fractionated parental magma suggesting a possible genetic relationship with rocks from the Costa Rica Tonalite intrusion (Figure 2-13). 2.6.5.2 Costa Rica Tonalite The Costa Rica Tonalite intrusion occurs to the east of the San Pedro River Lineament, 2.5 km southeast of the El Alacrán Deposit (Figure 2-3). This unit has a limited outcrop dimension (25 ha approx.) and displays intrusive contacts with the gabbroic to basaltic host rocks. This intrusion hosts some of the quartz-chalcopyrite sheeted veining at the Costa Rica prospect. The Costa Rica Tonalite intrusion corresponds to a holocrystalline rock with poikilitic texture. The mineralogy is dominated by plagioclase (52%) in two different (bimodal) sizes: 1) medium- to coarse-grained (<5 mm) and 2) very fine to fine-grained (<0.1 mm). Both size populations of plagioclase are embedded in a matrix composed of medium- to coarse-grained quartz (24%) hornblende (26%), and biotite (2%) (Figure 2-12, Appendix B.1). Primary magnetite occurs as very fine-grained (~0.05 μm) anhedral inclusions in hornblende. The Costa Rica Tonalite displays weak hydrothermal alteration, as evidenced by the occurrence of very fine-grained (<0.01 mm) saussurite (11%, clay + illite + epidote + chlorite) after plagioclase. Mineralization occurs as a medium- to fine-grained (<1.5 mm) anhedral aggregates of pyrite and chalcopyrite (3%). Major oxide geochemistry in one samples of this unit shows: SiO2 = 58.7%, Al2O3 = 17.2%, CaO = 6.3%, MgO = 3.15%, and TiO2 = 0.96%. The high TiO2 110 contents in these rocks evidence a remarkable difference with respect to the rest of the studied intrusions of the San Matías District (Figure 2-13). 2.6.6 Relationship of the volcanic rocks and intrusions of the San Matías District. Although, it was not possible to date the volcanic and volcanoclastic rocks of the San Matías District basement, the trace element and Rare Earth Elements (REE) patterns of basement rocks display an affinity with the San Matías District intrusions, suggestting a co-genetic relationship between the intrusions and the basement they intruded. The San Matías District basement rocks can be grouped based on their trace element geochemistry: The first group includes lithofacies from the El Alacrán Deposit (i.e. TufA, TufD, TufL, and TufF) and Montiel E volcanic basement (sample JM059, Figure 2-9D,F). The first group displays TiO2 > 0.8%, Y > 15ppm, and Zr > 80ppm, which are consistent with the values obtained in rocks from the San Pedro-Costa Rica magmatic suite. Conversely, a second group includes rocks from the El Alacrán Deposit Unit 1 sequence (e.g. TufR) and La Capitana volcanics (Figure 2-9D,F), which contains TiO2 < 0.5% and Y < 8ppm, and Zr < 80ppm, consistent with the bulk of the San Matías District magmatic suites (Figure 2-9). The MORB-normalized REE patterns of the El Alacrán Deposit volcanic rocks show a marked differentiation between the LREE and HREE with (La/Sm)N = 1.3 - 2.4 and (La/Yb)N = 3.5 - 6.4, respectively (Figure 2-17B, Table 2-1). The Eu* = 1.39, and low (Dy/Yb)N = 0.8 in samples from TufR lithofacies (Unit 1) indicates a higher degree of differentiation of the HREE with respect to the other San Matías District volcanic rocks. Conversely, the high (Dy/Yb)N values (1.4) in the TufA lithofacies from Unit 3 displays the lowest fractionation degree of the San Matías District volcanics rocks, which is expected for its mafic composition. The trace elements 111 pattern, quartz and hornblende occurrence in TufR (Unit 1) are more likely to be related with rocks from the San Matías-La Jagua magmatic suite. Similarly, the positive Eu anomalies in samples from Unit 1 and La Capitana prospects are more consistent with the intrusions from San Matías-La Jagua and San Jorge magmatic suites, respectively (Table 2-1). Figure 2-17 Trace Elements and REE pattern of the San Matías District volcanic rocks A. Chondrite Normalized Trace Elements pattern (Thompson, 1982). B. Normalized REE NMORB pattern (Sun & McDonough 1989). The background in grey indicates the pattern obtained for the San Matías District intrusive rocks. 112 2.6.7 Volcanic rocks of the SMD Compared to Other Volcanic Units of Western Colombia As described in section 2.2.2.3, the volcanic unit probably correlated with the El Alacrán Deposit volcanics corresponds to the Barroso Formation. However, some documented volcanic units in the western cordillera (e.g. Buriticá Dacite; Weber et al., 2015) and in the Lower Magdalena Valley (e.g. the Planeta Rica vulcanite and the Remolinos-1 andesite, Silva et al., 2016) could also have a genetic relation to the San Matías District volcanism based on their geographic proximity (Figure 1-4). The next paragraphs compare the whole rock geochemistry of the El Alacrán Deposit volcanics with geochemistry from these units using Chondrite-normalized trace element patterns to (Thompson, 1982) and NMORB-normalized REE patterns to (Sun and McDonough 1989) from the published data (e.g. Villagomez et al., 2011; Rodriguez and Arango, 2013; Weber et al., 2015; and Silva et al., 2016). 2.6.7.1 The Barroso Formation Rocks from the Barroso Formation have Rb, K, Sr values similar to those observed in El Alacrán Deposit volcanic rocks (Figure 2-18A). However, the REE pattern in the Barroso Formation rocks display a lower (La/Sm)N and (La/Yb)N values than those found in the El Alacrán Deposit (Figure 2-18A). Similarly, the Barroso Formation samples display a Middle Oceanic Ridge (MOR) to Arc tectonic environment dominated by island arc tholeiites (Figure 2-19A-B), which is consistent with the mixed signature between the Plateau (e.g. San Jose de Urama Diabases) and Arc rocks (s.s. Barroso Fm; Rodriguez and Arango, 2013). In contrast, the El Alacrán Deposit rocks only exhibit an arc-dominated affinity consistent with higher Y and Th content (Figure 2-19C). 113 Figure 2-18 Trace elements and REE patterns of the El Alacrán Deposit volcanics in comparison with other regional volcanic units. A. Trace element pattern of El Alacrán Deposit basement rocks in comparison to the whole rock geochemistry from the Arc group of the Barroso Formation (Rodriguez and Arango, 2013); whole rock geochemistry of the Plateau Group of the Barroso Formation (Villagómez et al., 2011). B. Trace element pattern of El Alacrán Deposit basement rocks in comparison to the whole rock geochemistry from the Buriticá Dacite (Weber et al., 2015); the Remolinos-1 Andesite and the Planeta Rica Vulcanite (Silva et al., 2016). 114 2.6.7.2 Buriticá Dacite Felsites are present as discontinuous intrusions within the Barroso Formation and have been described in Buriticá (Buriticá Dacite, Weber et al., 2015), the southern Western Cordillera (Millward, 1983; Aspden and McCourt, 1986; and Kerr et al., 1996) (Figure 1-4) and now in the El Alacrán Deposit (Unit 1, this work). The Buriticá Dacite (ca. 100 Ma; Weber et al., 2015) has high Sr, less Rb-K content, lack of the negative Nb-Ta anomaly, and displays a negative Ti anomaly not observed in rocks from El Alacrán Deposit felsites (Figure 2-18B). Conversely, the Buriticá Dacite displays a higher LREE enrichment, lacks the middle REE differentiation (Dy-Ho segment) and lacks the positive Eu* that is characteristic of Unit 1 rocks (Figure 2-18B). The higher Nb and Ta values in the Buriticá Dacite are consistent with transitional zones between destructive and inter-plate environments from Volcanic Arc to MORB rocks (Figure 2-19A-B). In contrast, El Alacrán Unit 1 rocks plot consistently in a calc-alkaline to tholeiitic Arc-affinity environment (Figure 2-19A-B). 2.6.7.3 Remolinos-1 Andesite The Remolinos-1 Andesite in the Lower Magdalena Valley displays higher Rb - Th values and a negative Hf anomaly not observed in the El Alacrán Deposit volcanic rocks (Figure 2-18B). However, its REE pattern displays similarities with the El Alacrán Deposit rocks (e.g. (La/Yb)N > 3.5, (La/Sm)N > 1.3), Table 2-1, Figure 2-18B) and plots in a tectonic environment consistent with calc-alkaline arcs similar to the El Alacrán Deposit rocks (Figure 2-19A). However, the extreme Th content of this unit (Figure 2-18B, Figure 2-19B) suggests a connection with a mature arc volcanic setting. 115 2.6.7.4 Planeta Rica Vulcanite The Planeta Rica Vulcanite has Rb, Sr and Ti values and a REE pattern similar to the Montiel E basement rocks (e.g. (La/Sm)N > 1.5, (La/Yb)N > 3.5, (Dy/Yb)N ~ 1,Table 2-1 , Figure 2-18B). Also, it displays a calc-alkaline affinity similar to the El Alacrán Deposit rocks (Figure 2-19C). However, this unit lacks the negative Ta anomaly observed in the El Alacrán Deposit rocks (Figure 2-18B). The high Ta content in the Planeta Rica Vulcanite is more consistent with volcanism developed between the transition of E-MORB and intra-plate alkali basalts (WPB) (Figure 2-19B) instead of Arc-tectonic setting as it is indicated for the El Alacrán Deposit rocks. 2.6.8 Magmatism of the SMD in Comparison to Other Intrusive Units 2.6.8.1 The Santa Fé Batholith Trace element values from the Santa Fé Batholith (tonalite I, Weber et al., 2015) (ca 89 Ma, Zapata-Villada et al., 2013) show positive Ba, Rb, K, Sr anomalies and negative Th, Nb, Ta, and Ti anomalies similar to those in the San Matías District intrusive rocks (Figure 2-20A). Conversely, the magnitude of LREE elements (e.g. La, Ce, Sm) and the degree of differentiation between the LREE-HREE in the Santa Fé Batholith, are markedly different to the bulk of San Matías District intrusives but close to the San Pedro-Costa Rica magmatic suite values (Figure 2-20A, Figure 2-8D). Although the Santa Fé Batholith (Tonalite I) has higher Th/Yb than then San Matías District intrusives, the tectonic setting is consistent with an oceanic-arc similar to the San Matías District intrusives (Figure 2-21). 116 Figure 2-19 Tectonic Environment for El Alacrán Deposit Rocks. The diagrams include the whole rock geochemistry from the Plateau and Barroso Fm., Arc groups (Villagómez et al., 2011; Rodriguez and Arango, 2013, respectively). The diagrams also include whole rock geochemistry data from the Buriticá Dacite (Weber et al., 2015); the Remolinos-1 Andesite and the Planeta Rica Vulcanite (Silva et al., 2016). A. Tectonic classification of mafic igneous rocks (Cabanis, and Lecolle, 1989). B. Basalt Th-Hf-Ta (Wood, 1980). C. Th-Co Discrimination Diagram (Hastie et al., 2007). 117 Figure 2-20 Trace elements and REE patterns of the San Matías District intrusions. Trace element pattern uses the normalized to Chondrite (Thompson, 1982) and the REE pattern uses the normalization to NMORB (Sun and McDonough 1989). A. The background in red corresponds to the bulk of the San Matías District intrusions, which is contrasted with whole rock geochemistry data from the Santa Fe Batholith (Tonalite I; Weber et al., 2015) and the Cicuco-22 Pluton (Silva et al., 2016). B. The background in red corresponds to the bulk of the San Matías District intrusions, which is contrasted with whole rock geochemistry data from the Buga Batholith (Villagómez et al., 2011) and the Buriticá Tonalite (Weber; et al., 2015). 118 2.6.8.2 The Buriticá Tonalite The trace element pattern from the Buriticá Tonalite (ca. 100.9 Ma; Weber et al., 2015) displays a negative Nb-Ta anomaly and Rb, K, Sr and Ti values similar to the San Matías District intrusive rocks. However, a significant difference is observed in the Sm-Hf segment, where the Buriticá Tonalite contains at least three times more of these elements (Figure 2-20B). Conversely, the normalized REE pattern shows a fractionation between the LREE similar to the bulk of San Matías Intrusions, but lacks the Eu anomaly and the HREE values found in San Matías District (e.g. (Dy/Yb)N = 0.96) indicating a low fractionation relative to the San Matías District magmatism. However, the Th/Yb and Nb/Yb values of the Buriticá Tonalite are similar to those in the San Matías District, which are consistent with oceanic-arc rocks (Figure 2-21). 2.6.8.3 The Buga Batholith In the Buga Batholith area, Nivia et al. (2017) obtained ages of ca. 88 - 69 Ma. Trace elements of the Buga Batholith display a negative Nb-Ta anomaly, a positive Sr anomaly and Rb, K and Ti content similar to those in the San Matías District intrusions (Figure 2-20B). The normalized REE pattern of rocks from the Buga Batholith displays a listric pattern and positive Lu anomaly consistent with hornblende, titanite or magnetite fractionation (e.g. Richards et al., 2012), which is also observed in San Matías District rocks. Similarly, (La/Sm)N ≈ 1.4, (Dy/Yb)N ≈ 0.94, and Sr/Y ≈ 21.2 in the Buga Batholith are consistent with the values displayed by San Matías District rocks (Table 2-1). Rocks of the Buga Batholith display a positive correlation between the Th/Yb and Nb/Yb values that is also observed in the San Matías District rocks and which are consistent with an oceanic-arc setting (Figure 2-21). 119 Figure 2-21 Nb/Yb vs Th/Yb plot (Pearce, 2008) for the San Matías District intrusions. The San Matías District intrusions are compared with whole rock geochemistry data from the Santa Fe Batholith (Tonalite I) and Buriticá Tonalite (Weber et al., 2015). The diagram also includes data from the Aruba and Buga Batholiths (White et al., 1999; Villagómez et al., 2011) and the Pujilí Granite and the Cicuco-22 pluton (Vallejo et al., 2006; Silva et al., 2016). Also shown the fields from oceanic and continental arcs, and ophiolite felsics after Condie and Kroner (2013). Note the marked low Th content in rocks from the San Jorge and El Alacrán Norte magmatic suite rocks. 2.6.8.4 The Cicuco-22 Pluton The Cicuco-22 granodiorite (Ca. 84 Ma, Silva et al., 2016) displays a higher concentration of radiogenic lithophile elements (e.g. Ba, Rb, Th, Nb, La, Ce) than those found in the San Matías District intrusions. In addition, this pluton lacks the negative Ta anomaly that characterizes the San Matías District bulk intrusions. The REE normalized values of the Cicuco-22 Pluton show a 120 significant LREE enrichment (e.g. (La/Sm)N = 4.7, (La/Yb)N = 24.2 (Dy/Yb)N = 2.4) (Figure 2-20A), which is not consistent with the values obtained in San Matías District rocks (Table 2-1). The large (Dy/Yb)N values, Eu*= 0.38 and the low Sr values (Sr/Y = 0.9) of the Cicuco-22 pluton may indicate some petrological processes that included plagioclase fractionation from a low-volatile magma (Richards et al., 2012). The Cicuco-22 pluton has extreme Th/Yb and Nb/Yb values, more consistent with deep crustal recycling in continental arcs (Pearce, 2008), and differs with the San Matías District intrusion setting (Figure 2-21). 2.7 The Structural Geology of the San Matias Distric 2.7.1 District Scale Structures The San Matías District displays a structural complexity related to the deformational history of the Calima Terrane, and related arcs approached the continental margin (section 1.11). The structures in the district seem to be consistent with the regional tectonic evolution for northwestern South America proposed by Kennan and Pindell (2009) (section 1.7). Along the San Matías District, three dominant sets of faults (NS-NNE, NW, and NEE-EW) are delineated (Figure 2-3). Field evidence such as kinematics indicators, crosscutting relationships, and association with mineralizations are used to establish a paragenetic framework for this set of faults (Figure 2-22). 2.7.1.1 NS-NNE Faults Set The NS-NNE set of faults corresponds to regional scale, orogen-parallel structures associated with the San Jacinto Fault (s.s. Cediel et al, 2003) Figure 2-1. The N-S strike of these faults tends to bend eastward along their northern termination and display > 60° to sub-vertical dip magnitudes. Along the San Matías District, the most significant faults are parallel to the San 121 Pedro River Lineament, which separates the main holocrystalline and porphyry intrusions occurrences in the east from the volcanoclastic sequence domain in the west (Figure 2-3). This set also includes the Valdés Fault, which separates the volcanoclastic rocks of the El Alacrán Deposit from mafic volcanics to the west (Figure 2-4). The NS-NEE faults are interpreted to be the earliest structures in the San Matías District district, parallel to the terranes accretionary fronts and may indicate either a thrusting/transpressional dynamics in the terrane/arcs boundaries to transtensional within intra-arc environments (e.g. back-arc basins) (Figure 2-22A-B). A dextral transpressive dynamics is widely accepted in the geological literature for these N-NNE structures (e.g. Kennan and Pindell, 2009, Figure 2-22A-B). 2.7.1.2 NW Faults Set The NW faults are second-order, district-scale structures limiting and locally offsetting the NS-NNE faults. The NW faults developed a minor antithetic NE fault set and near vertical dips. The spatial distribution of the NW faults suggests a key role in locating mineral deposits at the San Matías District. Particularly, the occurrence of the Montiel E and Costa Azul Cu-Au porphyries seems to be controlled or limited by this set of faults (Figure 2-3). The major NW fault in the San Matías District corresponds to the Las Claritas Fault (Figure 2-3, Figure 2-22). Las Claritas Fault displays a sinistral, strike-slip movement (transpressive) during mineralization (e.g. fault-fill veining mineralization and wall rock alteration; Manco and Davila, 2012; Starling, 2014). Additionally, this fault displays evidence of a dextral transtensive reactivation without associated mineralization (Cordoba Minerals Corp., pers. comm., 2016). The shift from sinistral-transpressive to dextral-transtensive in the Las Claritas Fault dynamics indicates a change in the stress field orientation from E-W to NW-SE in the district (Figure 2-22B-C). 122 Figure 2-22 Interpreted structural evolution for the SMD areas. A. The diagram includes a pre-mineral stage associated with the formation of the major structures. The scheme in diagram A is interpreted based on the regional NE relative motion of the Caribbean Plate with the South American Plate documented for the Early Cretaceous (ca. 125 - 120 Ma Kennan and Pindell, 2009). The NS-NNE structures are arc-parallel; therefore, either compressional or extensional dynamics are expected in the front- and intra-arc location, respectively. B. The diagram indicates a structural framework for the SMD areas that resolve the syn-mineral (~ 70 Ma, Leal-Mejía and Hart, 2017) fault kinetics and spatial orientation of the veins associated with the SMD prospects Montiel E = quartz stockwork, Mina Ra = mesothermal sulfide + quartz vein, and Mina Pirita = quartz fault-fill vein. During this stage, the major structures might have undergone a clockwise rotation for the structures formed in A. Symbols in red indicate the change in the fault dynamics en relation to the previous stage. C. The diagram shows the structural framework that resolves the post-mineral kinetics observed in the SMD areas (e.g. Manco and Davila, 2012; Starling, 2012), as well as the neo-tectonic in northwestern Colombia, which is highly influenced by the SE relative movement of the Caribbean Plate (Taboada et al., 2000). Symbols in red indicate the change in the fault dynamics en relation to the previous stage D. 123 Stereonet-Equal Angle (Wulff net) using 390 Dip/Dip directions measurements from El Alacrán Deposit. The diagram indicates the two major structural trends observed in the Deposit. E. Plan and section view of the 3D modelled structures of the El Alacrán Deposit. The diagram shows the distribution of the ABx Breccia in relation to the measured faults. The Montiel Fault is included in the NW Faults Set (Figure 2-3) and displays syn-mineral activity evidenced on controlling and limiting the extension of the porphyry stockwork occurrence at Montiel W and Montiel E (~ 70 Ma, Leal-Mejía and Hart, 2017). This set of faults also served as the principal fluid channel for some local NW oriented Au-bearing veins (e.g. the Mina Pirita artisanal mine, Figure 2-3). The principal veins orientation observed in the San Matías District porphyries Cu-Au and mesothermal veins (e.g. Mina Ra, Montiel E porphyry, respectively; Figure 2-22B), also support an E-W stress field orientation during the mineralizations events. 2.7.1.3 NEE-EW Faults The NEE-EW faults are second-order, regional- to district-scale structures that locally offset the NS-NNE and the NW faults. The NEE-EW faults display a near vertical to listric (dip <10°) and dip southwards (e.g. El Alacrán Fault; Cordoba Minerals Corp., pers. comm., 2018b). In the El Alacrán Deposit area, the El Alacrán Fault trace separates the Mina Norte hill from the Mina Seca hill to the south (Figure 2-4). The NEE-EW set displays variable offset magnitude from 10 m in the El Alacrán Deposit to 50 m in the San Matías area (Figure 2-3). Additionally, these faults display a consistent dextral offset with syn- to post-mineral deformation, and are interpreted to be the youngest reactivated faults in the San Matías District. According to the dominant stress-field during post-mineralization indicated by the NW faults (section 2.8.1.2), the NEE-EW faults might have evolved from a dextral-transtensive regime during a syn-mineral 124 stage (~ 70 Ma, Figure 2-22B) to a dextral-transpressive regime during post mineralization (Figure 2-22C). 2.7.2 Structures of the El Alacrán Deposit The El Alacrán Deposit displays two dominant faulting sets: 1) NNW/50°W faults, parallel to the host rock bedding, including a subordinated antithetic N-W/30°-10°NE system (Figure 2-22D), and probably linked with the NS-NNE faults of the Valdés Fault; and 2) N60E-EW/50-60°SE faults (Figure 2-22B) possibly associated with the El Alacrán Fault (Figure 2-4). Although the El Alacrán Fault fault did not produce a significant offset of the El Alacrán Deposit sequence, small (<10 m), dextral offsets have been mapped along some artisanal tunnels in the El Alacrán village (Mosher, 2011). In drill core, both, the NNW and the NE-EW set of structures show evidence of post-mineral deformation, as indicated by extensive (<30 m-thick) attrition breccias formation that includes intensely fractured and gridding rocks lacking syn-tectonic alteration or mineralization. At the deposit scale, the ABx breccia is preferentially located in the interception of the El Alacrán Fault with the N-NW faults (Figure 2-22E). 2.8 Conclusions • According to the texture and modal composition, the intrusives rocks in the San Matías District can be classified as: tonalites (e.g. Costa Azul, La Jagua), tonalite porphyries (e.g. Montiel E and Costa Azul), hornblende ± biotite quartz diorites to tonalites (e.g. San Jorge, Betesta), and pyroxene + hornblende diorite to tonalites (e.g. Alto San Pedro, El Alacrán Oeste Tonalite). • Based on the REE and trace element normalized geochemical patterns, the San Matías District intrusions can be grouped into five magmatic suites: 1) San Matías-La Jagua, 2) 125 San Jorge, 3) El Alacrán Norte, 4) Betesta-Mina Escondida, and 5) the San Pedro-Costa Rica magmatic suites. Moreover, whole rock geochemistry also suggests that the San Pedro-Costa Rica magmatic suite may have been formed from a primitive magma, whereas the San Matías-La Jagua magmatic suite may have been sourced from a more hydrous, oxidized and fractionated magma with high potential to form porphyry Cu-Au-related deposits. • At the El Alacrán Deposit, petrographic and chemical differences are observed between the north and the west tonalite intrusions: The El Alacrán Norte Tonalite has higher pyroxene > hornblende contents (~31%), less SiO2% and more MgO% than El Alacrán Oeste Tonalite, where hornblende > pyroxene (~7%), SiO2% = 55.9, and MgO% <4.4, respectively. Additionally, REE trace elements of the El Alacrán Oeste Tonalite are consistent with Betesta-Mina Escondida magmatic suite rocks, whereas, the El Alacrán Norte Tonalite displays a more primitive composition not observed in other San Matías District intrusions. • The El Alacrán Deposit sills display normalized trace elements and REE patterns comparable with the El Alacrán Norte or El Alacrán Oeste Tonalites, suggesting that the Sill 1a may have been associated to the El Alacrán Norte Tonalite, whereas the Sill 1b and Sill 2 are probably linked to the El Alacrán Oeste Tonalite. • The El Alacrán Deposit volcanoclastic host rocks display a calc-alkaline to tholeiitic arc-related chemistry with normalized REE and trace element patterns similar to those in the 126 San Matías District intrusions. This suggests of a co-magmatic relation between the San Matías District intrusions and their volcanoclastic basement rocks. Moreover, the El Alacrán Deposit basement rocks display chemistry consistent with the arc-related signatures observed for the Barroso Formation, which is preliminary used as evidence that confirms that the San Matías District basement is part of the Barroso Formation. • The San Matías District intrusions display similarities in their whole rock geochemistry with the Western Group Granitoids of the Western Cordillera of Colombia (Leal-Mejía, 2011). A remarkable feature of the San Matías District magmatism is its low Zr concentration (Average 40.1 ppm). • The Cretaceous intrusions displaying similar chemistry the San Matías District intrusions are the Buriticá Tonalite and the Buga Batholith located approximately 80 and 350 km south of the San Matias District, respectively. However, Late Cretaceous ages close to 70 Ma., have just been reported in some porphyritic dikes that cross-cut the Buga Batholith (Nivia et al., 2017). The similarities in chemistry and possibly in age between SMD intrusions and the Buga Batholith intrusions suggest the existence of a Late Cretaceous metalliferous belt in the Western Cordillera that can be traced from San Matías District to the Buga region and can preliminary support the country-scale terrane definition proposed by Restrepo and Toussaint (1988) and by Kennan and Pindell (2009), and argues the tectonic models proposed by Etayo-Serna et al. (1983), Cediel et al. (2003), and Cediel (2019) for western Colombia. 127 Chapter 3: The Hydrothermal Fluid Evolution of the El Alacrán Deposit, San Matías District, Colombia. 3.1 Introduction In the El Alacrán Deposit, at least 13 different volcanic clastic lithofacies and diorite sill intrusions exert an important lithological control on the alteration mineralogy. The deposit has asymmetrical mineral zoning patterns across three regions: a magnetite-chlorite-pyrite assemblage dominates the southern region, whereas carbonate-sericite-sphalerite and carbonate base metals veins are the dominant assemblage in the central and northern regions of the deposit (Figure 3‑1). Cu and Au grades correlate in the central and northern regions, whereas this relationship is not present in the southern region. The lack of unambiguous cross-cutting relationships between the different alteration phases presents challenges for the interpretation of the mineralizing fluid path, timing, and nature of the ore-forming fluid. This chapter documents various alteration mineral assemblages within the El Alacrán Deposit which are illustrated by comparing three cross-sections (855570 m N, 855450 m N, 855050 m N) (Figure 3-1). The alteration mineralogy is used to infer the fO2, pH and sulfidation state and also to propose cooling pathways of the mineralizing fluid at the deposit-scale. The chemical composition of gold, along with the alteration mineral associations, are used to infer the dominant chemical conditions that prevailed during gold precipitation. Furthermore, Pb and S isotope compositions of ore-stage sulfides are used to determine possible sources of the metals. The sulfide isotope composition from El Alacrán Deposit is also compared with the sulfide isotope composition of the porphyry Cu-Au prospects of the San Matías District (i.e. Montiel E and Costa Azul) to assess their genetic relationship. 128 Ar-Ar and Re-Os ages from ore-stage actinolite, sericite and molybdenite from the El Alacrán Deposit provide age constraints for the mineralization and are compared to new mineralization and magmatic ages from the Cu-Au porphyry prospects and holocrystalline intrusions of the San Matías District. The chemical and isotopic composition of the ore fluids, coupled with mineralization ages, help to contextualize the ore formation within the district-scale metallogenic framework. These results of this chapter contribute to a more robust mineral deposit model classification for the El Alacrán Deposit, which has significant implications for improving the future exploration strategies within the San Matías District. 3.2 Previous works Alteration and mineralization in the El Alacrán Deposit were previously described by Dunne (2016a) from a petrographic study of 20 samples from the El Alacrán Deposit for HPX Inc. The studied samples were collected by Gerry Ray, a geological consultant on behalf of HPX Inc., to provide an interpretation of the environment of deposition of the rocks associated with the mineralization in the Deposit. Moreover, these samples were intended to identify skarn-related minerals (e.g., pyroxene or garnet) to confirm or discard the hypothesized skarn model for the mineralization at the El Alacrán Deposit. Some offcuts of these petrography samples were also analyzed with X-Ray Diffraction (XRD) at the University of British Columbia (UBC) and some with Portable Infrared Mineral Analyser (PIMA) by Kim Heberlein at KH Spectral Analysis, Vancouver, Canada (Dunne, 2016a). The geological information available has increased markedly since extensive drilling campaigns accomplished by Cordoba Minerals Corp., between November 2016 and June 2018. 129 Figure 3-1 El Alacrán Deposit Alteration Map. Surface geology map displaying the location of the studied cross-sections. (a) 85570m N, (b) 855540m N, and (c) 855050m N. The distribution of the alteration assemblages was constructed using drill hole data and surface mapping. The El Alacrán Deposit major intrusions are displayed for reference. Cordoba Minerals Corp., provided the > 0.3% equivalent Cu (eCu) resource shell of the deposit. eCu = Cu % + 0.504*Au g/t for Cu > 0.4%; eCu=Cu% + 0.605*Au g/t for Cu < 0.4% (Kulla and Oshust, 2018). Based on the petrographic characterization and mineral assemblages, Dunne (2016a) proposed that hydrothermal alteration at the El Alacrán Deposit comprise four assemblages: 1) carbonate-propylitic (carbonate - chlorite ± sericite ± titanite ± epidote), 2) Chloritic (quartz-chlorite-sericite-carbonate-apatite), 3) Argillic (brown grungy clay after chlorite), and 4) Albitic (albite) and minor alterations dominated by apatite-actinolite and zeolites. Dunne (2016b) concluded that 130 El Alacrán Deposit alteration mineralogy exhibits characteristics of Volcanogenic Massive Sulfide (VMS) deposits. Mineralization at El Alacrán Deposit was previously dated at 75.8 ± 0.4 Ma (Re-Os) from disseminated molybdenite that occurred associated with carbonate + sphalerite, and sulphide stringers hosted within Unit 2 (sample GAL002, Leal-Mejía and Hart, 2017, Table 3-1). This age is older than the U-Pb LA-ICP-MS zircon age obtained by the same authors for the late intrusive porphyry phase ( PxHL ), which cross-cuts the mineralizing phase of the Montiel E porphyry suite (70.6 ± 1.4 Ma; Leal-Mejía and Hart, 2017, Table 3-1). In the San Matías District, three additional age dates of alteration and mineralization yielded Late Cretaceous ages (ca. 78 – 59 Ma): 1) 77.20 ± 0.9 Ma (Ar-Ar/hornblende) from the Montiel W prospect (Sernageomin, 2012). This amphibole occurred as interstices infill accompanied by sulfides and quartz hosted in a banded dioritic rock altered to actinolite, scapolite and montmorillonite (Sernageomin, 2012). 2) 75.95 ± 0.31 Ma (Re-Os/Molybdenite) age from the San Jorge area and 59.70 ± 1.80 Ma (Ar-Ar/Molybdenite) (Anglo American, pers. comm., 2014) with further sample details not provided to the author, 3) 71.9 ± 1.80 Ma (Ar-Ar/actinolite) from the mineralizing phase (PxHe) of the Montiel E Porphyry. The actinolite occurred as a coarse-grained vein (>1 cm) accompanied by quartz, chalcopyrite and magnetite (Sernageomin, 2018) (Table 3-1). 131 Table 3-1 Historic Geochronology Data of the San Matías District 3.3 Hydrothermal Alteration of the El Alacrán Deposit. Mineral assemblages commonly are defined as groupings of minerals that occur in direct contact and that do not display evidence of reaction with another (Barton et al., 1963). The "mineral association" term is applied to groups of minerals that are characteristic of a given zone of alteration or proportion of a vein system, but which are not all in contact and may have been deposited over multiple events (Einaudi et al., 2003). Volcanoclastic rocks of the El Alacrán Deposit are altered to different degrees to magnetite-chlorite-sericite-carbonate and quartz. Sulfide mineralogy includes pyrite, chalcopyrite and lesser sphalerite and pyrrhotite. At the drill core-scale, three major precipitation stages are recognized in the El Alacrán Deposit: 1) Magnetite Stage, 2) Sulfide Stage, and 3) Carbonate Base Metals (CBM) Stage (Cordoba Minerals Corp., 2018a). Detailed petrographic characterization and core logging conducted in this research identified thirteen different alteration mineral assemblages that are grouped into six mineral association groups: I) Barren Calc-Silicate (assemblages IA, IIB and IIIC), II) Calc-silicate (assemblages IIA, IIB and IIC), III) Calc-potassic (assemblages IIIA and IIIB), IV) Sericitic (assemblage IVA), V) Carbonate Base Metals (CBM) (assemblages VA and VB), and VI) Calcite-Zeolite (assemblages VIA and VIB) ( Figure 3-2, Appendix B.2). 132 3.3.1 Group I: Barren Calc-Silicate This group of alteration assemblages occurs preferentially associated with the Sill 2 and lesser with the Sill 1. Group I includes the calc-sodic, propylitic and sodic alteration assemblages. The spatial distribution of this group of alterations suggests a common genesis in the paragenetic evolution of the El Alacrán Deposit (Figure 3-2). 3.3.1.1 Calc-sodic assemblage: quartz - Mg-rich chlorite - albite ± apatite ± rutile-anatase (± pyrite) The calc-sodic alteration has a close spatial relationship with the mafic-poor diorite sills, especially with Sill 2 (Figure 3-3A-B). This assemblage preferentially developed in the middle-lower part of Unit 2 and locally developed on top of Unit 3 (Figure 3-3C). The alteration intensity varies from weak to strong, although when it occurs within the sills, the intensity tends to be strong, destroying the primary rock mineralogy. Calc-sodic alteration comprises intergrowths of fine-grained (< 1mm) pale-green anhedral chlorite with anhedral quartz (Figure 3-4A). This alteration also includes fine to very fine-grained (~0.05-0.1mm) albite that preferentially replaces felsic clasts from TufL and TufR lithofacies (Appendix B.2). Traces of apatite ± rutile are typical in this alteration. Mineralization is scarce and consists of <1 % disseminated pyrite and trace chalcopyrite. At the core scale, this alteration is recognized by a pale green coloration with a marked increase in the hardness due to the occurrence of quartz-albite aggregates. Replacement of chlorite and sericite after albite + quartz ± apatite suggests that the calc-sodic assemblage formed earlier than Group II and III (Appendix B.2, e.g. samples SMA_AL_1608_JM_091 and SMA_AL_1705_JM_064, respectively). 133 Figure 3-2 Mineral paragenesis diagram for the El Alacrán Deposit. The relationship between drill core -scale precipitation stages and groups and assemblages identified under the microscope is shown in the upper part of the diagram. 134 Figure 3-3 Studied cross-sections from El Alacrán Deposit. From north to south Section 855750m N, Section 855540m N, and Section 855050m N. The sections display the distribution and type of the alteration mineral assemblages. The background corresponds to the volcanoclastic lithofacies and intrusions of the host rock. 135 Figure 3-4 Calc-sodic and propylitic alteration assemblages of the El Alacrán Deposit in the San Matías District. A. Drill core interval showing pervasive replacement of the calc-sodic alteration assemblage affecting the Sill 2 lithofacies (Drill hole ACD035@115.20m to 117.50m). B. Photomicrograph (50x, PL) of the quartz and chlorite association from photo A. C. Drill core interval showing selective replacement of propylitic alteration in TufM lithofacies (Unit 3, drill hole ACD002@300.91m to 303.48m). D. Detail of photo C. E-F. Microphotographs (2x, XPL) of photo D. Note the fine-grained plagioclase rock and the distribution of the vesicles filled with chlorite and epidote. Ab: Albite, Qtz: Quartz, Chl: Chlorite, Ep: Epidote, Car: Carbonate, Plag: Plagioclase. 136 3.3.1.2 Propylitic assemblage: chlorite + carbonate + epidote The propylitic assemblage comprises zones of up to 70 m to the north and exceeds 130 m in the southern part of the deposit. The assemblage displays a clear lithological control, where it is preferentially developed in Unit 3 lithofacies (e.g. TufA+TufL, and TufM) (Figure 3-3, Figure 3-4C-D). The propylitic assemblage includes very fine-grained (<0.1 mm) chlorite, fine-grained (<1 mm) calcite, and anhedral epidote. The alteration style ranges from patchy to cavity in-fill with occasional quartz and zeolites (Figure 3-4.E-F). 3.3.1.3 Sodic assemblage: albite + titanite + carbonate The sodic alteration assemblage is mostly developed in the northern and middle regions of the El Alacrán Deposit (Figure 3-3A-B). Sodic altered zones comprise discontinuous segments greater than 20 m in the TufD and TudL lithofacies (Figure 3-5E), whereas, in the TufF lithofacies, the segments are greater than 60 m long (Figure 3-5F). This alteration assemblage is characterized by the occurrence of texturally destructive albite (~>70%), titanite, and rutile (Figure 3-5E-F, Appendix B.2). Cross-cutting relationships suggest that this alteration formed both early and late in the hydrothermal system and lacks sulfide mineralization. 3.3.2 Group II: Calc-Silicate This group of alteration assemblages occurs preferentially associated with the contact between Unit 1 and Unit 2 proximal to the MudSil lithofacies in the southern part of the El Alacrán Deposit (Figure 3-3). Group II includes the magnetite-quartz, mushketovite-pyrite and the chlorite alteration assemblages. Within the calc-silicate group, five phases of magnetite can be separated based on their textural and compositional differences (Appendix F). 137 Figure 3-5 Sodic and FeOx staining alteration assemblages from the El Alacrán Deposit in the San Matías District. A. Drill core interval showing patchy and selective replacement of Fe-staining alteration overprinting sodic alteration in the TufF lithofacies (Unit 2, drill hole ACD001@155.0m to 157.8m). B. Detailed core photo showing the Fe-staining overprinting calc-sodic alteration assemblage. C. Photomicrograph (50x, PPL) of the Fe stained chlorite areas (Photo B). D. Scanning Electron Microscope (SEM) image of the Fe-staining alteration after the calc-sodic alteration assemblage (albite - chlorite - quartz). E-F. Detailed drill core photographs of samples with albite alteration assemblage in the TufD and TufF lithofacies, respectively. Ab: Albite, Qtz: Quartz, chl: Chlorite, Car: Carbonate, Plag: Plagioclase, Ser: Sericite, Rut: Rutile. 138 3.3.2.1 Magnetite - quartz assemblage: magnetite - quartz - apatite ± Fe-rich chlorite (± pyrite). The magnetite - quartz assemblage extends almost 1 km along the contact between the ABx and the MudSil lithofacies, where it preferentially replaces the MudSil lithofacies (Figure 3-1, Figure 3-3). The replacement zones range from 20 to 30 m thick. This assemblage is absent in the northern part of the deposit (cross-section 855750m N, Figure 3-2A). Two magnetite types are observed in this alteration assemblage: 1) medium-grained (>1 mm) bladed magnetite (mushketovite), and; 2) very fine-grained (<0.1 mm) euhedral magnetite (s.s. magnetite). Both types occur with fine-grained (0.15 mm), anhedral to euhedral prismatic quartz (12%). The mushketovite occurs mostly with prismatic quartz in open-space filling textures surrounded by a replacement of magnetite and cryptocrystalline quartz. Apatite shows a marked lithological control within the MudSil lithofacies; this reflects compositional variation in that protolith chemistry (Figure 3-6A-B-C, Appendix B.2). Fe-chlorite also occurs as fine- to medium-grained (0.2 - 0.8 mm), flaky-radiated aggregates with mushketovite and quartz. Sulfide mineralization consists of sparse cubic pyrite that is locally intergrown with magnetite. Field evidence, such as magnetite boulders with no sulfide mineralization, supports the barren character of this alteration assemblage. 139 Figure 3-6. Magnetite-rich mineral assemblages of the El Alacrán Deposit. A. Core sample of the magnetite - quartz alteration assemblage in the MudSil lithofacies. B. Photomicrograph (2x,XPL, TL) of photo A. Note quartz - magnetite + carbonate (left side) vs the apatite bands with semi-massive magnetite + carbonate (right side). C. Drill core photograph showing the transition between Mushketovite + Pyrite assemblages and the Magnetite + Quartz (Drill hole ACD081@ 51.95m to 54.65m). D. Detail of photo C showing selective silica replacement after clasts of the ABx breccia. E. Photomicrograph (20x, PPL, TL+RL) showing the alteration of specularite to magnetite (Mushketovite). F. Photomicrograph (5x, PPL, TL+RL) showing the intergrowth of mushketovite and magnetite and traces of chlorite and carbonate. Chalcopyrite is the latest phase in this association. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Mag: Magnetite, Ap:Apatite, Musk: Mushketovite, Ccp:Chalcopyrite, Py:Pyrite. 140 3.3.2.2 Mushketovite - pyrite assemblage: mushketovite - quartz - apatite - Fe-rich chlorite – carbonate ± REE mineral (pyrite > chalcopyrite). This assemblage occurs as breccia in-fill and minor replacements along the ABx footwall in contact with Unit 2 (Figure 3-1, Figure 3-3). The mushketovite-pyrite alteration occurs as infill breccia embedding ABx and MudSil clasts (Figure 3-6D). The MudSil clasts are altered to cryptocrystalline quartz and magnetite and were possibly altered earlier during the magnetite-quartz- assemblage. This timing relationship, along with carbonate and sulfide mineralization in the mushketovite-pyrite assemblage, is used as criteria to separate this stage from the earlier magnetite-quartz assemblage (Figure 3-6E-F). The mushketovite-pyrite assemblage comprises coarse-grained (<7 mm) mushketovite (~40%) intergrown with medium to fine-grained (<1 mm) euhedral quartz and fine-grained (0.5 mm), dark green chlorite (Appendix B.2). EDS analysis of chlorite yield Fe/Mg ratios of 87/13 (Appendix D.2). Relict specular hematite partially altered to magnetite is observed in this assemblage (Figure 3-6E). Apatite and traces of a REE-bearing (Ce + La) mineral identified using EDS analysis (Appendix D.2), occurs associated with this assemblage. This REE-bearing mineral was also identified as semi-massive mineralization in the Buenos Aires prospect accompanied by pyrrhotite, chalcopyrite, ilmenite and pyrite (Appendix B.1). Sulfide mineralization occurs as coarse-grained (<10 mm) aggregates of pyrite and variable amounts of chalcopyrite accompanied by carbonates. Artisanal mine works in the southern El Alacrán Deposit (e.g. Mina Seca) coincide with the areas of this mushketovite - pyrite assemblage (Figure 3-6F). Available multi-element exploration geochemistry for the magnetite – 141 quartz and mushketovite – pyrite assemblages indicates enrichment in V, Co, Ni and P (Cordoba Minerals Corp., 2018a). 3.3.2.3 Chlorite assemblage: Fe-rich chlorite - carbonate - quartz (pyrite > chalcopyrite) The chlorite assemblage is mostly in the southern part of the deposit (e.g. Mina Seca area). This alteration is preferentially developed in rocks of the ABx lithofacies (Section 855050m N, Figure 3-3C). Increased secondary carbonate content is associated with more felsic lithofacies. (e.g. TufL, TufD and ABx). The chlorite assemblage is defined by high contents (>25%) of medium-grained dark-green chlorite. Chlorite usually displays euhedral and radiated habits (Figure 3-7A), and intergrowths with fine to medium-grained white carbonate, pyrite and quartz. Traces of crystalline epidote, titanite and apatite are typical in this alteration (Figure 3-7B). Sulfide mineralization is dominated by pyrite, which occurs as fine-grained (<1 mm), euhedral aggregates that are intergrown with carbonate, chlorite, and quartz (Appendix B.2). Pyrite displays either evidence of replacing or being replaced by magnetite. Lesser chalcopyrite occurs as fine-grained (< 1mm), anhedral ragged grains and aggregates that in-fill pyrite and magnetite crystals. Large amounts of pyrite are observed cutting the quartz - magnetite assemblage. This pyrite may be either associated with the chlorite or with the mushketovite - pyrite assemblage. The Chlorite assemblage is interpreted to be the buffered, distal expression of the mushketovite - pyrite assemblage (Section 855050m N, Figure 3-3C). 142 Figure 3-7 Chlorite and actinolite-vanadium mica alteration assemblages of the El Alacrán Deposit A. Drill core showing the chlorite alteration assemblage in the ABx lithofacies (Unit 1 Hole ASA037@58.9m to 76.48m). B. Detail of the Chlorite alteration assemblage in TufL lithofacies. C. Polished-thin section photo showing the occurrence of radiated V-rich mica occurrence intergrowing with carbonate and quartz. D. Photomicrograph (5x, XPL) of polished thin section in photo C. E. Relict acicular/bladed shapes (possible earlier mushketovite) replaced by quartz and pyrite. F. Photomicrograph (10x, PPL, TL+RL) showing the occurrence of sphalerite accompanied by chalcopyrite and the striated V-rich Mica in the actinolite - vanadium mica alteration assemblage. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Ep: Epidote, Act: Actinolite, Ccp: Chalcopyrite, Py: Pyrite, Ilm: Ilmenite. Sph: Sphalerite. 143 3.3.3 Group III: Calc-Potassic This alteration assemblage group occurs preferentially in the middle and northern part of the El Alacrán Deposit associated with the carbonate-illite alteration in the periphery of the ABx breccia (Figure 3-3A-B). This alteration is recognized for the association of actinolite with brownish mica (vanadium mica, Appendix B.2) and pyrrhotite. The Group III includes the actinolite – vanadium mica and pyrrhotite - actinolite assemblage assemblages. 3.3.3.1 Actinolite-vanadium mica assemblage: actinolite - vanadium mica - quartz - carbonate (chalcopyrite - pyrite ± pyrrhotite ± illmenite). The actinolite-vanadium mica assemblage is restricted to the central and northern regions of the deposit and occurs mostly in the ABx lithofacies footwall (Figure 3-3A-B). This alteration assemblage exhibits transitional mineralogy from high (apatite + actinolite + quartz) to lower temperature (sphalerite ± sericite). The actinolite-vanadium mica assemblage includes medium-grained (<2 mm) anhedral quartz (~30%), which displays multiple actinolite inclusions (Figure 3-7C, Appendix B.2). Quartz intergrowths with medium-grained (~2 mm) a brown-colored mica that contains variable amounts of vanadium, potassium, aluminum and magnesium (Figure 3-7C-F, Appendix D.2). Coarse-grained (>7 mm) carbonate intergrowths and locally replaces primary mineralogy. Pyrite and chalcopyrite pseudomorphs some earlier bladed mineralogy (Figure 3-7E), indicating that it formed after the magnetite-mushketovite assemblages. The dominant mineralization includes medium- to coarse-grained (<5 mm) pyrite - chalcopyrite with trace sphalerite and ilmenite (Figure 3-7F). This assemblage is spatially associated with some of the highest Cu and Au grades in the deposit. 144 3.3.3.2 Pyrrhotite - actinolite assemblage: pyrrhotite - quartz - actinolite ± chlorite ± clay The occurrence of the pyrrhotite - actinolite assemblage is restricted to the northern part of the deposit (section 855750m N, Figure 3-3A). Pyrrhotite occurs as an early-formed mineral intergrown with actinolite and locally with undefined pale-green clay mineralogy. Pyrite, chalcopyrite and intermediate sulfide (ISS) between pyrite and marcasite (?) crosscut the early-formed pyrrhotite. The occurrence of pyrrhotite might indicate local reducing conditions (e.g. organic matter) or high-temperature stages of the calc-potassic assemblage. Pyrite exolutions (flames) occur in some pyrrhotite specimens; these were reported as pentlandite by Dunne (2016a). 3.3.4 Group IV: Sericitic Sericitic hydrothermal alteration is the dominant alteration in the El Alacrán Deposit and is accompanied by an extensive amount of carbonate that defines the carbonate-illite alteration assemblage (Figure 3-3A-B). This assemblage is associated with the Cu-Au ores in the deposit. 3.3.4.1 Carbonate – illite assemblage: carbonate - illite - chlorite - titanite/rutile (chalcopyrite + pyrite ± molybdenite ± pyrrhotite ± ilmenite) The carbonate - illite assemblage dominates the northern and central part of the El Alacrán Deposit and preferentially occurs in felsic to intermediate lithofacies associated with Unit 1 (e.g. TufR, RBx and ABx). Sericitic alteration intensity varies from strong in the shallowest part of the ABx breccia (Figure 3-8A-B) and decreases to trace amounts at deeper levels (>150 m-depth) of this breccia. The alteration assemblage comprises medium-grained (<1.5 mm) anhedral carbonate (< 35%) accompanied by very fine-grained (<0.1 mm) sericite (< 25%), and anhedral Mg-rich chlorite 145 (Figure 3-8D, Appendix B.2). EDS analysis indicates a chlorite Fe/Mg ratio of (70/30) (Appendix D.2); however, the chlorite in the sericitic alteration tends to be pale green, which indicates a low Fe/Mg content. Titanite occurs as fine-grained (<0.2 mm) euhedral crystals intergrown with carbonates (Figure 3-8C). Petrographic observations confirm that this alteration occurred after the mushketovite-pyrite, chlorite, and the calc-sodic alteration assemblages (Appendix B.2, e.g. sample SMA_AL_1705_JM_064). SWIR analysis on the sericite of this assemblage has a marked absorbance feature at 1900 nm, indicating a low crystallinity phase (Figure 3-8E, Appendix D.1). The absorbance feature at 2200 nm (W2200) is higher than 2195 nm (Figure 3-9A), indicating an illite composition with variations to paragonitic and lesser to phengitic. Illite composition shows a dependency on the pre-existent alteration mineralogy (e.g. illite overprinting minerals of the calc-sodic alteration assemblage display lower crystallinity and a paragonitic composition) (Figure 3-9A, Appendix D.1). The dominant mineralization includes medium-grained (~2 mm) subhedral to cubic pyrite aggregates intergrown with chalcopyrite. Traces of sphalerite, molybdenite and electrum occur. A La – Ce-bearing mineral (lanthanite?, Appendix D.2) was identified in samples associated with this alteration assemblage. 146 Figure 3-8 Sericitic and Carbonate Base Metal (CBM) alteration assemblages in the El Alacrán Deposit of the San Matías District. A. Photo of drill core showing pervasive carbonate-sericite alteration assemblage in the ABx lithofacies (Unit 1, drill hole ACD036@57.33m to 59.85m). B. Detail of Photo A. C. Photomicrograph (10x, XPL) showing the occurrence of carbonate with euhedral titanite accompanied by sericite and chlorite. D. Scanning Electron Microscope (SEM) image of the sericite + carbonate + quartz paragenesis of the carbonate-sericite alteration assemblage. E. Short-wave infrared (SWIR) spectrum of the sericite in sample SMA_AL_1808_JM_133 consistent with Illite spectral response. F. Photomicrograph (2x, XPL) showing the open-space filling texture with prismatic quartz in the center and anhedral quartz in the host rock. Note a late carbonate vein event. G. Drill core photo of sphalerite + carbonate + sulfide veins of the CBM alteration assemblage. H. Oval-shaped, infill plugs with CBM alteration assemblage. Qtz: Quartz, Chl: Chlorite, Car: Carbonate, Ccp: Chalcopyrite, Py: Pyrite, Sph: Sphalerite, Ser: Sericite, Tita: Titanite, Ap: Apatite. 147 Figure 3-9 Short-wave infra-red (SWIR) analyses for samples from different alteration assemblages and lithofacies from the El Alacrán Deposit, San Matías District. A. White mica spectral value of the 2200 nm feature (W2200) respect to the dominant alteration assemblage. Note that the analyzed sericite samples from the carbonate-illite alteration assemblage coincide with the illite (s.s.) spectral values (2200-2210, Graham et al., 2018). B. Schematic diagram illustrating the relationship between equivalent Cu concentration (eCu, Kulla and Oshust, 2018), alteration assemblage, and hosting volcanoclastic lithofacies of the El Alacrán Deposit for samples along the selected cross-sections. Cu concentration values provided by Cordoba Minerals Corp. 148 3.3.5 Group V: Carbonate Base Metal (CBM) The CBM group comprises mineral assemblages dominated by carbonate, sphalerite and sulphides. The CBM group was subdivided into two different alteration assemblages given the differences in the interpreted formational timing. The CBM group includes CBM-apatite and the CBM veins assemblages and occurs in shallowly in the deposit (between 80 – 140 m, Figure 3-3A-B). 3.3.5.1 CBM – apatite assemblage: carbonate + quartz + apatite + chlorite (chalcopyrite ± sphalerite ± pyrite ± molybdenite) The CBM-apatite assemblage is restricted to the northern and middle parts of the deposit (Figure 3-3 A, B, respectively). The CBM-apatite assemblage occurs in 15 to 30 m wide discontinued zones with in-fill textures and minor replacement textures along the host rock bedding. In relation to the CBM veins, the CBM-apatite assemblage is scarce and was only observed in one sample (Appendix B.2, sample SMA_AL_1608_JM_083). A carbonate and base metal association defines this assemblage and includes coarse-grained (>10 cm) carbonate (calcite) with chalcopyrite in-fill textures. Quartz and apatite are abundant in this assemblage and exhibit open space and stringer textures (e.g. comb crystals, Figure 3-8F, Appendix B.2). Apatite occurs as a medium to coarse-grained (<5 mm) euhedral prismatic crystals intergrowing with quartz and partially replaced by carbonate. Sulfide mineralogy is dominated by fine to medium-grained (< 1mm) chalcopyrite that rims fine-grained (<0.1 mm) pyrite and coarse-grained (<8 mm) Fe-rich sphalerite. Molybdenite occurs as fine-grained (<0.2 mm) aggregates intergrown with chlorite and quartz. 149 3.3.5.2 CBM veins: carbonate (chalcopyrite + sphalerite + arsenopyrite + pyrite ± molybdenite) The CBM vein assemblage is also spatially restricted to the northern and middle parts of the deposit along a possible NNE structural control (Figure 3-1 and Figure 3-3). The CBM veins assemblage is dominated by sphalerite and comprises up to 30 cm thick veins (Figure 3-8G) and coarse-grained (up to 4 cm) oval-shaped plugs (Figure 3-8H) that indicate open-space in-fill formation. The lack of apatite and quartz indicate a lower formation temperature with respect to the CBM-apatite assemblage. The sphalerite in the CBM veins assemblage displays chalcopyrite exsolutions (Disease Texture) and locally cross-cuts the chalcopyrite. Trace sulfides include molybdenite, and Ni-Co-Sb bearing arsenopyrite (Appendix D.2). Au mineralization in this assemblage occurs as visible gold (VG). Au-bearing arsenopyrite-rich (< 35% arsenopyrite) veins are less abundant than the sphalerite-rich counterparts and occur mostly as fault-fill veins. The arsenopyrite veins comprise coarse-grained (>5 mm) anhedral arsenopyrite that intergrows with pyrite and chalcopyrite. Cross-cutting relationships of the CBM veins suggest that it is the latest mineralizing event in the El Alacrán Deposit. 3.3.6 Group VI: Zeolite-Calcite This group comprises a series of alteration assemblages interpreted to be formed after the main mineralization stage of the El Alacrán Deposit and possibly they are associated with the waning of the hydrothermal system. Group VI includes Late Calcic Veins and Fe-staining alteration assemblages. 150 3.3.6.1 Late calcite veins assemblage The late calcite alteration assemblage corresponds to a late-generated phase of carbonates dominated by calcite veinlets that cross-cut the main mineralizing assemblages. This assemblage is sulfide-poor with very scarce pyrite mineralization. 3.3.6.2 Fe-staining assemblage The Fe-staining assemblage is preferentially distributed in the northern part of the deposit and is associated with the Unit 1 lithofacies. This alteration assemblage comprises a spectrum of dark-brownish alteration minerals that occur as patchy, fracture infill and selective replacement. The Fe staining alteration might involve either weathering or low-temperature hydrothermal processes. This alteration assemblage overprints previous carbonate - illite and albite alteration assemblages (Figure 3-5A-B). The Fe-staining group includes different combinations of FeOx staining after rutile, chlorite, and albite ± illite. The staining is observed as iron leakage from chlorite when this is in contact with late calcite ± pyrite veinlets (Figure 3-5C, Appendix B.2). Texturally this alteration assemblage exhibits cryptocrystalline to spheroidal aggregates that either replace or are intergrown with clay minerals (illite and kaolinite?). Fine-grained (< 0.3 mm) anhedral aggregates of zeolites occur as a selective replacement after plagioclase. Zeolite was identified as Lawmontite (Na, K zeolite) using X-ray diffraction (XRD) (Dunne, 2016a). Petrographically, this alteration assemblage does not display an association with sulfide mineralization, which indicates that it was formed late to post-mineralization in the deposit. 151 3.4 Mineralization of the El Alacrán Deposit. 3.4.1 Metal distribution Metals grades are variable across the El Alacrán Deposit. In this study, ore zones are discussed primarily with respect to the spatial distribution of different paragenetic alteration assemblages. Mineralized intervals from 0.3 to 1 ppm Au and 0.25 – 3.0 % Cu based on the resource estimation grade shells (Cordoba Minerals Corp., 2018) were modelled with Leapfrog Geo (Appendix D.3) to understand the relationship of mineralization with the distribution of pyrite, chalcopyrite, and pyrrhotite along the selected cross-sections (Figure 3-10). The dominant alteration assemblages along the studied cross-sections include propylitic, carbonate-illite, calc-sodic, and chlorite assemblages (Figure 3-3), where the carbonate-illite assemblage has the highest Cu (mean 0.39 %, locally up to 4.9 %) and Au grades (mean 0.1 g/t, maximum of 1.6 g/t;). High-grade intercepts (e.g., 4,440 g/t Au + 10.25% Cu + 24.70% Zn + 347 g/t Ag over 0.90 m) in the central part of the deposit (Cordoba Minerals Corp, 2017) are associated with the CBM veins assemblage (Figure 3-10). The highest pyrite abundances (>4 wt%) are observed in the southern part of the deposit (section 855050m N; Figure 3-10E). This pyrite is paragenetically related to the mushketovite-pyrite and chlorite assemblages from the calc-silicate alteration group (Figure 3-10E). The high-grade Au mineralization (>1ppm Au) also coincides with the mushketovite-pyrite assemblage formed in the contact between the ABx and the MudSil lithofacies (Figure 3-11F). The Au high-grades are likely to have resulted from the interaction of mineralizing fluids with the previous magnetite altered and brecciated host rocks. 152 Figure 3-10 Leapfrog Geo model of sulfide shells along the selected cross-sections of the El Alacrán Deposit in the San Matías District. A-B. Pyrite, pyrrhotite, and chalcopyrite shells in the northern 855750m N section. C-D. Pyrite and chalcopyrite shells in the central 855540m N section. E-F. Pyrite and chalcopyrite shells in the southern 855050m N section. Sulfide distribution was modelled using Leapfrog Geo version 4.1.0 (spheroidal interpolant; global trend with dip 55°, dip azimuth 270°, pitch 52.5; ellipsoid ratios maximum 8, intermediate 6, minimum 1; resolution 25; 153 March 2019, Appendix D.3). Sulfide distribution and relative concentrations based on the core-logging database provided by Cordoba Minerals Corp. The major Au occurrence in the central part of the deposit (855540m N, Figure 3-11D) paragenetically coincides with the calc-potassic and the CBM assemblages. High-grade Au (>1ppm Au) is spatially associated with the intrusive contact between the ABx lithofacies and the magnetite-quartz altered rocks of the MudSil lithofacies. In contrast, high-grade Cu occurrences in the central El Alacrán Deposit comprise two different zones : 1) the eastern zone coincides with chalcopyrite, pyrite, and gold associated with the carbonate-illite assemblage, whereas, 2) the western zone shows a direct association with Au, chalcopyrite, and pyrite from the CBM assemblage (Figure 3-11C). Au distribution in the northern part of the deposit (section 855750m N, Figure 3-11B) decreases considerably in comparison with the central region. High-grade Au (>1 ppm) in northern El Alacrán Deposit is restricted to narrow zones associated with the CBM assemblage, whereas, intermediate-grade Au (0.3 - 1 ppm) is associated with the pyrrhotite occurrence of the calc-potassic assemblage. Chalcopyrite and thus Cu grades, however, show the opposite behaviour, with an increase in the northern part of the deposit (section 855750m N, Figure 3-11A) relative to the central and south region (Figure 3-11B-D-F). Chalcopyrite is more concentrated in the northern part of the deposit and coincides with the sericitic and calc-potassic assemblages (Figure 3-11A, Figure 3-12). Although calc-sodic and propylitic alteration assemblages are low-grade to barren, some minor pyrite mineralization is spatially associated. 154 Figure 3-11 Leapfrog modelled Cu (%) and Au (ppm) shells along the selected cross-sections of the El Alacrán Deposit in the San Matías District. Volcanoclastic lithofacies and alteration assemblages of Figure 3-2 are shown in the background. Cu and Au values distribution was modelled using Leapfrog Geo version 4.1.0 (spheroidal interpolant; global trend with dip 55°, dip azimuth 270°, pitch 52.5; ellipsoid ratios maximum 8, intermediate 6, minimum 1; resolution 25; March 2019, Appendix D.3) Cu and Au values from database provided by Cordoba Minerals Corp. 155 Figure 3-12. Cu (%) and Au (ppm) value distribution for selected altered samples from different alteration assemblages along the selected cross-sections of the El Alacrán Deposit in the San Matías District. A. and B. Tukey box plots showing the Cu (%) and Au (ppm) value distribution. Mean = black dot, median = black horizontal line. C. and D. Probability plot for Cu (%) and Au (ppm) values. Note the bulk of the carbonate-illite along with the mushketovite-pyrite alteration assemblages coincide with higher Cu % grades. Cu and Au values provided by Cordoba Minerals Corp. Alteration assemblages, according to the legend of Figure 3-2. 3.4.2 Deposit Au Fineness and Precipitation The Ag content of Au is commonly reported as gold fineness (Au/Au+Ag x1000) and has been used in some deposits to elucidate the origin of the fluids (Corbett and Leach, 1993). Porphyry Cu-Au and Cu skarns display an average of 920‰ (Rubin, 1993; Ramsden et al., 1985) and carbonate-base metal gold deposits an average of 765‰ (Brathwaite, 1989). At the El Alacrán Deposit, three different gold deportment events (Au1, Au2, and Au3) are delineated based on 156 their spatial distribution, associated mineralogy and gold fineness estimation (Table 3-2, Figure 3-13, and Appendix D.2). In event Au1, gold occurs as inclusions in pyrite of the calc-silicate alteration (mushketovite - pyrite assemblage). Samples of this assemblage lacked gold inclusions in pyrite when studied under reflected light. However, textural relationships and mineral associations (e.g. magnetite inclusions) in some relict pyrite grains are interpreted to belong to the mushketovite-pyrite assemblage. Gold in pyrite occurs as 20 μm inclusions, with anomalous Fe content and an estimated fineness of 980‰ (Table 3-2). In event Au2, gold occurs as fracture in-fill in the calc-potassic (actinolite-vanadium mica) and sericitic alterations. Silver-rich (electrum) gold occurs as >100 μm chalcopyrite bound-infill and has an estimated fineness of 441 ‰ (Figure 3-13, Table 3-2). Finally, in event Au3, gold occurs as > 1000μm visible gold (VG) with anomalous content of Zn and Ag and an estimated fineness of 765 ‰ (electrum) (Figure 3-13, Table 3-2). Table 3-2 Gold mineralizing events, characteristics and fineness for samples of the El Alacrán Deposit in the San Matías District. Gold fineness calculated after semi-quantitative normalized weight percent (wt. %) values obtained with EDS (Au/Au+Ag X 1000, Corbett and Leach, 1993) 157 Figure 3-13 Gold events of the El Alacrán Deposit in the San Matías District. A. Event Au1: Gold inclusion in pyrite from the mushketovite-pyrite alteration assemblage (Group II) (sample SMA_AL_1709_JM_077). B. Events Au1 and Au2: Back-Scattered Electron (BSE) Ag map showing the differences in the Ag content in gold particles from events Au1 and Au2 (sample SMA_AL_1709_JM_077). C. Event Au2: Fracture infill gold mineralization occurring in the contact of pyrite and chalcopyrite from the calc-potassic and sericitic alterations. D) Event Au3: Back-Scattered Electron (BSE) image visible gold (VG) intergrown with sphalerite from the CBM Vein alteration assemblage. 3.5 The Timing of the El Alacrán Deposit Ore Related Processes. To constrain the timing of the mineralization at the El Alacrán Deposit, we dated by Re-Os analysis, two samples of molybdenite associated with sulfide stage of the deposit. Additionally, one sericite separate sample from the carbonate-illite assemblage was dated by Ar-Ar analysis. At a district scale, molybdenite separates from the Montiel E and Costa Azul Cu-Au porphyry prospects were dated by Re-Os. The obtained geochronology data of this study was also contrasted with the available geochronology of the alteration and mineralization of the district. 158 3.5.1 Re-Os in molybdenite age dating of the El Alacrán Deposit and San Matías District porphyry Cu-Au prospects New Re-Os ages obtained in molybdenite samples from the El Alacrán Deposit, the Costa Azul and Montiel E Cu-Au porphyry prospects in the San Matías District are presented in Table 3-3. The molybdenite analyzed for the El Alacrán Deposit (sample SMA_AL_1704_JM_049; Appendix B.2) occurs as very fine-grained (<0.1mm) traces of patchy aggregates intergrown with chalcopyrite in a chlorite-clay-sericite-quartz and carbonate altered tuff associated with the carbonate-illite alteration assemblage. This molybdenite returned a 187Re/187Os age of 73.3 ± 1.5 Ma, which is younger than the previous molybdenite age known for the CBM-apatite assemblage (sphalerite-chalcopyrite-carbonate-quartz-chlorite-apatite ± molybdenite) of the El Alacrán Deposit (75.8 ± 0.4 Ma, Leal-Mejía and Hart, 2017, Table 3-1). The discrepancy between these two ages suggests that there were two temporally-distinct alteration assemblages containing molybdenite. The obtained ages also support the separation of the CBM group into two different paragenetic assemblages: the CBM - apatite (pre- sericitic) and the CBM veins, as a late mineralizing event. The obtained Re-Os age in molybdenite of the El Alacrán Deposit (73.3 ± 1.5 Ma) is also younger than the Re-Os in molybdenite obtained for the SMD porphyry Cu-Au mineralizations (76.6 ± 0.3 and 76.8 ± 0.3 Ma) (Table 3-3). 159 Table 3-3 New Re-Os ages for molybdenite samples from the El Alacrán Deposit and the Costa Azul and Montiel E porphyry Cu-Au prospects in the San Matías District The average Re concentration in molybdenite samples from the Costa Azul and Montiel E Cu-Au porphyries mineralizations is ~5021.5 ppm. This average is more than 2000 times higher than the Re concentration in the molybdenites samples from the El Alacrán Deposit (0.2 ppm, Table 3-3). The difference in the Re content in the analyzed molybdenites suggests a marked difference in the fluid nature and evolution between both prospect styles. However, in the El Alacrán Deposit sample (SMA_AL_1704_JM_049, Table 3-3, and Appendix E.3), the true Re abundance in molybdenite might be twenty times the reported value or more (e.g. close to 8 ppm) and can not be considered an absolute value (R. Creaser, pers. comm., 2019). The implications of the Re content in the analyzed molybdenites regarding their fluid nature is discussed in section 3.7.3. 3.5.2 Ar-Ar geochronology of alteration minerals from the El Alacrán Deposit and La Jagua (Mina Cocos) vein-type mineralization in the San Matías District New Ar-Ar age dating for alteration minerals from the El Alacrán Deposit and vein-type mineralization in the San Matías District are presented in Figure 3-14. Actinolite separated from the actinolite-vanadium mica assemblage (sample SMA-AL-1709-JM-043) returned a plateau age of 62 ± 11 Ma and included the 100% of the 39Ar (Figure 3-13A, Appendix E.2-Table 1). 160 Figure 3-14 40Ar/39Ar age spectra, normal and inverse isochrons for alteration minerals of the El Alacrán Deposit and the Mina Cocos (La Jagua) vein-type mineralization of the San Matías District. A. Actinolite associated with the actinolite-vanadium mica assemblage (sample SMA-AL-1709-JM-043). B. Sericite of the carbonate-illite alteration assemblage (sample SMA-AL-1709-JM-073). C. Sericite from La Jagua Mineralization (sample SMA-JA-1704-JM-048). 161 This actinolite corresponds to fine- to coarse-grained (0.2 - 5 mm) acicular crystals that occur as host rock replacement and intergrowths with quartz and vanadium mica. Normal and inverse isochron ages yielded the same age (76 ± 29 Ma, Figures 3-13A). Due to low K content and consequently low radiogenic Ar in the analyzed actinolite, the Ar-Ar age estimation has large errors (Appendix E.2) and is not considered reliable. Additionally, this sample returned another plateau age of 33.8 ± 2.1 Ma (Appendix E.2-Table 2), which indicates a thermal resetting of the actinolite at this age. One sericite sample of the ABx lithofacies (sample SMA_AL_1709_JM_073) was also dated by Ar-Ar analysis (Figure 3-14A-C; Appendix E.2, Table 3). This sericite occurs as very fine-grained (<0.1mm), flaky aggregates that are intergrown with carbonate and quartz of the carbonate-illite assemblage Appendix B.2. The sericite sample returned a plateau age of 68.31 ± 0.35 Ma, with a MSWD = 1.3 that includes 90% of the 39Ar ( Figure 3-15). Normal and inverse isochrons of the samples yielded 67.47 ± 0.45 Ma and 67.51 ± 0.46 Ma, respectively (Figure 3-13B), consistent with the plateau age, which is interpreted as the age of the sericite hydrothermal alteration assemblage. This sericite sample also returned a plateau age of 66.73 ± 0.60 Ma (Appendix E.2, Table 4), consistent with the previous obtained ages and suggesting a relatively homogenous distribution of the radiogenic Ar in the sample. The marked difference of the Ar-Ar age in sericite (68.31 ± 0.35 Ma) versus the Re-Os age obtained in molybdenite (73.3 ± 1.5 Ma; Table 3-3), from the same alteration assemblage, might reflect that the hydrothermal system was thermally warm over much time (~ 5 Ma). Alternatively, the young age (~68 Ma) in the El Alacrán Deposit sericite might represent both 162 another mineralizing fluid and the thermal resetting of the Ar-Ar system by the heat flux produced by an intrusion at that age. This suspected intrusion may be temporal-related with the waning of the Montiel E porphyry suite magmatism (e.g. 70.0 ± 2.0 Ma; Leal-Mejia and Hart, 2017). Finally, a sample of hydrothermal sericite associated to the vein-type mineralization at the Mina Cocos (La Jagua) prospect (sample SMA_JA_1704_JM_048, Figure 3-15), yielded ages of 68.84 ± 0.87 Ma and 68.83 ± 0.78 Ma, in the normal and inverse isochrons, respectively (Figures 3-13C, Appendix E.2, Table 5). An initial age dating attempt on this sample returned a plateau age of 47.16 ± 0.71 Ma (Appendix E.2, Table 6). The marked discrepancies between both age dates and the large variations of the K/Ca ratio in the heating steps process (Appendix E.2, Table 5 and 6) indicate that the K and the radiogenic Ar in the sample were not homogenous. The obtained age in the Mina Cocos prospect (68.84 ± 0.87 Ma), is consistent with ages obtained for the SMD samples, especially, with the sericite age for the carbonate-illite assemblage from the El Alacrán Deposit and might have formed from a magmatic or hydrothermal source associated to the Montiel E porphyry Cu-Au event. 163 Figure 3-15 Summary of geochronology data compilation for magmatism and mineralization in the San Matías District. The age of mineralization/hydrothermal alteration at the El Alacrán Deposit is constrained at ca.75.8 - 68.31 Ma (dark red zone). The vertical coloured boxes indicate the age intervals constrained for Costa Azul and Montiel E porphyry Cu-Au events in the San Matías District. Compiled ages from other authors include (1) Leal-Mejía and Hart (2017), (2) Sernageomin (2018), (3) Sernageomin (2012) and (4) Anglo American, pers. comm., 2014. 164 3.5.3 Conclusions and Remarks of the San Matias District Geochronology Data The obtained ages from the SMD porphyry prospects indicate two discrete Cu-Au porphyry events: 1) The Costa Azul event with ages of ca. 77 Ma obtained in the Costa Azul and Montiel W Porphyry prospects (76.6 ± 0.3 Ma in molybdenite and 76.8 ± 0.3 Ma in amphibole, respectively), and; 2) The Montiel E event with ages of ca. 72 Ma genetically associated with the intrusive phases of the Montiel E porphyry suite (PxHe, PxQF, and PxHL) dated with zircon and amphibole. Individual zircons ages obtained in the late phase of Montiel E Porphyry (PxHL) indicate that magmatism in the Montiel E event could have cooled slowly and lasted until ca. 68 Ma (Leal-Mejía and Hart, 2017, Figure 3-15). U-Pb zircon dates from the holocrystalline intrusions provided ages of 75.95 ± 0.3 Ma and 72.9 ± 1.2 Ma (Figure 3-15), which are intermediate between the two Cu-Au porphyry mineralizing events. The 75.8 ± 0.4 Ma Re-Os age (Leal-Mejía and Hart, 2017) obtained in the CBM-apatite assemblage is slightly younger (0.1 - 0.3 Ma) than the Costa Azul porphyry event and overlaps with ages of the regional SMD intrusions, specifically, with the age of the Betesta Quartz Diorite and some molybdenite mineralization dated in the San Jorge area (Table 3-1, Figure 3-15). The 73.3 ± 1.5 Ma Re-Os age from the carbonate-illite assemblage of the El Alacrán Deposit is within error of the zircon U-Pb age ages from the QFPx phase of the Montiel E Porphyry and overlaps with other recorded ages of the Montiel E porphyry event ( Figure 3-15). Similarly, the 73.3 ± 1.5 Ma Re-Os age overlaps with the ages of the holocrystalline SMD intrusions specifically, with the U-Pb (zircon) ages of the Betesta Quartz Diorite, La Jagua Tonalite and San Jorge Quartz Diorite (Table 3-1, Figure 3-15). 165 The 68.31 ± 0.35 Ma Ar-Ar age in sericite from the carbonate-illite assemblage of the El Alacrán Deposit is within error of the inverse isochron age from the sericite of the La Jagua mineralization (68.83 ± 0.78 Ma, sample SMA-JA-JM-048 Figure 3-15). Both sericite ages are close to the late ages recorded in the Montiel E porphyry event (PxHL). 3.6 Deciphering the Ore Forming Processes at El Alacrán Deposit: Mineralogy and Fluid Inclusion Analysis 3.6.1 Fluid Inclusions of the El Alacrán Deposit and the Montiel E porphyry prospect of the San Matias District Three different types of fluid inclusion assemblages (FIA) were identified at the El Alacrán Deposit: FIAIIHC, FIAIII, and FIAII (Figure 3-16). FIAIIHC corresponds to Type II, two-phase fluid inclusions (Nash, 1976) composed of liquid and vapour hydrocarbon (LHC+VHC). This FIA is mostly secondary to pseudo-secondary in origin and occurs in apatite from the calc-silicate alteration and quartz from the CBM alteration assemblages. This FIA was neither observed in the actinolite - vanadium mica assemblage nor in the porphyry samples. The vapour phase proportion (VHC/VHC+LHC) varies from 25% to 50%, and the FI length varies from 5.5 to 20 μm. Evidence for secondary entrapment prevents using these fluid inclusions to understand the mineralizing fluids at the El Alacrán Deposit. FIAIII corresponds to Type III, high-salinity fluid inclusions composed of brine, vapour, cubic halite and possibly sylvite (LH2O + VH2O + 2 solids) (Figure 3-16B). This FIA is pseudo-secondary in origin and was only observed in carbonates from the actinolite – vanadium mica assemblage (calc-potassic alteration). This type of FI is also present in the sample from the Montiel E porphyry prospect, where the fluid 166 inclusions carry a non-metallic daughter mineral (Figure 3-16D). The VH2O/VH2O+LH2O ratio varies from 0.25% to 0.39% (Figure 3-16H); FI length varies from 3 μm to 8 μm (Figure 3-16G) and occurs in restricted clusters up to five fluid inclusions. FIAII corresponds to Type II, low-salinity, two-phase fluid inclusions composed of brine and vapour (LH2O+VH2O). This FIA is primary and observed in apatite from the calc-silicate alteration (Figure 3-16A) and in quartz from the calc-potassic alteration. This FI group is prevalent in the porphyry prospects (Figure 3-16E) and occurs in one of the quartz-vein clasts from the RBx lithofacies in Unit 1 (Figure 3-16F). The (VH2O/VH2O+LH2O) ratio in El Alacrán samples varies from 28% to 50% (Figure 3-16H), whereas in the porphyry samples, this ratio varies from 12% to 45%. Overall, FI in the El Alacrán Deposit and porphyry prospects of the San Matias District are rare and usually smaller than 5μm (Figure 3-16G). The occurrence of high-salinity fluid inclusions either in the calc-potassic alteration of the El Alacrán Deposit and the Montiel E porphyry prospect indicates some possible similarities in the physical-chemical composition of the ore-forming fluid. The confirmation of this connection is not possible via a micro thermometric study because of the size (< 7μm) and scarcity of the primary fluid inclusion in both prospects. 167 Figure 3-16 Fluid Inclusions Assemblages (FIA) identified in samples of the El Alacrán Deposit in the San Matias District. A. FIAII in apatite from the magnetite-quartz alteration assemblage. B. FIAIII in carbonate from the actinolite-vanadium mica alteration assemblage. C. FIAIIHC (Hydrocarbon FI) in quartz from the CBM alteration assemblages. D. FIAIII in quartz vein from the Montiel E porphyry prospect. E. FIAII in quartz vein from the Costa Azul porphyry prospect. F. FIAII in quartz clast from the TufR lithofacies in Unit 1, at El Alacrán Deposit. G. Probability plot of the distribution of the FI length size. The largest fluid inclusions correspond to FIAIIHC of the CBM assemblages. H. Frequency histogram of the vapour-liquid ratio (V/V+L) in the fluid inclusions identified. 168 3.6.2 Paleo-Temperature, Acidity and Fluid Paths of the El Alacrán Deposit Ore-Forming Fluids The inferred temperature stability ranges for minerals identified at El Alacrán Deposit are shown in Figure 3-17. Alteration mineralogy in the barren calc-silicate group (Group I) indicates that calc-sodic assemblage formed from moderate-temperature fluids (chlorite - quartz - albite), whereas a later propylitic (chlorite - epidote - calcite) and sodic (albite) alterations are associated with progressively decreasing low-temperature fluids (Table 3-4). The calc-silicate group (Group II) in El Alacrán Deposit formed by high-temperature (magnetite/mushketovite - quartz - chlorite - epidote) fluids (Table 3-4). The calc-potassic group (Group III) alteration is associated with high- to moderate-temperature fluids, as indicated by the occurrence of the actinolite - quartz - mica assemblage observed in this stage. The Sericitic group (Group IV) is associated with low-moderate temperature fluids. Figure 3-17 Common temperature stability ranges in geothermal systems for hydrothermal minerals observed at the El Alacrán Deposit (modified from Escolme, 2017). Minerals arranged by their stability with respect to pH. Sulfide and magnetite formation temperatures from experimental studies (Simon et al., 2000). 169 Figure 3-18 Fluids paths for the El Alacrán Deposit in the context of the pH vs temperature conditions for the formation of hydrothermal alteration minerals and standard alteration types in hydrothermal systems (modified after Corbett and Leach, 1998). Apatite (Ap) added based on petrographic observations in samples from the El Alacrán Deposit. Path A shows the possible fluid evolution of barren calc-silicate and zeolite-calcite alterations. Path B shows the proposed 170 fluid evolution of the calc-silicate alteration. Path C shows the proposed fluid evolution of calc-potassic and sericitic alteration assemblages. The CBM-veins (in question marks) may represent continued cooling from the CBM-apatite assemblages or may represent another event associated with a late epithermal stage. Table 3-4 Summary of the El Alacrán Deposit alteration groups and mineral assemblages and inferred paleo-temperature and acidity. The alteration porphyry analogy after Gustafson and Hunt (1975) is also indicated for comparison. The mineralogy and distribution of the El Alacrán Deposit calc-silicate alteration might indicate an inward fluid-heating path from moderate-high-temperature in the chlorite assemblage to high-temperature in the magnetite-quartz and mushketovite-pyrite assemblages (300°- 500°C; Figure 3-17) (section 855050m N, Figure 3-11E-F). Alternatively, the mineralogy in the calc-silicate alteration might be the product of an outward fluid-cooling path from high-temperature in the magnetite-quartz and mushketovite-pyrite assemblages to a lower temperature gradient in the chlorite assemblage. The interpretation of the trajectory followed by Path B is described in section 3.7. The high temperature associated with the magnetite-quartz, along with the lower chalcopyrite content, may suggest that temperatures in the southern part of the deposit were 171 higher than sulfur and copper saturation of the mineralizing fluid composition. However, because pyrite (S availability) occurs in this early stage, this would instead suggest an initial copper-poor fluid. In contrast, chalcopyrite and pyrite are more abundant at a similar depth in the northern El Alacrán Deposit (section 855750m N, Figure 3-11A-B) and show a close relationship with the calc-potassic and sericitic alterations, which indicates another high-temperature center in the central-northern region of the deposit. In general, the observed mineralogy indicates a broad temperature gradient toward higher temperatures in the southern part of the deposit. The barren calc-silicate group (Group I) is consistent with the propylitic group of Corbett and Leach (1998), and are interpreted to have formed from intermediate (quartz – chlorite – albite) to lower (anhedral epidote – carbonate –chlorite) temperature fluids. Albite alteration is interpreted to have formed in the waning stages of hydrothermal activity (Table 3-4, Figure 3-18). Similarly, the calc-silicate group (Group II) (magnetite-quartz, mushketovite-pyrite and chlorite) is consistent with a calc-silicate group of Corbett and Leach (1998) and with the potassic assemblages from Gustafson and Hunt, (1975) (Table 3-4, Figure 3-18). Finally, the calc-potassic and sericitic groups (Group III and Group IV, respectively) are consistent with the transition to the chlorite group (Corbett and Leach, 1998) and phyllic assemblage from Gustafson and Hunt (1975) (Table 3-4, Figure 3-18). Thus, based on the observations and results of this research, the alteration mineral assemblages at the El Alacrán Deposit are interpreted to be the result of at least three discrete fluid pathways. Path A includes fluids that formed the barren calc-silicate, which are inferred to have been alkalic-neutral, at low-moderate temperatures (quartz – albite – chlorite ± apatite) and were 172 spatially associated with the Sill 2 occurrence. The spatial distribution of propylitic alteration indicates it to be a distal and lower expression of the Path A fluids (Figure 3-18). Path B is associated with the calc-silicate alteration that includes magnetite-mushketovite fluids with pervasive quartz alteration and is inferred to have formed from interaction with a high- to intermediate temperature alkalic to weakly acidic fluids responsible for the chlorite and mushketovite-pyrite assemblages formation (Figure 3-18). Fluids in Path B might represent either a cooling or a heating path depending on the interpreted fluid source. The introduction of a high- to moderate-temperature, neutral to weakly acidic fluids (Path C) is inferred to have formed the calc-potassic alteration group. Evidence for the juxtaposition of this Path C fluid is indicated by the occurrence of high-temperature assemblage (e.g. actinolite – quartz) and high-salinity fluid inclusions found in this alteration group (section 3.6.1). Path C is more likely to have evolved to become weakly acidic and reduced to a point where the early actinolite-vanadium mica became stable with sericite-illite-ilmenite. Path C might have evolved towards a CBM composition, as evidenced by the traces of sphalerite in the actinolite-vanadium mica alteration that is diagnostic of the CBM stage. The sodic alteration described in the barren calc-silicate group may also be a distal and lower temperature product of Path C (Figure 3-18). The fluids in Paths A, B and C were spatially separate at their time of formation. The available geochronology data for mineralization is mostly associated with assemblages that formed during Path C (73.3 ± 1.5 Ma, and 68.31 ± 0.35 Ma, Figure 3-15). However, the abundant occurrence of apatite in the sample GAL002 (Figure 3-15) suggests that this sample age (75.8 ± 0.4 Ma) might be considered the age of the Path B alteration assemblages. Petrographic evidence indicates that 173 the actinolite-vanadium mica alteration assemblage formed after the mushketovite-pyrite assemblage (Appendix B.2, e.g. sample SMA_AL_1709_JM_075). Similarly, the carbonate-illite assemblage formed after the mushketovite-pyrite and after the calc-sodic assemblages (Appendix B.2, e.g. sample SMA_AL_1704_JM_038). Mineral associations, cross-cutting relationships, and age dating suggest differences in the fluid that formed CBM veins. The sphalerite observed in the CBM veins (sphalerite + calcite + chalcopyrite + VG) exhibit open-space filling textures (e.g. comb carbonate, Figure 3-8F) indicating a low temperature (220 - 280°C) and shallow formation environment (300 - 800 m, <1 km; Hedenquist and Arribas, 2000). Additionally, the occurrence of the CBM veins adjacent to magnetite-bearing assemblages (Figure 3-3B, section 855540m N) indicates that significant exhumation and uplift occurred before the emplacement of these veins. The discussed evidence suggests that the CBM veins formed from a late epithermal overprint that may represent another fluid. 3.6.3 Sulfidation State of the El Alacrán Deposit Ore-Forming Fluids The occurrence of mushketovite (hematite pseudomorph) and pyrite in Path B indicates an intermediate to high sulfidation state for the ore-forming fluid. This initial fluid formed from slightly lower temperatures and sulfidation state than that expected for proximal fluids to a Cu-Mo porphyry source, Figure 3-19). If Path B corresponds to a cooling path, the fluid through time decreased in sulfidation state and fS2 to become stable with pyrite - magnetite in the chlorite alteration assemblage (green arrow path, Figure 3-19). However, if the opposite were true, a heating pathway for Path B would imply a progressive increase in sulfidation state and fS2 of the fluid until it became stable with mushketovite and pyrite at a higher temperature (green arrow path, Figure 3-19). 174 Figure 3-19 𝑳𝑳𝑳𝑳𝑳𝑳𝒇𝒇𝑺𝑺𝟐𝟐 − 𝟏𝟏,𝟎𝟎𝟎𝟎𝟎𝟎 𝑻𝑻� diagram illustrating the mineralizing fluid evolution for the fluid paths proposed for the El Alacrán Deposit in the San Matias District (modified after Einaudi et al., 2003). Path B (green arrow) indicates the trajectory of a possible cooling or heating fluid associated with the calc-silicate alteration. Path C (orange arrow) represents the trajectory of a cooling fluid associated with the calc-potassic and sericitic alterations. An additional path (light blue arrow) represents the late CBM veins epithermal fluids associated with the sphalerite ± arsenopyrite occurrence. The introduction of another fluid (Path C), in equilibrium with actinolite, vanadium-mica, and quartz, may have evolved from high-temperature, high- fS2, and low sulfidation state, as evidenced by the coexistence of pyrrhotite ± pyrite. Path C fluid may have buffered at constant intermediate sulfidation state and lower temperature (orange arrow path, Figure 3-19), where precipitation of chalcopyrite - pyrite occurred in the sericitic alteration. The CBM veins may have evolved from a different fluid following the zone base metals path (light blue arrow path, 175 Figure 3-19) and consistent with low sulfidation epithermal veins. That fluid may have buffered at the lowest fS2, suggested by the occurrence of arsenopyrite in these veins (Appendix D.2). 3.6.4 Redox conditions during Au and Cu mineralization at El Alacrán Deposit The El Alacrán Deposit mineralization resulted from three spatially and possibly temporarily distinct Au deposition stages (Section 3.4.2). The first stage in the southern El Alacrán Deposit includes an early, high-temperature mushketovite-magnetite-pyrite-Au deposition associated with alteration assemblages of the Path B, which is the volumetrically dominant in pyrite related to chalcopyrite. A second stage in the northern-central El Alacrán Deposit includes high- to low-temperature Au deposition associated with vanadium-mica, actinolite, sericite and sulfides chalcopyrite, pyrite ± pyrrhotite ± sphalerite of the cooling Path C. Finally, the third stage in the northern-central El Alacrán Deposit includes gold deposition that occurs as visible phase (VG) and intergrowth with sphalerite, chalcopyrite, and calcite associated with the CBM veins. The phase diagram in Figure 3-20 is used to illustrate the trajectory of a fluid that precipitated Au at moderate- to high-temperature (~350 °C). Path B includes an initial Cu-poor fluid stable with hematite. Gold precipitation may be produced at a constant SO42- / H2S ratio with a fO2 decrease in the transformation of hematite to magnetite (mushketovite). Also, a pH increase is expected during the pyrite formation by the H2S depletion in the fluid. For Path C, the correlation between Cu and Au indicates a co-varying solubility. The early pyrrhotite occurrence associated with the pyrrhotite – actinolite assemblage in the calc-potassic alteration, and the subsequent Au and Cu precipitation in the carbonate-illite assemblage is associated with pyrite-chalcopyrite suggesting a redox change in the Path C fluid. Similarly, the absence of high salinity fluid inclusions in the carbonate-illite assemblages suggests that the initial high-salinity 176 fluids (as indicated from fluid inclusions) from calc-potassic alteration possibly mixed with groundwater. The mixing with low-temperature groundwater is recognized as an efficient precipitation mechanism for Au-Cu precipitation via fO2 increase (Barnes, 1979). The mechanism associated with gold precipitation in the CBM veins (Au3) might have been controlled by a decrease in the fluid temperature and pressure. These conditions prevail in the gold deposition close to epithermal environments without a required involvement in the redox change (Henley, 1985). Figure 3-20 Fluid cooling paths proposed for the El Alacrán Deposit in the fO2-pH stability fields for Fe-oxides and sulfides (Huston et al. 1993) constructed at 350°C, calculated from mΣS = 10-2.5, mΣCl = 3.5, mΣNa = 3.0, mΣK = 0.30, mΣCa = 0.10 (e.g. Productora Deposit, Chile Escolme, 2017). Gold solubility as AuCl2- and Cu solubility as CuCl0. Path B arrow indicates the evolution of the calc-silicate alteration in the El Alacrán Deposit that precipitated pyrite and gold and minor chalcopyrite in the transition from hematite to mushketovite (magnetite). In contrast, Path C arrow is used to indicate a possible trajectory in the calc-potassic and sericitic alterations that precipitated both gold 177 and chalcopyrite from an initial fluid stable with pyrrhotite and later pyrite. Path C arrow, however, does not represent the real stability fields defined in the diagram. 3.7 The Source of Metals Responsible For El Alacrán Deposit Mineralization: Lead and Sulfur Isotope Analysis 3.7.1 Pb Isotopic composition 3.7.1.1 Introduction The Pb isotopic compositions of sulfide minerals and rocks can constrain the source(s) of fluids and fluid flow pathways in fossil hydrothermal systems (Heyl et al., 1966). In Phanerozoic ore-deposits, the U/Pb ratio is intrinsically low. Therefore, the measured Pb isotope compositions closely approximate the composition of the mineral and hydrothermal fluid at the time of the crystallization if the system remained closed (Tosdal et al., 1999). Furthermore, Pb isotopes can provide information about the absolute and relative timing of the ore-precipitation events (Tosdal et al., 1999). The inference of metal sources using Pb isotopes is based on the assumption that ore-metals such as Au, Ag, Cu and Zn, and other metals derive from the same source, are transported and deposited from the same fluid (Tosdal et al., 1999). 208Pb, 207Pb, and 206Pb are radiogenic daughter products of the radioactive decay of thorium (232Th to 208Pb)) and two uranium isotopes (238U to 206Pb and 235U to 207Pb). 204Pb is stable, meaning it does not decay to another Pb isotope. Because 204Pb is stable, and the abundances of 208Pb, 207Pb and 206Pb vary with time, measuring absolute Pb isotope abundances is difficult. As a result, Pb isotopes are expressed as ratios relative to the stable isotope 204Pb: 208Pb /204Pb (Pb8/4), 207Pb/204Pb (Pb7/4), and 206Pb/Pb204 (Pb6/4). Being able to verify the three different decay paths makes Pb isotopes a powerful tool for understanding the evolution and, thus, the age of the U-Th-Pb system (Tosdal et al., 1999). 178 Pb isotopes and associated Th/U, U/Pb data have been used to model the evolution of the earth and define idealized crustal reservoirs of U-Th-Pb (e.g. Stacey and Kramers, 1975). These conceptual models of the evolution of the U-Th-Pb system with time are useful because they provide a crustal reference value to compare Pb composition measurements in rocks and minerals. However, to understand Pb isotope behaviour, it is critical to know the Pb isotope compositions of rock reservoirs through which a particular hydrothermal fluid may have flowed to assess the degree of Pb scavenging from rock along the flow path (Macfarlane et al., 1990; Tosdal et al., 1999). This is critical, since, host rocks can cause significant modification to the Pb isotopic composition of the hydrothermal fluids, for example, granitic rocks can reflect the isotopic composition of the crust they intrude rather to the mantle composition of the magma source (Farmer and DePaolo, 1983, Davison 1996). This reasoning applies to hydrothermal fluids and associated mineral deposits (Tosdal et al., 1999). The Pb isotopic compositions of some potential Pb reservoirs from where the metals from El Alacrán Deposit might have been sourced are presented below. 3.7.1.2 Methodology The Pb isotopic composition of paragenetically constrained sulfide minerals such as pyrite and sphalerite from the El Alacrán Deposit alteration groups (e.g. calc-silicate, calc-potassic, sericitic, and CBM) were analyzed by thermal ionization mass spectrometry (TIMS) and compared with the Pb isotopic composition of pyrite samples from the Cu-Au porphyries and other prospects from the San Matias District (e.g. Mina Cocos and Buenos Aires) Figure 2-3. The objective with the comparison is to identify similarities between the Pb isotopic composition of the El Alacrán Deposit sulfides and the other San Matias District prospects to infer potential 179 genetic relationships. An extended description of the Pb isotopic analyses are presented in section 1.6.1.0. Additionally, the Pb isotopic composition of 41 feldspar grains (oligoclase to andesine) from ten samples from San Matías District intrusions were analyzed by LA-ICP-MS (NuAttom, section 1.6.1.0) and results are compared with the TIMS Pb isotopic composition of the El Alacrán Deposit sulfides. The feldspars grains are from the representative intrusions of San Matías District and from the El Alacrán Deposit basement (Unit 3, section 2.5.1). The Pb isotopic composition of the feldspars is used herein as a proxy of the Pb isotopic composition of the geological unit. The objective with comparing the Pb isotopic composition of the El Alacrán Deposit sulfides with the Pb isotopic composition of the regional units is to establish the regional units that potentially sourced the Pb and metals that formed the El Alacrán Deposit mineralizing fluids. 3.7.1.3 Results and Discussion The Pb isotopic composition of the analyzed sulfides and feldspars are presented in Table 3-5 and Table 3-6, respectively. The 204Pb values of feldspars with errors larger than ±3SD (Appendix H.2), and were excluded in the present analysis. The 208Pb, 206Pb, and 207Pb isotopes in the feldspars instead, showed acceptable errors (< 3SD) (Appendix H.2); therefore, their ratios 208Pb/206Pb (Pb8/6) and 207Pb/206Pb (Pb7/6) from the feldspars are used for comparison with the results in the sulfide samples. The El Alacrán Deposit sulfide data, yields a steep array indicating mixing from a low-radiogenic Pb in the mushketovite-pyrite assemblage to a higher radiogenic Pb in the carbonate-illite and actinolite-vanadium mica assemblages. The Pb values from veins of the mushketovite-180 pyrite and CBM assemblage in veins suggest that this mineralization style probably formed from a different fluid than the bulk of the El Alacrán Deposit mineralization (Figure 3-21A-B). The San Matias District Cu-Au porphyry prospects sulfides have marked differences in their Pb isotopic composition. The early phase of the Montiel E Porphyry (PxHe) displays the least radiogenic values. Similarly, the Costa Azul Porphyry displays intermediate radiogenic values, whereas, the late phase of the Montiel E Porphyry (QFPx) has the most radiogenic values (Figure 3-21). The Pb isotope sulfide results from the Costa Azul Cu-Au Porphyry indicate that the hydrothermal fluids had a different 208Pb and 207Pb isotopic composition than the Montiel E Cu-Au Porphyry (Figure 3-21). This difference supports two distinct Cu-Au porphyry events separated and time and in their fluid chemistry (the Montiel E and the Costa Azul Porphyry events, section. 3.5.1). Although the mineralogy at the Buenos Aires prospect resembles the mineralization from the El Alacrán Deposit (e.g. dominated by Ti-Fe Oxides), the Buenos Aires prospect sulfide sample has an extreme low 208Pb relative to 207Pb. This implies a high contribution of the initial 238Th relative to 235U content that is not observed in the El Alacrán Deposit samples (Figure 3-21A), and suggests that both mineralization events were derived from different sources. Considering the Pb isotopic data from the porphyry prospects as an end-members of Pb reservoir sources, the radiogenic Pb evolution of the Montiel E Porphyry prospect might follow a trend as indicated in Figure 3-21. The mixing array displayed by the radiogenic Pb of the El Alacrán Deposit sulfides, seems to follow a similar behaviour defined of the Montiel E Porphyry, which suggests a possible genetic link. 181 Figure 3-21 208Pb/206Pb vs 207Pb/206Pb diagram for Pb isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralization of the San Matias District. The plumbotectonics Pb evolution curves (Orogen curve) from Zartman and Doe (1981) are included for reference. 182 Table 3-5 Pb isotopic composition of the sulfides from the El Alacrán Deposit and other selected mineralization in the San Matias District Table 3-6 Weighted Average Pb isotopic composition of individual feldspars crystals from selected intrusions and volcano-sedimentary units from El Alacrán Deposit and the San Matias District 183 The 208Pb/206Pb and 207Pb/206Pb ratios of sulfide from the San Matías District prospects are within error of Pb isotopic composition of feldspars of their hosting intrusions (e.g. Montiel E, Costa Azul and La Jagua) (Figure 3-22A-B) except for the late porphyry phase (QFPx) of the Montiel E Porphyry. The disseminated pyrite value from this late porphyry phase differs from the host intrusion feldspars (QFPx). Similarly, the Buenos Aires prospect values differ from the bulk of the San Matías District intrusions but overlap with feldspars from the El Alacrán Deposit basement (Figure 3-22A-B). However, the large error on the Pb isotopes analyses from the basement feldspars precludes its use as evidence to affirm a genetic relationship with the Buenos Aires prospect. The large error in the result is likely due to the degree of high alteration in this sample (LOI= 4.09) (Figure 3-22A-B, Table 3-6, Appendix F.2). The 207Pb/206Pb values in the El Alacrán Deposit sulfides are within error of the isotopic composition from feldspars and sulfides from Montiel E (PxHe) porphyry and La Jagua Tonalite but are closer to the range from the El Alacrán Oeste Tonalite feldspars (Figure 3-22A). Most of the 208Pb/206Pb isotopic compositions in the feldspars from the regional units overlap within the error with the El Alacrán Deposit sulfides challenging to establish a genetic relationship to a specific unit. However, the variation range of the El Alacrán Oeste Tonalite coincides with the interval defined by the El Alacrán Deposit sulfides. The weighted averaged values of the 207Pb/206Pb isotopes suggest that the units in the San Matias District more likely to be related to the El Alacrán Deposit mineralization are: (in decreasing order) El Alacrán Oeste Tonalite, La Jagua Tonalite, and the Montiel E Porphyry. A similar conclusion can be obtained using only the average of the feldspars Pb values of the mentioned units, where the Pb isotopic composition of the El Alacrán Deposit sulfides are closer to the 184 averaged isotopic composition of the feldspars of the El Alacrán Oeste Tonalite, rather than to the La Jagua Tonalite and the Montiel E Porphyry (Figure 3-23). Figure 3-22 207Pb/206Pb (A) and 208Pb/206Pb (B) isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralization in the San Matias District (SMD) and feldspar grains from intrusions of the San Matias District. The bars in the SMD intrusions include the weighted average of the individual feldspars and their ±2σ error.185 Figure 3-23 207Pb/206Pb vs 208Pb/206Pb diagram for sulfides from the El Alacrán Deposit and other selected mineralizations in the San Matias District, and feldspar crystals from the El Alacrán Deposit and other intrusions in the San Matias District. The error lines correspond to ±2σ error. Note the proximity of the average isotopic composition of the El Alacrán Oeste Tonalite feldspars with the El Alacrán Deposit sulfide. It is important to note that the errors associated with the Pb isotopic measurement in the feldspars are large (Figure 3-23) and likely reflects the low Pb contents of the analyzed feldspars (e.g. 30 – 70 An%) and micro inclusions of alteration minerals observed in the analyzed grains. In conclusion, because of the radiogenic Pb analyses herein presented were obtained from different techniques (TIMS vs LA-ICP-MS) and materials (sulfides vs feldspars) (Figure 3-23), direct comparison of the Pb isotopic compositions may not be appropriate. The El Alacrán Oeste Tonalite, however, seems to be the best fit for a Pb source of the El Alacrán Deposit sulfides. 186 The relationship between the El Alacrán Oeste Tonalite and El Alacrán Deposit mineralization should be further assessed and supported using more robust analytical techniques. 3.7.2 S Isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizations of the San Matias District 3.7.2.1 Introduction In nature, the most abundant geological reservoir for S is meteoritic sulfur (δ34S = 0.2 ± 0.2‰) (Kaplan and Hulston, 1966) and sulfur as sulfate in seawater (Seal, 2006). The meteoritic sulfur value is generally regarded as approximating the bulk composition of the earth. This value is similar to the mantle sulfur composition (0‰), which is also recognized as the value for most mantle-sourced magmatic rocks (Ohmoto and Goldhaber, 1997). The sulfur isotopic composition of ancient seawater sulfate is recorded by evaporite sequences and has varied from near 0‰ during Archean times to +21.0 ± 0.2 ‰ in modern oceans (Seal, 2006). For the Late Cretaceous (age of mineralization at the El Alacrán Deposit and the San Matias District), the δ34S in seawater sulfate is estimated at +19 ± 0.2‰ (Paytan et al., 2004). The different mechanisms of sulfide formation from seawater are controlled by temperature (Ohmoto and Rye, 1979). Under low-temperature (T ˂ 50°C), perhaps the only mechanism for sulfide formation is by sulfate-reducing bacteria (Ohmoto and Rye, 1979). In deep euxinic basins where the sulfate reduction occurs slower than the SO42- supply (e.g. in the Black Sea), the δ34S values of sulfides vary between ~-50‰ to -10‰. Conversely, in environments where the sulfate reduction rate is faster than the SO42- supply (e.g. shallow marine and brackish environments), the δ34S values have a maximum population close to -3‰ but can be larger as +30‰ (Ohmoto and Rye, 1979). 187 For hydrothermal systems with temperature > 250°C the formation of sulfide might be controlled by inorganic reduction of seawater SO42- to form H2S. Under this scenario, seawater δ34S close to +20‰ can produce H2S between +20‰ and -5‰ depending of the degree of reduction (Ohmoto and Rye, 1979). In hydrothermal systems, the isotopic ratio of sulfur (34S/32S) in sulfide minerals is currently used for interpreting the sulfur source, transport and precipitation mechanisms of ore deposits (Ohmoto, 1972). The isotopic composition of sulfur in hydrothermal sulfides is strongly controlled by the fO2, pH of the fluids and by the temperature and isotopic composition of the S in the mineralizing fluid (Ohmoto, 1972). Differences in the δ34S along various paragenetic stages in a given hydrothermal deposit might reflect instead, changes in the evolution of the ore-forming fluid relative to its redox state (Ohmoto, 1972). In this respect, a variable δ34S values indicate that fluids precipitated from relative high-fO2 conditions, whereas uniform δ34S has been associated with sulfides that precipitated an intermediate to low-fO2 conditions (Ohmoto, 1972). In porphyry Cu-Au deposits, the majority of the δ34S values of the sulfides fall between -3 and +1‰ (Ohmoto and Rye, 1979). The sulfides in VMS deposits are thought to have formed at a near seawater-rock interface and display δ34S values are typically positive with an average of δ34S = 17‰ lower than the seawater δ34S (Ohmoto and Rye, 1979). These values indicate a mixture between magmatic sulfur and H2S produced by bacterial reduction at a low temperature (Ohmoto and Rye, 1979). In the literature vein-type and replacement-type deposits (e.g. skarns) that formed at 350°C-140°C (Rye and Ohmoto, 1974), usually lack sulfate minerals and have δ34S values of sulfide minerals in a narrow range close to 0‰. The sulfur in these ore-forming 188 fluids appears to have been derived from igneous-sources, and sulfides precipitated in pH-fO2 conditions where H2S was the dominant sulfur species (Ohmoto and Rye, 1979). 3.7.2.2 Methodology The δ34S isotopic composition of paragenetically-constrained sulfides (pyrite, sphalerite pyrrhotite, and arsenopyrite) from different alteration groups at the El Alacrán Deposit (e.g. calc-silicate, calc-potassic, sericitic, and CBM) was obtained. Sample selection also considered sulfides from each of the different mineralization styles (e.g. breccia in-fill, massive, replacement, and veins), and host rock lithofacies (e.g. ABx, TufL, TufF) of the El Alacrán Deposit. The obtained δ34S values were compared to the δ34S isotopic compositions of sulfides from the Cu-Au porphyries and other mineralization of the San Matias District (e.g. Montiel E, Costa Azul, La Jagua and Buenos Aires). 3.7.2.3 Results and Discussion El Alacrán Deposit has a wide δ34S variation from +7.4 to +14‰ (n = 12) (Table 3-7, Appendix H.3), whereas the SMD Cu-Au porphyries display tighter-constrained δ34S values between +7.5 to +7.9‰ (n= 4), which, are closer to the La Jagua mineralization δ34S values (+4.9 ‰, n=1) Figure 3-24A. The difference in δ34S between the El Alacrán Deposit and the SMD Cu-Au porphyries sulfides, suggest marked differences in the S source or fluid chemical conditions associated with the formation of each mineralization style. Samples from the actinolite-vanadium mica and CBM veins assemblage display well-constrained δ34S values (~ +11 ‰) independent of the nature of their hosting lithofacies (Figure 3-24B). This suggests that the S isotopic composition of the sulfides is not controlled by the stratigraphic unit in which they are hosted, so they are more useful for recognizing discrete variations in the chemical conditions of the ore-forming fluid(s). 189 Table 3-7 δ34S ‰ isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizaitons of the San Matías District. Pyrite separates from the mushketovite-pyrite assemblage displays a wide δ34S range from +14.8 ‰ (n= 4) as breccia-infill mineralization (sample SMA_AL_1704_JM_076, Figure 3-24B) to +7.4 ‰ in veinlet mineralization (sample SMA_AL_1704_JM_040, Figure 3-24B). Conversely, the S isotopic composition of sulfides from the actinolite-vanadium mica, carbonate-illite, and CBM assemblages are relatively uniform and vary between +9.5 to +11.7 ‰ (Figure 3-24A). 190 Figure 3-24 δ34S ‰ isotopic composition of sulfides from the El Alacrán Deposit and other selected mineralizations in the San Matias District, with respect to alteration assemblages (A) and host rock lithofacies or intrusions (B). Values for the magmatic (0 ± 5 ‰; Ohmoto and Goldharber, 1997) and seawater sulfate for Late Cretaceous times (+19 ± 0.2‰; Paytan et al., 2004), are indicated in orange and blue, respectively, for comparison purposes. The distribution pattern for δ34S ‰ values of H2S and sulfide minerals when sulfate of δ34S = +20‰ is reduced by Inorganic Reduction at T >250°C (Ohmoto and Rye, 1979) is displayed for comparison purposes. The labelled numbers correspond to the sample suffixes. Abbreviations include ABx=Andesite Breccia; TufL= Lithic tuff; TufF-TufC= fine-grained to coarse-grained tuff; MudSil=Laminated limestone; Lim=Massive fossiliferous limestone. The variability in the mushketovite-pyrite assemblages might indicate a high-oxygen fugacity (fO2) in the ore-forming fluid, as recognized in the literature (e.g. Ohmoto, 1972). This interpretation is consistent with the oxidation state attributed to the Path B pathway of the El 191 Alacrán Deposit discussed in section 3.6.4.2. Similarly, the uniformity of the δ34S values from the actinolite-vanadium mica, carbonate-illite and CBM alteration assemblages indicates that sulfides in these assemblages formed from a fluid with an intermediate- to low fO2 (Ohmoto, 1972), which is consistent with the characteristics attributed to the cooling Path C of the El Alacrán Deposit (section 3.6.4.2). The δ34S values obtained in the samples from the SMD Cu-Au porphyry prospects are shifted towards a heavier isotopic composition and lie out of the δ34S values typically found in porphyry deposits (0 ± 5 ‰; Ohmoto and Goldharber, 1997). Similarly, the sulfur in sulfide samples (i.e. pyrite, chalcopyrite, pyrrhotite, arsenopyrite, and sphalerite) from El Alacrán Deposit does not indicate a clear magmatic contribution; instead, the obtained values indicate various S sources. Alternative S sources might include ancient seawater indicating a reduction close to 8‰ (Difference between 19 ± 0.2‰ and 11 ‰, Figure 3-24). The δ34S in sulfides from El Alacrán Deposit varies from +7.4 to +14.8‰, whereas in the SMD Cu-Au porphyries prospects δ34S is consistent and close to +7.7‰ (Figure 3-24). The δ34S in the El Alacran Deposit can best be explained by a mechanism in which seawater became an ore-forming fluid by various degrees of inorganic reduction of its sulfate through reactions with Fe2+ components in volcanic rocks (e.g. Unit 3) Figure 3-24). The reduction might include the reaction = SO42- + 8Fe2+ + 10H+ ------> H2S +8Fe3+ + 4H2O. The ferric iron as a product of this reaction might explain the large magnetite occurrence associated with the calc-silicate alteration. This mechanism has been recognized as an important ore-forming fluid in environments where submarine volcanism was active, and the circulation of seawater through hot volcanic rocks was established (Ohmoto and Rye, 1979). Alternatively, if δ34S = +7.7‰ is assumed to represent the magmatic sulfur signature and δ34S = + 14.8‰ (the maximum value obtained in this study) represents the seawater-derivate H2S 192 signature, the median δ34S value of the main ore sulfides at El Alacrán Deposit is +11.05‰. Then, above +11.05‰, the fluid has more seawater input than magmatic. Applying this assumption to all the analyzed samples, we can also suggest that the ore fluid from the El Alacrán Deposit was 33% magmatic vs. 67% seawater-derived. In both cases, seawater seems to be the main fluid and sulfur source in the El Alacrán Deposit. 3.7.3 Re content in molybdenite as an indication of the ore-forming fluid conditions Re concentration in molybdenite has been used by some authors to interpret the origin of the chalcophile elements in an ore-forming fluid (e.g. Stein et al., 2001; 2006). Jingwen et al. (1999) concluded from their study on porphyry-related districts in China that Re contents in molybdenite decrease gradually from mantle sources (I-type intrusions) to mixing mantle and crust and then to a crustal source (S-Magmatism). Similarly, Stein et al. (2004) determined that elevated Re concentrations in molybdenites (> 400 ppm) in Central India indicate a subduction-related porphyry origin in the studied deposits. Stein (2006), using data from twelve geological distinct molybdenite-bearing samples in Northern Sweden, demonstrated that sub-ppm level Re concentrations in molybdenite indicated episodic melting of supra-crustal gneisses and concluded that these low concentrations of Re in molybdenites were a direct result of crustal contributions. Re concentrations in molybdenite from porphyry systems dominated by Cu are generally in the hundreds of ppm range, whereas concentrations in Cu–Au or Au–Cu systems reach into the thousands of ppm range (Stein, 2014). There is an interesting correlation between 87Sr/86Sr ratio in the porphyry rock and Re content in molybdenite mineralization in Cu-Mo Porphyry deposits (e.g. Shakhtama, Russia and Erdenetuin-Obo in Mongolia; Sotnikov et al., 2004). In those deposits, high 87Sr/86Sr isotopic 193 ratios (e.g. 0.70495-0.70642) are correlated with low Re concentrations in molybdenite, suggesting that the porphyry intrusion hosting the molybdenite mineralization has been affected by crustal material to a larger extent than deposits with higher Re concentrations and lower 87Sr/86Sr ratios (e.g. 0.70406-0.70416) (Sotnikov et al., 2004; Berzina et al., 2005). In most magmatic systems, the Re contents are elevated in those systems where moly is not a significant phase. There, the Re continues to be incompatible, and contents rise to thousands. As soon as the molybdenite precipitation occurs, the Re contents start to dive in hundreds (C.J.R. Hart, pers. comm., 2020). The Re concentrations reported for molybdenite in the literature may not necessarily reflect the true Re concentration for pure molybdenite; a molybdenite separate may be diluted 95% or more by silicate minerals without compromising age integrity (Stein, 2014). Although the Re-Os analysis on molybdenite samples in this study was made for age dating, the contrasting variation in the Re content in the molybdenite samples from El Alacrán Deposit and the Cu-Au porphyry mineralization in the San Matias District in section 3.5.1 are relatively consistent and reproducible (n= 5). A close relationship between low-Re concentrations in molybdenites with seawater and crustal materials, including evaporites related ore-fluids, has been observed (e.g. Sotnikov et al., 2004). This relationship is also indicated by the Re concentrations of molybdenite from the El Alacrán Deposit, supporting the hypothesis of the influence of a non-magmatic fluid in origin for the chalcophile elements of this deposit. 194 3.8 Conclusions In the following paragraphs, we present the main conclusions of Chapter 3. For this chapter, we obtained the mineral paragenesis of the El Alacrán Deposit and the control exerted by the host rock; also, we provided insights into the possible cooling paths responsible for the mineralogy in the deposit. From a genetic perspective, we obtained the timing of the mineralizing events from the El Alacrán Deposit and the relation with the district mineralizing events. Chemical and isotopic analyses in the El Alacrán Deposit sulfides supported the definition of various sources that might have been involved in the deposit formation. • The evolution of the El Alacrán Deposit produced a sequence of twelve assemblages that are separated into six groups in accordance with their composition and Au-Cu mineral fertility: I) Barren calc-silicate, II) Calc-silicate, III) Calc-potassic, IV) Sericitic, V) CBM, and VI) Calcite-zeolite. • The alteration assemblage distribution in the El Alacrán Deposit indicates a marked lithological control. The most direct control is indicated by magnetite-bearing assemblages that are preferentially developed in laminated limestone (MudSil) from Unit 2. • At the El Alacrán Deposit, apatite and crystalline epidote are paragenetically associated with high-temperature assemblages. Crystalline epidote can be used as a temperature indicator to differentiate between fertile vs barren calc-silicate alteration groups (Group I and II). Similarly, apatite occurrence in the CBM association is used to differentiate relative differences in the formation timing and temperature of the CBM group (e.g. CBM-apatite vs CBM veins assemblages). 195 • Mineral paragenesis and geochronological data indicate at least three evolution paths for the El Alacrán Deposit fluids separated in space and time. Path A responsible for the barren calc-silicate alteration group evolved in alkalic conditions and is spatially related to the Sill 2 occurrence. This fluid does not exhibit a relationship with the Au-Cu mineralizing events and suggests that it occurred earlier ~> 75 Ma than the fluids that formed assemblages from the Path B. However, it is not clear if the propylitic alteration assemblage of the barren calc-silicate alteration is a distal expression of the calc-silicate alteration of Path B. • Path B responsible for the calc-silicate alteration may have evolved at ~75 Ma from an alkaline, intermediate-high-temperature, Fe-rich fluid stable with hematite - magnetite - pyrite - Au in an intermediate-high sulfidation state. Path B is likely to have evolved at constant sulphate/sulfide ratios from a highly-oxidized, Cu-poor fluid, where gold precipitation may be associated 𝑓𝑓O2 decrease in the transformation of hematite to magnetite. Isotopically, Path B is characterized by 208Pb/204Pb ~ 38.21 and δ34S between +7.4 and +14.8 ‰. • Path C, between ~ 73 - 68 Ma may have evolved from a high-intermediate temperature, high-salinity, Cu-rich fluid stable with pyrrhotite - chalcopyrite - pyrite - Au at a low-sulfidation state (calc-potassic alteration group). Fluids in path C changed from a neutral to acidic pH and from low- to intermediate-sulfidation state as it cooled, which is consistent with the mineralogy observed in the sericitic alteration. Fluids from path C are likely to have evolved along a trajectory from pyrrhotite-pyrite stable conditions, where the Au-Cu precipitation might have been the consequence of an increase in the 𝑓𝑓O2. The fO2 increase might be supported by the absence of high-salinity fluid inclusions in the 196 lower-temperature assemblages (sericitic and CBM) that can indicate a mixing with low-salinity and low-temperature fluids (e.g. groundwater). Isotopically, Path C is characterized by 208Pb/204Pb ~38.51 and δ34S between +9.5 and +11.7 ‰. • The CBM veins indicate formation from low-temperature epithermal conditions. Their occurrence adjacent to magnetite-bearing assemblages indicates that significant exhumation and uplift occurred before the emplacement of these veins. This epithermal event may or not be related to the fluid(s) associated with the Path C. • The SMD Cu-Au porphyry prospects (i.e. Montiel E, Costa Azul, and Montiel W) are contemporaneous with the El Alacrán Deposit implying a common metallogenic timing. However, differences in the δ34S isotopic composition and Re concentration in their respective molybdenites indicate that the metals and S derivate from different sources (e.g. the Cu-Au Porphyries from a magmatic source, whereas for the El Alacrán Deposit from a source dominated by seawater). 197 Chapter 4: Genetic Model for the El Alacrán Deposit 4.1 Introduction The El Alacrán Deposit is a Cu-Au mineral deposit within the San Matías District (SMD) in northern Colombia that exhibits mixed characteristics that are usually associated with Iron Oxide Copper-Gold deposits (IOCG), Volcanogenic Massive Sulfides (VMS) and Skarn deposits. In many situations, the tectonic setting can constrain the mineral deposit model, but the tectonic setting of this part Colombia is controversial and does not provide a hard constraint. Additionally, the mineral paragenesis proposed for the El Alacrán Deposit is relatively complex due to significant lithostratigraphic control exerted by the host rocks. The deposit exhibits high-temperature mineral assemblages (> 350 °C) with contrasting redox and pH associations (calc-silicate and calc-potassic) that are difficult to explain with a single ore-forming fluid. Geochronological data indicate that the El Alacrán Deposit mineralization and alteration formed contemporaneously with the San Matías District porphyry Cu-Au occurrences (e.g. Montiel E porphyry); however, Pb and S isotopic data, suggests that the El Alacrán Deposit sulfides formed from a non-porphyry related source. Although this study focused on the El Alacrán Deposit, analytical data from additional mineral occurrences and holocrystalline intrusions of the San Matías District are integrated. Pb and S isotopic data from Andean deposits in Ecuador, Perú and Chile with a tectonic setting and mineralogy similar to the El Alacrán Deposit are used for comparison. Integration of the analytical and field-based data from the El Alacrán Deposit with other district-scale geological elements (e.g. magmatism, minerals deposits, structures, and regional 198 deformation and erosion) can improve the understanding of the evolution of the El Alacrán Deposit as part of a broader mineral system. The comparison with similar selected deposits in the Andes will help to classify the El Alacrán Deposit under accepted mineral deposit models. The preceding chapters documented the geology, the mineral paragenesis, and the geochronological and isotopic data of the El Alacrán Deposit. All these analytical data plus field-based data of the San Matías District are integrated and presented in a temporal framework to understand the pre-, syn-and post-accretional events responsible for the Cu-Au mineralization in the San Matías District. At the deposit scale, two genetic models are proposed for the mineralization at the El Alacrán Deposit, which should be considered for future exploration of similar deposits. 4.2 Tectonic Setting and Magmatic Evolution of the San Matias District The tectonic framework for the San Matias District was established integrating the regional tectonic evolution discussed in sections 1.7 and 1.9, with the field-based paragenetic framework presented in section 2.8. The evolution and current configuration of the San Matías District is discussed in relation to the pre-, syn-, and post- deformation and the dominant tectonic setting (extensional vs. compressional) suggested for the district. The discussion focuses on five geological events developed in the San Matías District area: 1) Early volcanism and plutonism; 2) Brecciation stage in the El Alacrán Deposit; 3) Main mineralization stage at El Alacrán Deposit, 4) Deformation and Orogenesis; and 5) Erosion. 199 4.2.1 Pre-Deformation, Extensional Tectonic Setting During the Late Cretaceous (>77 Ma), a series of oceanic island arcs and intra-oceanic arc basins (e.g. fore-arc, back-arc basins) developed on top of the Caribbean Lithospheric Igneous Province (CLIP). Both, the CLIP and the oceanic arcs are part of the Calima Terrane, which moved northeastward relative to the South American Plate before its collision with the continental margin (Kennan and Pindell, 2009; Villagomez et al., 2011) (Figure 4-1A). The Calima Terrane motion underwent a prevailing NE-SW oriented stress-field in the SMD areas (Figure 2-22) 4.2.1.1 Early Volcanism and Plutonism in the San Matías District At >77 Ma, within a possible back-arc basin, submarine volcanism evolved from mafic (e.g. El Alacrán Deposit Unit 3) to intermediate-acid and resulted in the formation of volcano-sedimentary sequences (e.g. El Alacrán Deposit Unit 2), and to intermediate-acid tuffs (El Alacrán Deposit Unit 1) Figure 4-1B. The occurrence of interbedded bio-clastic lithofacies in the El Alacrán Deposit Unit 2 suggests that this volcanism formed shallower than the carbonate compensation depth (CCD) (< 4000 m; Van Andel, 1975). The El Alacrán Norte Tonalite and Sill 1 represent the early primitive plutonism in the El Alacrán Deposit. At a district scale, the El Alacrán Norte Tonalite and Sill 1 intrusions might be associated with the Alto San Pedro Diorite (Figure 4-1B). 4.2.1.2 Brecciation Stage in the El Alacrán Deposit Around 77 Ma, a series of acid to intermediate phreatomagmatic breccias (RBx and ABx lithofacies, section 2.5.3.1) intruded the El Alacrán Deposit sequence along extensional fault conducts (e.g. paleo-Valdes Fault, Figure 4-1C). The breccias might represent the quenching of the Px1 porphyry intrusion during its shallow emplacement in contact with seawater. This Px1 porphyry represents the earliest Cu-Au porphyry evidence El Alacrán Deposit, and it is possibly 200 Figure 4-1 Pre-deformational evolution of the San Matías District (SMD). A. Schematic diagram indicating the pre-accretional setting of the Calima Terrane and location of the B, C and D diagrams. B., C. and D. diagrams show the tectono-magmatic evolution for the SMD under an extensional tectonic setting at > 77Ma, ~77 Ma, ~75 Ma, respectively. associated with the early Cu-Au porphyry pulses in the San Matías District areas (e.g. the Costa Azul porphyry event, Figure 3-15, Figure 4-1C). 201 4.2.1.3 Main Mineralization Stage at El Alacrán Deposit At 75.8 ± 0.4 Ma (Figure 3-15), the beginning of the El Alacrán Deposit ore formation coincides with the earliest stage of the Betesta-Mina Escondida magmatic suite ( Figure 3-15). This magmatic suite includes the El Alacrán Oeste Tonalite and Sill 2 (section 2.6.3); therefore indicating that the El Alacrán Oeste Tonalite also intruded the El Alacrán Deposit sequence at ca. 75 Ma (Figure 4-1D). Given the similarities in mineralogy between the El Alacrán Deposit and the Buenos Aires prospect (e.g. La-Ce-bearing minerals associated with Fe-Ti oxides, Figure 4-1D, Appendix B.1) both mineralizations might have also formed at ~75 Ma. 4.2.2 Syn-Deformation, Compressional Setting Between ~75 – 72 Ma, a light regional deformation in the San Matías District areas resulted in the inversion of the NS-NNE regional structures (Figure 2-22). This deformation event is possibly related to the approach of the Calima Terrane to the continental margin (~75 Ma, Villagómez et al., 2011) and subsequent accretion of its related arcs (73 - 60 Ma, Cardona et al., 2012, Figure 4-2A). 4.2.2.1 Deformation and Orogenesis in the San Matías District In the El Alacrán Deposit area, a west-dipping paleo-Valdes Fault might have exhumed the western extension of the El Alacrán Deposit sequence and juxtaposed it with deeper volcanic rocks of the Valdes area (Figure 4-2B). Field evidence, such as the widespread hematization of the volcanic rocks of the Valdes area, may reflect the roots of an extinct hydrothermal system. During this stage, the Valdes Fault might have configured its near-vertical dipping and strike-slip kinematics. 202 Figure 4-2 Syn-deformational evolution of the San Matías District (SMD) between ~75 – 69 Ma. A. diagram shows a syn-accretional regional setting for the Calima Terrane and the location of B and C diagrams. B-C diagrams show the deformational evolution of the SMD areas under a regional NEE-SWW-oriented stress-field. This district-scale stress-field is interpreted based on field evidence documented by Manco and Davila (2012) and Starling (2012). Abbreviations: Ca = Calima Terrane, Ta = Tahamí Terrane, Ch = Chibcha Terrane adopted from the tectonic model proposed by Restrepo and Toussaint (1988). As deformation progressed between 72 - 69 Ma, semi-ductile (?) deformation produced a series of asymmetrical anticlines in the San Matías District area. A regional anticline axis may be parallel to the paleo-San Pedro River lineament (Figure 4-2C). During this deformation stage, the NW faults set (e.g. Las Claritas, Teheran, and Montiel Faults) underwent sinistral-transpressional kinematics documented in the San Matías District area (Manco and Davila, 2012, Figure 2-22B, Figure 4-2C). 203 From a metallogenic point of view, the regional deformation in the San Matías District has significant implications because this was contemporaneous with the Montiel E porphyry event (72 – 68 Ma (U-Pb, zircon, section 2.4.1.1., Figure 3-15). This is supported by field evidence that indicates a syn-mineral NE-EW oriented strain prevailing during the Montiel E porphyry prospect emplacement (Starling, 2012; Manco and Davila, 2012). Ages contemporaneous with the Montiel E porphyry Cu-Au event are also recorded in the El Alacrán Deposit (i.e. 68.3 ± 0.5 Ma, Ar-Ar/Sericite, Figure 3-15) and the La Jagua vein (Mina Cocos) (i.e. 68.8 ± 0.8 Ma, Ar-Ar/sericite, Figure 3-15). The 68.3 ± 0.5 Ma age in the El Alacrán Deposit might indicate either the sericite formation by a hydrothermal fluid or the thermal resetting produced by a near intrusion, herein defined as Px2, Figure 4-2C). 4.2.3 Post-Deformation Setting After the Calima Terrane amalgamated to the continental margin (ca. 73-60, Cardona et al., 2012) Figure 4-3A, and under a prevailing NW-SE-oriented stress field in the district discussed in section 1.7 and section 2.8. The arcs in the Calima Terrane might have undergone subsidence and erosion (Cardona et al., 2012). 4.2.3.1 Erosion in the San Matías District The post-deformational tectonic setting is recorded in the San Matías District area by a dextral-transtensional reactivation of the NW-trending faults (section 2.8, Figure 4-3B). The arc erosion in the SMD areas might have sourced sedimentary sequences in the Tertiary San Jacinto Deformed Belt (SJDB) (Figure 4-3C). The San Matías District might be part of a series of dissected Caribbean Arcs that sourced the Late Cretaceous (ca. 80 – 72 Ma) detrital zircons and 204 Figure 4-3. Post- accretional and post-deformation evolution of the San Matías District under an NW-SE-oriented stress-field (Taboada et al., 2000). A. diagram shows the accretion and orogenesis of the Calima Terrane to the continental margin (Tahami Terrane) and the location of the B diagram. B. The diagram displays the current configuration of the San Matías District, where the NW faults (Las Claritas, Montiel, and Teheran Faults) exhibit a transtensional kinematics. Numbers highlight the field evidence that includes: 1. Spread hematization alteration in the west-dipping volcanics sequences west of the Valdes Fault. 2. Non-faulted San Pedro River Lineament. 3. Dextral, transtensive reactivation evidence in the Las Claritas Fault (Cordoba Minerals Corp., pers. comm., 2016). 4. The La Loma de San Juan quarry, where magnetite replacement in east-dipping volcanoclastics is observed. 5. Outcrops in the Betesta area, where west-dipping mineralized volcanoclastics similar to El Alacrán Deposit Unit 2, have been identified. C. The diagram represents the post-accretional arc erosion and formation of the San Jacinto Deformed Belt (SJDB) (Cardona et al., 2012). Abbreviations: Ca = Calima Terrane, Ta = Tahamí Terrane, Ch = Chibcha Terrane. The nomenclature adopted from the tectonic model proposal from Restrepo and Toussaint (1988). magmatic rock clasts to the conglomerates level of the Late Paleocene – Middle Eocene San Cayetano Formation (57 – 40 Ma, Cardona et al., 2012, section 2.2.3.1). La Mecedora locality in the SJFB foothills (Figure 1-1) hosts gold-bearing paleo-placers with tonalite clasts that might be the product of the erosion of magmatic rocks and Cu-Au mineralization from the San Matías District areas. 205 4.3 The Evolution of the Hydrothermal Fluid in the El Alacrán Deposit The model herein presented for the El Alacrán Deposit proposes an important role for the El Alacrán Oeste Tonalite and associated sills (e.g. Sill 2), either as the heat, or metals source. The magnetite and hornblende content, as well as the REE and trace element patterns in the El Alacrán Oeste Tonalite, indicate that the intrusion was relatively oxidized (Figure 2-8C1). The similarity between the 207Pb/206Pb isotopic composition of the El Alacrán Deposit sulfides and the El Alacrán Oeste Tonalite feldspars also indicate a possible genetic association (section 3.7.1.3, Figure 3-22). Finally, the inferred age for the El Alacrán Oeste Tonalite (~ 75 Ma) also coincides with the Re-Os ages in molybdenite from the El Alacrán Deposit mineralization (75.8 ± 0.4 Ma, Figure 3-15, section 3.5.1, section 3.6.2). 4.3.1 Pre-Mineralization Stage The evolution of the hydrothermal fluid in the El Alacrán Deposit started earlier than ~75 Ma with the emplacement of the Sill 2 in the bottom of the El Alacrán Deposit Unit 2. High-heat flux induced by the sill emplacement created a seawater convective system that added Na+, Mg2+ and Cl- from the seawater to the magmatic fluid to produce extensive zones of calc-sodic alteration (quartz + chlorite + albite + apatite). The convective system was fed through a paleo-fault(?) recharge zone, possibly located in the eastern El Alacrán Deposit (Figure 4-4A). As the temperature dropped, the intensity of calc-sodic alteration gradually decreased and manifested as a propylitic and sodic alteration assemblages (Path A assemblages, Figure 3-18). Early interaction with seawater might have caused the pervasive leaching of the Fe from the ferromagnesian minerals of Sill 2 (section 2.7.3.4), which raised upward through a discharge zone to combine later with Path B fluids. 206 207 Figure 4-4. Fluid evolution of the El Alacrán Deposit. A. West-looking schematic diagram of the initial configuration of the El Alacrán Deposit. The schematic diagram shows the El Alacrán Deposit sequence units (Unit 1, Unit 2, and Unit 3), the pre-mineral location of the El Alacrán Norte Tonalite magmatism, and the beginning of the Sill 2 magmatism that led to the formation of the cooling Path A alteration assemblages (Section 3.6.2.2). B. Model I explains the mineralizations and alteration assemblages under a single long-lived fluid as a product of the seawater interaction with the El Alacrán Oeste Tonalite. The lines in the top indicate the relative abundances on Zn-Ag, Au, and Cu in the deposit. C. Modell II explains the mineralizations and alteration assemblages formed from seawater interaction with at least two magmatic fluids; one fluid sourced from the El Alacrán Oeste Tonalite (in Path B) and other sourced from a possibly concealed porphyry source (Px2) consistent with the cooling Path C defined in Section 3.6.2.2. 4.3.2 Mineralizating Stage The intrusion at ~75 Ma of a hydrous and relatively oxidized magma (The El Alacrán Deposit Tonalite) in the El Alacrán Deposit sequence produced a high-temperature (300 - 500 °C, Appendix F) calc-silicate alteration assemblages (Path B, Figure 3-18, Figure 4-4B) and Au precipitation (Au1, section 3.6.4.) Fluid in Path B moved downward along a recharge zone and reacted with the hot host rock to form the intermediate to high-temperature (200 to 300 °C, Appendix F) chlorite alteration assemblage ( Figure 4-4B). To develop the chlorite alteration, the seawater Mg fixed to host rock with Ca from the limestones and possibly with Fe stripped from Sill-2 in Path A (section 3.3.2.3.) The approach of the Fe-enriched Path B fluids to the hot tonalite resulted in the magnetite-quartz assemblage development and subsequent mushketovite-pyrite alteration when Ce-La (possibly remobilized from Unit 3) and S (from the seawater sulfate reduction) combined. The δ34S values in the mushketovite-pyrite alteration assemblage vary from 7.4 to 14.8 ‰, which might indicate a mixed signature between magmatic and seawater sources (section 3.7.2.3). Path B fluid moved northwards through highly-reactive and highly-permeable rocks (e.g. MudSil and ABx lithofacies, respectively) until was buffered by the rock to form the CBM-apatite 208 assemblage at 75.8 ± 0.4 Ma (section 3.5.1).Whole rock geochemistry from the least altered rocks of the El Alacrán Deposit lithofacies generally indicates a low P contents (<1%, Appendix C.1). Therefore, the P to form apatite (Ca5 (PO4)3 (OH, F, Cl)), and possibly Au1 in Path B might have been sourced from the El Alacrán Oeste Tonalite (Figure 4-4B). From this stage, the subsequent evolution and copper mineralization in the El Alacrán Deposit could be the result of two alternative models. Model I derives the fluids from a single initial long-lived fluid (from ~75 to 68 Ma), whereas Model II derives from at least two fluids separated in space and time (~75 Ma and ~73 - 68 Ma). 4.3.2.1 Mineralizing Model I Under a single mineralizing fluid (Fluid Paths B + C, Figure 4-4B), the fluid that formed the early calc-silicate alteration at ~75.8 Ma evolved to be more reduced in the calc-potassic alteration (quartz + actinolite + vanadium mica + pyrrhotite ± ilmenite ± sphalerite) (Figure 4-4B). The V and Ti might have been remobilized from the underlying mafic volcanic rocks (Unit 3), which is a significant source for these elements relative to Units 2 and Unit 1 (Appendix C.1). As the fluid-cooled down, the fluid pH decreased so that the sericite was stable between ~73 - 68 Ma. The Cu solubility dropped and precipitated chalcopyrite + sphalerite + electrum ± molybdenite as part of the carbonate-illite alteration assemblage. Cu may have been sourced from the El Alacrán Oeste Tonalite or leached from the host rock units. Because most of the available Fe was consumed to form the calc-silicate alteration assemblages group, the late-formed chlorite in the sericitic alteration has a low Fe/Mg ratio. Finally, a carbonate base metal (CBM) event at epithermal conditions (220 - 280°C, Hedenquist and Arribas, 2000 section 3.6.2.2) developed from the evolving fluid as the last stage or as another independent fluid. 209 A single fluid model is supported by the consistent δ34S values close to + 11‰ in all the alteration assemblages within the deposit (Figure 4-4B) and by the lack of unambiguous cross-cutting relationships between the different alteration assemblages groups. However, Model I does not explain the following characteristics: • At least two stages of Au precipitation (e.g. Au1, Au2) with contrasting Cu associations. • The bimodal higher temperature gradients indicated by two spatially separated alteration assemblages groups: the magnetite-quartz group in the southern–central part of the El Alacrán Deposit and the actinolite-vanadium mica assemblage in the central-northern part of the deposit. 4.3.2.2 Mineralizing Model II Model II indicates a significant contribution from a distal (~1 km, Figure 1-10), magmatic source (suspected Px2, Figure 3-18) to explain the occurrence of a high-intermediate temperature mineral assemblage (actinolite + quartz and vanadium mica + ilmenite) in the calc-potassic alteration (Path C, Figure 3-18, Figure 4-4C). The magmatic fluid that produced the cooling Path C might have sourced the electrum Au (Au2 section 3.6.4), V, and Cu that co-precipitated with chalcopyrite in the calc-potassic and sericitic alteration assemblages (Figure 3-20). The magmatic fluid in Path C may have evolved from a high-temperature assemblage at ~ 73 Ma towards a lower temperature assemblage at ~68 Ma, consistent with the occurrence of sericite and peripheral base metal-bearing sphalerite and arsenopyrite CBM veins (Figure 4-4C, Figure 3-19). The suspected Px2 intrusion might have been located in the central and eastern part of the El Alacrán Deposit and the fluids introduced into the system through the ABx breccia footwall. 210 Thus, Model II explains the following characteristics: • The different Au precipitations events of the deposit (Au1, Au2, Au3). • The high-salinity fluid inclusions observed in carbonates from the calc-silicate alteration. • The lack of an unambiguous magmatic-derived δ34S signatures in the calc-potassic and sericitic alteration groups. • The very low Re concentrations in molybdenite from the sericitic alteration group. • The Ar-Ar age of the sericitic alteration group (i.e. 68.3 ± 0.4Ma) that is contemporaneous with an established regional porphyry Cu-Au event (The Montiel E event). However, Model II does not sufficiently explain the following characteristics: • The lack of abundant crosscutting relationship of the alteration assemblages from Path C over the Path B alteration assemblages. 4.4 Comparison of the El Alacrán Deposit with other deposits Pb and S isotopic data from the El Alacrán Deposit is compared to similar mineral deposits with ages and geological characteristics resembling those of the San Matías District. In Colombia, available Pb isotopic data comes from some Jurassic to Eocene porphyry prospects documented by Sillitoe and Hart (1984) and from Late Cretaceous intrusion-related mineralization in the Central Cordillera of Colombia documented by Leal-Mejía (2011). In addition, available Pb isotopic data from Cretaceous volcanic rocks of Gorgona Island are presented by Dupre and Echavarria (1984). From an Andean perspective, Pb isotopic data from the Late Cretaceous Ecuadorian deposits (e.g. La Plata, Maucuchi, and Las Pilas) formed under a tectonic setting 211 similar to San Matías District (Late Cretaceous intra-oceanic arc of the Macuchi terrane; Chiaradia et al., 2004) and Pb isotopic data from Upper Jurassic to Lower Cretaceous IOCG deposits in Perú (e.g. Raúl Contestable, De Haller et al., 2006) and Chile (e.g. Candelaria, Marschik et al., 2003) are also considered. When comparing to the available Pb data in a uranogenic diagram (Figure 4-5A), the lead isotope ratios for the samples of the El Alacrán Deposit sulfides (206Pb/204Pb =18.64-18.68, 207Pb/204Pb =15.52-15.59, Appendix H.1) are much less radiogenic compared to the sulfides from the analyzed deposits and provinces in Ecuador, Peru and Chile. The magnitude of the radiogenic Pb shows similar values with the 207Pb/204Pb values reported in primitive sources such as the Gorgona Island and the Antioquia Batholith province. On the other hand, when comparing to the available Pb data in a thorogenic diagram (Figure 4-5B), the lead isotope ratios for the samples of the El Alacrán Deposit sulfides (206Pb/204Pb =18.64-18.68, 208Pb/204Pb =38.21-38.55, Appendix H.1) vary considerably. This significant variation lacks a direct correlation with a single mineral deposit signature; instead, it compares with the isotopic signature of different deposits and provinces (Figure 4-5B). Given the mineralogical similarities between El Alacrán Deposit mineralization and some Andean IOCG deposits (e.g. Sillitoe, 2018), as well as the occurrence of Cu-Au porphyries in the El Alacrán Deposit surroundings, the S isotopic composition of Andean IOCGs and porphyry Cu-Au deposits is also compared with the San Matías District sulfides (Figure 4-6). As a result, the δ34S ‰ obtained in the El Alacrán Deposit are outside of the values (-5‰ to +5 ‰) displayed in the classical porphyry Cu-Au deposits in the Andes (Figure 4-6A). In opposition, the δ34S ‰ 212 Figure 4-5. Pb isotopes from non-galena sulfides of the El Alacrán Deposit mineralizations. The isotopic data are compared with sulfides and rocks from other deposits and provinces in Colombia, Ecuador, Peru, and Chile that formed under a tectonic environment or age similar to the San Matías District. A. Uranogenic diagram (207Pb/204Pb vs 206Pb/204Pb) displaying the El Alacrán Deposit sulfides in black. B. Thorogenic diagram (208Pb/204Pb vs 206Pb/204Pb) displaying the El Alacrán Deposit sulfides in black. Diagrams include the plumbotectonics modelled curves Version II from Zartman and Doe (1981). The displayed isotopic data in Colombia comes from Sillitoe and Hart 1984; Dupre 213 and Echavarria, 1984; and Leal-Mejia, 2011. In Perú comes from De Haller et al., 2006; in Chile from Marschik et al., 2003; and in Ecuador from Chiaradia et al.,2004. Figure 4-6 S isotopic comparison from the El Alacrán Deposit and other Andean deposits. A. Ranges of δ34S values determined for sulfide and sulphate minerals associated with Porphyry Cu-Au deposits. Modified from Escolme (2017). B. Compilation of δ34S values for sulfide minerals, mostly pyrite and chalcopyrite, from selected IOCG, manto-Cu, vein, skarn and magnetite-apatite deposits in northern Chile and southern Perú. Figure modified from Escolme (2017) and includes data from Sillitoe (2003), Ripley and Ohmoto (1977), De Haller and Fontbote (2009). Values are centred close to zero ‰, indicating a predominantly magmatic sulphur source (Barton, 2013). Large deviations at Raul-Condestable are interpreted to indicate a reduction of evaporitic or seawater sulphate (Ripley and Ohmoto, 1977; de Haller et al., 2002) and biogenic sulphur (de Haller et al., 2002). The light blue is the range found in the El Alacrán Deposit sulfides, whereas the darker blue represents the δ34S values obtained in the San Matías District Cu-Au porphyries. 214 of the El Alacrán Deposit sulfides is similar to the δ34S‰ values documented in the main ore stage of the Raúl-Condestable IOCG deposit in Perú (De Haller and Fontbote, 2009; Figure 4-6B). Besides the S isotopic composition, the Raúl-Condestable Deposit in Perú (De Haller and Fontboté, 2009) shares other characteristics with the El Alacrán Deposit, including: • The Raúl-Condestable Deposit has been controversial, initially classified as Cu-Fe-Skarn and Volcanogenic Massive Sulfide (VMS). • The Raúl-Condestable Deposit was formed in a volcanic island-arc to a continental-arc setting under submarine to subaerial conditions. • The Raúl-Condestable Deposit is hosted in volcanic and volcano-sedimentary rocks that include basalts, andesites and limestone (bioclasts-bearing) similar to the El Alacrán Deposit Unit 3 and 2, respectively. • Mineralization occurred contemporaneously with a magmatic complex (Raúl-Condestable Super Unit) that includes a dacite-andesite volcanic dome (El Alacrán Deposit, Unit 1 analogous) followed by subvolcanic quartz-diorite porphyry sill-dikes (El Alacrán Deposit, Sill 1 and Sill 2 analogous) followed by tonalite intrusion that is characterized by high-water content. (El Alacrán Oeste Tonalite analogous). • Mineralization paragenesis indicates the presence of early hematite (mushketovite) in the early-oxidized assemblage. Lateral and temporal zonation indicate a progressive shift to reduced conditions of the fluid until being stable with pyrrhotite. • Three possible sulfur reservoirs are considered in the Raúl-Condestable Deposit (magmatic, seawater and evaporitic where the S indicate 22% seawater-derived and 78% magmatic-derived). 215 Hf, Pb isotopes and lithogeochemical data suggest that the Raúl-Condestable magmas were generated by partial melting in the upper mantle with no direct involvement of continental crust (De Haller et al., 2006). These data are consistent with a local intra-arc extension via a pull-apart mechanism, suggested in the literature to explain the lack of sialic basement underlying that part of the Peruvian coast (De Haller et al., 2006). Raúl-Condestable Deposit is a 32 Mt (De Haller et al., 2006) IOCG mineralization with ore grades close to 1.9 Eq Cu. (Compañía Minera Condestable pers. comm., 2019). In this deposit, the actinolite (± magnetite ± chlorite ± titanite ± albite ± epidote) assemblage represents the high-temperature core of the system with the highest Cu grades that grades upward to a low-Cu grade in the sericite + Fe-rich chlorite assemblage. The actinolite also coincides with an early biotite zone overprinted by quartz stockwork. The upper/distal halo of the Raúl-Condestable Deposit comprises hematite and chlorite + albite (±epidote ± calcite). Scapolite occurs proximal to feeder veins (De Haller et al., 2006). Mineralogy and mineralization styles vary depending on the host rock: disseminated ores are preferentially developed in the massive volcanic rocks, whereas veins and mineralized crackle breccias dominate in the permeable and reactive units (e.g. limestones) (Compañía Minera Condestable pers. comm., 2019). Two different mineral associations are recognized in the deposit: The oxidized association (hematite + magnetite + pyrite + chalcopyrite) and the reduced association (pyrrhotite + pyrite + chalcopyrite) (De Haller et al., 2006). Both associations sequence ends with pyrite, chalcopyrite, and ± sphalerite ± galena. Gold occurs as inclusion in chalcopyrite (De Haller et al., 2006). 216 4.5 El Alacrán Deposit Classification Model Previous works (e.g. Ray G., 2016) suggested that the El Alacrán Deposit mineralization can be explained by a highly-retrograded skarn deposit model. However, the petrographic analyses from this study show no evidence for prograde mineralogy (e.g. garnet or pyroxene) or retrograde textures (Appendix B.2). Similarly, the size of the hydrolytic alteration and calc-sodic alteration assemblage of the El Alacrán Deposit is difficult to explain under a skarn model. Similarly, Dunne (2016b) suggested that the El Alacrán Deposit formation environment is consistent with volcanogenic massive sulfide (VMS) deposits. However, the El Alacrán Deposit lacks syn-volcanic textures that indicate a volcanogenic formational environment. Additionally, the occurrence of a large amount of high-temperature epigenetic magnetite in the El Alacrán Deposit (> 400°C, Appendix F) is not consistent with the amount of magnetite and formational temperatures reported with VMS deposits (<250 - 350 °C, Galley et al., 2007). The carbonate replacement deposit (CRD) was suggested as a genetic model that explains the mineral assemblages of the El Alacrán Deposit (Cordoba Minerals Corp, pers. comm., 2017). However, CRD systems are highly reduced where no oxidized mineralogy (e.g. magnetite/hematite) is documented. A CRD model can only partially explain the El Alacrán Deposit mineralogy, but not a large amount of magnetite/mushketovite (hematite) of the Deposit. The El Alacrán Deposit is a controversial; however, its geological features are more consistent with two mineral deposit models: IOCG and CRD related to a porphyry source. 217 4.5.1 Features Consistent with CRD mineralization (Porphyry Cu-Au -related) • Tectonic environment The El Alacrán Deposit formed under an extensional to compressional intra-oceanic arc setting developed in thin and juvenile oceanic crust similar to many geological environments where porphyry deposits and associated CRDs and epithermal systems are recognized elsewhere (e.g. Southeast Asia, Sillitoe 2010). In contrast, the IOCG formation environment is mostly associated with a continental back-arc extensional setting from a thickened crust (see section 1.12.1). • Porphyry Cu-Au magmatism and mineralization evidence The RBx breccia in the El Alacrán Deposit Unit 1 contains porphyry Cu-Au deposit type clasts with quartz stockwork mineralization (Figure 2-7D). Additionally, trace and minor element geochemistry in magnetite from some magnetite + chalcopyrite-bearing quartz fragments collected in the El Alacrán Deposit Unit 1 are similar to the chemical composition of the magnetites from the San Matías District porphyry Cu-Au deposits (Sample JM113, Figure 10 Appendix F). This evidence suggests the presence of a porphyry intrusion near the El Alacrán Deposit. Similarly, whole rock geochemistry in samples from the TufR lithofacies from El Alacrán Deposit displays a positive Eu anomaly and a REE pattern equivalent to the characteristics found in the Cu-Au porphyries from San Matías District (e.g. (PxHe, QFPx phases from Montiel E, Figure 2-8). This indicates that the Unit 1 rhyolitic tuffs may represent the extrusive expression of a porphyry source. • Contemporaneous porphyry Cu-Au events The mineralization ages obtained in the El Alacrán Deposit are contemporaneous with the Costa Azul and Montiel E porphyry events (ca. 77 and 70 Ma, respectively). Similarly, the Ar-Ar age in sericite from the El Alacrán Deposit alteration (i.e. 68.3 ± 0.4 Ma) is consistent 218 with the youngest individual zircon ages recorded in the Montiel E porphyry (e.g. ~ 68 Ma; Leal-Mejía and Hart 2017). • Acid Alteration assemblage and sulfide content The hydrolytic alteration in IOCG systems (e.g. Andean IOCGs) is less voluminous than the calc-sodic alteration and lacks sulfide mineralization (e.g. Marschik and Fontbote 2001; Barton, 2013). However, the El Alacrán Deposit displays sericite alteration paragenetically associated with sulfides (chalcopyrite and pyrite), which is volumetrically dominant relative to the calc-sodic alteration. The high volume of sericite with sulfide mineralization is a feature more common in porphyry systems (e.g. phyllic alteration, Sillitoe 2010) and CRDs (Megaw and Lentz., 1988) than Andean IOCG systems. 4.5.2 Features Consistent with an IOCG Model • No clear progenitor intrusion Although an association between the El Alacrán Deposit sulfides and the El Alacrán Oeste Tonalite is inferred based on Pb isotopic data (section 3.7.1.3), a clear causative intrusion has not been confirmed for the El Alacrán Deposit. This is a characteristic observed in many IOCG deposits (Williams et al., 2005). • REE- and Co-bearing minerals Ce + La minerals and Co-rich sulfides are recognized either in an early assemblage (e.g. mushketovite-pyrite) and late assemblage (e.g. carbonate-sericite) of the El Alacrán Deposit. REE and Co, along with other crustally derived lithophiles such as Fe, K, Ca, and U, are interpreted to have been incorporated into the fluid during a high-temperature alteration in IOCG systems (e.g., Hitzman, 2000; Richards and Mumin, 2013). 219 • Evidence for non-magmatic surface derivate brines A dominant seawater fluid source in the El Alacrán Deposit mineralization was interpreted from sulfur isotope studies. Connate and basinal fluids are common mineralization drivers in IOCG deposit models (e.g., Barton and Johnson, 1996 Figure 1-7A-B) but have only been rarely reported to be fundamental for porphyry deposits (e.g. Bowman et al., 1987). 4.5.3 Genetic Model Summary The genesis of the El Alacrán Deposit is interpreted to be the product of a complex tectono-magmatic evolution in an intra-oceanic arc setting. The El Alacrán Deposit shows some similarities with porphyry-related origin deposits (e.g. CRD) given the sulfide content, size of the hydrolytic alteration and temporal association with surrounding porphyry Cu-Au occurrences. Similarly, REE mineralogy occurrence, an unclear progenitor intrusion and the evidence of seawater involvement as a main driver of the mineralization are mostly documented in IOCG deposits. In the El Alacrán Deposit, the mineralizing fluid, by the inference of the metals were predominantly sourced from seawater (67%) vs. (33%) magmatic-derivate (section 3.7.2.3). Although the San Matías District hosts porphyry Cu-Au occurrences, which are contemporaneous with the El Alacrán Deposit mineralization, a single porphyry-related fluid cannot explain all the alteration assemblages and the Pb and S isotopic values of the El Alacrán Deposit. A hybrid model between two magmatic sources with marked involvement of seawater seems to explain better the mineralogy, chemistry and isotopic composition of the El Alacrán Deposit. Using a hybrid model (Model II, Figure 4-4C) between IOCG-style mineralization in the south of the deposit and distal porphyry Cu-Au -related mineralization (CRD) in the central-northern part, best accommodates the analytical results. The IOCG-style mineralization (Barton, 220 2013; Figure 1-7A-B) results from a non-porphyry intrusion (El Alacrán Oeste Tonalite and Sill 2, ~75 Ma) that sourced the heat and elements (e.g. P, Si, Fe, and Au) that combined with the seawater S and leached the key elements from host rock (Ce, La, ± Fe) that were critical to forming the calc-silicate alteration mineralogy (apatite + magnetite + mushketovite + pyrite ± Au). The CRD mineralization formed at ~68 Ma in the central-northern part of the deposit from a fluid stable with high- to medium-temperature mineralogy (e.g. actinolite + quartz + ilmenite) and hydrolytic alteration that sourced the large volume of chalcopyrite ± Au. The distal porphyry-related fluids associated with the CRD mineralization might have interacted with seawater and produced an additional enrichment in seawater-derived Cu and S. The lack of a clear magmatic signature in the δ34S values seems to contradict a porphyry-related hypothesis in the central-northern part of the deposit; however, the seawater-derived signatures (δ34S ~ 11‰) can be attributed to an extreme interaction with seawater and the long path of the fluid which masked its original magmatic signatures. This modification in fluid chemistry has been previously recognized in CRD deposits (Megaw and Lentz., 1988). 221 Chapter 5: Conclusions, Exploration Implications and Future Research in the San Matías District, Colombia 5.1 Conclusions Characterization of the El Alacrán Deposit mineralization and the San Matías District geology are nearly absent in the academic literature. The high spatial variability of the alteration assemblages relative to the volcanic lithofacies and the lack of clear cross-cutting relationships make the El Alacrán Deposit challenging to classify. Previous attempts to classify the deposit lacked the integration of regional literature, field evidence, and analytical data. Therefore, this study aimed to characterize the El Alacrán Deposit within the tectonomagmatic-evolution of the San Matías District. The major objectives of this study are: to understand the geological framework for the El Alacrán Deposit, characterize the El Alacrán Deposit mineralogy, establish the timing of the El Alacrán Deposit mineralization, characterize the San Matías District magmatism to identify fertility indicators and to establish a genetic exploration model that can be applied to the whole district. The tectono-magmatic framework of the San Matías District was constructed with sparse available regional literature and field evidence. The mineralogy of the El Alacrán Deposit was characterized using petrography, SWIR spectroscopy, EDS, and EMPA analysis. Re-Os, Ar-Ar, U-Pb geochronology was used to establish the mineralization timing. Whole rock geochemistry and trace elements in zircon supported the characterization and fertility assessment of the San Matías District intrusive rocks. Lastly, S and Pb isotopic analyses were completed to constrain the metals source and ore fluid evolution of the El Alacrán Deposit. 222 The major conclusions of this study are: • The El Alacrán Deposit and the San Matías District formed in a pre- to syn-accretional, allochthonous island-arc tectonic setting in a submarine environment in the Calima terrane previous to its accretion with the continental margin (Tahami Terrane). The arc-related magmatism was built on top of MORB rocks associated with the Caribbean Lithospere Igneous Province, which are the bulk of the Western Cordillera of Colombia. • The El Alacrán Deposit comprises 13 alteration assemblages: calc-sodic, propylitic, sodic, magnetite-quartz, mushketovite-pyrite, chlorite, actinolite-vanadium mica, pyrrhotite-actinolite, carbonate-illite, CBM-apatite, CBM veins, late calcic, and Fe-staining. Based on their composition and spatial distribution, the alteration assemblages are grouped into six major alteration groups (barren calc-silicate, calc-silicate, calc-potassic, sericitic, CBM, and zeolite-calcite). These six alteration groups formed following three different fluid paths (Path A, Path B, and Path C). • Based on petrography, the trace element, and REE patterns, five magmatic suites are distinguished in the San Matías District (Alto San Pedro, El Alacrán Norte, San Jorge, Betesta, and San Matías-La Jagua,). The Alto San Pedro and the El Alacrán Norte magmatic suites are primitive and formed from an anhydrous magma. The San Jorge and Betesta magmatic suites indicate plagioclase and minor hornblende fractionation from intermediate- to low-hydrous magmas. The San Matías-La Jagua magmatic suite indicates a significant fractionation degree consistent with hornblende fractionation from 223 a hydrous and oxidized magma. The porphyry Cu-Au prospects of the San Matías District belong to this later magmatic suite. • Along the Calima Terrane, the district that displays similarities in age (~ 70 Ma) with the San Matías District intrusions corresponds to the Buga Batholith area in Ginebra Valle del Cauca Department, Southern Colombia. The Buga batholith intrusion exhibits similar (La/Sm)N, (Dy/Yb)N, and Sr/Y ratios to those found in the San Matías District intrusions. Preliminarily, we conclude that the magmatism similar to the San Matías District might extend to the Valle del Cauca Department in southern Colombia. • In the El Alacrán Deposit, two different holocrystalline intrusions and sill events are recognized. 1) The El Alacrán Norte Tonalite and Sill 1, which correspond to low-fractionated, anhydrous magma that belongs to the El Alacrán Norte magmatic suite. And 2) The El Alacrán Oeste Tonalite and Sill 2, which formed from relatively fractionated and oxidized magma of the Betesta-Mina Escondida magmatic suite. • The intrusive rocks of the San Matías District have low Zr concentrations (~40.1 ppm) that inhibit zircon growth and the ability to obtain significant analytical data such as U-Pb age, trace element geochemistry and zircon cooling temperature. • The porphyry Cu-Au prospects of the San Matías District formed during two pulses: 1) The Costa Azul pulse (~77 Ma) recognized in the Ar-Ar age in an amphibole alteration of the Montiel W prospect and in the Re-Os ages from molybdenites from the Costa Azul porphyry and some local mineral occurrences around the San Matías and San Jorge 224 village areas. 2) The Montiel E pulse (ca. 72 - 68 Ma). This event is recorded in the Montiel E porphyry zircon ages, the sericite from El Alacrán Deposit, and the Mina Cocos (La Jagua) mineralizations. • The El Alacrán Deposit mineralization formed contemporaneously with the holocrystalline intrusions of the San Matías District (~75 Ma) and overlap in time with the mineralization and alteration age (~68Ma) of the Montiel E Porphyry Cu-Au event. • The El Alacrán Deposit mineralogy, chemistry and isotopic data can be better explained under a hybrid model between proximal IOCG-style mineralization and a distal Carbonate Replacement Deposit (CRD) associated with a porphyry Cu-Au source. The IOCG mineralization is responsible for the calc-silicate alteration assemblage dominated by a large amount of magnetite and mushketovite, whereas the CRD mineralization is responsible for the calc-potassic and sericitic alterations that accompany the high Cu-Au grades in the deposit. • At an Andean scale, the deposit that displays similarities in the host-rock, tectonic setting and mineralogy with the El Alacrán Deposit corresponds to the Raul-Condestable IOCG deposit in Peru. However, the Raul-Condestable IOCG deposit lacks field evidence that suggests having the influence of a porphyry Cu-Au-related source. 225 5.2 Exploration Implications 5.2.1 Deposit Scale The suspected porphyry Cu-Au intrusion (Px1) (section 4.2.1) at the El Alacrán Deposit may lie beneath or in the vicinity of the RBx breccia lithofacies. Textual evidence, such as milled aplite composition-clasts and porphyry with stockwork mineralization embedded in the RBx, suggests this breccia formed under an intrusion-centred position relative to a magmatic source. The SIWR analysis performed in white mica from the El Alacrán Deposit also indicates a high-temperature gradient associated with the RBx breccia position (Appendix D.1) and should be used as an exploration vector. The sector between latitude 855540 - 855750m N in the central-northern part of the El Alacrán Deposit is the more prospective area to explore for a suspected concealed porphyry Cu-Au occurrence (Px2, section 4.2.1) that might be responsible for the CRD-style mineralization. The fact that the calc-potassic alteration occurs paragenetically associated with reduced mineralogy (e.g. pyrrhotite + ilmenite) might indicate a long-travelled fluid from a deep or lateral source if still preserved. Detailed logging of the calc-potassic mineralogy (e.g. vanadium mica), may help delineate the distribution of this alteration, which might help to vector for the Px2 intrusion. Within the IOCG-style mineralization suggested as responsible for the calc-silicate alteration, low-S, hypogene high-grade copper mineralization (e.g. bornite and chalcocite) may occur. Similar Cu-rich mineralization has been recognized in the Raúl-Condestable Deposit, among other IOCG deposits. In well-developed IOCGs, the sulfidation state of the fluid evolution is delineated by zones characterized by changes from pyrite to chalcopyrite + bornite + chalcocite (hypogene). All can occur with either magnetite or hematite, depending on the oxidation state of 226 the fluids (Dr. Alan Wilson pers. comm., 2019). Bornite and chalcocite occurrences are also recognized in the Manto-type IOCG mineralization (e.g. Sillitoe, 2003). 5.2.2 District Scale • Porphyry Cu-Au -related Mineralization The Eu* anomaly and Dy/Yb ratios in zircons of representative samples of the San Matías District magmatic suites (Section 2.5) indicate that the rocks that belong to the San Matías-La Jagua magmatic suite and the Betesta-Mina Escondida magmatic suites are fertile for Cu-Au porphyry mineralization (Appendix G). The fertility analysis in zircons from the La Jagua Tonalite, however, differs from the fertility results using whole rock geochemistry. The whole rock chemistry of La Jagua Tonalite meets the adakite criteria elements (Richards et al., 2012; section 2.3); however, the Eu* in zircons indicate this rock was sourced from a relatively anhydrous magma with a low fO2. In this respect, priority should be given to zircon analyses as they are less susceptible to be perturbed by alteration, rather than to whole rock geochemical analyses (Appendix G). The La Jagua prospect (Mina cocos vein), deserves more attention since the Ar-Ar age (68.83±0.78 Ma) in the sericite that accompanies the pyrite mineralization is coetaneous with the reported ages of the Montiel E porphyry Cu-Au event. This pyrite-rich mineralization might be coherent with the phyllic alteration associated with a blind porphyry Cu-Au source. • IOCG related mineralization Calc-sodic and sodic alteration should be used as a field indication of Fe and metals leaching processes similar to those described for the pre-mineral stage of the El Alacrán Deposit (Path A, section 4.3.1). Additionally, the fact that the mafic volcanics on the western side of the Valdes 227 Fault are strongly hematized can be used as a field indication of the proximity to mineralization similar to that of El Alacrán Deposit. Structural controls are recognized to be an essential feature of IOCG deposits. These deposits are typically localized along high- to low-angle faults, which are generally splays off major, crustal-scale faults (Hitzman, 1992; Williams et al., 2005). In the San Matías District, the structures associated with regional crustal-scale fault systems (e.g. San Jacinto Fault) are associated with the N-S NNE faults set (e.g. The Valdes Fault section 2.8.1). The Valdes Fault seems to have an important control in the location of the El Alacrán Deposit mineralization. Attention should be paid to the delineation of these structures. Faults similar to Valdes Fault are properly recognized either by morphology (e.g. LIDAR images) or airborne geophysics. Because Pb isotopes in the El Alacrán Deposit indicate an association with El Alacrán Oeste Tonalite, identifying the extension of this magmatism, which is geochemically associated with the Betesta-Mina Escondida magmatic suite in contact with reactive and permeable volcano-clastic units should be considered as a favourable scenario to explore for mineralization similar to the El Alacrán Deposit. La-Ce geochemical anomalies in the regional sampling should be included in the geochemical elemental packages given their marked affinity to the El Alacrán Deposit Mineralization. 5.2.3 Regional Scale On a Western Cordillera of Colombia perspective, volcanic rocks of the El Barroso Formation with the unequivocal arc-related signature (marked fractionated REE and trace elements patterns, Figure 2-18), seem to be more promising to explore for mineral occurrences similar to the ones from the San Matías District. Similarly, Late Cretaceous magmatism in the Western Cordillera 228 associated with ages close to ca 75 -70 Ma should be preferred as exploration criteria. In this respect, the available geochronological and geochemical data from the Buga Batholith in the Ginebra Valle del Cauca, Southern Colombia, indicate to be consistent with the San Matías District mineralization (section 2.7.2) and could represent a new focus of exploration. Paleo-placer Au-bearing mineralization should also be considered as a regional exploration potential in the San Matías District surroundings. As previously mentioned in section 4.2.5, Au mineralization from the San Matías District might have sourced some conglomeratic levels of the San Cayetano Formation in the San Jacinto Deformed Belt, in northwestern the Cordoba Department. The definition and exploration strategy should focus on the identification and delineation of the Au-rich paleo-placers similar to the mineral showing identified at La Mecedora locality, northeastern El Alacrán Deposit (Figure 1-1). The strategy might include the use of ground induced polarization (IP) geophysics in the area where the paleo-placers are outcropping. 5.3 Future Research 5.3.1 Deposit Scale • Alternative radiometric age dating (e.g. U-Pb, TIMS in titanite) in the El Alacrán Oeste Tonalite in order to determine the temporal association with the El Alacrán Deposit ore mineralization and validate the current genetic model. • Radiometric dating (U-Pb, TIMS in the available titanite separates) of the TufD lithofacies of the El Alacrán Deposit to date the deposit host rock. 229 • A systematic S isotope study in sulfides of the El Alacrán Deposit that include sulfides samples from different depths in order to and to vectorize magmatic signatures associated with the suspected porphyry Cu-Au sources (Px1 and Px2). 5.3.2 District Scale • Radiometric dating (U-Pb, TIMS in titanite) in the Costa Azul porphyry suite in order to validate the porphyry Cu-Au event at 77Ma. • Radiometric dating (U-Pb TIMS in the available zircons samples) in the Montiel E porphyry intrusive phases in order to constrain the evolution of this porphyry suite. • Radiometric dating (Ar-Ar in whole rock) of the San Matías District volcanic and vulcanoclastic rocks in order to stablish the absolute age of the SMD basement. • Age dating in macro and microfossils from bioclasts-bearing units recognized in the SMD, such as the Lim lithofacies from the El Alacrán Deposit Unit 2 and the La Capitana - William areas (Figure 2-3). • Obtain the whole rock Pb isotopic of the main geological units of the SMD that include a representative unit of the magmatic suites defined in this study and basement rocks. This will help to interpret the Pb isotopic composition from the SMD sulfides as well as to constrain or validate the Pb data obtained from feldspars. 5.3.3 Regional Scale • On a Western Cordillera of Colombia perspective, new research should focus on the delineation of the Late Cretaceous mineral belt that hosts the SMD mineralizations. 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Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1602_JM_001 2016-02-01 historic sample ACD001 160.9 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 90.9 SMA_AL_1602_JM_002 2016-02-01 historic sample ACD002 93.4 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 140.1 SMA_AL_1602_JM_003 2016-02-01 historic sample ACD002 219.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanoclastic 34.2 SMA_AL_1602_JM_004 2016-02-01 historic sample ACD002 293.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic -28.2 SMA_AL_1602_JM_005 2016-02-01 historic sample ACD003 27.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 178.1 SMA_AL_1602_JM_006 2016-02-01 historic sample ACD003 88.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 121.7 SMA_AL_1602_JM_007 2016-02-01 historic sample ACD003 94.6 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 115.6 SMA_AL_1602_JM_008 2016-02-01 historic sample ACD003 146.1 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 67.6 SMA_AL_1602_JM_009 2016-02-01 historic sample ACD005 243.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanoclastic -22.7 SMA_AL_1602_JM_010 2016-02-01 historic sample ACD004 88.3 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 165.9 SMA_AL_1602_JM_011 2016-02-01 historic sample ACD004 218.8 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 62.4 SMA_AL_1602_JM_012 2016-02-01 historic sample ACD005 131.4 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 164.6 SMA_AL_1602_JM_013 2016-02-01 historic sample ACD005 171.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanic 133.6 SMA_AL_1602_JM_014 2016-02-01 historic sample ACD006A 292.1 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanoclastic 4.5 SMA_AL_1602_JM_015 2016-02-01 historic sample ACD007 142.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Sedimentary 133.6 SMA_AL_1602_JM_016 2016-02-01 historic sample ACD001 214.7 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 79.4 SMA_AL_1602_JM_017 2016-02-01 historic sample ACD007 261.2 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 45.0 SMA_AL_1602_JM_018 2016-02-01 historic sample ACD008 159.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 97.6 SMA_AL_1602_JM_019 2016-02-01 historic sample ACD012 51.8 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 177.6 SMA_AL_1602_JM_020 2016-02-01 historic sample ACD06A 92.8 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 146.2 SMA_AL_1612_JM_021 2016-12-01 historic sample Tunnel 1.0 JM EL Alacrán 7.74 -75.73 Tunnel El Alacrán Sill1 Sill/Dike 200.0 SMA_AL_1705_JM_022 2017-05-01 Campaign1 ASA001 254.0 JM EL Alacrán 7.74 -75.74 Core El Alacrán Sill2 Volcanic 123.6 Continuation of Table 1 Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1705_JM_023 2017-05-01 Campaign1 ASA009 172.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Sill1 Sill/Dike 170.5 SMA_AL_1705_JM_024 2017-05-01 Campaign1 ACD042 96.2 JM EL Alacrán 7.74 -75.73 Core Alacrán Oeste Tonalite Porphyry 170.5 SMA_AL_1705_JM_025 2017-05-01 Campaign1 ASA016 81.3 JM EL Alacrán 7.74 -75.73 Core Alacrán Norte Diorite Porphyry 235.4 SMA_AL_1705_JM_026 2017-05-01 Campaign1 ACD039 54.6 JM EL Alacrán 7.75 -75.73 Core Alacrán Norte Diorite Porphyry 232.5 SMA_SJ_1705_JM_027 2017-05-01 Campaign1 SJDDH001 65.0 JM San Jorge 7.76 -75.70 Core San Jorge Diorite Holocrystalline 236.9 SMA_SM_1705_JM_028 2017-05-01 Campaign1 Surface 1.0 JM Rio Verde 7.73 -75.67 Outcrop RioVerde Tonalite Holocrystalline 230.0 SMA_SM_1705_JM_029 2017-05-01 Campaign1 Surface 1.0 JM Alto San Pedro 7.70 -75.72 Outcrop San Pedro Diorite Holocrystalline 190.0 SMA_SM_1705_JM_030 2017-05-01 Campaign1 Surface 1.0 JM Betesta 7.71 -75.70 Outcrop Betesta Tonalite Holocrystalline 270.0 SMA_SM_1705_JM_031 2017-05-01 Campaign1 Surface 1.0 JM Mina Escondida 7.69 -75.71 Subcrop Mina Escondida Tonalite Holocrystalline 260.0 SMA_SM_1705_JM_032 2017-05-01 Campaign1 Surface 1.0 JM Costa Rica 7.72 -75.71 Subcrop Costa Rica Tonalite Holocrystalline 170.0 SMA_SM_1705_JM_033 2017-05-01 Campaign1 Surface 1.0 JM Bucaramanga 7.71 -75.69 Subcrop Bucaramanga Diorite Holocrystalline 250.0 SMA_CA_1705_JM_034 2017-05-01 Campaign1 Surface 1.0 JM Costa Azul 7.72 -75.72 Outcorp Costa Azul Tonalite Porphyry 180.0 SMA_JA_1705_JM_035 2017-05-01 Campaign1 Surface 1.0 JM La Jagua 7.71 -75.71 Outcrop La Jagua Tonalite Holocrystalline 222.0 SMA_SM_1705_JM_036 2017-05-01 Campaign1 Surface 1.0 JM La Capitana 7.71 -75.74 Outcrop La Capitana Aglomerate Holocrystalline 180.0 SMA_SM_1705_JM_037 2017-05-01 Campaign1 Surface 1.0 JM Las Claritas 7.74 -75.70 Outcrop Las Claritas Tonalite Holocrystalline 145.0 SMA_AL_1704_JM_038 2017-04-01 Campaign1 ASA011 43.1 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 149.0 SMA_AL_1704_JM_039 2017-04-01 Campaign1 ACD009 62.2 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 170.0 SMA_AL_1704_JM_040 2017-04-01 Campaign1 ASA009 104.9 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 79.3 SMA_AL_1704_JM_041 2017-04-01 Campaign1 ACD036 113.4 JM,HL EL Alacrán 7.74 -75.73 Core CBM-Ore Ore 83.1 SMA_AL_1704_JM_042 2017-04-01 Campaign1 ACD036 106.7 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 88.0 SMA_AL_1704_JM_043 2017-04-01 Campaign1 ACD036 106.3 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 88.3 SMA_AL_1704_JM_044 2017-04-01 Campaign1 ASA011 96.0 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Ore 110.4 Continuation of Table 1 Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1704_JM_045 2017-04-01 Campaign1 ASA011 105.0 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 103.8 SMA_AL_1704_JM_046 2017-04-01 Campaign1 ASA011 111.3 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 99.2 SMA_AL_1704_JM_047 2017-04-01 Campaign1 ACD036 115.1 JM,HL EL Alacrán 7.74 -75.73 Core CBM-Ore Ore 81.8 SMA_JA_1704_JM_048 2017-04-01 Campaign1 Surface 1.0 JM,HL La Jagua 7.71 -75.71 Mine La Jagua Tonalite Ore 152.0 SMA_AL_1704_JM_049 2017-04-01 Campaign1 ASA051 99.6 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 148.2 SMA_AL_1704_JM_050 2017-04-01 Campaign1 ACD06A 104.0 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 168.1 SMA_AL_1704_JM_051 2017-04-01 Campaign1 ACD036 106.9 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Sill1 Sill/Dike 85.9 SMA_AL_1704_JM_052 2017-04-01 Campaign1 ACD036 39.6 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 136.6 SMA_CA_1704_JM_053 2017-04-01 Campaign1 CADDH002 69.4 JM,HL Costa Azul 7.73 -75.72 Core Costa Azul PxH Porphyry 200.9 SMA_CA_1704_JM_054 2017-04-01 Campaign1 CADDH002 70.0 JM,HL Costa Azul 7.73 -75.72 Core Costa Azul PxH Porphyry 200.5 SMA_ME_1704_JM_055 2017-04-01 Campaign1 SMDDH008 312.5 JM,HL Montiel E 7.75 -75.72 Core Montiel E Andesite Hostrock Volcanic -69.1 SMA_ME_1704_JM_056 2017-04-01 Campaign1 SMDDH011 84.2 JM,HL Montiel E 7.75 -75.72 Core Montiel E Andesite Hostrock Porphyry 41.2 SMA_JA_1704_JM_057 2017-04-01 Campaign1 Surface 1.0 JM La Jagua 7.71 -75.71 Outcrop La Jagua Tonalite Holocrystalline 152.0 SMA_CA_1705_JM_058 2017-05-01 Campaign1 CADDH001 30.4 JM,HL Costa Azul 7.73 -75.72 Core Costa Azul PxH Porphyry 220.6 SMA_ME_1705_JM_059 2017-05-01 Campaign1 SMDDH019 205.0 JM,HL Montiel E 7.75 -75.72 Core Montiel E Andesite Hostrock Volcanic -15.7 SMA_ME_1705_JM_060 2017-05-01 Campaign1 SMDDH008 70.0 JM,HL Montiel E 7.75 -75.71 Core Montiel E_QFPx Facie Porphyry 121.0 SMA_ME_1705_JM_061 2017-05-01 Campaign1 SMDDH012 62.2 JM,HL Montiel E 7.75 -75.71 Core Montiel E_PxHe Facie Porphyry 125.1 SMA_ME_1705_JM_062 2017-05-01 Campaign1 SMDDH026 337.0 JM,HL Montiel E 7.75 -75.71 Core Montiel E_PxTo Facie Porphyry -42.5 SMA_AL_1705_JM_063 2017-05-01 Campaign1 ASA017 158.0 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 17.4 SMA_AL_1705_JM_064 2017-05-01 Campaign1 ACD016 128.2 JM,HL EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Ore 123.6 SMA_AL_1705_JM_065 2017-05-01 Campaign1 ASA046 181.0 JM,HL EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 18.4 SMA_SJ_1709_JM_066 2017-08-02 Campaign2 SJDDH001 67.5 JM San Jorge 7.76 -75.70 Core San Jorge Diorite Holocrystalline 179.5 Continuation of Table 1 Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1709_JM_067 2017-08-02 Campaign2 ACD020 259.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanic -57.5 SMA_AL_1709_JM_068 2017-08-02 Campaign2 ACD002 115.9 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Ore 121.0 SMA_AL_1709_JM_069 2017-08-02 Campaign2 ACD003 192.1 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 24.7 SMA_AL_1709_JM_070 2017-08-02 Campaign2 ACD005 34.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Ore 240.1 SMA_AL_1709_JM_071 2017-08-02 Campaign2 ACD003 91.6 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Ore 118.4 SMA_AL_1709_JM_072 2017-08-02 Campaign2 ACD025 171.0 JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 64.1 SMA_AL_1709_JM_073 2017-08-02 Campaign2 ACD036 51.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 128.4 SMA_AL_1709_JM_074 2017-08-02 Campaign2 ACD032 89.7 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanic 73.1 SMA_AL_1709_JM_075 2017-08-02 Campaign2 ACD055 131.2 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 57.7 SMA_AL_1709_JM_076 2017-08-02 Campaign2 ASA037 112.0 JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit1 Volcanoclastic 104.4 SMA_AL_1709_JM_077 2017-08-02 Campaign2 ACD050 114.4 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit1 Volcanoclastic 113.7 SMA_AL_1709_JM_078 2017-08-02 Campaign2 ACD042 325.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanoclastic 150.0 SMA_AL_1709_JM_079 2017-05-01 Campaign1 ACD042 96.2 JM EL Alacrán 7.74 -75.73 Core Alacrán Oeste Diorite Porphyry 86.8 SMA_AL_1608_JM_080 2016-08-01 historic sample ACD001 42.5 GR,JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit1 Volcanoclastic 187.4 SMA_AL_1608_JM_081 2016-08-01 historic sample ACD001 165.0 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 87.5 SMA_AL_1608_JM_082 2016-08-01 historic sample ACD001 181.8 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 73.6 SMA_AL_1608_JM_083 2016-08-01 historic sample ACD009 60.3 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 171.5 SMA_AL_1608_JM_084 2016-08-01 historic sample ACD009 76.2 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 158.9 SMA_AL_1608_JM_085 2016-08-01 historic sample ACD009 88.4 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 149.1 SMA_AL_1608_JM_086 2016-08-01 historic sample ACD009 148.5 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 100.9 SMA_AL_1608_JM_087 2016-08-01 historic sample ACD009 149.5 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 100.2 SMA_AL_1608_JM_088 2016-08-01 historic sample ACD009 162.5 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 89.7 Continuation of Table 1 Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1608_JM_089 2016-08-01 historic sample ACD016 40.5 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 197.3 SMA_AL_1608_JM_090 2016-08-01 historic sample ACD016 67.2 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 175.0 SMA_AL_1608_JM_091 2016-08-01 historic sample ACD016 139.2 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 114.4 SMA_AL_1608_JM_092 2016-08-01 historic sample ACD016 170.8 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 87.7 SMA_AL_1608_JM_093 2016-08-01 historic sample ACD018 55.6 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 162.2 SMA_AL_1608_JM_094 2016-08-01 historic sample ACD019 29.3 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 147.4 SMA_AL_1608_JM_095 2016-08-01 historic sample ACD021 36.2 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 158.4 SMA_AL_1608_JM_096 2016-08-01 historic sample ASA022 54.0 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 194.5 SMA_AL_1608_JM_097 2016-08-01 historic sample ASA022 73.8 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 179.0 SMA_AL_1608_JM_098 2016-08-01 historic sample ASA037 91.0 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 120.3 SMA_AL_1608_JM_099 2016-08-01 historic sample ASA037 95.5 GR, JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 116.9 SMA_ME_1612_JM_100 2016-12-01 historic sample SMDDH005 101.0 JM Montiel E 7.75 -75.71 Core PxHL Porphyry 161.1 SMA_ME_1612_JM_101 2016-08-01 historic sample ACD009 60.3 GR, JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 171.5 SMA_AL_1801_JM_104 2018-01-12 Campaign 3 ACD081 63.8 JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 187.2 SMA_AL_1801_JM_105 2018-01-12 Campaign 3 ACD055 130.4 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 47.9 SMA_AL_1801_JM_106 2018-01-12 Campaign 3 ACD070 197.0 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 11.1 SMA_AL_1801_JM_107 2018-01-12 Campaign 3 ASA017 98.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 62.8 SMA_AL_1801_JM_108 2018-01-12 Campaign 3 ACD079 81.2 JM EL Alacrán 7.74 -75.73 Core Sill_2 Porphyry 77.7 SMA_AL_1801_JM_109 2018-01-12 Campaign 3 ACD075 207.0 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit1 Volcanoclastic -34.9 SMA_BA_1801_JM_110 2018-01-12 Campaign 3 Surface 1.0 JM Buenos Aires 7.72 -75.72 Mine Buenos Aires Ore Ore 320.0 SMA_BA_1801_JM_111 2018-01-12 Campaign 3 Surface 1.0 JM Buenos Aires 7.72 -75.72 Mine Buenos Aires Ore Ore 320.0 SMA_AL_1801_JM_112 2018-01-12 Campaign 3 ACD015 166.9 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit3 Volcanoclastic 39.9 Continuation of Table 1 Sample ID Sampling date Campaign DH_ID DH Depth Sampler Location Latitude Longitude Sample Type Unit Lithology Elevation m.a.s.l SMA_AL_1801_JM_113 2018-01-12 Campaign 3 ACD030 89.9 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 110.1 SMA_AL_1801_JM_114 2018-01-12 Campaign 3 ACD034 115.5 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 36.9 SMA_AL_1801_JM_115 2018-01-12 Campaign 3 ACD034 269.0 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic -85.4 SMA_AL_1801_JM_116 2018-01-12 Campaign 3 ACD054 257.7 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic -65.9 SMA_AL_1801_JM_117 2018-01-12 Campaign 3 ACD068 105.3 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 147.5 SMA_AL_1801_JM_118 2018-01-12 Campaign 3 ACD081 72.2 JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 180.2 SMA_AL_1801_JM_119 2018-01-12 Campaign 3 ASA030 59.0 JM EL Alacrán 7.73 -75.73 Core El Alacrán Unit2 Volcanoclastic 163.3 SMA_MW_1801_JM_120 2018-01-12 Campaign 3 MWDDH003 48.8 JM Montiel W 7.75 -75.72 Core MW Host Rock Volcanic 121.0 SMA_AL_1801_JM_121 2018-01-12 Campaign 3 ACD079 115.9 JM EL Alacrán 7.74 -75.73 Core El Alacrán Unit2 Volcanoclastic 48.9 SMA_BT_1801_JM_122 2018-01-12 Campaign 3 Surface 1.0 JM Betesta 7.71 -75.70 Outcrop Betesta Tonalite Holocrystalline 270.0 SMA_SM_1801_JM_123 2018-01-12 Campaign 3 Surface 1.0 JM Alto San Pedro 7.70 -75.72 Outcrop San Pedro Diorite Holocrystalline 190.0 SMA_AL_1801_JM_124 2018-01-12 Campaign 3 ACD075 74.6 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit1 Volcanoclastic 73.1 SMA_AL_1801_JM_125 2018-01-12 Campaign 3 ACD075 102.4 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit1 Volcanoclastic 50.3 SMA_AL_1801_JM_126 2018-01-12 Campaign 3 ACD075 126.5 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 30.6 SMA_AL_1801_JM_127 2018-01-12 Campaign 3 ACD075 133.8 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 24.7 SMA_AL_1801_JM_128 2018-01-12 Campaign 3 ACD075 141.0 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 18.8 SMA_AL_1801_JM_129 2018-01-12 Campaign 3 ACD075 152.4 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 9.5 SMA_AL_1808_JM_132 2018-08-16 Campaign 3 Surface 1.0 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 144.0 SMA_AL_1808_JM_133 2018-08-16 Campaign 3 ACD065 110.4 JM EL Alacrán 7.74 -75.74 Core El Alacrán Unit2 Volcanoclastic 83.0 SMA_AL_1808_JM_134 2017-05-01 Campaign 3 ACD039 54.6 JM EL Alacrán 7.75 -75.73 Core Alacrán Norte Diorite Holocrystalline 232.5 Appendix B : Macroscopic and Petrographic Images and Petrography Report B.1 Petrography Report from the San Matias District Intrusions and Prospects. B.2 Petrography Report from the El Alacrán Deposit samples. B.1 Petrography Report from the San Matias District Intrusions and Prospects Begins on following page… PETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Mina Norte Artisanal showsEl Alacran SMA_AL_1612_JM_021Country: ColombiaStained section offcutSummaryLithology: Porphyritic Px+Hb Gabro (200-250 point-counted)Alteration minerals: Chlorite, Actinolite, EpidoteIntensity of alteration: PervasiveMineralization: Traces of Pyrite Fracture infill: Nv Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclaseClinoPyroxene50.0%48.0%1.0%Fine-grained (<0.1mm) groundmass composed plagioclase altered to albite and pyroxene and amphibole altered to chlorite.Medium to fine-grained (up to 1mm), euhedral, tabular phenocrysts with an intense alteration to cryptocrystalline mineral “UknownMineral1” and to Saussurite (Ep+Chl+Car)Medium to fine-grained (~1.2mm- 2mm) euhedral crystals with tabular shapes and semi hexagonal facets in orthogonal cuts to C axis. It occurs as semi radiated aggregates produced by the nucleation on previous minerals. This is altered to “UknownMineral” 2 described below. Given the pervasive alteration is hard to distinguish pyroxene from hornblende. Optically this clinopyroxene is highly pleocroic with high birefringence, high relief and an angled extinction.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1612_JM_021Hornblende 35.0% Medium to fine-grained (~1.2mm- 2mm) euhedral crystals with tabular shapes and semi hexagonal facets in orthogonal cuts to C axis. It occurs as semi radiated aggregates produced by the nucleation on previous minerals. This is altered to “UknownMineral” 2 described below. Given the pervasive alteration is hard to distinguish pyroxene from hornblende. Optically this clinopyroxene is highly pleocroic with high birefringence, high relief and an angled extinction.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description The sample corresponds to a fine to medium porphyritic rock with a groundmass (~50%) composed Al-bite-altered plagioclase, chloritized pyroxene and amphibole. The phenocrysts correspond to medium to fine-grained plagioclase (~10%), euhedral clinopyroxene and eu-hedral hornblende.The sample is pervasively altered to a very fine-grained cryptocrystalline, anhedral, brownish mineral that replaces the plagioclase (8%). The rock also present a propylitic alteration produced by the occurrence of me-dium to fine grained (0.5-1mm), pale green aggregates of chlorite (10%), actinolite (3%) and traces of epidote that replaces the clinopyroxene and hornblende.Mineralization is almost absent and occurs as traces of fine-grained (up to 1mm), anhedral aggregates of py-rite replacing plagioclase. Negative reaction of sample to etching by HF sodium cobaltinitrate (yellow) stain.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 10.0%Medium to fine-grained (0.5-1mm) anhedral crystals of pale green coloration. It occurs as isolated aggregates and replacing tabular shapes possibly of Pyroxene and horn-blende. Actinolite 2.0% Fine-grained (~0.2mm length), pale green, acicular and radiated habit aggregates com-panied with Chl and Epidote. This occurs as selective replacement within crystals and nucleate from Titanite.Titanite 1.0% Fine-grained (up to 1mm), euhedral crystals of pale brown colouration and high relief. It occurs as Isolated crystals and is replaced by chlorite and actinolite.Epidote Tr Fine-grained (~0.2mm), pale yellow, high relief subhedral crystals that replace plagioclase as part of a Saussurite alteration. It is also accompanied by Chl and Act.pyrite Tr Fine grained (up to 1mm), anhedral aggregates replacing plagioclase. carbonate Tr Fine to very fine-grained (<0.1mm), light brown to colourless anhedral aggregates that replaces and rims some mafic mineral crystals. UknownM1 8.0% Very fine-grained (<0.05mm) to cryptocrystalline, anhedral, brownish mineral that replaces the plagioclase superficially and some possible secondary albite. No distinct optical properties characterize this mineral. Possibly the properties were masked out by the plagioclase properties. The composition of this mineral is described in the SEM report (See Appendix D2)* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite UknownM2 7.0% Very-fine grained (<0.01mm) striated, micaceous aggregates with basal cleavage and brownish coloration. This mineral replaces partially to completely the mafic minerals. No distinct optical properties characterize this mineral. Possibly the properties are masked out by the mafic minerals properties. This mineral produces a Na-Al-Si loss and a gaining of Fe-Si compared to the parental horblende mineral.(See Appendix D2)Comments K-felds alteration is not present in this sample. AMag: 2xPPL+RL2mmCBDPhotomicrographsA)Photograph 2X, showing the mineral components of the rock. Note the porphyritic texture of the sample and the pervasive altered groundmass. B) Same as photo A, but with crossed-polars C) Photograph 5X, showing the mineral components of the rock. Note the hornblende macle intergrowth and their border re-placement to carbonate in the lower right corner. D) Same Photo C, but with parallel Nicolls. Note the intense alteration in the plagioclase + albite? Rich groundmass to the UknownM 1. As well as the distribution of the UknownM 2 replacing the mafic minerals.Mag: 2xXPL+RLMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)Hb<CarchlUknownM2 >UknownM1 ><Plag<ClPx<Ab<AbHb<CarchlUknownM2 >UknownM1 ><Plag<ClPx<Ab<AbHb<CarchlUknownM2 >UknownM1 ><Plag<ClPx<AbHbchl Epidote ><Plag<ClPx<Ab<AbHb<CarchlUknownM2 >UknownM1 ><Plag<ClPx<AbHbchl Epidote ><PlagPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ASA01@254mEl Alacran SMA_AL_1705_JM_022Country: ColombiaStained section offcutSummaryLithology: Pervasively altered porphyritic Plag? Gabro (200-250 point-counted)Alteration minerals: Albite, Chlorite , QuartzIntensity of alteration: PervasiveMineralization: Traces of Pyrite Fracture infill: Nv Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase (Phenocrysts)85.0%15.0%Fine-grained groundmass composed mostly of secondary Albite. Also composed of Qtz (~10% ) that varies from 1μm to 0.25mm and minor Chlorite.Fine-grained (0.5-1mm) dusty-brownish coloration , euhedral to subhedral tabular phe-nocrysts. In some crystals, the twining has disappeared for the intensity of the alteration.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_022Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample corresponds to a fine holocrystalline rock, with porphyritic texture. The groundmass constitutes about 85% of the sample, the preserved phenocrysts corresponds to fine-grained (0.5-1mm) euhedral to sub-hedral plagioclase (~15%).The sample is highly altered to an early calcic? alteration, defined by the occurrence of fine to very fine-grained albite (45%), which is also partially altered to a clayish, dusty, brownish mineral defined here as “UknowmM1”. Chlorite (30%) is present in two different fractions. 1) Very fine-grained (<0,1mm) aggregates that intergrows albite and quartz and 2) A medium-grained (>1mm) aggregates with a random distribution in the sample. Negative reaction of sample to etching by HF sodium cobaltinitrate (yellow) stain.Mineralization occurs as fine grained (<0,1mm) traces of anhedral pyrite accompanying chlorite MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 5.0%Medium to fine-grained (0.5-1mm) anhedral crystals of pale green coloration. It occurs as isolated aggregates and replacing tabular shapes possibly of Pyroxene and horn-blende. Carbonate 3.0% Fine-grained (0.1-0.2mm) colourless, anhedral aggregates replacing plagioclase and Quartz. Titanite Tr Fine-grained (<0.1mm), colourless, anhedral aggregates with high relief that accompany carbonate. UknownM -- Very fine-grained (<0,05mm) cryptocrystalline clay as product of alteration of plagioclase and albite. No distinguish optic properties.pyrite Tr Fine-grained (<0,1mm) anhedral, isolated aggregates accompanying chlorite. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Comments Quartz+ Chlorite constitutes an assemblage previous with the carbonate + titanite assemblage. Possible Albite is part of the Qtz + chlorite assemblage. AlbiteChlorite45.0%30.0%Fine to very fine-grained (~0.05-0.1mm length), elongated to sub tabular shapes occur-ring mostly in the groundmass intergrowing and partially replaced by chlorite. This is also partially altered to a clayish, dusty, brownish mineral “UknowmM”. There are two chlorite fractions.1. Very fine-grained (<0.1mm), elongated, pale green aggregates that intergrow with albite and Qtz and the groundmass. 2. Fine to Medium grained (>1mm) anhedral, pale green, anhedral aggregates with a random distribution in the sample. AMag: 2xPPL+RL2mmCBDPhotomicrographsA) Photograph 2X exhibiting the mineral components in the sample. Note the parental porphyritic texture of the rock. Also note the pervasive alteration to the clayish mineral. B) Same Photo A, but with crossed Nicolls. C) Photograph 20X, Representative of the chlorite and albite distribution in the groundmass. D) Same Photo C, but with Parallel Nicolls. Nothe the distribution of the claying mineral and some Fe-Ox in the chlorite in the upper central part.Mag: 2xXPL+RLMag: 20xPPL+RL0,2mm Mag: 20xXPL+RL0,2mm2mm<Car<chl<Plag<Ab<chl< UknownMXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length)<qtzchlQtz>Qtz><Car<chl<Plag< UknownMQtz>Qtz><Plag<chl<Ab<Ab<chl<qtzchl<Plag<chl<AbPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ASA09@172.5mEl Alacran SMA_AL_1705_JM_023Country: ColombiaStained section offcutSummaryLithology: Fine-grained porphyritic Px+Hb diorite (200-250 point-counted)Alteration minerals: Albite, Chlorite, carbonate, Intensity of alteration: Intermediate Mineralization: Traces of PyriteFracture infill: NvMineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase (Phenocrysts)58.0%33.0%Fine-grained (<0,1mm) groundmass composed of partially altered plagioclase to albite, and chloritized clinopyroxene and amphiboles. Medium-grained (up to 2mm), subhedral to anhedral partially replaced to sericite and clay. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_023HornblendeClinoPyroxene28.0%3.0%Medium-grained (1- 2.0mm length) pale green to brown. Possibly some of the defined here as hornblende correspond to pyroxene. However, given the pervasive alteration is hard to distinguish both phases. (As a total the sample has 20% of mafic minerals, 30% of them possibly corresponds to hornblende). Optically, it is pleocroic from green to brown and exhibit a low relief. Medium-grained (1- 2.5mm length) euhedral, tabular aggregates altered to chlorite and carbonate. Possibly some of these crystals corresponds to hornblende, but given the pervasive alteration, it is hard to distinguish between both phases. (As a total, the sam-ple has 20% of mafic minerals, 70% of them possibly corresponds to Pyroxene). Optically it corresponds to a high pleocroic, high birefringence, high relief, mineral with absent cleavage development. Magnetite 1.0% Fine-grained (up to 0,5mm), euhedral, sub-rounded Isolated crystals Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample corresponds to a fine to medium-grained holocrystalline rock with porphyritic texture. Ground-mass constitutes about 58% of the sample and it is composed mostly of plagioclase and mafic minerals. The phenocrysts are mostly of medium-grained (up to 2mm), subhedral to anhedral plagioclase (16%), medi-um-grained (1- 2.5mm length) euhedral pyroxene and (1- 2mm length) hornblende. Primary magnetite occurs as fine-grained, euhedral to sub-rounded isolated crystals in the sample. Alteration intensity is intermediate to low and it is produced by the occurrence of fine grained (<1.0mm) stri-ated, aggregates of albite (15%) mostly replacing the fine plagioclase in the groundmass. Also by chlorite that occurs as medium to fine grained (up to 1mm) pale green aggregates replacing pyroxene and hornblende. Also actinolite, carbonate, apatite and epidote are present in the sample (up to 3%).Patchy reaction of sample matrix to etching by HF sodium cobaltinitrate (yellow) stain.Mineralization is almost absent, it was just observed as very fined-grained traces of disseminated pyrite. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsIllite 2.0%Very fine-grained (<0.1mm) flaky aggregates that occurs mostly as partially replacement of the plagioclase. Carbonate 2.0% Fine to medium-grained (~1mm), anhedral, colourless, aggregates occurs replacing mafic minerals and plagioclase. This also occurs with epidote and chloriteActinolite 3.0% Fine-grained (0.2mm) pale-green, high relief, acicular aggregates replaced partially by chlorite. Occurs mostly with epidote. Optically present birefringence of gray and yellow of 1st order. Epidote 1.0% Fine-grained (up to 0.5mm), anhedral, pale-yellowish, high-relief, aggregates. pyrite Tr Fine-grained (<0,1mm) anhedral, disseminated in the sample. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite AlbiteChlorite15.0%6.0%Fine-grained (<1mm), striated, semi tabular aggregates mostly replacing the fine pla-gioclase-rich groundmass.Medium to fine-grained (up to 1mm) pale green, anhedral aggregates that occur in the ground mass and replacing tabular shapes possibly of pyroxene and hornblende. Also chlorite show intergrowth textures with carbonate and epidote and replaces previous actinolite crystals. Apatite Tr Fine-grained (~0.4mm), colourless with multiple inclusions, subhedral, occurs with traces of Qtz and both minerals are cut and replaced by carbonate.AMag: 2xPPL+RL2mmCBDPhotomicrographsA) Photograph 2X exhibiting the distribution of the minerals in the sample. Note the porphyritic texture and Albite altered groundmass.B) Same Photo A, but with crossed Nicolls. C) Representative photo of the distribution of Chl and Actinolite around some apatite crystals, Note the later placement of Car-bonate.D) Same Photo C, but with Parallel Nicolls.Mag: 2xXPL+RLMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mm2mm<Ab<chlXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Ap<Ab<Plag<ClPx<Act<Car<ClPxHb><Plag<Ab<Plag<ClPxHb><Plag Hb/Px><Ab<Ab<chlAp<ClPx<Act<Car Hb/Px><AbPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ACD042@96.2mEl Alacran SMA_AL_1705_JM_024Country: ColombiaStained section offcutSummaryLithology: Medium-grained inequigranular Px+Hb tonalite (200-250 point-counted)Alteration minerals: silica, chlorite, carbonate, clay and minor sericiteIntensity of alteration: Intermediate to weakMineralization: Traces of pyriteFracture infill: NvPolished Thin section Description The sample corresponds to a medium-grained, holocrystalline, sub-hypidiomorphic rock composed mostly of medium-grained (~2mm) euhedral plagioclase crystals (50%), medium-grained (~2.5mm) euhedral clinopy-roxene (7%), fine-grained (~0.5mm) anhedral quartz (13%), and fine-grained (~0.25mm) euhedral hornblende (16%). Magnetite (~2%) is widespread as fine-grained (<0.25mm), euhedral aggregates that intergrow with plagioclase.Alteration intensity is medium to weak and is represented by silicification (11%), a very fine-grained pale-green chlorite (15%) after mafic minerals and sericite and carbonate (~2%) as alteration product of the plagioclase and chlorite. Weak to absent reaction of sample matrix to etching by HF sodium cobaltinitrate (yellow) stainMineralization is almost absent, just represented by a very fine- grained fraction (<0.04mm) of pyrite that occurs with chlorite.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseClino Pyroxene50.0%7.0%Medium-grained (~2mm), euhedral tabular shapes with a weak to intermediate alter-ation to clay and sericite. Medium-grained (~2.5mm) euhedral, colourless, high relief, equidimensional to tabular shapes partially altered to Chl. Optically present an inclined extinction and high birefrin-gencePETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_024Quartz 13.0% Fine-grained (~0.5mm) anhedral, colourless, aggregates randomly distributed in the sample. This is distinguished from secondary quartz given the granular shapes of the primary crystals. Hornblende 16.0% Fine-grained (~0.25mm), euhedral, greenish coloration (pleocroic), highly altered to chlorite. Magnetite 2.0% Fine-grained (<0.25mm), euhedral, sub rounded, isolated crystals disturbed in the groundmass and as inclusion in the mafic minerals and plagioclase.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 15.0%Very fine-grained (<0.1mm) anhedral, pale green aggregates selectively replacing some previous pyroxenes and hornblende. This is altered to carbonate. Carbonate 2.0% Fine to medium-grained (up to 1mm), anhedral, colourless aggregates, occurs as chlorite replacements from previous pyroxene and hornblende. Sericite 1.0%pyrite Tr Very fined grained (<0,04mm) anhedral aggregates associated with the Chl occurrence (Just identified in one spot).* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Comments Given the distribution and size of the magnetite, this is interpreted to have a primary origin.Silica 11.0% Cryptocrystalline masses (<0.01mm), colorless replacing selectively the border of pla-gioclases.AMag: 2xPPL+RL2mmBPhotomicrographsA) Photograph 2X, Exhibiting the distribution of the minerals in the sample. Note the Sub-porphyritic texture and the silicification effects in the plagioclase. B) Photograph 2X, same as Photo A but with crossed Nicolls. Note the relict habit of pyroxenes replaced by chlorite. Mag: 2xXPL+RL2mmXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<Qtz<Plag<ClPxHb><Mag<Silice<ClPx<Plag<Qtz<Plag<ClPxHb><Mag<Silice<ClPx<PlagFine to very fine-grained (<0.05mm) flaky aggregates, partially replacing plagioclase. Usually it is accompanied by Clay. This is partially stainned to yellow with HF sodium cobaltinitratePETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ASA16@81.3mEl Alacran SMA_AL_1705_JM_025Country: ColombiaStained section offcutSummaryLithology: Fine to medium-grained inequigranular Px+Hb Tonalite (200-250 point-counted)Alteration minerals: silica ± sericite ± chloriteIntensity of alteration: Weak to intermediateMineralization: Pyrite tracesFracture infill: Quartz veinletsPolished Thin section Description Fine to medium-grained holocrystalline rock with inequigranular distribution composed mostly of (~2mm length) euhedral plagioclase (40%), quartz (13%) and up to 1.5mm length anhedral hornblendes (21%) and traces of pyroxenes. Primary magnetite occurs as very fine to fine grained (<0.1 to mm) anhedral disseminated aggregates mostly intergrowing with titanite in hornblende.Alteration of the samples is produced by silicification of the plagioclase borders and minor quartz veinlets oc-currence. The sample also presents a strong alteration of the plagioclase to clay and minor sericite (2%). Also, minor chlorite and epidote after hornblende and pyroxene (<2%). Patchy reaction of sample matrix and strong reaction of fracture infill to HF sodium cobaltinitrate (yellow) stain.Mineralization is almost absent, it was just observed as very fined-grained traces of disseminated pyrite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_025Plagioclase 40.0% Medium-grained (~2mm length) euhedral, tabular aggregates with strong alteration to a very fine grained (<0.05mm) dusty clayish aggregates and minor sericite. No zonation was observed.Hornblende 21.0% Medium-grained (up to 1.5mm), anhedral, pale greenish to brownish pleocroism, exhibit more elongated and tabular shapes. It is mostly altered to chlorite. Quartz 13.0% Fine-grained (~0.5-0.7mm) Occurs mostly in the groundmass, with irregular shapes. This was separated from the secondary Qtz, by the granular aggregate texture and inter-growth with the primary minerals. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Magnetite 3.0% Very fine to fine-grained (<0.1 to mm), anhedral, disseminated aggregates mostly inter-growing with titanite in hornblende.Pyroxene-Augite? 1.0% Medium-grained (~2mm to 3.5mm), euhedral to anhedral crystals highly altered to am-phibole? that gives a striated texture and remarkable pleocroism. Optically presents 2nd middle order of birefringence. Mineralizationpyrite Tr Very fine to fine-grained (~0.2mm), anhedral aggregates that occur as isolated crystals replacing mostly hornblende.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSericite 2.0% Very fine-grained (<0.1mm) flaky aggregates selectivity replacing plagioclase and also occurring in fractures and veinlets. Chlorite 1.0% Fine-grained (>0.1mm), pale green, anhedral aggregates selectively replacing horn-blende. Amphibole 1.0% Fine-grained (up to 0.5mm), anhedral, replaced selectively by chloriteSilica 12.0% Fine to medium-grained (0.8-1.2mm), anhedral aggregates that occurs as rim-ming pla-gioclase and as quartz veinlets (0.25mm wide). Epidote Tr Fine-grained (~0.2mm), yellowish, high relief, euhedral crystals overgrowing plagioclase. K-Feldspar 5% Very fine-grained (<0.1mm), colorless, dusty aggregates patchy distributed in the sample. Occures in the proximity of yellowish, high relief, euhedral crystals overgrowing pla-gioclase. It was identified using HF sodium cobaltinitrate (yellow) stain.AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 4X exhibiting the distribution of the minerals in the sample. Note the distribution of Magnetite in the sample. As well as the alteration mineral after the rock former hornblende. B) Photograph 4X, same as Photo A, but with crossed Nicolls. Note the silica and sericite veinlets and the rimming silica from plagioclase borders.C) Photograph 10X showing the occurrence of epidote, chlorite and silica alteration in the sample. Note the sericite cutting the chloritized hornblende. Mag: 2xXPL+RLMag: 10xPPL+RL0,4mm2mmXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 2.18mm (Length)<Hb<Plag<Ser<Silica<Plag<Ep<chlHb<Tita<Ser Hb/Px><Chl<Silica<Hb <Qtz<Chl<Hb<Plag<Ser<Silica<Plag<Silica<Hb <Qtz<Chl<HbPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ACD039@54.6mEl Alacran SMA_AL_1705_JM_026Country: ColombiaStained section offcutMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseHornblende> PyroxeneAugite?56.0%23.0%Medium-grained (up to 2mm) subhedral to anhedral, tabular shapes partially replaced to saussurite-clay. That gives to the plagioclase a black-brown dusty coloration. Medium-grained (~2mm to 3.5mm), euhedral to anhedral crystals highly altered to am-phibole? and chlorite that gives a striated texture and remarkable pleocroism. Optically presents 2nd middle order of birefringence. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_026Quartz 13.0% Fine-grained (~0.5-0.7mm) Occurs mostly in the groundmass, with irregular shapes. This was separated from the secondary Qtz, by the granular aggregate texture and inter-growth with the primary minerals. Magnetite 1.5% Fine-grained (up to 2.5mm), anhedral, isolated crystals mostly related with mafic miner-als occurrence. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SummaryLithology: Medium-grained inequigranular pyroxene dioriteAlteration minerals: Silica, k-felds+clay, chlorite Intensity of alteration: Medium Mineralization: Pyrite TracesFracture infill: NVPolished Thin section Description This sample correspond to a medium-grained holocrystalline rock with an inequigranular to porphyritic in texture composed mostly of a plagioclase-rich groundmass (56%). The phenocrysts correspond to medium-grained (up to 2mm) subhedral to anhedral plagioclase and medi-um-grained (~2mm to 3.5mm) euhedral clinopyroxene (augite) with diuretic replacement to hornblende. Also it presents a fine-grained (~0.5-0.7mm) occurrence of anhedral quartz (13%). This quartz was differentiated of the secondary quartz by its granular aggregate texture and intergrowth with the primary minerals. The main alteration is silicification (18%) that occurs rimming plagioclase. Also, a very fine-grained to cryp-tocrystalline aggregate of a dusty mineral that occurs as an alteration product of plagioclase (10%). In some ares this mineral coincides with the patchy reaction to HF sodium cobaltinitrate (yellow) stain. Suggestion K-Feld alterationPale green, flaky aggregates of chlorite occurs in the groundmass and replacing previous pyroxene crystals. The mineralization occurs as fine-grained (0.2mm) anhedral aggregates of pyrite that selectively replaces maf-ic minerals. (~0.5%). MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 4.0%Fine to very fine-grained (~0.12mm), pale green, anhedral to flaky aggregates that occurs in the groundmass and replacing previous pyroxene crystals. Actinolite Tr Fine-grained (~0.5mm) pale green, acicular aggregates intergrowing with chlorite. pyrite 0.5% Fine-grained (0.2mm), anhedral aggregates that selectively replaces mafic minerals. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaSaussurite3.0%10.0%Fine-grained (~0,5mm) anhedral, disseminated aggregates. Also occurs as alteration product rimming plagioclase. Very fine-grained to cryptocrystalline aggregates that occurs in plagioclase, producing a grey dusty texture. AMag: 4xPPL+RL1mmCBDPhotomicrographsA) Photograph 4X, Exhibiting the distribution of the minerals in the sample. Note the saussutirization effects in the plagioclase. Also the amphibole alteration (Brownish colour) on the pyroxene crystals. B) Photograph 4X, same as Photo A, but with crossed Nicolls. Note the silicification rimming in the plagioclase crystals. C) Representative 2X of the distribution of the major minerals in the sample. D) Same Photo C, but with Parallel Nicolls.Mag: 4xXPL+RLMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mm1mmPPL FOV~ 5,9mm (Length) XPL FOV~ 5,9mm (Length)XPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<ChlPlag<ClPx Silica><Chl<Plag<Hb after ClpXPlag<ClPxSilica><Chl<PlagHb>PlagSilica><Chl<PlagClPx<SaussuritePlagSilica><Chl<PlagClPx<Saussurite<SilicaPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: SJDDH001@65mEl Alacran SMA_AL_1705_JM_027Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb+Bt diorite (200-250 point-counted)Alteration minerals: chlorite, sericiteIntensity of alteration: Weak to very weakMineralization: Traces of disseminated pyriteFracture infill: Veinlet of pyrite and chloriteMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseHornblende56.0%21.0%Medium-grained (up to 2mm) colourless, euhedral to subhedral, tabular aggregates partially replaced to sericite (up to 5% average of the crystal). Correspond to Anortite 62 Medium-grained (up to 3mm length), dark green to pale yellowish brown, subhedral to anhedral aggregates intergrowing with biotite and partially replaced to chlorite, pyrite and magnetite. In addition, hornblendes show overgrowth after pyroxene. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_027Biotite 9.0% Fine-grained (0.5-1mm) brownish, striated, basal habit. Occurs as flaky and isolated crystals intergrowing with hornblende and partially altered to chlorite. Quartz 13.0% Fine grained (up to 0.2mm), colourless, anhedral aggregates intergrowth plagioclase and hornblende. There are fluid inclusions up to 5μm. Magnetite 1.5% Fine-grained (up to 2.5mm), anhedral, isolated crystals mostly related with mafic miner-als occurrence. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample correspond to a medium-grained (up to 2mm), holocrystalline, phaneritic equigranular rock com-posed of euhedral to subhedral crystals mostly of plagioclase (58%), hornblende (22%) and fine-grained (up to 0.2mm) anhedral aggregates of quartz in intergrowth with biotite (3%). Primary magnetite occurs as very fine-grained (~25μm) subhedral aggregates that intergrow with hornblende.The rock is weakly altered, showing a weak propylitic alteration produced by the occurrence of fine-grained, pale green to light brown chlorite that occurs with traces of epidote and carbonate and a weak silicification (4%). The sample presents a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain.Mineralization is almost absent, just traces of pyrite were observed along an isolated vein accompanied by chlorite and weakly developed epidote selvages.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSilica 4.0%Very fine-grained to fine grained (~0,1mm), colourless, anhedral aggregates replacing some plagioclase borders. pyrite Tr t is observed in anhedral shapes along an isolated vein accompanied by chlorite and weak developed epidote selvages. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite ChloriteSericite3.0%1.0%Fine-grained, striated, basal habit, markedly pleocroic from pale green to light brown. Occurs as replacing product after hornblende and biotite. Also occurs along one vein accompanied by pyrite. Very fine grained (<0.05mm) pale green, high relief, flaky aggregates that occurs replac-ing plagioclase and as part of the veinlets. AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X, exhibiting the distribution of the minerals in the sample. Note the Py veinlet in the sample accompanied by chlorite. B) Photograph 2X, same as Photo A, but with crossed Nicolls. Note the distribution of the silicification effects in some plagioclase. C) Photograph 10X, showing a possible relictic crystal of pyroxene embedded or altered to hornblende. Also, note the close rela-tion of the primary magnetite and the biotite. Mag: 2xXPL+RLMag: 10xPPL+RL0,4mm2mmXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 2.18mm (Length)<ChlSilica><Chl<Silica<HbPlagSilica>HbMagClPxClPx<Bt<PyPlag<Qtz<Ep<ChlSilica><Chl<Silica<Hb<Bt<PyPlag<Qtz<Ep<ChlQtz<BtPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Rio VerdeEl Alacran SMA_AL_1705_JM_28Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb+Bt tonalite (200-250 point-counted)Alteration minerals: chlorite, sericiteIntensity of alteration: Weak to very weakMineralization: Traces of disseminated pyriteFracture infill: Veinlet of pyrite and chloriteMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseHornblende53.0%27.0%Medium-grained (~1.5mm) colourless, mostly euhedral, tabular aggregates partially replaced to sericite. The crystals show a weak zonation. Medium-grained (up to 1.3mm length), dark green to pale yellowish brown, anhedral aggregates intergrowing with biotite and partially replaced to chlorite.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_028Quartz 16.0% Fine-grained (up to 0.2mm), colourless, anhedral aggregates in intergrowth with pla-gioclase and hornblende. The criteria to define it as primary quartz is the lack of reaction with touching crystals. Biotite 4.0% Fine-grained (0.5mm) brownish, striated, basal habit. Occurs as flaky and isolated crys-tals intergrowing with hornblende and partially altered to chlorite. Magnetite 2.0% Very fine-grained (~0.5mm), subhedral aggregates. Occurs replacing or intergrowing with hornblende. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample correspond to a holocrystalline, sub-hypidiomorphic to allotriomorphic rock, composed most-ly of medium-grained (~1.5mm) euhedral plagioclase (61%), fine-grained (~0.7mm) anhedral aggregates of hornblende (15%) and fine-grained (up to 0.2mm) anhedral aggregates of primary quartz (up to 3%). Traces of biotite were also identified. Alteration is mostly dominated by silica, exhibiting some reaction textures in contact with primary quartz and plagioclase. Chlorite is also present as fine-grained (<0.1mm), pale green to light brown aggregates that re-place hornblende and biotite. Minor sericite is present (~5%) as very fine grained (<0.05mm) flaky aggregates that occur replacing plagioclase.Primary magnetite occurs as very fine-grained (~0.5mm), subhedral aggregates that replaces and intergrowth hornblende. Positive fracture infill reaction to etching by HF sodium cobaltinitrate (yellow) stain. This coincides with some sericite areas. Mineralization is just observed as traces of fine-grained (<0.1mm) anhedral disseminated pyrite.MineralizationHydrothermal alteration mineralspyrite Tr Fine-grained (<0.1mm), anhedral, disseminated aggregatesAMag: 2xPPL+RL2mmBPhotomicrographsA) Photograph 2X, exhibiting the distribution of the minerals in the sample. Note the weathering effects on the plagioclases.B) Photograph 2X, same as Photo A but with crossed Nicolls. Note the distribution of sericite alteration on the plagioclase. Also the silica replacement around some plagioclases (left middle photo) and some micro Qtz veinlets crossing the sample.Mag: 2xXPL+RL2mmXPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<ChlSilica><Qtz<Ser<Hb<BtPlag<Silica<Qtz Veinlet<ChlSilica><Qtz<Ser<Hb<BtPlag<Silica<Qtz VeinletMineral Modal Textural and Mineral DistributionSilica 10.0%Very fine-grained to fine-grained (~0.1mm), colourless, anhedral aggregates replacing some plagioclase borders also is present as some micro veinlets. Most of the Qtz present in the sample was interpreted as secondary mineral, because there are some reaction textures and embayments when it is in contact with primary Qtz crystals. ChloriteSericite2.0%5.0%Fine-grained (<0.1mm), striated, basal habit, markedly pleocroic from pale green to light brown. Occurs as replacing product after hornblende and biotite. Also occurs along one vein accompanied by Pyrite. Very fine-grained (<0.05mm) pale green, high relief, flaky aggregates that occurs replac-ing plagioclase.K-Feldspar TrVery fine-grained aggregates that occur. That occurs as selvage in some late quartz vein-ing and coincides with sericite alteration after plagioclase. PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Alto San Pedro RiverSan Pedro SMA_SM_1705_JM_029Country: ColombiaStained section offcutSummaryLithology: Medium to coarse-grained equigranular Px+Hb diorite (200-250 point-counted)Alteration minerals: chlorite-zoisite, saussuriteIntensity of alteration: Moderate to strongMineralization: Traces of Ccp+Bo+chalcociteFracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseClino Pyroxene57.0%27.0%Medium-grained (2.5mm up to 4mm length), euhedral with a grey dusty coloration pro-duced by the saussutirization and minor sericite alteration. No visible zonation. Coarse-grained (up to 5mm) pale yellow, high relief, non-pleocroic, euhedral with tabular shapes. This corresponds to a fresher and newer phase that shows over growing texture around the first crystals stage. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_029Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Magnetite 5.0% Fine grained (~0.4mm), subhedral to anhedral, disseminated and the sample and inter-growing with plagioclase. Quartz 1.0% Fine grained (~0.5mm), anhedral intergrowing with plagioclase. Hornblende? 12.0% Coarse-grained (up to 5mm)highly fractured and highly altered to Chl-zoisite and to an unknown mineral. Optically it presents an inclined extinction. . Polished Thin section Description This sample correspond to an holocrystalline, hypidiomorphic rock, composed mostly of medium-grained (up to 4mm length) euhedral plagioclase (57%) and two stages of clinopyroxene growing (~27%): One coarse-grained (up to 5mm) euhedral with tabular shape and highly altered to chlorite-zoisite and a second clinopy-roxene phase that overgrown around the first mineral stage. Primary magnetite (~5%) occurs as fine-grained (~0.4mm) subhedral to anhedral aggregates disseminated in the sample and intergrowing with plagioclase. Alteration is marked by a strong clay alteration (9%) in almost the 80% of the plagioclases. Also by the occur-rence of fine-grained (~0.25mm) pale green aggregates of chlorite (10%) that replace the early stage clinopy-roxene. There are minor occurrences of very fine –grained (<0.05mm) flaky aggregates of Illite with traces of carbonate. Some weak patchy reaction of sample matrix to etching by HF sodium cobaltinitrate (yellow) stain are present.Mineralization occurs as traces of very fine-grained (<57μm length) patchy aggregates of chalcopyrite + borni-te + chalcocite in the rock groundmass. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite-zoisite 10.0%Fine-grained (~0.25mm), pale green, anhedral aggregates, with selectively replacement of previous crystals. Principally as alteration products of 1st stage of Pyroxenes. Ccp+Bo+Chalcocite Tr Very fine-grained (<57μm length) anhedral, patchy aggregates in the rock groundmass. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite IlliteSaussurite-Clay1.0%9.0%Very fine-grained (<0.05mm) colourless, flaky aggregates accompanied by clay selectively replacing some plagioclase borders. Very fine-grained to cryptocrystalline aggregates replacing the plagioclase in a dusty-like texture that produces a dark grey coloration in the plagioclase. Almost 80% of plagioclase is altered to saussurite-clay. Carbonate Tr Fine-grained (~0.5mm), colourless, anhedral aggregates filling some crystals interstices. Unknown Mineral 5.0% The chlorite-zoisite that replace the stage 1 pyroxenes is also altered to a brownish, weak pleocroic (to darker brown) mineral, which is mainly developed along some fractures. Possibly associated with a forming amphibole and a diuretic alteration. Interference colors of this mineral are of middle second order.AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X, exhibiting the distribution of the minerals in the sample. Note the 1st stage pyroxene characterized by the highly fracturing and alteration, and surrounded by 2nd pyroxene generationB) Photograph 2X, same as Photo A, but with crossed Nicolls. Note the selective replacement of chlorite-zoisite in the 1st stage pyroxene. C) Photograph 20X, reflected light micro photograph to show the distribution of the occurrence of bornite, chalcopyrite and chalcocite aggregates.D) Photograph 40X, reflected light micro photograph to show the distribution of the occurrence of bornite, chalcopyrite and chalcocite aggregates Mag: 2xXPL+RLMag: 20xRL0,2mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)RL FOV~ 1094μm (Length)<Chl<PlagMagPlag><Bt<Car<ClPx1<Bo+Ccp+CcDMag: 40xRL0,1mmRL FOV~ 575mm (Length)<Mag<ClPx2<ClPx2<ClPx2UnknownM><Chl<Plag<Bt<Car<ClPx1<Mag<ClPx2<ClPx2<ClPx2UnknownM><ClPx1<ClPx2Plag><Bo+Ccp+Cc<Bo+Cc<CcpPETROGRAPHY REPORT (APPENDIX 1)Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: BetestaBetesta SMA_SM_1705_JM_030Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb+Bt tonalite (200-250 point-counted)Alteration minerals: silica, chlorite, clinozoisite and carbonateIntensity of alteration: Medium to weak Mineralization: Traces of disseminated pyrite ± chalcopyriteFracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 42.0% Medium-grained (2mm in length), euhedral, tabular aggregates with a grey dusty coloration produced by the saussutirization alteration and minor sericite. Weak but still zonation is visible in the plagioclase. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_030Hornblende 31.0% Medium-grained (up to 2.5mm length), dark green to pale yellowish brown, anhedral to subhedral aggregates partially replaced to chlorite.Quartz 14.0% Fine-grained (up to 0.2mm) colourless, anhedral aggregates that intergrow plagioclase and hornblende. The criteria to define this phase as primary, is the lack of visible reac-tion zones with the touching crystals. Magnetite 5.0% Fine-grained (~0.4mm), subhedral to anhedral, disseminated and the sample and inter-growing with plagioclase. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample correspond to a holocrystalline, subhypidiomorphic rock composed mostly of medium-grained (2mm in length) euhedral and weakly zoned plagioclase (42%) that intergrows with dark green anhedral to subhedral hornblende (31%). Quartz (14%) occurs as fine grained (up to 0.2mm) anhedra aggregates that intergrow with biotite (1%). Primary magnetite occurs as very fine-grained (~0.05mm) subhedral aggregates. The rock alteration is low and correspond to silica that exhibits rimming textures and embayment when is in contact with primary quartz crystals. Hornblende is altered to a medium-grained (~1.2mm) pale to colorless clinozoisite (4%) and chlorite (2%). Carbonate and sericite after plagioclase occurs as traces in the sample.The sample presents a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain .Mineralization occurs as a very fine grained (up to 0.1mm) traces of anhedral chalcopyrite and pyrite aggre-gates that accompany carbonate and sericite. Biotite 1.0% Fine-grained (~0.3mm), brownish aggregates intergrowing with plagioclase. This is partly altered to chlorite.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsActinolite 1.0%Fine-grained (~0.2mm length) pale green with high relief, striated, acicular aggregates that occur as overgrown mineral in hornblende. It presents a birefringence of middle 2nd order. Pyrite+Chalcopyrite Tr Very fine-grained (up to 0.1mm) anhedral, aggregates accompanied by traces of chalco-pyrite. Also present as replacing mineral of some Hb , Chl and Ser. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite ClinozoisiteSilica4.0%6.0%Medium-grained (~1.2mm) pale to colourless yellow, non-pleocroic, striated aggregates with medium to low relief that occur replacing hornblende. Optically it presents Indigo blue interference colors. Very fine-grained to cryptocrystalline aggregates replacing the plagioclase in a dusty-like texture that produces a dark grey coloration in the plagioclase. Almost 80% of plagioclase is altered to saussurite-clay. Carbonate Tr Fine to very fine-grained (~0.25mm) colourless, anhedral aggregates filling crystals interstices. Chlorite 2.0% Very fine-grained (<0.1mm), pale green, striated aggregates with basal habit. They occur as alteration product of hornblende. It is differentiated by the clinozoisite by the pale green coloration and subtle pleocroism that is absent in the clinozoisite. Optically it pres-ents 1st order grey to yellow interference colors. Sericite Tr Fine-grained (~0.25mm length) pale green with high relief, striated flaky aggregates pro-duced as alteration product after hornblende and lesser in plagioclase. AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X, exhibiting the distribution of the minerals in the sample. Note the silicification effects around the plagioclase borders. B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photograph 4X representing the distribution of the major alteration minerals in the sample. D) Photograph 4X, same as photo C, but with crossed Nicolls. Note the actinolite alteration from hornblende crystals. Mag: 2xXPL+RLMag: 4xPP+RL1mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 5,9mm (Length)<Plag<SilicaCMag: 4xXP+RL1mmXPL FOV~ 5,9mm (Length)<Hb<Plag <Chl<Hb<Hb<Hb<Plag<Chl<Act<Plag<Qtz<Qtz<Plag<Silica<Hb<Plag <Chl<Hb<Hb<Hb<Plag<Chl<Act<Plag<Qtz<Qtz<MagPETROGRAPHY REPORT (APPENDIX 1)Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Mina EscondidaMina Escondida SMA_SM_1705_JM_031Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb tonalite (200-250 point-counted)Alteration minerals: Silica, chlorite, clinozoisite Intensity of alteration: Medium to strong in chlorite. Mineralization: Traces of pyrite + chalcopyrite. Fracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 50.0% Fine to medium-grained (0.5-2mm) euhedral, tabular aggregates with a grey dusty col-oration produced by the clayish-saussutirization. The plagioclase crystals present a weak zonation. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_031Hornblende 29.0% Medium-grained (1-3mm in length), dark green to pale yellowish brown, anhedral to subhedral aggregates partially replaced to chlorite.Quartz 14.0% Fine-grained (up to 1mm), colourless, anhedral aggregates in intergrowth with pla-gioclase and hornblende. The criteria to define this phase as primary quartz is the lack of reaction with the touching primary crystals. Magnetite 2.0% Fine-grained (>0.1mm), euhedral, disseminated intergrowing with hornblende. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section Description This sample corresponds to a holocrystalline, sub hypidiomorphic rock, composed mostly of fine to medi-um-grained (0.5-2mm) euhedral aggregates of plagioclase (50%) that present a weak zonation. This intergrows with a medium-grained (1-3mm in length) anhedral to subhedral aggregates of hornblende (29%) and with anhedral aggregates of quartz (14%). Primary magnetite occurs as fine-grained (>0.1mm) euhedral, disseminated aggregates that intergrow with hornblende. Alteration in the samples is dominated very fine-grained to fine-grained (~0.1mm) anhedral aggregates of silica (10%) that replace some plagioclase borders. Also by a combination of very fine-grained (<0.1mm), pale green chlorite with medium-grained (~1.2mm) clinozoisite after hornblende. Lastly, carbonate occurs as crys-tal interstices filling in the rock. The sample presents a negative reaction to etching by HF sodium cobaltini-trate (yellow) stain .Mineralization is present as traces of very fine grained (up to 0.06mm), anhedral aggregates of pyrite accom-panied by traces of chalcopyrite that replace hornblende. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsClinozoisite 4.0%edium-grained (~1.2mm) pale brown, non-pleocroic, striated medium to low relief aggre-gates replacing hornblende. It presents the same interference color than chlorite.Pyrite Tr Very fine-grained (up to 0.06mm), anhedral, aggregates accompanied by traces of chal-copyrite. Also as replacing mineral of Hb , Chl and Car. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chal-copyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaChlorite10.0%7.0%Very fine-grained to fine grained (~0.1mm), colourless, anhedral aggregates replacing some plagioclase borders. Most of the Qtz present in the sample is interpreted as second origin, because there are some reaction textures as embayments when this phase is in contact with primary minerals. Very fine-grained (<0.1mm), pale green, striated aggregates with a basal habit. It occurs as alteration product of hornblende and presents some brownish to reddish tint. (Fe-rich Chl?)Carbonate 2.0% Fine-grained (~0.4mm) colourless, anhedral aggregates filling crystals interstices. AMag: 2xPPL+RL2mmBPhotomicrographsA) Photograph 2X, exhibiting the distribution of the minerals in the sample. B) Photograph 2X, same as Photo A, but with crossed Nicolls. Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<Hb<Plag<Plag<Qtz<Hb Silica> Silica><Chl<Plag<Hb<Plag<Plag<Qtz<Hb Silica> Silica><Chl<PlagPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Costa RicaCosta Rica SMA_SM_1705_JM_032Country: ColombiaStained section offcutSummaryLithology: Coarse to medium-grained inequigranular Hb+Bt+Qtz tonalite (200-250 point-counted)Alteration minerals: saussurite-clay, carbonate Intensity of alteration: Medium to strong in plagioclaseMineralization: Disseminated pyriteFracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 47.0% There are 2 different populations of plagioclase.-Medium to coarse-grained (2.5 to 5mm in length), euhedral, tabular with marked twin-ing, and highly altered to saussurite and clay. -Very fine to fine-grained (up to 0.1mm), subhedral to anhedral, tabular aggregates with not marked twining development. Occurs accompanied by Qtz as inclusion in coarse Qtz and Hb defining Poikilitic texture. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_032Hornblende 26.0% Medium-grained (up to 2.5mm) dark green to pale brown and yellow, anhedral aggre-gates intergrowing with Qtz and plagioclase. It posses multiple inclusions of magnetite and plagioclase. Quartz 24.0% There are 2 different populations of Qtz-Medium to coarse-grained (2 to 5mm in length), colourless, anhedral aggregates inter-growing with hornblende and plagioclase. -Very fine to fine-grained (up to 0.1mm), anhedral aggregates enclosed by coarser frac-tion of plagioclase and hornblende as part of a poikilitic texture. Magnetite 0.5% Fine grained (~0.4mm), subhedral to anhedral, disseminated and the sample and inter-growing with plagioclase. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section DescriptionThis sample correspond to a holocrystalline rock with poikilitic texture composed mostly of two size pop-ulations of plagioclase (52%): 1. A medium to coarse-grained (2.5 to 5mm in length) and 2. A very fine to fine-grained (up to 0.1mm) subhedral aggregates that occur accompanied by very fine to fine-grained (up to 0,1mm), anhedral quartz. Both phases are embedded by a medium to coarse-grained intergrowth of quartz (24%) and hornblende (26%) defining a poikilitic texture. Primary magnetite occurs as very fine-grained (~0.05μm), anhedral aggregates that occurs as inclusions mostly in hornblende, primary biotite is also ob-served in the sample (2%). Alteration in the samples is produced by the occurrence of very fine-grained (<0.01mm) saussurite (10%) replacing plagioclase and occurring with traces of Illite and epidote. Also chlorite (1%) is present as alteration product after hornblende. The sample presents a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain .Mineralization occurs as medium grained to fine-grained (up to 1.5mm) anhedral aggregates of pyrite ± chal-copyrite (3%) that exhibit in some cases a rounded, droplets-like texture with the surrounded minerals. Biotite 2% Fine grained (~0.3mm), subhedral to anhedral intergrowing with hornblendeMineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 1.0%Fine-grained (~0.2mm), pale green, anhedral aggregates occurring as disseminated and interstitial filling in the grains boundaries. It also occurs as partially alteration in horn-blendes. Pyrite+Chalcopyrite Tr Medium-grained to fine-grained (up to 1.5mm) anhedral, disseminated aggregates that exhibit in some cases rounded and droplets shapes. This pyrite intergrows with chalcopy-rite in some areas.* Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Comments The pyrite in the sample, exhibit some droplets-texture that could suggest a primarymagmatic? origin as exolutions of the primary minerals, mostly from hornblende.Clay-SaussuriteCarbonate10.0%2.0%Very fine-grained (<0.01mm), black, dusty texture aggregates, replacing plagioclase and occurring with traces of Illite and epidote. Fine-grained (~0.5mm), colourless, anhedral aggregates that occur mostly as crystals in-terstices infill and as selective replacement of plagioclase. AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X exhibiting the distribution of the minerals in the sample. Note the poikilitic texture mostly in the hornblendes, with inclusions of plagioclase and Qtz. B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photograph 10X showing the distribution of the pyrite and magnetite in the sample. Note the droplet texture of the magnetite and possibly of the pyrite, can can suggest their primary origin. D) Photograph 4X, exhibiting the poikilitic texture from quartz and plagioclase as inclusions in hornblende.Mag: 2xXPL+RLMag: 10xPP+RL0,4mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 2,18mm (Length)<Chl<HbMag Chl><CarDMag: 4xXP+RL1mmXPL FOV~ 5,9mm (Length)<Plag<Qtz<Qtz<PyPlag<Plag Inclusion HbSaussurite+ClayHb<QtzHb<Chl<Hb<Car<Plag<QtzHb<QtzHb<MagQtz<Silica<Qtz inclusionPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Bucaramanga areaBucaramanga SMA_SM_1705_JM_033Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb diorite (200-250 point-counted)Alteration minerals: silica, actinolite, chlorite Intensity of alteration: Medium to strong Mineralization: Py dissminatedFracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 42.0% Medium-grained (~1.5mm), colourless, euhedral to subhedral, tabular aggregates par-tially replaced to clay. Plagioclase displays a weak zonation.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1705_JM_033Hornblende 23.0% Medium-grained (up to 4mm length), dark green to pale yellowish brown, subhedral to anhedral aggregates intergrowing with plagioclase. Hornblende is highly altered to actinolite and chlorite. Quartz 10.0% Fine-grained (up to 0.2mm), colourless, anhedral aggregates intergrowing plagioclase and hornblende, also as up to 5μm fluid inclusion.Magnetite 2.0% Very fine-grained (~50μm) subhedral, elongated aggregates that occurs as exolutions along some hornblende cleavages. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section DescriptionThis rock correspond to a holocrystalline, sub-hypidiomorphic rock composed mostly of medium-grained (~1.5mm) euhedral and weakly zoned aggregates of plagioclase (42%) that intergrow with and medium-grained subhedral aggregates of hornblende (23%) and with a fine-grained (up to 0.2mm), colorless, anhedral aggre-gates of quartz (10%). Primary magnetite (2%) occurs as very fine-grained (~50μm) exolved phase along some hornblende cleavages.Alteration in the sample is produced by the occurrence of fine-grained (up to 0.5mm length) acicular aggre-gates of actinolite (12%) and fine-grained, pale green chlorite after hornblende. Silica (10%) is present as fine-grained (~0.3mm) aggregates replacing and cutting some plagioclases.The sample presents a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain .Mineralization occurs as fine-grained (up to 0.25mm) disseminated pyrite (1%) that occurs mostly with horn-blende.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 5.0%Fine-grained (<0.1mm) striated aggregates with a basal habit and markedly pleocroic from pale green to light brown. It occurs as replacing product after hornblende.Pyrite 1.0% Fine-grained (up to 0.25mm) subhedral, disseminated aggregates that occur mostly with hornblende. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Actinolite Silica12.0%10.0%Fine-grained (up to 0.5mm length), pale brownish to colourless, weakly pleocroic, striat-ed and acicular aggregates that occur as alteration product of hornblende. Fine-grained (~0.3mm), colourless, anhedral aggregates that occur replacing and cutting some plagioclases. AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X exhibiting the distribution of the minerals in the sample. Note the effects of the silicification around the pla-gioclases.B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photograph 4X showing the reaction of silica in the plagioclase borders and the pervasive alteration of the actinolite after hornblende. D) Photograph 4X, same as Photo C, but with crossed Nicolls. Mag: 2xXPL+RLMag: 4xPP+RL1mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 5,9mm (Length)<Chl<HbDMag: 4xXP+RL1mmXPL FOV~ 5,9mm (Length)<Silica<QtzHbAct Plag<QtzQtz<Silica<Act<Hb<Act<Chl<Silica<Qtz<Qtz<Act<Hb<Act Plag<Silica Plag>HbAct Plag<Silica Plag<Silica Plag> PlagPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Costa AzulCosta Azul SMA_CA_1705_JM_034Country: ColombiaStained section offcutSummaryLithology: Medium-grained equigranular Hb+Bt+Qtz Tonalite Alteration minerals: sericite ± Illite, chlorite Intensity of alteration: Medium to weakMineralization: Disseminated pyrite and chalcopyrite Fracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 41.0% Medium-grained (1.5mm in length), euhedral, tabular aggregates that present a medium to strong alteration to sericite. Plagioclases show a weak zonationPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_CA_1705_JM_034Hornblende 12.0% Medium-grained (up to 4mm in length), anhedral to subhedral crystals that intergrown with plagioclase and are altered to chlorite. Biotite 3.0% Fine-grained (~0.8mm) brownish, striated aggregates that intergrow with plagioclase, hornblende and quartz and are partially altered to chlorite. Optically biotite displays a marked pleocroism. Quartz 23.0% Fine to medium grained (up to 1.5 mm) colourless , anhedral aggregates intergrowing with plagioclase, hornblende.Magnetite 2.0% Fine-grained (~0.5μm), anhedral to euhedral crystals that intergrowth with hornblende and is altered to chlorite and pyrite. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section DescriptionThis sample correspond to a holocrystalline, hypidiomorphic rock dominated by medium-grained (1.5mm in length) euhedral plagioclase (41%) and fine to medium-grained (up to 1.5 mm) anhedral aggregates of quartz (23%). The mafic minerals correspond to medium-grained (up to 4mm) anhedral to subhedral hornblende (12%) and fine-grained (~0.8mm) biotite (3%).The primary magnetite occurs as fine-grained (~0.5μm), anhe-dral to euhedral crystals that intergrowth with hornblende. Alteration is relatively low to intermediate and it is produced by the occurrence of very-fine grained aggregates of sericite ± Illite that occur as selective replacement of plagioclase and by chlorite that occurs as fine-grained (up to 0.8mm) anhedral aggregates replacing hornblende and biotite. Patchy reaction of sample matrix to etching by HF sodium cobaltinitrate (yellow) stain.Mineralization is present as fine-grained (up to 0.5mm length) anhedral to subhedral aggregates of pyrite ± chalcopyrite replacing magnetite and hornblende. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsPyrite ± chalcopyrite 1.0% Fine-grained (up to 0.5mm length) anhedral to subhedral aggregates replacing magnetite and hornblende. (5/1) in the relation (Py/Ccpy)Sericite>IlliteChlorite10.0%7.0%Very fine-grained (<0.1mm) pale green, flaky aggregates that occur as selective replace-ment of plagioclase along some of the plagioclase zonation boundaries. Fine-grained (up to 0.8mm), pale green to colourless, pleocroic, anhedral aggregates re-placing hornblende and biotite. AMag: 2xPPL+RL2mmBPhotomicrographsA) Photograph 2X exhibiting the distribution of the minerals in the sample. Note the clay and alteration along some plagioclase zonations and the chloritizing biotite and magnetite.B) Photograph 2X, same as photo A but with crossed Nicolls. Note the sericite alteration in the plagioclase. Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<Chl<Qtz<QtzPlag<Bt<HbPlag<Bt<Bt<Qtz<Qtz<Mt<Chl<Qtz<QtzPlag<Bt<HbPlag<Bt<Bt<Qtz<Qtz<Mt<Py* Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite PETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Las ClaritasLas Claritas SMA_SM_1705_JM_037Country: ColombiaStained section offcutSummaryLithology: Medium to fine-grained inequigranular Hb+Bt tonalite (200-250 point-counted)Alteration minerals: Silica, chlorite, actinolite, epidoteIntensity of alteration: Medium to weakMineralization: Pyrite in veinletsFracture infill: NVMineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 50.0% Medium-grained (1.5mm in length) euhedral, tabular shapes intergrowing with horn-blende, biotite and quartz. It presents a weak alteration to clay.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_SM_1705_JM_037Hornblende 28.0% Exhibit 2 size populations 1)Medium-grained (up to 4mm), anhedral aggregates intergrowing with plagioclase. This is altered to a fine-grained greenish and pleocroic mineral with medium to high birefrin-gence (possibly chlorite), also to magnetite.2)Fine to very fine-grained (up to 0.1mm) anhedral aggregates intergrowing in a grano-blastic texture and defining a poikilitic texture within the population 1.Quartz 14.0% This corresponds to a fine-grained (<1.0mm), colourless, anhedral aggregates inter-growing with plagioclase and hornblende. Given that, the rock present silicification it is difficult to estimate the primary and secondary quartz. Biotite 3.0% Fine-grained (up to 0,3mm), pale brownish to dark brownish, striated aggregates with basal habit , that is partially to totally replaced to chlorite intergrowing with Hb.Magnetite 4.0% Fine-grained (~0.5mm), either intergrowing or as fine-grained inclusions with horn-blende. Magnetite is also present in veins accompanied with quartz and chlorite. Most of the magnetite in the sample can have a secondary origin.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Polished Thin section DescriptionThis sample corresponds to a holocrystalline rock, with poikilitic texture composed by the intergrowth of medium-grained (1.5mm) euhedral plagioclase with fine-grained (up to 0,3mm) aggregates of quartz, biotite and hornblende. The hornblendes exhibit two size of populations: 1. Medium-grained (up to 4mm), anhedral aggregates and 2. A Fine to very fine-grained (up to 0.1mm) anhedral aggregates intergrowing in a granoblastic texture and defining a poikilitic texture. Primary magnetite occurs, as fine-grained (~0.5mm) aggregates inter-growing and overgrown by hornblende, as well as in veinlets accompanied by pyrite and chlorite. Alteration is mostly related to the occurrence of fine-grained (0.8mm) silica in veinlets and as selective re-placement of plagioclase borders. Also defined by the occurrence of fine-grained (up to 0.5mm) aggregates of acicular actinolite that is accompanied by chlorite ± epidote. The sample presents a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain .Mineralization is dominated by fine-grained (0.2- 0.8mm) aggregates of pyrite ± chalcopyrite that occurs as veinlets, disseminated and nucleation magnetite. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 2.0%Fine-grained (up to 0.5mm), pale to dark green striated aggregates with a basal cleavage that occur replacing selectively hornblendes. It is also accompanied by epidote.Pyrite 1.0% Fine-grained (up to 0.25mm) subhedral, disseminated aggregates that occur mostly with hornblende. SilicaActinolite 10.0%5.0%Fine-grained (0.8mm) aggregates that occur as selective alteration product of the pla-gioclases and minor as veinlets. Fine-grained (up to 0.5mm) pale green to colourless, acicular aggregates accompanied by chlorite and replacing hornblende. Epidote 1.0%Fine to very fine-grained (up to 0.2mm), pale yellow and anhedral aggregates occurring as veinlets accompanied by chlorite, pyrite and minor magnetite. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photograph 2X exhibiting the distribution of the minerals in the sample. Note the distribution of the 2 populations of horn-blende. Also the effects of chloritization around the hornblende crystals and the effects of the secondary quartz (silica) as vein and rimming plagioclases. B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photograph 4X showing the actinolitization of the hornblende and the occurrence of a quartz vein accompanied by magnetite, pyrite and epidoteD) Photograph 4X, same as Photo C, but with crossed Nicolls. Mag: 2xXPL+RLMag: 4xPP+RL1mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 5,9mm (Length)<Chl chlDMag: 4xXP+RL1mmXPL FOV~ 5,9mm (Length)HbHb Plag<QtzQtz<Silica<Act<Hb Plag<Mt Plag><Fine HbPlag<Chl <Plag<Silica<Chl chlHb<Qtz veinlet<Qtz<Act<Hb<Fine HbPlag<Chl <Plag<Silica<Act<Qtz <EpPy> PlagHbHb PlagQtz<Silica Plag<Mt Plag><Act<Qtz <EpPy> PlagHb<Qtz Ep><Act<Chl<Qtz veinletPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: Teheran MineMontiel E SMA_ME_1612_JM_100Country: ColombiaStained section offcutSummaryLithology: Medium to fine-grained porphyritic Hb+Bt+Qtz tonalite (300 point-counted)Alteration minerals: sericite-chloriteIntensity of alteration: WeakMineralization: Pyrite in veinletsFracture infill: NVPolished Thin section DescriptionThis sample correspond to a holocrystalline rock with a crowded porphyritic texture. The groundmass is exclu-sively formed by very fine-grained (up to 0.05 μm), anhedral aggregates of quartz. The phenocrysts are mostly dominated by fine to medium-grained (up to 2mm), euhedral plagioclase (28%) that exhibit a marked zoning. and intergrows with fine to medium-grained (<1mm - 2.7mm) subhedral hornblende (5%), fine to very fine-grained (up to 0.1mm), subhedral aggregates of biotite (2.5%), and fine-grained (up to 0.1mm) K-feldspar. Primary magnetite occurs as fine-grained (up to 0.7mm), subhedral aggregates with irregularities produced mostly by chlorite alteration.Alteration minerals are dominated by the occurrence of very fine-grained (<0.1mm), pale green aggregates of sericite (15%) that occur as selective replacement of the plagioclase, also by the occurrence of fine-grained (~0.3mm), pale green aggregates of chlorite (4%) and traces of actinolite as alteration of biotite and horn-blende. Mineralization occurs mostly as veinlets (up to 2mm wide) of fine grained (up to 0,6mm), subhedral aggre-gates of pyrite accompanied by traces of chlorite, epidote, sericite, and carbonate.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 38.0% Fine to medium-grained (up to 2mm), euhedral, tabular aggregates with a marked zoning that occur in intergrowth with hornblende. Present a partial to pervasive alteration to sericite and clays along the zoning boundaries PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_ME_1612_JM_100Quartz 25.0% 2 stages: 1) Groundmass that is formed by exclusively quartz this corresponds to a very fine-grained (up to 0.05 μm), colourless, anhedral aggregates. 2) As phenocrysts phase that corresponds to fine to medium-grained (0.5mm to 1mm) colourless, anhedral aggregates intergrowing with hornblende and plagioclase. Hornblende 5.0% Fine to medium-grained (<1mm – 3mm) subhedral to euhedral crystals with plagioclase and quartz inclusions. It is characterized by two perfect cleavages that intersect at about 60° or 120°K-Felds 2% Fine to very fine-grained (up to 0.1mm), colorless, subhedral to euhedral aggregates that occurs as isolated crystals and as anhedral interstices in the rock groundmass. It was recognized using HF sodium cobaltinitrate (yellow) stain.Magnetite 2.5% Fine-grained (up to 0.7mm), subhedral aggregates with irregularities produced mostly by chlorite alteration. Magnetite seems to intergrow with the plagioclase and quartz. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Biotite 2.5% Fine to very fine-grained (up to 0.1mm), brownish, subhedral aggregates that occurs with hornblende, plagioclase and quartz. It is altered to chlorite along some of the basal cleavage.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate TrFine-grained (up to 0.3 μm) colourless, anhedral aggregates that occurs mostly along some veins accompanied with chlorite.Pyrite 1.0% Fine-grained (up to 0,6mm), subhedral to euhedral aggregates that occur in veinlets accompanied by chlorite, sericite and carbonate. It present some brecciated textures. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SericiteChlorite15.0%7.0%Very fine-grained (<0.1mm), pale green, flaky aggregates that occur as selective replace-ment of the plagioclase along the crystals zoning. The average of alteration per individual crystal is about 15%.Fine-grained (~0.3mm), pale yellow to pale green, striated aggregates mostly as alteration of biotite and hornblende. It is slightly similar to the hornblende content. Also it is ob-served in some veins accompanied by sericite and pyrite.Epidote TrFine to very fine-grained (0.3mm), pale yellow, high relief, aggregates that occurs accom-panying pyrite, actinolite and altering biotite.Actinolite TrVery fine to fine-grained aggregates that occurs as alteration products of hornblende.AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photomicrograph showing the porphyry texture. Note the fine-grained quartz-rich groundmass and the occurrence of a pyrite veinlet accompanied of chlorite. Note also the marked zonation in the plagioclase phenocrysts.B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photograph 4X showing the occurrence of actinolite + epidote + chlorite aggregates replacing hornblende. Note the sericitization of the plagioclases.D) Photograph 4X, same as Photo C, but with crossed Nicolls. Mag: 2xXPL+RLMag: 10xPP+RL0,4mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 2,18mm (Length)DMag: 10xXP+RL0,4mmXPL FOV~ 2,18mm (Length)<Qtz<Py veinlet<Bt<Qtz<Chl<Plag<Plag<Qtz<Qtz<Py veinlet<Bt<Qtz<Chl<Plag<Plag<Qtz<Qtz< Ser <Bt<Qtz<Chl<Plag<Act<QtzPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. JUNE 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: CADDH001@30.40Costa Azul SMA_CA_1705_JM_058Country: ColombiaStained section offcutSummaryLithology: Medium-grained porphyritic Hb+Bt+Qtz tonalite (300 point-counted)Alteration minerals: silica, chlorite, Tr actinoliteIntensity of alteration: WeakMineralization: Ccp+Bo+pyrite quartz veins, Ccp veinletsFracture infill: Ccp+Bo+pyrite quartz veins, Ccp veinletsPolished Thin section DescriptionThis sample correspond to a holocrystalline, porphyritic rock dominated by phenocrysts (70%) in relation to the groundmass (30%). The phenocrysts correspond to medium-grained (up to 2mm in length) euhedral pla-gioclase (21%) and anhedral to subhedral crystals of hornblende (6%) that intergrow with primary magnetite and traces of Biotite Based on 300-grain counts the primary quartz in the sample is close to the 27%. This occurs as fine-grained (up to 0.5mm) anhedral phenocrysts that intergrow with plagioclase and hornblende. Additionally occurs as Very fine grained (<0.05mm) granoblastic aggregates that conform the rock groundmass. Alteration is relatively low to intermediate and it is produced by the occurrence of silicification (29%) replacing the plagioclase borders. Also, by the occurrence of fine-grained (up to 0.5mm), anhedral aggregates of Chlo-rite (3% ) that replace hornblende and some traces of actinolite that replaces primary biotite.Mineralization is dominated by the chalcopyrite that occurs in two different stages. 1. As very fine to fine grained (>0.1mm) anhedral aggregates that occurs with bornite ± pyrite in quartz B veins. 2. Fine-grained (~0.3mm), anhedral aggregates that occurs as 0.2mm wide veinlets that cut the B veins. Mineral Modal Textural and Mineral DistributionRock-forming mineralsQuartz 27.0% 3 populations. 1 Fine-grained (up to 0.5mm) colourless, anhedral phenocrysts intergrowing with pla-gioclase, hornblende.2 Very fine grained (<0.05mm) granoblastic aggregates that conform the rock ground-mass. 3 Qtz veins along veins that occurs as Fine-grained (~0.8mm) crystals intergrowing with magnetite and chalcopyrite.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_CA_1705_JM_058Plagioclase 21.0% Fine to Medium-grained (0.5 to 2mm in length), euhedral, tabular aggregates that show a strong zonation and a marked silicification in their borders.Hornblende 6.0% Medium-grained (up to 1.5mm in length), anhedral to subhedral crystals that intergrown with plagioclase and magnetite and are partially altered to hydrothermal biotite. . Biotite Tr Fine-grained (~0.8mm) brownish, striated aggregates that intergrow with plagioclase, hornblende and quartz and are partially altered to chlorite actinolite. Optically present a marked pleocroism. Magnetite 5.0% Fine-grained (~0.2μm), anhedral to euhedral crystals that intergrowth and as inclusions within hornblende and with the quartz veins. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsActinolite TrFine-grained (<0.3mm), pale green, That occurs as partially replacement after primary biotite. Chalcopyrite 1.0% 2 stages: 1. Fine-grained (~0.3mm), anhedral aggregates that occurs as 0.2mm wide veinlets that cut Qtz + Sulphides veins.2. As very fine to fine grained (>0.1mm) anhedral aggregates that occurs with bornite ± pyrite in quartz veins. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaChlorite29.0%3.0%Occurs as pseudo-morphed mineral replacing the plagioclase borders.Fine-grained (up to 0.5mm), pale green to colourless, pleocroic, anhedral aggregates re-placing hornblende.K-Feldspar TrThat occurs as selvage in some Ccp+quartz veining. It is altered to sericite AMag: 2xPPL+RL2mmCBPhotomicrographsA) Photomicrograph 2X showing the crowded porphyry texture of this rock and the quartz vein of the sample. Note the marked plagioclase zonation. B) Photomicrograph 2X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 5X showing chal-copyrite veinlets that cut earlier quartz+chalcopyrite+magnetite+bornite veins. D) Photograph 5X, same as Photo C, but with crossed Nicolls. E) Photomicrograph 10X showing secondary biotite altering former hornblende. Also, note the chlorite alteration of the secondary biotite. F) Photograph 10X, same as Photo E, but with crossed Nicolls.Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)DHb<Qtz<Hb<Plag<Mag<Qtz veinletEMag: 10xPP+RL0,4mmPPL FOV~ 2,18mm (Length)FMag: 10xXP+RL0,4mmXPL FOV~ 2,18mm (Length)<PlagHb<Qtz<Hb<Plag<Mag<Qtz veinlet<Plag<Hb<BoQtz<Ccp<BoQtz<Hb<BoQtz <CcpQtz<Hb<Qtz<Hb<CcpQtz<Biot/Chl?<Chl<Biot?<Hb<Chl<Qtz<Hb<CcpQtz<Biot/Chl?<Chl<Biot?<Py <PyMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mmXPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)<Ccp<Bo<CcpPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. JUNE 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: SMDDH008@70Montiel E SMA_ME_1705_JM_060Country: ColombiaStained section offcutSummaryLithology: Medium-grained porphyritic tonalite (300 point-counted)Alteration minerals: silica, sericite+clayIntensity of alteration: WeakMineralization: Disseminated pyrite and chalcopyrite Fracture infill: actinolite and chlorite rock infill Polished Thin section DescriptionBased on 300-grain counts this sample corresponds to a holocrystalline, sub idiomorphic rock dominated by an inequigranular-size (0.5 to 2mm) distribution of anhedral K-feldspar (14%) and euhedral plagioclase(10%) that intergrows with fine-grained (0.5mm to 1mm) equigranular-size distribution of quartz (40%). <1% of the sample corresponds to mafic minerals. This is represented by medium-grained (up to 1.5mm in length), anhe-dral hornblende. Primary magnetite is not present in this section.Alteration is relatively low to intermediate and it is produced by the occurrence of silicification (16%) replacing the plagioclase borders. Also, by the occurrence of fine-grained (up to 1mm), anhedral aggregates of chlorite (3% ) that replaces a fibrous- acicular mineral possibly actinolite. Sericite + clay and carbonate (3%) occurs as fine-grained (<0.3mm) selective replacement controlled by the plagioclase zonation, suggesting some Na-rich zonation within the plagioclase. Mineralization is dominated by the chalcopyrite and pyrite hat occurs in interstices infill accompanied by ac-tinolite and chlorite respectively. Mineral Modal Textural and Mineral DistributionRock-forming mineralsQuartz 40.0% Fine-grained (0.5mm to 1mm) colourless, anhedral phenocrysts, with a equigranular distribution. It is intergrowing with plagioclase.PETROGRAPHY REPORTv. JUNE 2018Sample ID: SMA_ME_1705_JM_060Plagioclase 10.0% Fine to Medium-grained (0.5 to 2mm in length), euhedral, tabular aggregates that show a medium to strong zonation, sericite alteration and a marked silicification in their borders.Hornblende Tr Medium-grained (up to 1.5mm in length), anhedral to subhedral crystals that in-ter-grown with plagioclase it is partially to complete altered to chlorite. . Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.K-Feldspar 24.0% Fine to Medium-grained (0.5 to 2mm), anhedral aggregates that occurs with quartz and plagioclase. Some silication border and sericite alteration are observed as overimposed minerals. This phase was recognized using HF sodium cobaltinitrate (yellow) stain.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 1.0%Medium-grained (up to 1mm), pale green to colourless, pleocroic, striated oc-curs as replacing mineral after a fibrous- acicular mineral possibly actinolite.Pyrite 1.0% Medium-grained (up to 1mm), anhedral, occurs as quartz interstices infill ac-companied by chlorite. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaSericite+Clay16.0%3.0%Occurs as pseudo morphed mineral replacing the plagioclase borders.Fine-grained (<0.3mm), pale green, That occurs as selective replacement controlled by the plagioclase zonation. It occurs with carbonate. Chalcopyrite 1.0% Medium-grained (up to 1mm), anhedral, occurs as quartz interstices infill accompanied by actinolite traces. AMag: 2xPPL+RL2mmCBPhotomicrographsSample JM060. A) Photomicrograph 2X showing the subhedral to euhedral equigranular texture. Note the silica rims and the selective clay to sericite alteration in the K-feldspar. B) Photograph 2X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 5X showing the occurrence of chlorite replacement after a fibrous mineral, possible secondary biotite. Note the selective sericitization of the feldspars. D) Same as photo C, but under crossed Nicolls. E) Photomicrograph 10X showing some selective sericite replacement after feldspar. F) Same as photo E, but under crossed Nicolls. Mag: 2xXPL+RLMag: 10xPP+RL0,4mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL FOV~ 2,18mm (Length)DMag: 10xXP+RL0,4mmXPL FOV~ 2,18mm (Length)<Qtz<Ser<PlagE F<Qtz<Plag<Silica Rim<Qtz<Qtz<Qtz<Qtz<Chl<K-Felds<Qtz<Qtz<Chl<K-Felds<Qtz<Qtz<Chl<K-Felds<Ser<Ser<Qtz<Qtz<Chl<K-Felds<Ser<SerMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mmXPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)<Biot?<K-Felds<K-Felds<K-Felds<K-Felds<Qtz<Ser<Plag<Qtz<Plag<Silica Rim<K-Felds<K-Felds<K-Felds<K-FeldsCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL)Stained section offcutPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. JUNE 2018Project:SAMPLE LOCATIONSample ID:1 cm HAND SAMPLE San Matias Project Prospect:Location: SMDDH012@62.16Montiel E SMA_ME_1705_JM_061Country: ColombiaSummaryLithology: Medium-grained crowded porphyritic Hb+Bt+Qtz tonalite (300 point-counted)Alteration minerals: silica, chloriteIntensity of alteration: WeakMineralization: Disseminated pyrite and chalcopyrite Fracture infill: ccp + quartz + magnetite bearing veins Polished Thin section DescriptionThis sample correspond to a holocrystalline, sub idiomorphic, porphyritic rock dominated by phenocrysts (70%) in relation to the groundmass (30%). The phenocrysts correspond to medium-grained (up to 2mm in length) euhedral plagioclase (29%) and anhedral to subhedral crystals of hornblende (2%) that intergrow with primary magnetite and traces of primary biotite. Based on 300-grain counts the primary quartz in the sample is close to the 21% and occurs as fine-grained (up to 0.5mm) anhedral phenocrysts that intergrow with plagioclase and hornblende. Additionally, Qtz occurs as very fine grained (<0.05mm) granoblastic aggregates that conform the rock groundmass. Low to intermediate alteration produced by the occurrence of silicification (23%) replacing the plagioclase borders. Also by the occurrence of fine-grained (~0.2-0.4mm) anhedral hydrothermal biotite that replac-es hornblende and cut the rock in veinlets. Chlorite (2%) occurs as fine-grained (up to 0.5mm), anhedral aggregates that replace hornblende and hydrothermal biotite. In the section there is traces of fine-grained (<0.3mm) actinolite that occurs as alteration mineral after former hornblende. Traces of sericite and epidote are also present as selective replacement of plagioclase and rock interstices infill selectively. The samples showed a negative reaction to etching by HF sodium cobaltinitrate (yellow) stain.Mineralization is dominated by fine-grained (~0.3mm), anhedral aggregates of chalcopyrite that occurs as infill in quartz + magnetite bearing veins and minor as disseminated fraction. In the veins, chalcopyrite occurs with actinolite, hydrothermal? hornblende and traces of bornite.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 29.0% Fine to medium-grained (0.5 to 2mm in length), euhedral, tabular aggregates that show a strong zonation and a marked silicification in their borders. Also, present a selective replacement of sericite + clay.PETROGRAPHY REPORTv. JUNE 2018Sample ID: SMA_ME_1705_JM_061Quartz 21.0% 2 populations. 1 Fine-grained (up to 0.5mm) colourless, anhedral phenocrysts intergrowing with pla-gioclase, hornblende.2 Very fine grained (<0.05mm) granoblastic aggregates that conform the rock groundmass. Biotite 8.0% Fine-grained (~0.2-0.4mm) brownish, anhedral, striated aggregates that replaces horn-blende and occurs in veinlets. This is altered to chlorite. This is interpreted as hydrother-mal biotite for the style occurrence (veinlets)Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Hornblende 2.0% Medium-grained (up to 4mm in length), anhedral to subhedral crystals that intergrown with plagioclase and quartz. Present multiple inclusions of magnetite and are altered to chlorite and actinolite. Magnetite 3.0% Fine-grained (~0.5m), anhedral to euhedral crystals that mostly replaces hornblende and occurs in quartz vein accompanied by chalcopyrite. . MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsActinolite TrFine-grained (<0.3mm), pale green. That occurs as partially replacement after primary hornblende. * Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaChlorite23.0%2.0%Occurs as pseudo morphed mineral replacing the plagioclase borders and also as quartz veins. In the vein quartz it is accompanied by magnetite + chalcopyrite and secondary hornblende? Some of the hornblendes are altered to biotite, chlorite and actinolite Fine-grained (up to 0.5mm), pale green to colourless (pleocroic), anhedral aggregates re-placing hornblende and secondary biotite. Chalcopyrite 2.0% Fine-grained (~0.3mm), anhedral aggregates that occurs as infill in the quartz bearing veins and minor as disseminated fraction. Along the vein, this occurs with actinolite, hornblende, and traces of bornite. Epidote TrVery fine-grained (<0.05mm), anhedral, pale yellow , occurs as interstices filling in quartz.Sericite Tr Very fine-grained (<0.1mm), flaky, aggregates accompanied by weathering clay. It occurs as selective replacement after plagioclase.AMag: 2xPPL+RL2mmCBPhotomicrographsSample JM061. A) Photomicrograph 2X showing the crowded porphyry texture of the sample. Note the biotite + magnetite vein-let replaced by chlorite. B) Photomicrograph 2X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 10X showing the occurrence of hornblende and magnetite replaced by hydrothermal biotite. Note the marked plagioclase zonation. D) Same as photo C, but under crossed Nicolls. E) Photomicrograph 2X showing the chalcopyrite infill texture in a quartz rich vein. Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)DE<Qtz<Ser<Plag<Plag<Ep<Qtz<Qtz<Hb<K-Felds?Porphyry RockMag:10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<BiotMag: 2xRL2mmPPL FOV~ 11mm (Length)<Mag<Mag<Qtz<Plag<Chl<Qtz<Ser<Plag<Plag<Mag<Mag<Qtz<Plag<Chl<Biot<Plag<Mag<Qtz<Qtz<Hb<K-Felds?<Biot<Biot<Plag<MagQtz VeinCcp>Ccp>PETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. JUNE 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: SMDDH026@337Montiel E SMA_ME_1705_JM_062Country: ColombiaStained section offcutSummaryLithology: Medium-grained crowded porphyritic Hb+Bt+Qtz tonalite (300 point-counted)Alteration minerals: silica, sericite and chlorite Intensity of alteration: Medium to weakMineralization: Disseminated pyrite Fracture infill: quartz + pyrite with traces of carbonate + epidote + chloritePolished Thin section DescriptionThis sample correspond to a holocrystalline, sub idiomorphic, porphyritic rock dominated by phenocrysts (80%) in relation to the groundmass (20%). The phenocrysts correspond to medium-grained (0.5 to 2mm in length) euhedral plagioclase (38%) and anhedral to subhedral crystals (up to 4mm length) of hornblende (~8%) that intergrow with fine-grained magnetite (~1%). Based on 300-grain counts the primary quartz in the sample is close to the 32% and corresponds to a fine-grained (up to 1mm) anhedral aggregates that constitutes the major phase in the rock groundmass.Intermediate alteration produced by the occurrence of silicification (5%) replacing the plagioclase borders. Also by the occurrence of fine-grained (~0.2-0.4mm) anhedral hydrothermal biotite that replaces hornblende. Chlorite (7%) occurs as radiated to anhedral aggregates replacing hornblende and as infill in quartz veins. In the sample there is a marked occurrence of very fine-grained (<0.1mm), flaky aggregates of sericite + clay. This alteration occurs as selective replacement after plagioclase where the intensity tends to increase in the prox-imity to quartz veinlets. Traces of carbonate occurs as replacement of hornblende accompanied by chlorite and traces of chalcopyrite. K-Feldspar (5%) occurs as selvages in qtz+py veinlets. Mineralization is dominated by coarse-grained (>5mm), anhedral aggregates of pyrite (1%) that occurs as infill in the quartz bearing veins and minor as disseminated fraction. Along the vein, pyrite is a accompanied by traces of carbonate + epidote + chlorite and it locally cut by quartz.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 38.0% Fine to medium-grained (0.5 to 2mm in length), euhedral, tabular aggregates that show a medium to strong zonation and silicification in their borders. Also, present a selective replacement of sericite + clay that varies from weak to pervasive. PETROGRAPHY REPORTv. JUNE 2018Sample ID: SMA_ME_1705_JM_062Quartz 32.0% Fine-grained (up to 1mm) colourless, anhedral phenocrysts intergrowing with plagioclase, hornblende. This constitutes the mayor phase in the rock groundmass.Hornblende 8.0% Medium-grained (up to 4mm in length), anhedral to subhedral crystals that intergrown with plagioclase and quartz. Present multiple inclusions of magnetite and are altered to chlorite, biotite, calcite and epidote. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Biotite 1.0% Fine-grained (~0.2-0.4mm) brownish, anhedral, striated aggregates that replaces horn-blende. (Secondary)Magnetite 1.0% Fine-grained (~0.5m), anhedral to euhedral crystals that mostly replaces hornblende. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSericite 4.0%Very fine-grained (<0.1mm), flaky, aggregates accompanied by weathering clay. It occurs as selective replacement after plagioclase. The intensity tends to increase in the proximi-ty to Qtz + epidote veins contact.* Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SilicaChlorite5.0%7.0%Occurs as pseudo-morphed mineral replacing the plagioclase borders and as quartz veins. In the quartz in vein is accompanied by epidote, pyrite, and chlorite.Fine-grained (up to 0.5mm), pale green to colourless (pleocroic), radiated to anhedral ag-gregates replacing hornblende and as infill in quartz veins. Pyrite 1.0% Coarse-grained (>5mm), anhedral aggregates that occurs as infill in the quartz bearing veins and minor as disseminated fraction. Along the vein, it is locally cut by quartz.Epidote TrMedium-grained (<2mm), anhedral, pale yellow, occurs as interstices filling in quartz and selective replacement of hornblende accompany chloriteCarbonate Tr Medium-grained (<2mm), anhedral to subhedral, colorless, occurs as selective replace-ment of hornblende accompany chlorite and traces of chalcopyrite.K-Felds 5%Medium-grained (<2mm), anhedral aggregates that occurs as selvage of Py+Chl+quartz veinlets. This was recognized using HF sodium cobaltinitrate (yellow) stain.AMag: 2xPPL+RL2mmCBPhotomicrographsSample JM062. A) Photomicrograph 2X showing the crowded porphyry texture of the sample. B) Photomicrograph 2X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 5X showing the occurrence of hornblende and magnetite replaced by hydrothermal biotite. D) Same as photo C, but under crossed Nicolls. E) Photomicrograph 2X showing the occurrence of quartz + pyrite + chlorite + epidote veinlets. Note the selective sericite replacement of the plagioclase. F) Same as photo E, but under crossed Nicolls.Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)DE <PyMag: 2xPPL+RL2mmPPL FOV~ 11mm (Length)<Qtz<Ser<Plag<Plag<Mag<Mag<Qtz<Hb<Chl<Qtz<Qtz<Hb<K-Felds?<Biot<Biot<Plag<Mag<Qtz VeinChl> Ep>FMag: 2xXPL+RL2mmPPL FOV~ 11mm (Length)<Silica<Qtz<Ser<Plag<Plag<Mag<Mag<Qtz<Hb<Hb<Silica<Hb<Qtz<Qtz<Hb<K-Felds?<Biot<Biot<Plag<Mag<HbMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mmXPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)<Ser<Qtz<Plag<Py<Qtz VeinChl> Ep><Ser<Qtz<PlagPETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. JUNE 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: SMDDH026@337Montiel E SMA_JA_1704_JM_048Country: ColombiaOffcut sampleMacroscopic Sample DescriptionThis sample was taken from the patio material of the artisanal mills at Mina Cocos, in the eastern side of the La Jagua Creek. This correspond to a concentrate of hydrothermally altered wall rock to sericite from active mining workings at Mina Cocos. Sericite in this sample displays sizes from fine to very fine fraction (<0.05mm) and intergrows with chlorite (after hornblende?), calcite and pyrite. There are some remnants of the host rock. This host rock corresponds to La Jagua tonalite, composed of quartz, plagioclase and hornblende (Sample SMA_JA_1705_JM_035) . The host rock fragments seem to be underwent shearing process. The sericite seems to be the product of alteration of plagioclase in the host rock. These plagioclases present sizes up to 2mm in diameter. The goal with this sample is to separate de sericite to be dated by Ar-Ar. Polished Thin section DescriptionThis sample corresponds to a fine to medium-grained pervasively altered rock with ~15% former relictic quartz from the protolith. Alteration is dominated by fine-grained (up to 0.5mm) sericite (~40%) that intergrows with fine-grained (up to 0.8mm) chlorite (~25%), and fine to medium-grained (1mm) carbonate (~15%). Carbonate is also observed as veinlets and locally replacing early sericite and chlorite. Fine-grained titanite occurs also along the carbonate veinlets. The sericite phase does not exhibit post formation alteration and can be used for age dating analysis. The mineralization is present, as traces of fine grained (up to 0.5mm) pyrite that show evidences of having formed along with the sericite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsQuartz 15.0% Medium-grained (3mm) , subhedral to anhedral , colourless with some possible shearing effects in the contacts with other minerals PETROGRAPHY REPORTv. JUNE 2018Sample ID: SMA_JA_1704_JM_048Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 15.0%Fine to medium-grained (1mm), colorless, anhedral aggregates, cutting Qtz crystals, and showing some local evidences of replacing sericite and chlorite.* Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite SericiteChlorite40.0%25.0%Fine-grained (up to 0.5mm), colorless, flaky radiated, intergrowing with chlorite and carbonate. All the three mineral seems to be in equilibrium and are observed cutting Qtz crystals Fine-grained (up to 0.8mm), pale-green, flaky radiated to striated aggregates that enclos-es the quartz crystals accompanied of sericite and carbonatePyrite Tr Fine-grained (up to 0.5mm), euhedral aggregates cut by carbonate. This has some flaky inclusions that suggest an intergrown with sericite. Titanite 3%Fine grained (up to 0.2mm), colorless, high relief , euhedral occurs with carbonate along some trails (veins)Quartz 3.0% Fine to very fine-grained aggregates , colorless, subhedral to prismatic, showing some open space-filling textureACBPhotomicrographsSample JM048. A) Photomicrograph 10X, showing some relictic quartz embedded in a sheared sericite + chlorite matrix. B) Pho-tomicrograph 10X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 10X showing the intergrow texture of chlo-rite and sericite. In the central phot some of the coarser grains observed in the sample. D) Same as photo C, but under crossed Nicolls. E) Photomicrograph 20X with conoscopy light (CL) showing the occurrence of sericite and carbonate intergrowth that cut some quartz crystals. F) Same as photo E, but under crossed Nicolls.DE<Qtz<Ser<Qtz<Chl<ChlF<SerMag:10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag:10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 20xPPL+RL+CL0,2mm Mag: 20xXPL+RL+CL0,2mmPPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length)<Ser<Qtz<Ser<Qtz<Chl<Chl<Ser<Qtz<Ser<Qtz<Chl<Chl<Silica<Ser<Qtz<Ser<Qtz<Chl<Chl<Silica<Ser<Ser<Qtz<Car<Ser<Qtz<Car<Ser<Qtz<Car<Ser<Qtz<CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: La CapitanaLa Capitana SMA_SM_1705_JM_036Country: Colombia1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Stained section offcutPolished Thin section Description Hypocrystalline, clast supported, monomictic, poorly sorted mafic volcanic breccia. The rock matrix is close to 40% and it is composed of fine to very fine grained glass with different stages of palagonitization?. This mate-rialreacted to to etching by HF sodium cobaltinitrate suggesting a K-rich composition (alkaline composition).The dominant phenocrysts correspond to fine to medium grained (~1mm) anhedral to subhedral plagioclase. This occurs as free crystals accompanied by fine grained (0.3mm) subhedral amphibole (Hornblende). A mi-nor component is related with rock fragment (3%) that exhibit the same composition of the rock (auto clast). Magnetite occurs as fine to very fine-grained, disseminated in the rock. Alteration is weak, and it is related with primary? Synvolcanic devitrification process that produce clay recrys-tallization to clay an minor chlorite. (~15%). Carbonate alteration occurs as fine-grained (~0.4mm), fracture filling minor as replacement after former plagioclase.This sample correspons to a alkalic basalt breccia. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Plagioclase 30% Fined to medium-grained ( 1mm ), subhedral to anhedral , tabular , zoned with twinning lamellaeMatrix 40% Fine to very fine-grained, composed of glass with different stages of palagonite alteration that varies from dark amber to brownish green. This material is K-rich and is reactive to to etching by HF sodium cobaltinitrate (yellow stain).SMA_SM_1705_JM_036Macroscopic Sample DescriptionThis is a representative sample of an intrusive defined by Cordoba Minerals as La Capitana Micro Diorite. The interpreted extension of this unit is close to 1.6 km N-S between the San Juan River (south of Mina Seca) and the William-San Juan Medio villages. This sample corresponds to a grab sample from a 10m length outcrop along one small drainage in the San Juan Media area. Under microscope, it is evident that this unit corre-sponds to a hypocrystalline, medium to fine porphyritic rock , with a development of phenocrysts with sizes around 1mm and a glassy? matrix. Alteration is medium to strong in plagioclase to clay and chlorite in some of the yroxenes. Magnetite is widespread in the entire sample. The main goal with this sample was to stablish if this unit corresponded to an intrusive body and characterize it with lithogeochemistryHornblende 5% Fine grained (0.3mm), pale green to pale brown, pleocroic, occurs as phenocrystsRock Fragments 3% Fine-grained (0.7), coherent fragments composed of plagioclase with a glassy matrixMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite-Clay 15.0% -Very Fine-grained (<0.1mm), dark green, occurs as devitrification product after glass?. It seems to be stained by FeOx that also stains Car-Fine-grained (~0.4mm), colorless, anhedral aggregates, occurring as fracture filling , intersecting filling and minor as replacement after former plagioclase2%*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite CarbonateIncludes CalciteSample ID:MineralizationPyrite Tr -Fine-grained (~0.1mm), subhedral aggregates, occurs as disseminated in the sampleSMA_SM_1705_JM_036-Fine-grained (~0.1mm), subhedral aggregates, occurs as disseminated in the sampleTrMagnetiteACBDPhotomicrographsJM036. A and C) Sample JM036. Microphotograph showing the breccia- pyroclastic texture of the sample with restricted carbon-ate alteration. Note the occurrence of hornblende crystals embedded in a glass matrix. B and D) Same as microphotograph A and C respectively, but under XPL + RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)<Hb <Qtz+Clay<Plag<Glass<Hb <Glass<Car<Glass<Hb <Qtz+Clay<Plag<Glass<Hb <Glass<Car<GlassMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Plag<Plag<Car +Ser<Glass<Qtz<Qtz+Clay<Plag<Plag<Car +Ser<Glass<Qtz<Qtz+ClaySMA_SM_1705_JM_036<Hb <Hb PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: CADDH002@70.02Costa AzulCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_CA_1704_JM_054 Polished Thin section Description This sample correspond to a holocrystalline, porphyritic rock dominated by phenocrysts (70%) in relation to the groundmass (30%). The phenocrysts correspond to medium-grained (up to 2mm in length) euhedral pla-gioclase (21%) and anhedral to subhedral crystals of hornblende (6%) that intergrow with primary magnetite and traces of biotite. The primary quartz in the sample is close to the 27% and occurs as fine-grained (up to 0.5mm) anhedral phenocrysts that intergrow with plagioclase and hornblende. Additionally occurs as very fine grained (<0.05mm) granoblastic aggregates that conform the rock groundmass. Alteration is relatively low to intermediate and it is produced by the occurrence of silicification (15%) replacing the plagioclase borders. Also by the occurrence of fine-grained (up to 0.5mm), anhedral aggregates of chlo-rite (15% ) that replace hornblende. Molybdenite in the sample occurs in quartz-bearing veins as medium to coarse-grained (up to 4mm) subhe-dral aggregates that intergrows with fine to very fine-grained (<0.7mm), subhedral pyrite. The quartz in the vein is also accompanied by carbonate, epidote and traces of zoisite-chlorite. Sericite occurs as fine to very fine-grained (<0.15mm) flaky aggregates that defined some selvages around the quartz veinlets. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole CADDH002@70.02m in the Costa Azul prospect. This sample corre-sponds to medium fine-grained porphyritic rock. The hornblende phenocrysts are complete altered to chlorite, magnetite and biotite(?). The crystals display an anhedral and irregular shapes. The major phenocrysts are of plagioclase that exhibit textural zonations. The groundmass correspond to a cryptocrystalline aggregates of quartz. The magnetite occurs as fine aggregates in hornblende crystals and disseminated in the groundmass. Pyrite is the main mineral phase with lesser 1% on the sample. A later event of quartz+molybdenite ± chalco-pyrite is present as an isolated vein that cuts the Ccp-rich veinlets. SMA_CA_1704_JM_054 Mineral Modal Textural and Mineral DistributionRock-forming mineralsQuartz 27.0% 2 populations: 1. Fine-grained (up to 0.5mm) colourless, anhedral phenocrysts inter-growing with plagioclase, hornblende. 2 Fine to very fine grained (<0.14mm), anhedral, granoblastic aggregates that conform the rock groundmass. Plagioclase 21.0% Fine to medium-grained (0.5 to 1mm in length), euhedral, tabular aggregates that show a strong zonation and a marked silicification in their borders as well as selective alteration Hornblende 6.0% Medium-grained (up to 1mm in length), anhedral to subhedral crystals that intergrown with plagioclase and magnetite and are partially altered to chlorite.Biotite Tr Fine-grained (~0.8mm) brownish, striated aggregates that intergrow with plagioclase, hornblende and quartz.Magnetite 5.0% Fine-grained (~0.2μm), anhedral to euhedral crystals that intergrowth and as inclusions within hornblende and with the quartz veins. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChalcopyrite Tr Very fine-grained (<0.1) anhedral aggregates disseminated in the sample. In the macro scale description it is present some early chalcopyrite-rich veinlets * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Chlorite15.0%10%Qtz veins along veins that occurs as medium-grained (~1.8mm) crystals intergrowing with carbonate, pyrite, epidote and molybdenite. Silica occurs as pseudo-morphed min-eral replacing the plagioclase borders.Fine-grained (up to 0.3mm), pale green to colourless, pleocroic, fibrous habit aggregates replacing hornblende. The BR is of 1st orderQuartz-SilicaActinolite Tr TrFine-grained (<0.3mm), pale green, occurs as relictic mineral after chlorite alterationSericite 3%Fine to very fine-grained (<0.15mm), colorless, flaky aggregates selectively replacing plagioclase and as subtle selvage around the quartz veinletEpidote TrFine to very fine-grained (<0.1mm) high relief, pale yellow coloration, Euhedral aggre-gates that intergrows with molybdenite. AlterationQuartzChloriteActinoliteSericiteEpidote MineralizationChalcopyritePyriteMolybdeniteMolybdenite <1% Coarse-grained (up to 4mm), grey coloration, subhedral aggregates that intergrows with qtz 3 along some veins. This intergrows with carbonate, epidote and traces of zoisite-chlorite SMA_CA_1704_JM_054 Pyrite 1% Fine to very fine-grained (<0.7mm), subhedral to euhedral, disseminated and accompa-nying quartz veinlets. C DPhotomicrographsJM054. A) Photomicrograph 5X showing the occurrence of molybdenite along the quartz vein with some sericite selvages. B) Pho-tomicrograph 5X, same as Photo A, but with crossed Nicolls. C) Photomicrograph 10X showing the molybdenite intergrowth with epidote, carbonate and zoisite-chlorite. D) Photograph 10X, same as Photo C, but with crossed Nicolls. E) Photomicrograph 10X showing relictic textures of actinolite replaced by chlorite. Also, note the disseminated chalcopyrite associated with the actinolite occurrence. F) Photograph 10X, same as Photo E, but with crossed Nicolls. Sample ID:A BEMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)QtzVeinMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 10xPPL+RL0,4mmPPL FOV~ 2.18mm (Length)<Primary Qtz<Car<EpSMA_CA_1704_JM_054 FMag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length)<Moly<SerQtzVein<Primary Qtz<Car<Ep<Moly<SerQtzVein<Zois<Ep<Moly<CarQtzVein<Zois<Ep<Moly<CarQtzVein<Act<Chl<Plag<Act<CcpQtzVein<Act<Chl <Plag<Act<CcpPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: SMDDH019@205El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_ME_1705_JM_059Polished Thin section Description This sample correspond to a holocrystalline rock with pyroclastic to pseudo-porphyritic texture defined by an aphanitic matrix (~50%) of acicular amphibole, pyrrhotite and very fine grained brownish aggregates of secondary Biotite? The microphenocrysts corresponds to fine to very fine-grained (~0.2) anhedral to weakly tabular plagioclase (12%), fine-grained (up to 0.5mm in length) anhedral hornblende (2%) and fine-grained (~0.1mm) traces of anhedral quartz with sharp edges. Alteration intensity is moderate to strong and is produced by the occurrence of very fine grained (<0.05mm), anhedral to sub rounded aggregates of secondary biotite (18%). This biotite do not present the typical stri-ations of basal cleavage denoting a metasomatic origin. 10% of the sample consists of very fine-grained (<0.1mm) acicular amphibole (actinolite?) that occurs as selective replacement of the groundmass and locally replacing plagioclase.Mineralization is present as very fine-grained (~0.2μm), anhedral pyrrhotite (8%) that occurs in the rock ma-trix with secondary biotite and traces of chalcopyrite + pyrite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample corresponds to medium to a fine-grained crystal tuff, with a groundmass altered principally to biotite? and pyrrotite?/ Mag?. The phenocrysts corresponds to irregular plagioclase that do not exhibit an al-teration. This sample present a transition to a fine to very fine-grained crystal phase, possibly along a bedding. No carbonate alteration was observed. Mineralization was evidenced as some hairline veinlets of pyrite and chlorite, as well as chlorite in the groundmass is also common.Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase 50.0%12.0%Very fine-grained composed of acicular amphibole, pyrrhotite and brownish aggregates (Biotite?)Fine to very fine-grained (~0.2) anhedral, weakly tabular aggregates, that occurs as phe-nocrysts in the sample.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_ME_1705_JM_059Hornblende 2.0% Fine-grained (up to 0.5mm in length), anhedral to subhedral crystals that area altered to chlorite and biotite? MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz TrFine-grained (~0.1mm) anhedral, with some sharp edges Pyrrhotite 8% Very fine-grained (~0.2μm), anhedral , that occurs disseminated in the sample accompa-nied by traces of chalcopyrite and pyrite* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Amphibole (Actinolite?)18.0%10%Very fine grained (<0.05mm), pale to dark brown, anhedral to sub rounded aggregates , with interference colors of secondary biotite , (Low second order) occurs disseminated in the sample accompanied with Pyrrhotite. Very fine-grained (<0.1mm), pale-green to dark-green, acicular aggregates with interfer-ence colors of high 1st order. This occurs as selective replacement of the groundmass BiotiteSMA_ME_1705_JM_059C DPhotomicrographsJM059. A) Microphotograph 2X, showing former plagioclase embedded in an amphibole + pyrrhotite rich matrix. B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the pyroclastic texture of the rock. Note the patchy biotite alteration. D) Same photo C, but under XPL + RL. E) Microphotograph 50X, showing some pervasive replacement of secondary biotite and pyrrhotite after plagioclase. F) Same photo E, but under XPL + RL.Sample ID:A BMag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)E FMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<PlagMag: 50xPL+RL0.08mm Mag: 50xXPL+RL0.08mm PPL FOV~ 441Um (Length) XPL FOV~ 441Um (Length)<Po<Hb<Act?<Chl<Plag<Qtz<Bio<Plag<Plag<Po<Hb<Plag <Plag<BioSMA_ME_1705_JM_059<Bio<Plag<Po<Hb<Act?<Chl<Plag<Bio<Chl<Qtz<Bio<Plag<Plag<Chl<Po<Bio<Po<Hb<Plag <Plag<Bio<Bio<BioPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: SMDDH011@84.2Montiel ECountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_ME_1704_JM_056 Polished Thin section Description This sample corresponds to matrix supported andesite volcano clastic breccia highly altered with no clear rock former mineralogy. The dominant alteration mineralogy correspond to quartz (~50%) that occurs as very fine-grained selective replacement of the rock matrix, fragments and interstices infill. Quartz also occurs in some 0.08mm-width veinlets. The second major alteration mineral corresponds to actinolite (~35%). This mineral occurs as very fine to fine-grained (<0.1-0.3mm), pale green to dark green, acicular aggregates that intergrows with quartz, molybdenite, chalcopyrite and traces of clay and titanite. This is partially altered to very fine to fine-grained (<0.1-0.3mm) chlorite.Molybdenite occurs in the sample as fine to very fine-grained (up to 0.7mm), anhedral, disseminated aggre-gates that occurs with fine to very fine-grained (<0.5mm), aggregates of pyrite, chalcopyrite ± magnetite and enclosed by very fine-grained (<0.05mm) greenish clay with epidote traces. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole SMDDH011@84.2m in the Montiel East Prospect. This was selected after revising the higher Mo concentrations in the drillcore samples. This sample corresponds to a possible intrusion breccia. The major alteration mineral corresponds to chlorite ± albite in the groundmass (GMASS ~40%). Albite also occurs (up to 4cm patches) with pyrrhotite and pyrite and seems to be cut for some small veins of Py + Qtz. Molybdenite occurs as isolated and disseminated crystals up 1mm. Some of Mo crystals seem to intergrow Py, but are also cut by Py in veins. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_ME_1704_JM_056 Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChalcopyrite Pyrite Tr Fine to very fine grained (<0.5mm), anhedral aggregates intergrowing with molybdenite traces of pyrite and clay * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite, Mo= Molybdenite, Act=ActinoliteAmphibole (Actinolite)50.0%35%3 populations1-Very fine-grained subhedral to anhedral occurs as fine replacement of the previous rock matrix (possibly lapilli-rich breccia rock). 2- Fine-grained (up to 0.2mm), anhedral to subhedral, occurs as rock interstices in-fill and as selective replacement of previous former fragments.3- 0.08mm -width quartz veinlets Very fine to fine-grained (<0.1-0.3mm), pale-green to dark-green, acicular aggregates with interference colors of high 1st order. Actinolite occurs intergrowing with quartz and locally intergrows with molybdenite, chalcopyrite and clay. Act is also altered to chloriteQuartzChlorite 5%Very fine to fine-grained (<0.1-0.3mm), pale-green to colorless, acicular aggregates with interference colors of 1st order. Chl replaces selectively the actinolite crystals. Magnetite 5%Fine to very fine-grained (up to 0.5mm), anhedral aggregates that occur disseminated in the sample accompanied by traces of chalcopyrite, pyrite, and quartz.Clay 3%Very fine-grained (<0.05mm), greenish with a FeOx staining. Calys occur as patchy re-placement accompanied by sulphides and traces of epidote. AlterationQuartz Amphibole ChloriteClayMagnetiteTitaniteEpidote MineralizationChalcopyritePyriteMolybdeniteSMA_ME_1704_JM_056 Titanite TrFine to very fine-grained (up to 0,1mm) euhedral aggregates, colorless, high relief with acicular rutile inclusions Molybdenite Tr Fine to very fine-grained (up to 0.7mm), anhedral, occurs mostly as disseminated accom-panied by traces of chalcopyrite, pyrite and clay C DPhotomicrographsJM056. A) Microphotograph 5X, showing the contact between a relictic former fragment from an auto breccia?, and the per-vasive alteration to quartz and actinolite. B) Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the patchy occurrence of molybdenite accompanied by chalcopyrite and enclosed by clay+chlorite alteration. D) Same photo C, but under XPL + RL. E) Microphotograph 10X under XPL + RL, showing another patchy molybdenite occurrence accompanied by chalcopyrite clay+chlorite. Sample ID:A BEMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Relictic fragmentMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length)SMA_ME_1704_JM_056 <Qtz<Qtz<Act<ActRelictic fragment<Qtz<Qtz<Act<Act<Qtz<Qtz<Act<Clay+Chl<Mo <MoCcp><Qtz<Qtz<Act<Clay+Chl<Mo <MoCcp><Qtz<Act<Clay+Chl<MoCcp>PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. August 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: Buenos AiresBuenos AiresCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_BA_1801_JM_111 Polished Thin section Description This section corresponds to a massive ore sample with not evidences of the primary mineralogy. Texturally this corresponds to a hydrothermal breccia. The samples is dominated (~65%) by fine-grained (0.2mm), anhedral aggregates of chalcopyrite that intergrows with pyrrhotite, pyrite, ilmenite and traces of molybdenite. The sulfide assemblage is embedding prismatic and equant crystals of a REE composition (Ce-La, Appendix D2). The REE mineral (20% abundance) intergrows with apatite (10%) and The EDS indicate La con-tent in the chalcopyrite, indicating to be coetaneous with the REE mineralogy. Magnetite was not observed in this sample. PETROGRAPHY REPORTv. Auguts 2019Sample ID:Macroscopic Sample DescriptionThis sample was taken from the artisanal mining works at the Buenos Aires prospect. The sample corresponds to a grab sample from the dumping mined material. The sample comprises a massive sulfide ore, composed of chalcopyrite, pyrite, pyrrhotite and some fine-grained (1mm), colorless elongated aggregates that possibly correspond to apatite. This ore is hosted in a porphyritic andesite rock. The goal with this sample is to characterize the paragenesis of apatite + sulphides in the Buenos Aires prospect to make some comparisons with the El Alacrán Deposit mineralization. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_BA_1801_JM_111 Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration minerals* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite, Mo= Molybdenite, Act=ActinoliteChalcopyrite 30% Fine-grained (0.2mm), anhedral aggregates embedding crystals of REE mineral and ap-atite. The EDS indicate La content in the chal-copyrite, indicating to be coetaneous with the REE mineralogy. Pyrrhotite 25%Fine-grained (0.2mm), anhedral aggregates intergrowing with chalcopyrite and embed-ding crystals of REE mineral and apatite.Pyrite 10%Fine-grained (0.2mm), anhedral, aggregates that occurs as two populations: 1) as matrix in-fill, intergrowing with chalcopyrite and embedding crystals of REE minerals and apa-tite. 2) As vein-lets, this cuts Py1, chalcopyrite and pyrrhotite. Ilmenite 3%Fine to very fine-grained (<0.1mm), grey to pinkish coloration, anhedral, aggregates intergrowing with chalcopyrite. Highly aniso-tropic. This was confirmed by EDS. MineralizationChalcopyritePyrrhotitePyriteIlmeniteMolybdenite AlterationLa-Ce MineralApatite SMA_BA_1801_JM_111 Molybdenite TrVery fine-grained (<0.05mm), grey colored, acicular aggregates intergrowing with chalco-pyrite. Apatite 10%Medium grained (<2mm), colorless, tabular to prismatic shapes, fractured and partially altered through the fractures. La-Ce Mineral 20%Fine-grained (0.5mm), euhedral, with shapes varying form equant to prismatic and form-ing some radiated aggregates. Highly pleocroic from light yellow to light grey. BR varies from low 1st order in the longitudinal sections to low 2nd order in transversal sections. The transversal sections (001), is concentrically zoned indicating changes in the composi-tion. This mineral intergrows with apatite and is embedded in the sulphide groundmass. The EDS indicate an Al, Ca, Ce, La composition. C DPhotomicrographsJM111. A) Microphotograph 2X showing the hydrothermal breccia texture and major components of the Buenos Aires mineraliza-tion. B) Same photo A, but under XPL + RL. C) Microphotograph 10X showing the intergrowth of sulphides with a REE mineral and apatite. Note zonation in the REE mineralogy. D) Same photo C, but under XPL + RL. E) Microphotograph 5X under XPL + RL showing the two stages of pyrite. Py2 occurs as final stage cutting the pyrrhotite and non-metallic gange mineralization. F) Microphotograph 20X under XPL + RL showing the occurrence of ilmenite with the pyrrho-tite and chalcopyrite mineralization. Sample ID:A BEMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)SMA_BA_1801_JM_111 <Ap<CcpFMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)Mag: 20xPPL+RL0,2mmXPL FOV~ 1094μm (Length)Mag: 5xPPL+RL0,8mmXPL FOV~ 4.35mm (Length)<REE Mineral<REE MineralPy><Ap<Po<Po<Ap <Ccp<REE Mineral<REE MineralPy><Ap<Po<Po<Ap<Ccp<REE Mineral<REE Mineral<Ap<Po<Po<Ap<Ap<Ccp<REE Mineral<REE Mineral<Ap<Po<Po<Ap<Ap<Ccp<REE Mineral<Py1<Po<Po<Ap<Py2<Py2<Ap<Ccp<Ilmenite<Py1<Po<Ap<Ccp<ApPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. August 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: SMA_MW_1801_JM_120Montiel WCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_MW_1801_JM_120 Polished Thin section Description This sample correspond to a holocrystalline, porphyritic rock dominated by phaneritic groundmass (80%) Tex-turally, the 10% of the rock contains anhedral amygdales miarolitic cavities with open-space growing minerals and sulfides. The miarolitic cavities display a white halo of highly altered (weathered?) plagioclase and an inner formation to amphibole and sulphides. The groundmass is dominated by a very fine-grained anhedral, green-colored aggregates of amphibole (horn-blende?) accompanied of very fine-grained (~0.05mm) subhedral to anhedral plagioclase and magnetite.The phenocrysts correspond to medium-grained (~1.5mm) weakly tabular aggregates of plagioclase (7%) that occurs with medium-grained (up to 1mm in length) anhedral hornblende (~3%).Alteration is relatively low and it is produced by the occurrence of fine-grained (up to 0.5mm) aggregates of chlorite ± zoisite (3%) that replaces hornblende. Also by traces of a fine-grained (<0.2mm) striated mineral (unknown) that occurs as pervasive replacement and veins accompanied by zoisite ± carbonate and formed after amphibole phenocrysts. Traces of apatite also occurs as in-fill in the miarolitic cavities.Mineralization is dominated by the occurrence of traces of fine-grained (~0.2mm) anhedral aggregates of bornite with exolutions of chalcopyrite and coveline. It occurs along some quartz + zoisite + epidote ± sericite veinlets cutting the sample. PETROGRAPHY REPORTv. Auguts 2019Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole MWDDH003@48.80m and is a representative sample of the host rock of the Montiel West prospect. This sample was taken from the drill hole with higher quart + magnetite + chalcopyrite B-vein stock work density. This thin section corresponds to a fine- to medium- grained porphyritic andesite with a dark-green groundmass (60%) and vesicles filled with plagioclase/zeolite. The vesicles present hornblende and chalcopyrite in-fill. Possibly some of the defined vesicles corresponds to miarolitic cavities and the rock is a mafic porphyry. The goal with this sample is to characterize by petrography and by lithogeochem-istry of the Montiel West host rock. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmass 80% Very fine-grained (<0.1mm) phaneritic groundmass composed of anhedral, green-col-ored aggregates of amphibole (hornblende?), that is accompanied of very fine-grained (~0.05mm) subhedral to anhedral plagioclase and magnetite.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Plagioclase 7% Medium-grained (~1.4mm) dusty-colored, subhedral phenocrysts that are selective-ly argillized and locally overgrown by amphibole. SMA_MW_1801_JM_120 Amphibole Hornblende?3% Medium-grained (up to 1mm in length), euhedral phenocrysts that occurs as free crystals and as in-fill interstices accompanied of quartz, zoisite-clinozoisite, apatite and are in-fill Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChalcopyrite 1% Medium-grained (<2mm), anhedral aggregates intergrowing with amphibole in the rock interstices or bugs and accompanying by pyrite in veinlets. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite, Mo= Molybdenite, Act=Actinolite, Trem=TremoliteChlorite50.0%3%Very fine-grained (<0.1mm), pale-green to light brown, anhedral aggregates selective replacing the rock groundmass and some former amphibole. This al-teration is observed as border reaction from primary amphibole. Amphibole also occurs with chalcopyrite and magnetite along some veins. Fine-grained (up to 0.5mm), pale green to colourless, pleocroic, anhedral ag-gregates replacing amphibole.Amphibole Tremolite 1%Fine-grained (~0.2mm), colorless, acicular aggregates that occurs as veinlets cutting the amphibole veins Quartz 1%Fine-grained (<0.5mm), colorless, anhedral, aggregates that occurs as interstic-es in-fill accompanied of magnetite and with inclusions of acicular mineral pos-sibly amphibole or Magnetite/Illmenite? 30%Very fine-grained (<0.1mm), euhedral to euhedral aggregates intergrowing with amphi-bole in the rock groundmass and accompanying chalcopyrite in veins and as interstices infill accompanied by chalcopyrite. AlterationPrimary MineralsAmphiboleMagnetiteApatiteTremoliteMineralizationChalcopyritePyriteSMA_MW_1801_JM_120 Apatite TrMedium-grained (>1mm), euhedral to subhedral, tabular to prismatic aggre-gates inter-growing with chalcopyrite in the rock interstices.Pyrite Tr Fine-grained (<1mm), euhedral to subhedral aggregates intergrowing with chal-copyrite. C DPhotomicrographsJM120. A) Microphotograph 2X showing the mineralogy of the miarolitic cavities. Note the occurrence of apatite intergrowing prismatic crystal within the cavities. B) Same photo A, but under XPL + RL. C) Microphotograph 2X showing a cross-cutting relationship of a late Tremolite veinlets cross-cutting the sulphides mineralization. Note in the upper right corner the mineralogy associated with the miarolitic cavities. D) Same photo C, but under XPL + RL. E) Microphotograph 10X under XPL + RL showing the disseminated occurrence of amphiboles (hornblende) and magnetite/ilmenite? Note the acicular mineral embedded in quartz, possibly actinolite or rutile. Sample ID:A BEMag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length)SMA_MW_1801_JM_120 <Ccp<Hb<QtzQtz<Act/Rutile?<Plag<MagCcp>Mag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)Mag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)<ApPlagArgillized Plag<Ccp<Hb<Qtz<ApPlagArgillized Plag<Ccp<Hb<Trem<ApPlagArgillized Plag<Ccp<Ccp<Hb<Trem<ApPlagArgillized Plag<Ccp<Hb<Hb?<Hb?<Plag B.2 Petrography Report from the El Alacrán Deposit samples. Begins on following page… PETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ACD002@293El Alacran SMA_AL_1602_JM_004Country: ColombiaMacroscopic Sample DescriptionThis sample was taken from the Drillhole ACD002@293, in the El Alacran Unit 3. The sample comprises a weak-laminated, pale brown and greenish altered lapilli tuff?. The sample has some isolated (0.4cm) accre-tionary lapillies (?) surrounded by a carbonate halo. The brownish and chlorite alteration are distributed along the rock bedding. The goal with this sample is to define the nature of the brownish alteration and confirm the presence of accretionary lapillies in tuffs from the Unit 3.Polished Thin section Description The predominant texture of this sample correspond to a banded, very fine-grained tuff with some relictic ac-cretionary lapillies, approximately of 0,5cm diameter. No primary minerals were recognized. The alteration assemblages comprise an early calcic alteration, with a minor component of sodic and brownish alteration, defined by the occurrence of fine-grained (~0,4mm) chlorite (25%) as selective replacement of frag-ments and in the groundmass as very fine-grained (<0,1mm) acicular shaped intergrowing with rutile (25%), quartz (30%) and minor albite (4%). The association with the FeOx staining gives to the rock a dark brownish coloration. Albite occurs as very fine-grained (<0,1mm) tabular to needle-like selective replacement of the rock frag-ments. Albite indicates an early occurrence to the major quartz+ chlorite association. Traces of Py were observed in the sample. Conclusions: •The brownish mineral does not corresponds to hydrothermal biotite. This mineral corresponds instead to a combination of fine-grained rutile aggregates and the FeOx stain in the Chl.•Given the several inclusions of Chl in Qtz, both minerals are interpreted to belong to the same phase.•All the Qtz observed in the sample was interpreted as secondary in origin.The intimate relation of Qtz with Chl and also because the host rock (Unit 3) lacks of primary Quartz. •Some possible very fine-grained relicts of actinolite are present. Similarly, the acicular habit in the chlorite possibly indicate a replacement after that actinolite (?).Mineral Modal Textural and Mineral DistributionRock-forming minerals0.0%0.0%0.0%PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_004MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralschlorite 25.0%Fine-grained (~0,4mm), pale-green (Mg-rich) as selective replacement of fragments? Also chlorie occurs in the groundmass as very fine-grained (<0,1mm) acicular shaped intergrowing with rutile, albite and minor quartz. The chlorite present a FeOx staining. rutile 25.0% Very fine-grained (<0,1mm) selective replacement along some of the host rock bedding. Rutile intergrows with Chl and Qtz.quartz 30.0% Fine to very fine-grained (0,1mm) anhedral to subhedral, colourless replacement aggre-gates. The quartz contains several inclusions of elongated pale green mineral (Chl?). Rock banding controls the distribution on the sample. The Qtz selectively replaces some of the bands given a lighter color to the sample. Qtz intergrows with Chlorite. albite 4.0% Very fine-grained (<0,1mm) tabular, and needle-like replacement in previous fragments. The alteration is overprinted by a quartz+ chlorite association.magnetite 1.0% Anhedral rounded primary crystals (0.1-4mm) disseminated in the rockpyrite <1.0% Anhedral crystals (100-750microns) disseminated in the rockchalcopyrite <1.0% Anhedral crystals (20-350microns) disseminated in the rockcarbonate 8.0% Fine-grained (1-1,5mm) patches of carbonate mostly rimming some previous lapilli rel-icts that were replaced to Qtz+Chl. FeOx Staining 5.0% Microcrystalline, leaking-like texture that stains the chlorite and rutile?. The FeOx in-crease the brownish colour in the rock.* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chal-copyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationalbitechloriterutilequartzcarbonateFeOx StainMineralizationmagnetitepyritechalcopyriteStage 2 Stage 3 Stage 4Sample ID: SMA_AL_1602_JM_004>20%10-20%1-10%<1% Undefined Distribution??AMag: 10xXPL+RL0,4mmCBDPhotomicrographsA) Representative view of the two replacement banding. Upper part (Very fine grained Chl+Rut minor quartz). Lower part (quartz-rich+Chl minor albite and rutile) B) Parallel-polars photograph of Photo A. Note the reddish brown color of the samples produced by the rutile and the Fe-rich stain. C) Crossed-polars in conoscopic light photograph of the relation of very fine grained rutile , chlorite, albite and quartz D) Photograph 50X of the Fe stained chlorite areas. Note the acicular habit developed in the chlorite Mag: 10xPPL+RLMag: 20xXPL+RL+CL0,2mm Mag: 50xPPL+RL+CL0,08mm0,4mm<qtzRut><chl<Abchl><Qtz<Ab<chl<chl<chlXPL FOV~ 2.18mm (Length) PPL FOV~ 2.18mm (Length)XPL FOV~ 1094μm (Length) PPL FOV~ 441μm (Length)<qtzRut><chl<Ab<chl<Rut<chlFeOx Stain><Rut<chlchlSample ID: SMA_AL_1602_JM_004PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location: ACD003@27.48El Alacran SMA_AL_1602_JM_005Country: ColombiaPolished Thin section Description The predominant texture of this sample correspond to a porphyritic diorite with phenocrysts mostly of pla-gioclase (40%) with sizes around 2mm and anhedral to subhedral fine-grained quartz phenocrysts (less than 5%) and lesser primary titanite.Alteration is dominated by early calcic and later hydrolytic, produced by the occurrence of selective replace-ment of medium-grained (~2,5mm), pale green, crystalline chlorite (20%) after primary amphibole and very-fine grained (<0,1mm), green-pale flaky aggregates of sericite replacing selectively plagioclase crystals. Finally, a cryptocrystalline, spheroidal, brownish aggregates mineral replaced the plagioclases and give to the rock a brownish color (Fe-Stain?). Some fracture-filling calcite is present in the sample as part of a late calcic event.No sulphide occurrence was evidenced in the sample. Conmments•The rock corresponds to a mafic minerals-poor diorite. Given the quartz content in the sample, and strati-graphic location, possibly correspond to an apophysis of the El Alacran Norte Diorite.•The brownish mineral do not correspond to hydrothermal biotite, instead corresponds to crypto-crystalline FeOx aggregates that replace the plagioclase. •(XRD) is recommended to define the nature of the cryptocrystalline brownish mineral.•Suspected occurrence of K-feldspar given the occurrence of an alteration process over the plagioclase that produce its twinning loss. It is recommended to stain the sample to corroborate.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclaseQuartzTitanite40.0%5.0%TrThere is a bimodal distribution defining a porphyritic texture. The phenocrysts are medium-grained (~2mm) euhedral with a overimposed brownish dusty alteration. The plagioclase has a clear twinning and zoning texture. Fine-grained (~0,5mm) ahedral to subhedral phenocrysts.Fine-grained (~0,3mm), euhedral, colourless, intergrowing with quartz and plagioclase. Optically the titanite presents a high-relief and strong birefringence.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_005Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD003@27.48m, in the El Alacran Unit 1. The sample corresponds to a pale-green micro-diorite to porphyritic diorite with phenocrysts of plagioclase with sizes varying from <1mm to 2mm. These phenocrysts are possibly albitized. The groundmass is altered to fine chlorite and subor-dinated carbonate. A brownish alteration is also present in the groundmass possibly after the chlorite. Neither mineralization nor magnetite are observed. The goal with this sample is to define if this rock correspond to an intrusive with secondary biotite alteration. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 20.0%Medium-grained (~2,5mm), pale-green, selective replacement of previous tabular shaped mineral possibly hornblende. Also occur as fracture in-fill.K-Feldspar 10.0% Very fine-grained (<0,1mm), dusty, altered to a brownish claying mineral. selectively replacing and rimming plagioclase crystals. The pervasive alteration produce mask of the parental plagioclase twinning. Carbonate 5.0% Fine to medium-grained, anhedral aggregates with a patchy distribution and a selective replacement and fracture filling in the sample. It replaces apatite crystals and a fibrous, acicular mineral that possibly occurred with apatite. Sericite-Illite 8.0% Very-fine grained (<0,1mm) , green pale , flaky aggregates replacing selectively pla-gioclase crystals.pyrite Tr Fine-grained Anhedral disseminated in the rockApatite 1.0% Fine-grained (~0,5mm) colourless, anhedral to subhedral aggregates as filling texture possibly intergrowing with Chlorite. This is partially to highly altered to CarbonateCryptocrystalline FeOx? 10.0% Cryptocrystalline, spheroidal, brownish aggregates that replaces the plagioclase and give to the rock a brownish color. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chal-copyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationK-Feldsparchloriteapatitecrypt MineralcarbonateMineralizationmagnetitepyritechalcopyriteStage 2 Stage 3 Stage 4??Sample ID: SMA_AL_1602_JM_005>20%10-20%1-10%<1% Undefined Distribution??AMag: 2xXPL+RL2mmCBDPhotomicrographsA) Representative view of the brown cryptocrystalline mineral (UknMin) replacing plagioclase. B) Same as Photo A, but with PPL. C) Crossed-polars light photograph showing the potential K-felds rimming previous plagioclase. Note The porphyritic texture of the rock with a groundmass conformed of plagioclase and chlorite. D) Photograph 50X of the FeOx stained chlorite areas. Note the acicular habit developed in the chlorite in some areas. E) Photograph 10X, showing the primary Titanite intergrowing with quartz and plagioclase.Mag: 2xPPL+RLMag: 2xXPL+RL2mm Mag: 2xXPL+RL2mm2mmPlag>chl<Plag<CarXPL FOV~ 1094µm (Length) PPL FOV~ 1094µm (Length)XPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) <Uknown<CarPlag>chl<Plag<Car<Uknown<Carchl<qtzPlag><Plag<Car<K-Feldchl<qtzTitaPlag><Car<CarSample ID: SMA_AL_1602_JM_005PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD004@88.32El Alacran SMA_AL_1602_JM_010Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The predominant texture of this sample corresponds to a clast supported polylithic volcanic breccia made of close 1cm length fragments and with possible primary cryptocrystalline aggregates of quartz in the matrix. No additional primary minerals were recognized. Alteration is dominated by early calcic calteration produced by the occurrence of two populations of chlorite (25%). One very fine-grained (<0,1mm) flaky aggregates pervasive altering some rock fragments and accom-panied by albite. A second, fine-grained flaky aggregates (>300μm) mostly intergrowing with quartz (20%), pyrite, minor chalcopyrite. A late calcic-CBM event is also recorded produced by the occurrence of medi-um-grained (>1mm) crystals of carbonate intergrowing with quartz, chalcopyrite and sphalerite Subordinated hydrolytic alteration is also present (<5%) with the occurrence of sericite, carbonate and minor chlorite. Some relictic albitization in fragments show a late replacement to FeOx staining + possibly kaolinite. Mineralization is dominated coarse-grained (up to 1cm), anhedral pyrite mostly related with the early calcic alteration. This pyrite is brecciated and cut by carbonate that accompanies chalcopyrite and Sphalerite (Late calcic-CBM stage).Comments:•The albite herein is interpreted as the first alteration mineralization phase. This and its posterior alteration products (kaolinite?) are stained to Fe-Oxides producing the selective brown coloration in the fragments.•No hydrothermal biotite was observed in the sample.•It is suggested to confirm the existence of Kaolinite/Dickite in the sample with XRD. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_010Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD004@88.32, El Alacran Unit 2 and lithofacie TufL?. The sample corresponds to an altered lapilli to lithic tuff? with fragments up to 1 cmm in diameter the matrix is composed by chlorite that seems to be replaced by a brownish-orange mineral that replaces all the fragments and the matrix. There are some fragments possibly of Qtz and selective and patchy replacement of pyrite+ chalco-pyrite + apatite? A final stage seems to correspond to calcite with chalcopyrite that replace/cut the previous phases. The goal with this sample is to characterize the orange-brown alteration as well as define if the rock correspond to an lithic tuff, agglomerate or conglomerate.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 20.0%Occurs as fine-grained (150μm) euhedral, prismatic aggregates filling the rock grain inter-stices and cavities with Ccp, Py and Carbonate. Also, possibly in the same stage as anhedral aggregates replacing the rock matrix, em-bedding Ap crystals, and intergrowing with Chl. Late Qtz also occurs cutting Py+Ccp. Albite 8.0% Fine-grained (>100μm) striated crystals, with selectively replacement of the rock frag-ments. Albite displays a marked staining to Fe oxides? , allowing differentiate them form the rest of alteration minerals. Some of the albite is also subtle altered to sericite a to a very low birefringence clay mineral (Kaolinite?)Chlorite 25.0% -Very fine-grained flaky aggregates pervasive altering some fragments. It is accompanied by albite? minor sericite and very fine rutile aggregates. -Fine-grained flaky aggregates (>300μm) mostly intergrowing with Qtz in the sample matrix. Also present some reaction halos (silicification?). This intergrowth with Ccp and Carbonate 7.0% -Medium grained (>1mm) crystals intergrowing with quartz, chalcopyrite and sphalerite.-Very fine-grained aggregates in 1mm-length patches, accompanied by rutile and sericite and minor chlorite.pyrite + Chalcopyrite 30.0% Coarse-grained (up to 1cm), anhedral, filling occurrence around the euhedral Qtz. It is brecciated and cut by Carbonate. Sphalerite 1.0% Fine-grained (up to 200μm), anhedral aggregates accompanied by chalcopyrite. Do not present Ccp exolutions and present reddish internal reflections. Sericite 3.0% Fine-grained (>100μm), flaky aggregates selectively replacing albite. Sericite occurs inter-growing with Car, after Chl and after Py+Ccp occurrence.Titanite/Anatase 1.0% Fine to very fine-grained (~50μm) isolated aggregates, transparent to amber coloured exhibiting some euhedral shapes. It mostly related with Pyrite and Car occurrence. Opti-cally correspond to Opaque, medium to dark-grey colour.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chal-copyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationAlbiteApatiteQtzTitanite/AnataseChlCarMineralizationPyChalcopyriteSphaleriteStage 2 Stage 3 Stage 4??Apatite 1.0% Medium to fine grained (~1mm in length), anhedral crystals. Occurs as isolated crystals embedded and cut by Qtz, chalcopyrite and coarse carbonate. It is altered to carbonate. optically Apatite presents a low birefringence and high relief. ??Sample ID: SMA_AL_1602_JM_010>20%10-20%1-10%<1% Undefined Distribution??AMag: 10xPPL+RL0,4mmCEBDFPhotomicrographsA) Representative view of the relict albitized fragments altered to Kao?+Chl in their periphery. Note the brownish color in the albite produced by Fe-Staining. B) Crossed polars of photo A. Note the two textures of Qtz, the quartz in the rock matrix and the one euhedral filling spaces embedded by Ccp in the upper right corner. C) Photograph 5X, representative of the euhedral crystals of quartz embedded by carbonate + Pyrite +Chalcopyrite. Note in the center a subhedral crystal of apatite altered and cut by carbonate and embedded by anhedral quartz aggregates. D) Photograph 5X, of Photo C. Note the open-filling texture exhibited by the chalcopyrite and pyrite embedding prismatic quartz crystals. Also the stain over the Albite-altered clasts. E)Representative view of the cutting relation of Chalcopyrite + carbonate + Sphalerite in the Apatite. F) Parallel Nicolls of photo E. G) Photograph 20X, representative of wall-matching crack filled with Qtz after the Pyrite and Chalcopyrite main phase. H) Photograph 5X, repre-sentative view of the Albite-Altered clasts remplaced by Sericite and embedded in a chlorite-rich gmass.Mag: 10xXPL+RLMag: 5xXPL+RL0,8mm Mag: 5xPPL+RL0,8mmMag: 10xXPL+RL0,4mm Mag: 10xPPL+RL0,4mm0,4mmPPL FOV~ 2,18mm (Length) XPL FOV~ 2,18mm (Length)XPL FOV~ 4,35mm (Length) PPL FOV~ 4,35mm (Length) <Kao?Rut><Qtz<Ab<chlCar>Ccp>Qtz>Ser><Kao?Rut><Qtz<Ab<chlCar>Ccp>Qtz>Ser><Kao?+ChlAp<Py<AbCar>Ccp>Qtz>Qtz><Kao?+ChlAp<Py<AbCar>Ccp>Qtz>Qtz>XPL FOV~ 2,18m (Length) PPL FOV~ 2,18m (Length)<chl <chl<ChlAp<SerCcpCar>Ccp>Qtz>QtzAb><Car<Sph<ChlAp<SerCcpCar>Ccp>Qtz>QtzAb><Car<SphSample ID: SMA_AL_1602_JM_010GMag: 20xXPL+RL0,2mm<qtzCcp<car<Ccp<PyXPL FOV~ 1094µm (Length)HMag: 5xXPL+RL0,8mm<qtz<car<SerAbXPL FOV~ 4,35m (Length)Abchl<QtzSample ID: SMA_AL_1602_JM_010PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD004@218.75El Alacran SMA_AL_1602_JM_011Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The predominant texture of this sample correspond to a fine-grained (~0,2mm) porphyritic andesite with relictic primary plagioclase (3%). The alteration is dominated by a massive-destructive sodic alteration produced by the occurrence of very fine-grained (<0,05mm) euhedral albite (70%) that pervasively replaced the rock groundmass. This sodic alteration is accompanied by an early calcic alteration produced by the occurrence of very fine-grained (<0,05mm, an-hedral, pale-green crystalline texture (Mg-rich) chlorite aggregates (~10%) that preferentially intergrown with fine-grained (~0,2mm), anhedral quartz (7%). Sericite alteration occurs as very fine-grained (<0,05mm), flaky aggregates that selectively replaces chlorite and albite. A later overprinting effect of a microcrystalline clay-FeOx stain? Is present in the albite and primary plagioclase. The sample corresponds to a thin section (no reflected light microscopy was realized), however the occur-rence of sulphide minerals is lower than the 0.5%. Comments•Quartz corresponds to an equilibrium phase that either intergrowth or overgrowths albite.•Sericite correspond to a late mineral phase and it not in equilibrium with the albite and the chlorite. •The patchy coloration in the sample correspond to FeOx? , clay mineral. Further research as XRD is required to characterize this alteration mineral.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 3.0% Fine-grained(0,2mm) Euhedral tabular shapes, colourless, selectively replaced to Sericite and Clay mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_011Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD004@218.75, El Alacran Deposit Unit 2 and lithofacie TufC?. This sample corresponds to fine-grained crystal tuff? with relict plagioclase crystals and some possibly primary quartz crystals. The sample is pervasive-altered to Ab>Chl, and later Ser+Ca. The predominant texture of the samples is massive-destructive albite alteration. The available sample corresponds to a thin section (no polished). The goal with this sample is to characterize the extensive alteration of Ab+Chl and the paragenetic relation with a possible biotite occurrrence.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsAlbite 70.0%Very fine-grained (<0,05mm) Euhedral, semi tabular shapes, colourless, pervasive replacing groundmass intergrowing with chlorite. Albite has an overprinting effect of a microcrystalline clay-FeOx. Stain. Chlorite 10.0% Very fine-grained (<0,05mm) anhedral, pale-green crystalline texture (Mg-rich) aggre-gates in the groundmass, intergrowing with Ab.Chlorite also occurs as fine grained aggregates, colourless, semi-radiated , and nucleating quartz crystals Quartz 7.0% Fine-grained (~0,2mm), anhedral to subhedral, colourless, random aggregates in the groundmass, intergrowing? with Ab+Chl.Carbonate 5.0% Fine- to medium-grained anhedral aggregates, colourless, selective replacing rock former plagioclase. Also, carbonate occurs as in-fill aggregates in quartz+ chlorite and as a late vein-in fill in the sample0.0%0.0%Sericite 3.0% Very fine-grained(<0,05mm), flaky aggregates , colourless to light pale-green, occurs usu-ally as aggregates with sericite nucleating quartz and carbonate Titanite and as selective replacing of former plagioclase. Titanite/Anatase 1.0% Fine-grained (~0,3mm), euhedral, isolated aggregates, brownish colored, nucleated by Quartz. Possibly primary? titanite partially replaced to rutile. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalco-pyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4Sample ID: SMA_AL_1602_JM_011??>20%10-20%1-10%<1% Undefined Distribution??Alterationquartz albite tita/rutile chlorite 10sericite 3carbonate 5MineralizationpyritechalcopyritesphaleriteAMag: 20xPPL+RL0,2mmCBDPhotomicrographsA) Representative view of chlorite aggregates and Fe-stained plagioclase groundmass. B) Cross-polars photograph of Photo A. Note the relation of sericite + carbonate that cut and nucleates the chlorite and quartz assemblage. Also note the albite altered groundmass. C) Cross-polars photograph of the relation of sericite and later carbonate as a final phase that alter and fill the quartz-chlorite interstice. D) Representative 5X Photograph showing primary Titanite altered to quartz and sericite. Mag: 20xXPL+RLMag: 5xXPL+RL0,8mm Mag: 5xXPL+RL0,8mm0,2mmPPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length)XPL FOV~ 4,35mm (Length) XPL FOV~ 4,35mm (Length) <Tita<Ser<Ab<chlCar><chl altered to SerApAb<AbCar>Ccp>Qtz>Qtz>ApAb<AbCar>Ccp>Qtz>Qtz><Tita<Ser<Ab<chlCar>Ser><chlTitaSample ID: SMA_AL_1602_JM_011PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD005@131.39El Alacran SMA_AL_1602_JM_012Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The predominant texture of this sample corresponds to a very fine grained (<0,1mm) pervasive altered volca-nic rock with no primary minerals evidence. This sample possibly correspond to a lapilli tuff.The alteration is dominated by a early calcic alteration, produced by the occurrence of fine to very fine grained (<0,05mm) groundmass of acicular chlorite that occurs with fine- to very fine-grained (~0,15mm) anhedral quartz aggregates and rutile. Some possible relictic of albite are also present in this alteration. Locally the chlorite is associated with a Fe-oxide staining alteration, giving to the rock a brownish coloration.Alteration also occurs as vesicles-filling and patchy replacement of fine-grained (~1,1mm) euhedral, tabular aggregates of apatite and quartz that are later overgrowth and replaced by a late-calcic event dominated by colourless, anhedral aggregates and fracture-filling carbonate accompanied by pyrite in veinlets.The main sulphide phase is represented by fine veinlet (0,05mm width) of pyrite + chalcopyrite (2%) that oc-curs with carbonate veins.Comments•The green soft mineral that was the objective of this thin section analysis, does not correspond to sericite. It corresponds to a mixture of chlorite and minor quartz instead. Sericite just occurs as traces in the sample.•Similarly to SMA_AL_1602_JM_004 sample. The brownish alteration in the sample is produced by the com-bination of FeOx stain overprint of rutile, albite and chlorite. •The FeOx stain seems to be spatially related with the contact of carbonate + pyrite assemblage with the earlier chlorite. •The crystal shape of the chlorite in the groundmass may correspond to previous actinolite that intergrown early albite (Calc-Sodic alteration).•The layered zonation in the rock cavities of this sample may provide a clue in the precipitation timing of the minerals associated with apatite. Based on this, apatite is an early alteration whereas sulphides + carbonate assemblage are usually late. •It is recommended to apply an in-situ technique to identify the nature of this FeOx Stain-clay mineral. This mineral does not resemble to any one previously identified by XRD and PIMMA by Dunne K, 2016. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_012Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD005@131.39 in the El Alacran Deposit Unit 2, lithofacie TufF. It corresponds to a brownish and greenish altered, fine-grained ash tuff, with some lapillies up to 2mm in diame-ter. The sample groundmass has a pervasive alteration of chlorite + sericite? with the lapillis altered to calcite. The sericite seems to have been altered to a fine-grained brownish mineral in the 70% of the sample. The lapillies are also altered to rutile?-carbonate (no HCl reactive). Associated with the brownish alteration there are some Py stringers. The goal with this sample is to define the paragenesis of chlorite+sericite alteration in relation with the brownish alteration.Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 45.0%Very fine-grained (<0,05mm), acicular, striated, pale-green, randomly distributed in the sample. Mostly associated with Qtz and albite in the groundmass. It is usually stained to FeOx after contact with Carbonate. Optically, chlorite displays a bluish interference colours. Anatase/Rutile 30.0% Very fine-grained (<0,1mm), anhedral, sub-rounded, brownish aggregates that occurs intimate associated with chlorite in the groundmass. Rutile might have been stained to Fe Oxide. Optically, rutile is brownish colored with a high-relief and isotropic. Quartz 10.0% 1- Fine to very fine-grained (~0,15mm) anhedral aggregates intergrowing with Chl+Rutile. 2- Fine-grained euhedral phase filling cavities. Quartz is also locally stained to Fe Oxide.Both populations present Interference colors mostly from blue and brown (poor polish).Carbonate 7.0% Fine-grained (0,5mm) colourless, anhedral aggregates as patchy and as fracture filling in quartz. It is also accompanied by Py in veinlets. pyrite + chalcopyrite 2.0% Occurs as a thin veinlet (0,05mm width) that cuts Qtz, apatite, and chlorite. Also it is present with rimming texture around the Qtz that fill some cavities. Apatite 3.0% Fine-grained (~1,1mm) euhedral, tabular aggregates that occurs as cavity-filling. Also occurs as layered precipitating mineral usually in the external part (first precipitating phase). The apatite euhedral phase is embedded by quartz, chalcopyrite and pyriteTitanite 3.0% Fine-grained (0,5mm) elongated, euhedral aggregates that occur as cavity filling in an early precipitation with Apatite. Also as disseminated in all the sample.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chal-copyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1Alterationalbite apatite titanite quartz chloritecarbonate Fe-Stain Mineralizationpyritechalcopyrite Stage 2 Stage 3 Stage 4??>20%10-20%1-10%<1%Sample ID: SMA_AL_1602_JM_012>20%10-20%1-10%<1% Undefined Distribution??AMag: 20xPPL+RL0,2mmCBDPhotomicrographsSample JM012. A) Photomicrograph 20X of the rock groundmass. In the detail the minerals that produce the brown coloration in the sample, which corresponds to a Fe-stain in the chlorite. B. Photomicrograph in crossed Nicolls of Photo A. Note the semi-acicular habit of the chlorite that intergrown with quartz and possible with some relictic Albite?. C) Photomicrograph 5X, representative of the layered texture in the rock cavities. Note the proximal dark-brown halo of Fe stain and the gradation to the rock groundmass. D) Photomicrograph 5X with crossed polars of photo C. Note the gradation of minerals from the wall to the center of the cavity, from apatite, titanite-quartz, and carbonate-chalcopyrite in the central part. Also in the upper left corner the a pyrite veinlet that rims and crosscuts the rock cavities. Mag: 20xXPL+RLMag: 5xXPL+RL0,8mm Mag: 5xXPL+RL0,8mm0,2mmPPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length)XPL FOV~ 4,35mm (Length) XPL FOV~ 4,35mm (Length) <Rut<chlQtz>Sample ID: SMA_AL_1602_JM_012chl>Stained Ab?><Rut<chlQtz>chl>Stained Ab?><Tita<Ap<PyFe Stain>chl> Qtz><Ap<Ap<Tita<Ap<PyFe Stain>chl> Qtz><Ap<ApQtz+Chl<PyPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD007@261.2El Alacran SMA_AL_1602_JM_017Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The predominant texture of this sample corresponds to a very fine-laminated (<0,1mm) bedding texture of a pervasive-altered ash tuff with no relictic primary minerals evidence. The alteration is dominated by an early calcic alteration formed by the occurrence of fine to very fine-grained (<0,1mm), euhedral to subhedral aggregates of apatite (35%) and pale chlorite (5%). This association is al-tered along a front replacement margin to a fine-grained (~0,12mm) dark chlorite (Fe Rich) (Chloritic assem-blage) that intergrowth with a second event of pyrite. Sericite occurred as isolated flaky crystals (<1%) that cut titanite and dark chlorite. Mineralization is dominated by pyrite (~28%) which displays two growing phases. 1. Early, highly-pitted mar-casitic? that possibly belong s to the early calcic event bearing apatite. A second stage of pyrite correspond to medium-grained (1-5mm), fresher aggregates that replaces apatite. This pyrite is accompanied by carbonate veins and replaces the early stage pyrite. Comments•The white pale bands in the sample do not correspond to albitization. Instead, it corresponds to an early apatite alteration that intergrowth pale chlorite, titanite and lack of rutile occurrence. •The main chlorite (Chl2) and pyrite stage was formed after the apatite-dominated alteration. This seems to control de occurrence of some of the chalcopyrite in the sample. •This sample do not present the amount of quartz expected in the early calcic assemblage. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_017Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD007@261.2 in the El Alacran Unit 2 and lithofacie (TufF). This sample corresponds to a fine-grained ash tuff? with 40% of pyrite + chlorite as small disseminated crystals fol-lowing the bedding structure? The pyrite + chlorite seems to be overgrowth by albite + rutile (pale) replacing the pyrite to rutile. The goal with this sample is to characterize the chlorite + pyrite (dark gree) and in relation to the sericite alteration (pale green). MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsApatite 35.0%Fine to very fine-grained (<0,1mm), euhedral to subhedral, colourless aggregates with several inclusions of pale green apatite + chlorite?. Apatite intergrows with Chl1 and is overgrown by titanite.Also apatite is altered to Chl2, leaving some relictic texture. Chlorite 1 (Chl1) 5.0% Fine-grained (~0,3mm) anhedral, pale-green, crystalline aggregates, filling texture around the apatite crystals. In overall, chlorite intergrows with apatite. Chl1 phase is paler and coarser than Chl2. This association provides the green-light coloration in the sample. Optically, this chlorite phase is pleocroic with a subtle pinkish tint. 25.0% Fine to very fine-grained (~0,15mm), anhedral to acicular shapes, dark-green crystals replacing apatite and rimming pyrite. However, it is likely that both phases (Chl2+Py) intergrow together. Chl2 and Py1 growth after Titanite. The chlorite interference colors vary from yellow to green of 2nd order. Titanite 4.0% Medium to fine grained (0,5mm-1mm) irregular crystals , fresh, no transformed to rutile, embedded by Chl1Pyrite 28.0%Fine to medium-grained (>1mm), anhedral to subhedral aggregates, showing two differ-ent growing stages. -Py 1 Correspond to highly fracture-pitted pyrite that resembles to marcasite however it lacks of the marcasite properties. (It is Isotropic) -Py 2 Medium-grained aggregates, overgrowing on apatite and accompanying carbonate veins as well as overgrowing over previous Pyrite1.Chalcopyrite 1.0% Fine grained (~0,2mm), anhedral, aggregates with No pitted textured as Py1. It seems to intergrowth in a latter stage of Py2 and sericite and carbonate.Sericite 1.0% Fine grained (>1mm) isolated flaky crystals , colourless, cutting titanite and altering Chl1. There is no clear relation to the sulphides but it is likely that intergrown with that phase. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalco-pyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1Alterationapatitetitanite carbonate chlorite sericite Mineralizationpyrite chalcopyrite Stage 2 Stage 3 Stage 4Sample ID: SMA_AL_1602_JM_017??Chlorite 2 (Chl2)>20%10-20%1-10%<1% Undefined Distribution??AMag: 2xPPL+RL2mmCEBDFPhotomicrographsA) Photograph representative of the alteration front buffer of the dark chlorite (Chl2) + pyrite over the pale association of apatite + Chl1. B) Crossed polars of photo A. Note the crosscutting relationship of Py+Chl2 in the apatite+Chl1. C) Crossed-polars micro-photograph showing the relation of titanite embedding euhedral apatite crystals. D) Representative view in parallel polars and reflected light of the dark, fine-grained chlorite (Chl2) and Py1 (texturally resembles to marcasite). E) Microphotograph of the relation of Chl2 altering apatite crystals and being embedded by Py2. F) Microphotograph in crossed Nicolls of Photo E. Note the relict texture of the apatite altered to Chl2 and being embedded by Py2. Also, the reaction border of the contact of Py2 with the previous formed Chl2. Mag: 2xXPL+RLMag: 20xXPL+RL0,2mm Mag: 20xPPL+RL0,2mmMag: 50xPPL+RL+CL0,08mm Mag: 50xXPL+RL+CL0,08mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 1094μm (Length) PPL FOV~ 1094μm (Length)<Chl2 after Ap<Ser<Chl1<CarApChl2>PyTita<Chl2<ApCar>Ccp>Ap>Chl1>PPL FOV~ PPL FOV~ 441μm (Length) XPL FOV~ PPL FOV~ 441μm <chlApPy2Chl2<Chl2 after Ap<Ser<Chl1<CarApChl2>Py<chl<Ser<CarPy1<Chl2<Reaction Margin<Reaction MarginApChl2Py2Chl2<Reaction MarginSample ID: SMA_AL_1602_JM_017PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD012@51.76El Alacran SMA_AL_1602_JM_019Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This rock texture is a fine to coarse grained (1mm-1cm) volcanic breccia with a polymictic clast compositions. The alteration in the sample is dominated by an early calcic alteration, composed of very-fine grained to cryptocrystalline (<0,1mm), anhedral aggregates of quartz (40%) that selectively replaces the rock matrix. This intergrown with fine-grained (~0,2mm) flaky aggregates of pale-green, crystalline chlorite. This assemblage, specially the chlorite is replaced by a very fine-grained (<0,1mm) aggregates of sericite + Illite that occurs as selective replacement and fracture in-fill. A FeOx staining is overimposed on the sericite. Some relictic albite alteration is visible in some fragments. Possible this alteration pre-dates the quartz + chlorite stage. Mineralization is dominated by coarse-grained (~5mm) pyrite, that corresponds to anhedral patchy replacing aggregates that are cut and embedded by a later carbonate event that occurs with titanite .Comments•The dark brownish mineral called “hydrothermal Biotite” corresponds to a staining of FeOx in the albite and Illite altered fragments. This Fe-leaking? staining seems to correspond to the latest phase formation. •Sericite occurs as a final alteration stage, therefore, it is not in equilibrium with the albite rich-phase in the sample. •Most of the quartz in this sample is interpreted as hydrothermal, since, no typical quartz fragments were observed. Additionally, the lithogeochemistry data of this sample indicate no association with quartz-rich volcaniclastics units (e.g. Unit 1). Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_019Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD012@51.76m in the El Alacran Deposit Unit 2, lithofacie (TufL). This sample corresponds to dark brown coarse-grained lithic tuff? with clasts varying from 1mm to 5mm in diameter. The clasts are pervasive altered to chlorite, albite, and minor sericite. The sample groundmass is selectively altered to a brownish dark mineral. There is also a minor occurrence of rutile and pyrite with chlo-rite. The goal is to define if the brownish alteration corresponds to biotite. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 40.0%Very-fine grained to cryptocrystalline (<0,1mm), anhedral, colourless, aggregates re-placing the matrix. In some fragments occurs with albite as semi-rounded, aggregates. Usually Qtz intergrows with Chl. Sericite 15.0% Very fine-grained (<0,1mm) flaky, colourless to pale green, aggregates selectively replac-ing parental rock fragments and as fracture in-fill. The sericite texture indicates to have formed after the chlorite. 12.0% Very fine-grained (<0,1mm) flaky, elongated, pale-green, replacing selectively albite in volcanic fragments. Illite is preferentially stained to Fe oxides.Chlorite 10.0% Fine-grained (~0,2mm) flaky aggregates, pale green, crystalline, with bluish and brown extinction, replaced by sericite and intergrowth with Qtz.Pyrite 1.0% Coarse-grained (up to 5,5mm length) aggregates , mostly occurs as replacement of frag-ments and are cut and embedded by carbonateCarbonate 10.0% Medium-grained (~1,2mm) selective replacement in fragments and rimmed by sericite. The carbonate is colourless, and it is associated with titanite. Cleavage is observed. Op-tially, the carbonate presents a light pink birefringence color. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalco-pyrite, Sph=Sphalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationQuartz Albite Chlorite Carbonate Titanite Sericite Illite FeOx-Stain MineralizationPyrite Stage 2 Stage 3 Stage 4Sample ID: SMA_AL_1602_JM_019??IlliteFeOx-Stain 5.0% Very fine-grained to cryptocrystalline aggregates replacing Illite>Ser in the rock frag-ments. The occurrence of the Fe however, was not detected using SEM (Apprendix II) Albite 4.0% Fine-grained (~0,12mm) elongated, sub-tabular, colourless shapes replacing selectively some volcanic fragments. When occurring it is highly stained to Fe oxides. (See the Appendix II)Titanite 3.0% Fine-grained (~0,5mm) euhedral aggregates embedded in Carbonate.????>20%10-20%1-10%<1% Undefined Distribution??Sample ID: SMA_AL_1602_JM_019CMag: 20xPPL+RL0,2mmADBPhotomicrographsA) Representative view of chlorite aggregates partially altered to carbonate and sericite. B) Cross-polars photograph of Photo A. Note the relation of sericite + carbonate that cut and nucleates the Chlorite and quartz assemblage. C) Representative view of albite as selective replacement of former rock fragments embedded in a quartz + chlorite matrix.D) Cross-polars photograph of Photo C. Note the FeOx staining of the albite and illite that produces the brownish coloration in the rock.Mag: 20xXPL+RLMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mm0,2mmPPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length)PPL FOV~ 4,35mm (Length) XPL FOV~ 4,35mm (Length) <Fe Stain<Ser<Ab<chlCar>Car>Car><Qtz + Chl <Illite <Ser Car><Ser<chlCar>Car>Car>Car><Fe Stain<Ab <Qtz + Chl <Illite <Ser <Fe StainPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD06A@92.8El Alacran SMA_AL_1602_JM_020Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This rock corresponds to an altered crystal-rich vulcanoclastic rock. Euhedral plagioclase is the only recognized crystal phase (~15%).The sample alteration is dominated by the occurrence of fine-grained (~0,25mm) magnesium rich chlorite (~30%) pervasively altering the rock groundmass and selectively replacing a relictic acicular mineral possibly previous actinolite(?). Quartz in this phase is present as medium to fine-grained (up to 1mm), anhedral aggre-gates with multiple inclusions of chlorite. A sodic alteration is also present as fine to very fine-grained (up to 0,1mm) aggregates of albite that replace primary plagioclase crystals. Albite is replaced to carbonate, sericite and a clay mineral (~13%) (Possibly Ka-olinite?) That seems to intergrowth with chlorite. The mineralization is dominated by medium to coarse-grained (0,5->2mm), anhedral aggregates of pyrite that exhibit two generations of formation. The first generation correspond t a highly pitted (marcasite-like texture) that is replaced and embedded by a second pyrite generation. Mineralization also occurs as medium to coarse-grained anhedral aggregates of pyrrhotite (~5%) that inter-grown chalcopyrite. Traces of Sphalerite are also observed in this association as representative of a late CBM assemblage.Comments•Carbonate, rutile and chalcopyrite occurs in equilibrium. •The yellowish soft mineral in this sample corresponds to a clay + chlorite aggregate after albite. The clay is possible correspond to kaolinite/dickite? as the product of the acidification produced by a Py-rich event? •The relictic acicular mineral could correspond to an early actinolite or mushketovite that was transformed to chlorite in the early calcic event (Qtz + Chl + Pyrite). •It is possible that some of the “albite” correspond instead to previous striated-acicular relictic texture that was replaced by quartz. (Given the crystal size is difficult to differentiate). •It is suggested to apply PIMMA to identify properly the clay mineral (kaolinite/dickite?).Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 10% Medium-grained (~1mm) euhedral, tabular, light brown coloured and altered to albite and clay. The crystals have a lamellae extinction.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_020Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD06A@92.8 in the El Alacran Deposit Unit 2 and lithofacie (TufL). This sample corresponds to a pale pink and greenish, medium to coarse-grained lithic tuff with clasts < 1mm in diameter. The clasts are pervasive altered to chlorite and albite and minor sericite?. There is also the occur-rence of rutile+calcite alteration after the chlorite assemblage. Chlorite is also associated with pyrite, chalco-pyrite.The goal with this sample is to characterize the paragenesis of rutile + carbonate + chalcopyrite with the yellowish soft mineral that seems to intergrows. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsClay - Kaolinite? 13.0%Very fine grained(<0,1mm) acicular, elongated, high relief, pale green with a brownish tint, resembles and can be confused with chlorite but the BR is lower than chlorite and higher than cpatite. This mineral occurrence seems to be related to the contact with Py and Car veinlets.Chlorite 30.0% Fine-grained (~0,25mm) flaky, pale green (Mg-rich), bluish in extinction, strongly re-placing the sample matrix. Also, it occurs as pervasive replacement of some previous acicular mineral (actinolite?). This chlorite birefringence increase its birefringence when stained by Fe Ox (Fe-rich?). Optically, chlorite displays a bluish to yellow birefringence 8.0% Fine to very fine-grained (up to 0,1mm) aggregates replacing previous plagioclase crys-tals. Albite is replaced to Car, Ser, and Clay Quartz 7.0% Medium to fine-grained (up to 1mm), mostly anhedral aggregates (replacement) show some reabsorption borders in contact with Car, also multiple inclusions of Chl? Pyrite 13.0%Medium to coarse-grained (0,5 - >2mm), anhedral, irregular aggregates exhibiting two generations. Py1) Highly pitted (marcasite-like texture) that is replaced and embedded a second Py2 generation. Py2 cuts Qtz and Chlorite in veins. Pyrrhotite 5.0% Coarse-grained (Max~5,2mm) anhedral aggregates occurring as Qtz interstices in-fill ac-companying Ccp. It presents 2 generations. Identified because one early stages exhibits major micros scratches and it is present as inclusions in the outer later phase. Optically correspond to a light grey, with a bluish-pink tint. No BR, anisotropic. No IR.Paragenetic TableMineral Stage 1Alterationalbite - Act??apatitequartzchloritecarbonatetitaniteFeOx-StainMineralizationpyrite pyrrhotitesphaleritechalcopyriteStage 2 Stage 3 Stage 4Sample ID: SMA_AL_1602_JM_020AlbiteCarbonate 3.0% Medium-grained (>1mm length). Colourless, patchy and trail-filling intergrowing with Sph, Ccp and overgrowing prismatic quartz crystals. Illite>Ser 3.0% Very fine grained aggregates (<0,1mm), brownish color, replacing Ab+Chl. No clear the relation to the carbonate + sulphide event. Apatite 2.0% Fine-grained (0,13mm), colourless, with fine inclusions, anhedral to subhedral isolated crystals embedded by pyrite and partially replaced by Qtz.Titanite/Rutile Tr Fine-grained (1,5mm) euhedral, colourless (titanite) and anhedral-dark brown (rutile) aggregates patchy distribution and intergrowing with Car and Sph.Chalcopyrite 3.0% Fine to medium-grained (0,2-1,3mm) anhedral aggregates, exhibiting in-fill texture around the apatite and quartz. chalcopyrite is spatially related to carbonate and sph.??>20%10-20%1-10%<1% Undefined Distribution??AMag: 20xPPL+RL0,2mmCEBDFPhotomicrographsA) Representative microphotograph showing the Chl + Qtz replacement in the matrix, whereas, Ab+Ser occurrence is related with the fragments. B) Same as Photo A, but under XPL. C) Microphotograph showing the pyrite embedding and cutting apatite and Qtz crystals. Also note the birefringence of the clay (Kaolinite?)+chlorite stained aggregates. D) Microphotograph in reflected light of the suggested occurrence of pyrrhotite. Note in the middle of the crystal the inclusion of a previous pyrrhotite phase marked by the difference of hardness. E) Representing the acicular minerals highly chloritized, overgrowth by quartz and embedded by latter chalcopyrite. Note the acicular ghost texture within the quartz overgrowth. F) Microphotograph in crossed Nicolls showing a relictic pyrite within the major phase of pyrite. Mag: 20xXPL+RLMag: 20xXPL+RL0,2mm Mag: 20xRL0,2mmMag: 10xXPL+RL0,4mm Mag: 20xXPL+RL0,2mm0,2mmPPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length) XPL FOV~ 1094μm (Length) RL FOV~ 1094μm (Length)PyKao+Chl QtzQtz>PyApXPL FOV~ PPL FOV~ 2.18mm XPL FOV~ 1094μm (Length)QtzQtzPy2Ccp<QtzAb<Ccp<Rut <chl+Qtz<Py2<pyrrhotite<Ccp<Reaction Margin<chlNewer Py> CcpChl2Py2<StainedKao+Chl+Ab?<Relictic Py (Py1)<QtzAb<Ccp<Rut <chl+QtzAb<Ccp<CcpGhostTextureChl<CcpQtzSample ID: SMA_AL_1602_JM_020PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD009@60.3El Alacran SMA_AL_1608_JM_083Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The main alteration in this sample corresponds to early calcic alteration superimposed by a late calcic-CBM alteration. Texturally this sample comprises a weak developed banding defined by the occurrence of (apatite + carbonate) bands and (quartz + chlorite + carbonate) bands. Apatite occurs as coarse-grained (~5,5mm length, euhedral, prismatic crystals that intergrowth with quartz and are cut and replaced by carbonate. Quartz (25%) occurs in two different populations. One population comprises euhedral, prismatic, medium grained (2,5mm) aggregates with cockade textures typical of opens space filling. A second population comprises fine-grained (~1mm) aggregates as wall rock alteration around the vein/stringers zones. This phase intergrown with a fine-grained (~0,3mm) radiated and semi-rounded rounded magnesium-rich chlorite. Mineralization consist of a patchy stringer of medium to coarse grained (~5,1mm length) Fe-rich Sphalerite aggregates that intergrown with calcite, pyrite, chalcopyrite and molybdenite. Molybdenite occurs as fine-grained (0,2mm), irregular, semi striated crystals that are filling chlorite and quartz interstices along the in the stringers walls. Comments•The dated molybdenite of this sample is related with the CBM-Late calcic event.•Two different stringers zones are recognized in the sample (similar to plate JM089). One, dominated by apa-tite and other dominated by quartz. The apatite seems to correspond to the early event, followed by a Qtz + Chl + Py phase. However, given their spatial distribution both phases can be grouped in the same early calcic assemblage.•In this sample two different pyrite stages are differentiated. First one related with the early calcic alteration and a second one related with CBM-late calcic event.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_083Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD009@60.3 in the Unit 2, from the lithofacie TufF of the El Alacran Deposit and was analyzed previously by Dunne K, 2016. The interval where this sample was taken yielded >1% Zn (maximum assay), 8460 ppm Cu and 30.1 g/t Au. The initial goal was to characterize the gold paragenesis. This sample corresponds to an altered ash tuff cut by veins of black Fe-rich sphalerite up to 5 cm thick. These appear to post-date and enclose chalcopyrite. The current goal with this sample is to define the paragenesis of the dated by Re-Os molybdenite in this sample. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsApatite 35.0%Coarse-grained (Max 5,5mm) euhedral, prismatic, colourless with a dusty brownish texture. It occur as infilling intergrowth with Qtz and it is cut and replaced by carbonate. Also as alteration in the vein wall. Quartz 25.0% Fine to medium-grained phases in two different populations. 1) Euhedral, prismatic, medium grained (2,5mm) aggregates as filling minerals in vein forming cockade textures typical of opens space filling. 2) Anhedral fine-grained (1mm) aggregates as alteration wall rock around the vein/stringers zones. This phase intergrown with Chl. 18.0% Fine-grained (~0,3mm) Radiated, rounded, exhibit a compositional zoning from brownish central part grading to green pale periphery. It is growing with Qtz and cut by Car.Carbonate 7.0% Coarse-grained (>5mm) crystals, colourless, with marked cleavage, occurring as inter-granular and fracture filling in apatite and Qtz stringers, accompanied by Sph and Ccp. Sphalerite 5.0%Medium to coarse-grained (~5,1mm length) crystals, exhibiting acute angle filling texture in the apatite and Qtz. This mostly intergrown with calcite although is some areas is cut by this. Sphalerite is an Iron-rich variety. Some of the crystals present disease texture of Ccp.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationApatiteQuartzChloriteCarbonateTitaniteMineralizationPyrite SphaleriteMolybdeniteChalcopyriteStage 2 Stage 3 Stage 4Sample ID: SMA_AL_1608_JM_083ChloriteCarbonate 3.0% Medium-grained (>1mm length). Colourless, patchy and trail-filling intergrowing with Sph, Ccp and overgrowing prismatic quartz crystals. Titanite/Rutile Tr Very fine-grained (<1mm) euhedral aggregates accompanied by carbonate Chalcopyrite 5.0% Medium-grained (~2,5mm) crystals, exhibiting acute angle filling texture in the apatite and Qtz. This is cut by Carbonate. Pyrite 2.0% Fine-grained (~0,3mm) anhedral to subhedral aggregates formed in two phases. Py1) rel-ictic texture of a pitted, anhedral pyrite that is embedded and replaced by a later phase Py2 that intergrows with Ccp, Car and Sph.Molybdenite Tr Fine-grained (0,2mm), irregular, semi striated soft texture. Occurs as filling interstices of chlorite and Qtz in the walls of the main stringers. This is accompanied by sphalerite, chalcopyrite and pyrite. ????>20%10-20%1-10%<1% Undefined Distribution??AMag: 10xXPL+RL0,4mmCEBDFPhotomicrographsA) Representative microphotograph showing the distribution of the molybdenite in the sample. Note the in-fill texture in the previous chlorite and quartz intergrowth. B) Same as Photo A, but under RL. Note the direct relation of the molybdenite and the occurrence of the Sph + Ccp. C) Microphotograph showing some apatite crystals embedded in Qtz and replaced by carbonate. D) Microphotograph showing the relation of euhedral chlorite and apatite embedded in sphalerite. Also note that sphalerite is cut sporadically by carbonates fracture-faulted? Fillings. E) Microphotograph representing the two generations of pyrite. Note the highly pitted pyrite that is cut by chalcopyrite in contrasts with the fresh, clean pyrite that intergrowth with sphalerite and chalcopyrite. F) Microphotograph in crossed Nicolls showing the carbonate replacement and veining after apatite, quartz and chlorite.Mag: 20xXPL+RLMag: 10xXPL+RL0,4mm Mag: 5xXPL+RL0,8mmMag: 20xXPL+RL0,2mm Mag: 5xXPL+RL0,8mm0,2mmXPL FOV~ 2,18mm (Length) XPL FOV~ 1094μm (Length) XPL FOV~ 2,18mm (Length) XPL FOV~ 4,35mm (Length)<Car QtzQtz>Car<ApXPL FOV~ 1094μm (Length) XPL FOV~ 4,35mm (Length)<SphCcp+Sph><CcpQtz<MolyAp<ChlCarChlQtz>chl<SphCcp+Sph><CcpQtz<MolychlAp<Car<ApSph<Chl<ChlQtz><ApAp<Car<ApSph<Chl<Car<CarQtz>Ccp<Py1Ap<Car<ApSph<Chl<Py2<Py2Ap<CarApQtz>Sample ID: SMA_AL_1608_JM_083PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD016@40.5El Alacran SMA_AL_1608_JM_089Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description The alteration of this sample corresponds to an early FeOx metasomatic alteration produced by the occur-rence of two generations of the magnetite (50%). The first generation comprises a medium-grained, dark-brown, bladed magnetite (mushketovite?) and a second generation of very fine-grained (<0,1mm) aggregates of euhedral magnetite, both generations occur with a fine-grained (0,15mm) subhedral to euhedral prismatic aggregates quartz (12%). The bladed magnetite and quartz occur as open-filling minerals surrounded by a combination of the fine magnetite + quartz + apatite possibly from the same generation stage. Chlorite occurs as fine to medium-grained (0,2-0,8mm), dark-green flaky-radiated aggregates that occurs as filling? texture around the bladed magnetite and quartz. Pyrite occurs as medium-grained anhedral aggregates (up to 3mm) embedding fine-grained euhedral magne-tite and bladed magnetite and possibly intergrowing with chalcopyrite and chlorite. The present carbonate corresponds to a Fe-Rich carbonate (siderite) Comments•Bladed magnetite + quartz association occurs as potential open-space filling whereas the fine euhedral mag-netite + Apatite correspond to the wall rock alteration possibly of the same event.•No clear relationship of titanite with quartz. The major occurrence of Titanite/Rutile + carbonate alteration in the deposit, seems not be associated with this stage.•Neither albite nor actinolite were recognized in this early magnetite phase. Suggesting that are not in equi-librium with the magnetite phase. •A further characterization of the dusty effect in some quartz crystals is required to define if it is recrystalliza-tion or multiple apatite inclusions.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_089Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD016@40.5 in the Unit 2, from the lithofacie MudSil of the El Alacran Deposit and was analyzed previously by Dunne K, 2016. The initial goal consisted on verifying the occurrence of skarn silicates(granates and pyroxenes). This sample corresponds to a layered, magnetite-rich replaced ?siltstone. Layers, which are probably remnant bedding are up to 1 cm thick. The current goal with this sample is to define the paragenesis of mangnetite-quartz-carbonate-chlorite-apatite bands. MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsMagnetite 50.0%Two generations of the magnetite: 1) Bladed magnetite (mushketovite?): Medi-um-grained, bladed, dark brown, not anisotropic mostly embedded by Qtz. 2) Fine to very fine-grained aggregates of euhedral magnetite, the optic properties are similar to the bladed magnetite. This magnetite tends to be as wall rock alteration of the bladed magnetite +Qtz, and it is mostly embedded by apatite. Quartz 12.0% Fine-grained (0,15mm) subhedral to euhedral prismatic aggregates developed along bands with in-fill texture in the bladed magnetite (mushketovite?). The quartz is also filled by chlorite - apatite and presents multiple Ap inclusionsFine to medium-grained (0,2-0,8mm) aggregates of flaky-radiated medium to dark-green chl. (Fe Rich).Chlorite has in-filltexture around the bladed magnetite and Qtz and displays an intergrowth with apatite.10.0%Carbonate (Siderite?) 10.0% Very fine grained (<0,1mm), anhedral, reddish brown aggregates cutting and embedding all the sample. When carbonate rimmed chlorite or magnetite, produced a leaking Fe-Stain? carbonate also exhibits replacement textures after bladed magnetite. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1AlterationBladed Magnetite Eu Magnetite Quartz Apatite Chlorite Carbonate MineralizationPyriteChalcopyrite trStage 2 Stage 3 Stage 4Sample ID: SMA_AL_1608_JM_089ChloriteApatite 8.0% Medium-grained (0,8-1mm), anhedral, colourless, aggregates that occur as in-fill and replacement along some rock bedding with euhedral qtz crystals and cubic-euhedral magnetite. Ap has multiple fluid inclusions, some of them seems to correspond to oil inclusions. Titanite/Rutile Tr Very fine-grained (<1mm) euhedral aggregates accompanied by carbonate Chalcopyrite Tr Fine grained (0,2mm) Minor traces intergrowing with Chl and embedding some euhedral Py crystals. Pyrite 5.0% Medium-grained aggregates (up to 3mm) of anhedral aggregates embedding fine grained euhedral magnetite and bladed magnetite.????>20%10-20%1-10%<1% Undefined Distribution??AMag: 2xPL+RL2mmCEBDFPhotomicrographsA) Representative view of the Qtz+ mushketovite + Car (Left side) vs the apatite bands with semi-massive magnetite + Car (right side) B) Cross-polars photograph of photo A. Note the reddish brown color of the samples produced by the Fe-rich carbonate. C) Crossed-polars and reflected light photograph of the relation of Py and carbonate replacing bladed magnetite. Note the euhe-dral prismatic Qtz embedded in massive apatite. D) Crossed-polars and reflected light photograph of the relation of Py replacing and embedding fine to very fine grained magnetite. Note the relation of chalcopyrite filling pyrite. E) Photograph 50X of the massive Apatite aggregates. Note the 2 types of fluid inclusions generations as well as the euhedral Qtz crystals embedded in the anhedral apatite groundmass. F) Microphotograph in crossed Nicolls showing the apatite and quartz intergrowth and the relation with wsiderite. Mag: 2xXPL+RLMag: 5xXPL+RL0,8mm Mag: 10xXPL+RL0,4mmMag: 50xPPL0,08mm Mag: 5xXPL0,8mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL + RL FOV~ 4,35mm (Length) XPL + RL FOV~ 2,18mm (Length) QtzPy>Car<ApPPL FOV~ 441μm (Length) XPL FOV~ 4,35mm (Length)<Qtz<MagAp<Car<Eu MagQtz>chl<Qtz <ApBladed MagPy Qtz><CcpAp<Qtz<ApSph<MagMagApOil FI> Ccp<Py1Mag<QtzAp<Car Ap<Fe-CarQtz<Qtz<Ap<Bladed Mag<Qtz<Magchl<Ap<Bladed Mag<Car Car<Aqueous FI<Fe-CarApSample ID: SMA_AL_1608_JM_089PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD002@93.35El Alacran SMA_AL_1602_JM_002Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This sample corresponds to a fine-grained crystalline(?) rock with a texturally destructive alteration. Alter-ation consists of chlorite+quartz and carbonate that gives to the rock the greenish coloration. Chlorite (10%) corresponds to a Mg-rich chlorite that occurs as fine-grained aggregates replacing previous rock-former mafic crystals. Mg-rich chlorite occurs with two generations of quartz: 1) Fine to very fine-grained as patchy al-teration and 2) Fine-grained prismatic crystals along veins and in-fill. The chlorite alteration is replaced by very-fine grained, flaky aggregates of sericite (30%) and medium-grained, anhedral aggregates of carbonate (35%). The sericite alteration is also overprinting fine to medium quartz grains and rock-former tabular shapes possibly plagioclase. Mineralization is not observed in this rock.Comments •No evidences of the nature of the rock, some possible tabular ex-plagioclase crystals are interpreted as part of a microdioritic rock. •Using the available lithogeochem this intervals falls in the “Int1”, that correspond to the signature of the Alacran Oeste suite. Is this intrusive of parts of the intrusive underwent that intensity of alteration; suggest a pre or syngeneic relation to the mineralizing events. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_002Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD002@93.35m , in the El Alacran Deposit Unit 2. It corresponds to a pale-green, fine-grained microdiorite? with medium to pervasive alteration of sericite+chlorite? and carbon-ate in the groundmass. The sample displays a relict texture of plagioclase and amphiboles altered to chlorite and a brownish alteration with not clear paragenesis to the chlorite sericite alteration. No sulphide are visible. The goal with this sample is defining if this corresponds to an intrusive rock. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 35.0% Fine to medium-grained (<1.5mm), anhedral aggregates, occurs as overprinting former fine to medium-grained (<1mm) quartz grains in the rockVery fine-grained, flaky aggregates that occur with with carbonate as replacement of former tabular shapes (plagioclase?) and quartz. 30.0%Carbonate (siderite?) 20.0% -Fine to very fine-grained (<0.2mm), anhedral and subhedral aggregates, as patchy alteration and as in-fill accompanied with Mg-rich chlorite and replaced by sericite + carbonate.-Fine grained (<0.5mm), interstitial prismatic crystals along veins.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationQuartz ChloriteSericiteCarbonateMineralizationPyriteChalcopyrite trCarbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%Sericite??Sample ID: SMA_AL_1602_JM_002Fine-grained (<0.3mm), anhedral aggregates occur replacing previous mafic crystals?. Mg-rich chlorite , it is replaced by Ser+Chl. Occurs with quartz as alteration and as vein-lets.10.0%Chlorite Undefined Distribution????AMag: 5xPL+RL0.8mmCEBDPhotomicrographsA) Photo A. Representative view of the quartz – chlorite altered groundmass. B) Cross-polars photograph of Photo A. Note the relict former mafic? mineral replaced by chlorite. C) 5X Representative view of the fracture-filling quartz and chlorite assamblage. D) Same as photo C, but with crossed-polars of photograph C. E) Photograph 20X of the carbonate + sericite carbonate after chlorite and quartz. Also note the replacement of former plagioclase by quartz.Mag: 5xXPL+RLMag: 10xXPL+RL0.4mm Mag: 10xXPL+RL0.4mmMag: 20xXPL0.2mm0.8mmPPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)PPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)XPL FOV~ 1094μm (Length)<Qtz< Chl after Relict Hb?<Qtz<Car + Ser<Chl<Chl<Chl<Qtz<Qtz< Chl after Relict Hb?<Qtz<Car + Ser<Chl<Chl<Chl<Qtz<Qtz< Relict Plag<Qtz<Car + Ser<Chl<Chl<Chl<Qtz<Car + Ser<Qtz<Qtz<Car + Ser<Chl<Chl<Chl<Qtz<Car + Ser< Qtz<Chl<Ser<Chl<Ser<Car< QtzSample ID: SMA_AL_1602_JM_002PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD002@218.95El Alacran SMA_AL_1602_JM_003Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This thin section comprises a patchy epidote-altered in a 2mm diameter vesicular andesite, composed of mostly (>40%) of fine-grained, euhedral tabular plagioclase. The alteration correspond to a epidotization related to the occurrence of very fine-grained, semi radiating aggregates of chlorite that occurs as infill in cavities, along with fine to medium-grained epidote (15%) and fine to very fine grained aggregates of carbonate (8%). In the rock vesicles, the propylitic assemblage is also accompanied by fine-grained, anhedral and subhedral aggregates of quartz (~1%) with local prismatic shapes. Finally, chlorite and quartz also occurs as late 0.02 mm wide veinlets the epidote+carbonate association. This section is not polished, however in hand specimen no mineral occurrence can be defined. Comments•This alteration is in equilibrium with carbonate that is a difference with the calc-sodic also present an equi-librium with epidote. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 40.0% Fine-grained (<0.5mm) euhedral tabular to acicular shapes aggregates occurring as the main former mineral in the rock.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_003Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD002@218.95, in the El Alacran Deposit Unit 3. It corresponds to a green altered fine-grained rock with a brownish alteration. The sample displays amygdales filled with epidote and chlorite. The amygdales have 3mm-size in average and asymmetrical shapes. This sample belongs to the TufA lithofacies (amygdaloidal tuff). The goal with this sample is to characterize the Ch+Ep alteration in TufA lithofacies. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 30.0% Very fine-grained (<0.1mm), semi radiating aggregates, occurs as the main product of cavities infill. Occurs with epidote, and carbonate. Fine to medium-grained (<1.5mm), yellowish, subhedral aggregates, occurs with quartz, and carbonate as patchy alteration and cavities infill.15.0%Carbonates. Including Calcite8.0% Fine to very fine-grained (<1mm), anhedral aggregates, occurs as overprinting rock-for-mer fine to medium grains. Also carbonate occurs as 0.02 mm-wide veinlets accompa-nied by quartz and cutting the epidote association. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral PropyliticAlterationChloriteCarbonatesEpidoteQuartzMineralizationPyriteChalcopyrite trLate Calcic Stage 3 Stage 4>20%10-20%1-10%<1%Epidote??Sample ID: SMA_AL_1602_JM_003-Fine-grained (<0.4mm), anhedral and subhedral aggregates, locally prismatic when occurs as cavities infill.-Fine grained (<0.2mm), anhedral aggregates that occur patchy accompanied by epidote and carbonate. -Very fine-grained <0.1mm, anhedral aggregates occurring with carbonate (calcite) as late fracture infill. 1.0%Quartz Undefined Distribution????AMag: 2xPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 2X showing the distribution of the rock major minerals. Note the fine-grained plagioclase rock and the distribution of the vesicles filled with chlorite. B) Same as microphotograph A, but under RL. C) Microphotograph showing the relation of the minerals that define the propylitic alteration. Note the chlorite as central infill and as rimming mineral around epidote. D) Same as microphotograph C, but under RL. E) Microphotograph showing the distribution of the propylitic assemblage minerals cut by a later phase. (late calcic) of Quartz + Chlorite ± carbonate veinlets. F) Same as microphotograph E, but under RL.Mag: 2xXPL+RLMag: 5xPL+RL0.8mm Mag: 5xXPL+RL0.8mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL + RL FOV~ 4.35mm (Length) XPL + RL FOV~ 4.35mm (Length)<Qtz<Car<Car<ChlPlagSample ID: SMA_AL_1602_JM_003E FMag: 10xPPL+RL0.4mm Mag: 10xXPL+RLPPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)Plag<Chl<Chl<Qtz<Car<Car<ChlPlagPlag<Chl<Chl<Car<Qtz<Car<Ep<Chl<Plag<Chl0.4mm<Car<Ep<Qtz<Chl<Qtz<Ep<Ep<Car<Ep<Qtz<Chl<Qtz<Ep<Ep<Qtz<Car<Ep<Chl<Plag<ChlPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@88El Alacran SMA_AL_1602_JM_006Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section corresponds to a tuffaceous rhyodacite rock, composed of fine-grained k-feldspar (~25%), fine to very-fine grained sub angular aggregates of quartz (~10%) and fine-grained plagioclase aggregates with a subtle superimposed pale-brown dusty coloration.Alteration is dominated by fine-grained aggregates of patchy carbonate (20%) that occurs with fine-grained (70μm) flaky sericite (1%) and traces of fine to very fine grained, grains of titanite with local replacement to rutile/anatase. The quartz + chlorite alteration is altered to an association of fine to very fine-grained (0.05 -0.1mm) anhedral aggregates of quartz (~18%) that occurs with fine-grained, pale-green chlorite (10%) as se-lectively replacement on former minerals in the rock groundmass. The mineralization in this sample corresponds to fine to medium-grained aggregates of pyrite that occurs with carbonate in patches. Comments•Albite is not observed in the sample. Instead, alteration is related to carbonate alteration over a quartz-chlo-rite groundmass with former quartz and K-feldspar. This denotes that the coloration of the rock is mostly related to their primary mineralogy.. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 7.0% Fine-grained (<0.5mm) , with a pale brown dusty coloration, tabular shapes, replaced to carbonate and sericite.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_006Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. K-Feldspar? 25.0% Fine-grained (<0.5mm), with a pale brown dusty coloration, tabular shapes, replaced to carbonate and sericite. (Lack of lamellae as observed in the plagioclase).Quartz 10.0% Fine to very fine-grained (0.05 -0.1mm), irregular, sub angular to aggregates, occurs mostly as former mineral in the rock groundmass. Also (just in one point) occurs as 1mm angular phenocrysts.Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD003@88, in the El Alacran Deposit Unit 1. It corresponds to a Pale-grey to white, medium to fine grained (1mm-1,5mm) rock with some visible quartz grains embedded by a highly albite? altered groundmass. The sample presents some selective replacement of previous mafic phe-nocrysts altered to chlorite and carbonate and pyrite. At meso-scale this sample come from a suspected clast in a volcanic breccia. The goal with this sample is to define if this rock correspond to an intrusive clast with secondary biotite alteration. Also defined if this rock can compares to the Qtz Feldspar Porphyry (QFPx) that occurs at the Montiel East porphyry. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 20.0% Fine-grained aggregates (<1mm), colorless, anhedral patchy aggregates altering pla-gioclase and locally chloriteFine to very fine-grained (0.05 -0,1mm), irregular, anhedral aggregates, occurs mostly in the rock groundmass. It is difficult to separate from the primary quartz.18.0%Chlorite 10.0% Fine-Grained (<0.5mm), flaky, pale-green, selectively replacement on previous mafic? , tabular former minerals. It is replaced by carbonate and sericite*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Sodic-CalcicAlterationChlorite 10%Quartz 18%Carbonate Sericite 1%Titanite TrMineralizationPyrite 1%Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%QuartzSample ID: SMA_AL_1602_JM_006Fine-grained (70μm) flaky aggregates. Pale green to colourless, selective replacement after former plagioclase and k-feldspar. Occurs with carbonate1.0%Sericite Undefined Distribution????Fine to very fine grained (<0.2mm), subhedral grains, occurs partly replaced by rutile/anatase, occurs within fragments as patchy alteration accompanied by carbonate TrTitaniteMineralizationPyrite 1.0% Fine to medium-grained (<2mm), anhedral grains and aggregates, occurs with carbonate patches after chlorite. %AMag: 2xPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 2X showing the distribution of the rock major constituents. Note the clastic quarts and the microphenocrysts altered to carbonate. B) Same as microphotograph A, but under RL. C) Microphotograph showing the par-agenetic relationship of a selective replacement of a former mafic? mineral by Mg-rich chlorite, and the later replacement to carbonate sericite. Also Note the brownish coloration in the former plagioclase and K-feldspar. D) Same as microphotograph C, but under RL. Mag: 2xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)Sample ID: SMA_AL_1602_JM_006<Qtz<Ser <Ser<K-Feldspar?Plag<Chl<Car<Car<Qtz<Ser <Ser<K-Feldspar?Plag<Chl<Car<Car<Qtz<Chl<Car<Former Qtz<Car<Car<Car<Chl<Chl<Qtz<Chl<Car<Former Qtz<Car<Car<Car<Chl<ChlPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@94.60El Alacran SMA_AL_1602_JM_007Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section corresponds to a tuffaceous rhyodacite rock, composed of fine-grained k-feldspar (~5%) with a subtle superimposed pale-brown dusty coloration., fine to very-fine grained sub angular aggregates of quartz (~5%) and fine-grained plagioclase (25%).Alteration is dominated by carbonate (20%) that occurs as fine to medium-grained aggregates that patchy re-places the former minerals. Carbonate occurs with fine-grained flaky sericite (15%) aggregates and with traces of fine to medium-grained euhedral titanite. This alteration overgrew an association of very fine-grained anhe-dral quartz ± Ab? aggregates (~25%) that occurs as an early alteration accompanied by fine-grained (<1mm), chlorite (8%). Apatite also occurs in the sample as fine to medium-grained aggregates with tabular shapes that are replaced to carbonate and sericite.Mineralization occurs as very fine to medium grained (up to 1mm), aggregates of pyrite that occurs with chal-copyrite and carbonate. The pyrite / chalcopyrite ratio is close to 10/2PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_007Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 25.0% Fine-grained (<0.5mm) , with a pale-brown dusty coloration, tabular shapes, replaced to carbonate and sericitePercentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. K-Feldspar? 5.0% Fine-grained (<0.5mm), with a pale brown dusty coloration, tabular shapes, replaced to carbonate and sericite. (Lack of lamellae as observed in the plagioclase)Quartz 5.0% Fine to medium grained (0,1 - 2mm), anhedral sub rounded shapes that occurs isolated and as clusters, present reabsorption in the borders. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD003@94.60, in the El Alacran Deposit Unit 1. It corresponds to a white and dark green volcanic(?) breccia that presents some visible and irregular quartz with sizes varying from <1mm to 4mm. The groundmass is composed of pervasive sericite + albite? intergrowing with chlorite calcite and pyrite. Pyrite occurs replacing selective mafic phenocrysts. This section corresponds to the ground-mass material that embedded in the rhyodacite clasts (SMA_AL_1602_JM_006). The goal with this sample is to define if this rock corresponds to an intrusive breccia and the relation with the mineralization. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQtz >> Ab 25.0% Very fine-grained (<0.01mm), colorless, anhedral aggregates, some isolated elongated shapes. Occurs mostly in the rock groundmass. Intergrowing with chlorite. Probably most of Qtz correspond to primary quartz.Fine to medium grained (<25μm), colourless, selectively replacing plagioclase. Occurs with sericite pyrite, chalcopyrite, and inclusions of titanite. Also as fractures infill.20.0%Sericite+Illite 15.0% Fine-grained (>0.1mm) flaky aggregates. Pale-green to colourless replacing former pla-gioclase and quartz.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationQtz >> AbApatiteChloriteCarbonateSericite+IlliteTitaniteMineralizationPyriteChalcopyrite Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%Carbonate??Sample ID: SMA_AL_1602_JM_007Fine-grained (<1mm), colourless to pale green, anhedral selectively replacement and groundmass intergrowing with Qtz + Ab?8.0%Chlorite Undefined Distribution????MineralizationPyrite 5.0%Chalcopyrite TrVery fine to medium grained (up to 1mm), anhedral aggregates that occurs with chalco-pyrite and carbonate Fine to very fine-grained (<0.2mm), anhedral aggregates that occurs with chalcopyrite and carbonate. Ratio 10/2 (Py/Ccp)Very fine-grained (<0,05mm), irregular aggregates of reddish brown, dusty texture, patchy and related with carbonate occurrence.4.0%TitaniteFine to medium-grained colorless euhedral crystals with tabular shapes. Occurs as relict after carbonate + sericite alteration.Tr ApatiteAMag: 2xPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 2X showing the distribution of the rock major minerals. Note the primary quartz embay-ments and recrystallization? texture as well as the carbonate alteration in the rock groundmass. B) Same as microphotograph A, but under RL. C) Microphotograph showing the clastic former K-feldspars? and 2 populations of quartz. Note the fragmental quartz with borders reabsorption possibly produced by fine-grained quartz + chlorite groundmass. D) Same as microphotograph C, but under RL. E) Microphotograph showing the selective replacement of Carbonate + Pyrite + Chalcopyrite after relict apatite ± quartz groundmass. F) Same as microphotograph E, but under RL.Mag: 2xXPL+RLMag: 5xPL+RL0.8mm Mag: 5xXPL+RL0.8mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL + RL FOV~ 4.35mm (Length) XPL + RL FOV~ 4.35mm (Length)<Car<Car<Car<Recrystallized QtzFormer QtzSample ID: SMA_AL_1602_JM_007E FMag: 10xPPL+RL0.4mm Mag: 10xXPL+RLPPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)Plag<Embayments<Chl<PyriteCar><K-Feldspar?<Former Qtz<Chl0.4mm<Qtz<Car<Car<Recrystallized QtzFormer QtzPlag<Embayments<Chl< Hydrothermal QtzSer>Ser><PyriteCar><K-Feldspar?<Former Qtz<Chl< Hydrothermal QtzSer>Ser><Chl<PyRecrystallized Qtz<K-Feldspar?<Former Qtz<Chl< SerSer>Apatite><Ccp<Car<Chl<PyRecrystallized Qtz<K-Feldspar?<Former Qtz<Chl< SerSer>Apatite><Ccp<Car<ChlPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@146.09El Alacran SMA_AL_1602_JM_008Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section corresponds to a thin section (no polished thin section) pervasive altered banded tuff?, with elon-gated lapillies defining a tuff with fiamme texture. The alteration is dominated by the occurrence of albite (~50%). This occurs in two populations. 1) Very fine-grained (<0,01mm), tabular aggregates selective replacing some former clasts/lapillies. 2) Very fine-grained anhedral aggregates that occur in the groundmass possibly accompanied with very fine-grained quartz and traces of pale-chlorite. The albite association is altered to very fine-grained flaky aggregates of sericite (25%) that occurs and locally encloses very fine-grained aggregates of carbonate that occurs as patchy replacement with rutile. In hand specimen, no significate mineralization was identified. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_008Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Comments•Quartz ± Chlorite + fine-grained Ab in the groundmass and coarser Albite more associated with clasts. •The greenish material within the fiammes, correspond to sericite and carbonate.Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD003@146.09m in the El Alacran Deposit Unit 2 and lithofacie TufD. It corresponds to a pale-colored lapilli tuff with ash groundmass. The lapillies size varying from 2mm to 1.5cm and indicate a parcial welding process. The groundmass is highly altered to sericite? + albite? and the fiammes or lapillies are altered to chlorite and sericite, calcite and chalcopyrite. The goal with this sample is to characterize the suspected albite alteration in the TufD lithofacie. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsAb >> Qtz 50.0% Very fine-grained (<0,01mm), subtle tabular aggregates pervasive destructive texture selectively replacing fragments and altered by carbonate and Illite>Sericite.-Very fine grained (<0.005mm), anhedral, occurs in the groundmass possibly accompa-Very fine-grained (~0.07mm) flaky aggregates. Pale green to colourless replacing former fiamme-lapillies and locally rimming carbonate.25.0%Carbonate 20.0% Vey fine-grained aggregates (<25μm), colourless, selectively replacement and patchy over former lapillies.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationAlbite>>QtzCarbonateSericite+IlliteRutileMineralizationPyriteChalcopyrite Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%Sericite+Illite??Sample ID: SMA_AL_1602_JM_008 Undefined Distribution????Very fine-grained (<0,05mm), irregular aggreagtes of reddish brown , dusty texture, patchy and realted with carbonate ocurrence4.0%RutileAMag: 10xPPL+RL0.4mmCBDPhotomicrographsA) Representative microphotograph 2X showing the distribution of the rock major minerals. Note the pervasive sericite and car-bonate alteration in the groundmass and over some relict apatite crystals. B) Same as microphotograph A, but under RL. C) Microphotograph showing the fine to very fine-grained albite + quartz replaced by sericite, the darker and blurry spots corre-sponds to rutile. D) Same as microphotograph C, but under RL. Mag: 10xXPL+RLMag: 20xPPL+RL0.2mm Mag: 20xXPL+RL0.2mm0.4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length) PPL FOV~ 1094 μm (Length)<Car<CarSericiteSample ID: SMA_AL_1602_JM_008<Apatite<Sericite<Rutile< Qtz + AbSericite<Car<Clay+Chl?<Car<Car<CarSericite<ApatiteSericite<Car<Clay+Chl?<Car<Rutile<Sericite<Rutile< Qtz + Ab<RutileXPL FOV~ 1094 μm (Length)PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD006A@292.1El Alacran SMA_AL_1602_JM_014Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section corresponds to a fine-grained (<1mm) andesite tuff with relictic occurrence of mafic crystals pos-sibly pyroxenes (2%) that are partially to complete altered to carbonate. The dominant alteration in the sam-ple correspond to a very fine-grained (<0.01mm), pale green with a yellowish stain clay-sericite aggregates. This occurs mostly in the sample groundmass and it is partially replaced to Illite-sericite?. The alteration is also defined by the occurrence of fine-grained, pale green chlorite (10%) that intergrows with fine to very-fine grained acicular aggregates of actinolite? (2%) and fine-grained anhedral aggregates of ceolites ± quartz? (10%) that occur as vesicle infill and as selective replacement of former minerals with. Carbonate also occurs as part of this alteration as fine-grained (<1mm) aggregates that selectively replaces plagioclase? and pyroxenes.Mineralization in the sample is represented by the occurrence of fine to medium-grained aggregates of pyrite (2.5%) that occur with carbonate and chlorite either as selective replacement of former minerals and as ves-icle infill.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_014Mineral Modal Textural and Mineral DistributionRock-forming mineralsPyroxene 2.0% Fine-grained (<1mm), sub tabular shapes partyally and complete replaced to carbonate Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD006A@292.1m in the El Alacran Deposit Unit 3 and TufA lithofa-cies. This sample corresponds to a fine-grained andesite tuff with relictic occurrence of mafic crystals possibly pyroxenes. It presents a pale green with a yellowish stain. Carbonate also occurs as selective replacement of plagioclase and pyroxenes. The goal with this sample is to define if this corresponds to a one of the defined El Alacran Sills, or if it is part of a mafic andesite of Unit 3.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsClay-Chl? 55.0% Very fine grained (<0.01mm), pale green yellowish stain, flaky, occur in the sample groundmass, partially replaced to Illite-sericite? Fine-grained (<1mm) , colourless, tabular shapes after replacing former plagioclase or mafic minerals10.0%Ceolite ± Qtz? 10.0% Fine-grained (~0.5mm), colourless, anhedral aggregates that occur as vesicle infill ac-companied by chlorite and actinolite. Also it occurs as selective replacement of former plagioclase.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Propylitic?AlterationChloriteCeolite-Quartz?CarbonateClay-ChloriteActinoliteMineralizationPyriteStage 2 Stage 3 Stage 4>20%10-20%1-10%<1%CarbonateSample ID: SMA_AL_1602_JM_014Fine-grained (up to 1mm), pale green to colourless, anhedral, with selective replacing after former mafic minerals (sub tabular shapes). This intergrows with actinolite, quartz and pyrite.10.0%Chlorite Undefined Distribution??MineralizationPyrite 2.5% Fine to medium grained (<2.5mm) , anhedral aggregates that occur with carbonate and chlorite as selective replacement of former minerals and as vesicle infill. Fine to very-fine grained (<0.1mm) , colourless to pale green, acicular aggregates accom-panied by chlorite mostly replacing former pyroxenes.2.0%Actinolite AMag: 2xPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 2X showing the distribution of the rock major minerals. Note the former pyroxenes (Clino-pyroxene) altered to clay and carbonate and also the chlorite vesicles with pyrite + carbonate ± zeolites? infill in the sample. B) Same as microphotograph A, but under RL. C) Microphotograph showing the distribution of the clay and minor chlorite associating altering the rock groundmass. Note the former pyroxene replaced to chlorite and quartz and surrounded by carbonate. D) Same as microphotograph C, but under RL. E) Some vesicles infill of carbonate + pyrite and the defined actinoliteMag: 2xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)PPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)Py><Zeo<Car<ChlSample ID: SMA_AL_1602_JM_014EMag: 10xXPL+RL0.4mmXPL + RL FOV~ 2.18mm (Length)ClPx<Chl<ClPx<ClPxCar><Clay+Chl?Py><Car<Car<ChlClPx<ClPx<ClPxCar><Clay+Chl?<Zeo<ZeoPy><Zeo<Car<Chl ClPx<Relict ClPx<Qtz?Car><Clay+Chl?<Zeo<ChlPy><Zeo<Car<Chl ClPx<Relict ClPx<Qtz?Car><Clay+Chl?<Zeo<Chl<Clay+Chl?<Chl<ChlPy><Zeo<Car<Chl<Car<Qtz?<Clay+Chl?<Zeo<Actinolite<Chl<CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD007@142El Alacran SMA_AL_1602_JM_015Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description 50% of this section correspond to a relictic fossil structure embedded in a fine-grained replaced groundmass. The dominant alteration corresponds to an intergrowth of chlorite-quartz ± apatite. Chlorite occurs in two populations. 1) Fine-grained (~1mm) anhedral and radiated aggregates that intergrows with medium-grained aggregates of quartz in the groundmass. 2) Very fine-grained (<0.05mm) semi-acicular aggregates that occurs as inclusions in quartz. Fine-grained apatite occurs with the chlorite and quartz groundmass and as coarse-grained prismatic aggregates that occur with pyrite replacing-infilling the former fossil structure. Mineralization occurs in two stages. One dominated by pyrite, associated with the early quartz + chlorite assemblage and a second dominated by chalcopyrite +sphalerite +carbonate that crosscuts the early mineral stage. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_015Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Comments•Clear evidence of carbonate and chalcopyrite cutting pyrite, apatite, locally chlorite and quartz. If crosscut-ting criteria is applied carbonate and chalcopyrite can be grouped in the same alteration stage, the occurrence of sphalerite along with chalcopyrite and carbonate represent the CBM stage in this sample. •No observed albite in the association of Qtz+ChlMacroscopic Sample DescriptionThis sample was taken from the Drillhole ACD007@142 in the El Alacran Deposit Unit 2 and Lim lithofacies. The sample corresponds to an altered shell-debris, originally sedimentary carbonate with bivalves shells. The shells are replaced to chalcopyrite, pyrite, carbonate, and chlorite. The groundmass is pervasively altered to chlorite, minor albite(?) and some small occurrences of siderite? or rutile + carbonate?.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 25.0% Medium-grained (~2mm), coloured by multiple very fine grained chlorite inclusions , irregular , anhedral intergrowing with chloriteTwo Populations -Fine-grained (<1mm), pale green anhedral aggregates exhibiting some radiated shapes. Intergrows with quartz and apatite. -Very fine grained (<0.05mm), pale green, semi acicular in shape, occurs as inclusions in quartz. Booth are partially stained to FeOx25.0%Apatite 15.0% Two populations-Fine-grained (<1mm) anhedral, colourless aggregates intergrowing with chlorite and quartz.-Coarse-grained (<5mm), colourless, prismatic shaped (1,5mm wide), occurs with pyrite in a fossil replaced structure. Both apatite populations are cut and replaced by carbon-ate.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationQuartz Chlorite ApatiteCarbonatesTanite MineralizationPyrite Chalcopyrite SphaleriteLate Calcic CBM Stage 3 Stage 4>20%10-20%1-10%<1%ChloriteSample ID: SMA_AL_1602_JM_015Fine to very fine-grained (<0.5mm), colourless (calcite) and brown-reddish (Siderite?) That occurs with sphalerite, titanite and chalcopyrite as fracture in-fill8.0%CarbonatesIncudes Fe-rich Undefined Distribution????MineralizationPyrite 25.0%Chalcopyrite 5.0%Coarse-grained, euhedral to subhedral aggregates replacing the shape of a fossil struc-ture. It is highly pitted and fractured and infilled by carbonate and locally by chalcopyriteMedium-grained (~2mm), anhedral aggregates that occurs with carbonate and sphaleriteFine-grained (~0.2mm) , brownish yellow, opaque, euhedral intergrowing with chalcopy-riteTrTitaniteSphalerite Tr Very fine-grained (~0.05mm), anhedral aggregates occurs with chalcopyrite and titanite.AMag: 5xPL+RL0.8mmCBDPhotomicrographsA) Representative microphotograph 5X showing the distribution of the rock major minerals. Note the intergrowth of quartz + chlorite ± apatite as pervasive replacement of the rock matrix. Also not the carbonate alteration after apatite and after chlorite.B) Same as microphotograph A, but under RL. C) Microphotograph showing the paragenetic relationship of the quartz + chlorite + Pyrite and apatite replacement > infill in the fossiliferous structure replaced and cut by carbonate. D) Same as microphotograph C, but under RL. E) Microphotograph showing the intergrowth of chlorite + quartz. Note the smoky texture in the quartz given the multiple chlo-rite inclusions. F) Microphotograph 50X showing the relation of irregular Mg-Rich chlorite as inclusion of quartz.Mag: 5xXPL+RLMag: 5xPL+RL0.8mm Mag: 5xXPL+RL0.8mm0.8mmPPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)PPL + RL FOV~ 4.35mm (Length) XPL + RL FOV~ 4.35mm (Length)<Car<Car<Qtz Apatite>Sample ID: SMA_AL_1602_JM_015E FMag: 10XXPL+RL0.4mm Mag: 50xPPL+RLXPL + RL FOV~ 2.18mm (Length) PPL + RL FOV~ 441 μm (Length)<Chl0.08mm<Chl<Car<Car<Qtz Apatite><Chl<Chl<CarPyrite <Qtz Apatite><Chl<Chl<Car<Car<CarPyrite <Qtz Apatite><Chl<Chl<Car<Car<Qtz<Chl<Chl<CarChl<Qtz<Qtz<Chl<Qtz<QtzPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD001@214.72El Alacran SMA_AL_1602_JM_016Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section correspond to a pervasive altered rock with no evidence of primary mineralogy. The dominant alteration corresponds to fine-grained aggregates of albite (40%) intergrowing with fine to very fine-grained, anhedral aggregates of quartz (20%) - chlorite (25%) as a selective replacement of the rock groundmass. The albite is selectively replaced by a medium to coarse-grained aggregates of carbonate (7%) and very fine-grained flaky aggregates sericite (4%) with traces of titanite/rutile.The carbonate and sericite occurs as local infill accompanied by fine-grained, euhedral quartz, fine-grained (<1mm), anhedral aggregates of pyrite (2%), chalcopyrite (1%) and traces of sphalerite. Two generations of pyrite are recognized. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_016Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Comments•In comparison with other CBM occurrences, the Py and Chalcopyrite here are in equilibrium. Possibly the enclosed? pyrite was formed during early calc-sodic alteration of Qtz+Chl•Pyrite is in equilibrium with the carbonate CBM and with sericite. Does Sericite and CBM correspond to the to a transitional phase?•Although chlorite is not evidently altered to sericite in comparison with albite. It is interpreted that albite and chlorite belong to the same early phase.Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD001@ 214.72in the El Alacran Deposit Unit 2 and lithofacie (TufC). This sample corresponds to a pale-green, medium to coarse-grained lapilli tuff with fragments varying from <1mm to 4mm in diameter. The rock groundmass is highly altered to sericite, albite?, whereas the clasts are selectively replaced to carbonate. There is also a selective alteration of rutile+carbonate and chalcopyrite Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsAlbite 40.0% Fine-grained (<0,1mm) flaky aggregates in the groundmass intergrowing with quartz and chloriteTwo Populations -Fine-grained (<1mm), pale green anhedral aggregates exhibiting some radiated shapes. Intergrows with quartz and albite-Very fine-grained (<0.05mm), pale green, semi acicular in shape, occurs as inclusions in quartz.25.0%Quartz 20.0% Two populations -Fine to very fine-grained (<0.1mm), anhedral aggregates intergrowing with fine chlorite and with inclusions of very fine-grained chlorite.-Fine-grained (~0,2mm), colourless (less inclusions compared to very fine quartz), sub to euhedral, exhibit some prismatic shapes as local infill textures accompanied of pyrite, chalcopyrite.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationQuartz Chlorite AlbiteCarbonatesTaniteSericite MineralizationPyrite Chalcopyrite SphaleriteLate Calcic CBM Stage 3 Stage 4>20%10-20%1-10%<1%ChloriteSample ID: SMA_AL_1602_JM_016Medium to coarse-grained (<5mm), colourless aggregates, occurs with sphalerite, titanite, carbonate, and chalcopyrite as local infill and patchy after albite. 7.0%Carbonates Undefined Distribution????MineralizationPyrite 2.0%Chalcopyrite 1.0%Fine-grained (<1mm), anhedral aggregates occurs as infill in quartz grain boundaries and intergrowing with chalcopyrite. Hardness differences suggests two Py events. Medium-grained (~2mm), anhedral aggregates that occurs with carbonate and sphaleriteVery fine-grained (<0.1mm) pale green, flaky aggregates replacing albite and former minerals, intergrowing with sericite, chalcopyrite and pyrite. 4.0%SericiteSphalerite Tr Very fine-grained (~0.05mm), anhedral aggregates occurs with chalcopyrite and titanite.Fine grained (<0.1mm), euhedral aggregates intergrowing with CarbonateTrTitanite/Rutile??????AMag: 10xPL+RL0.4mmCBDPhotomicrographsA) Representative microphotograph 5X showing the distribution of the rock major minerals. Note the intergrowth of quartz + chlorite + albite. B) Same as microphotograph A, but under RL. C) Microphotograph showing two possible generations of quartz, one associated with albite chlorite in the groundmass (right side) and the other related with the infill occurrence of sulphides in the left side. Note that Py and Ccp are in equilibrium in this stage. D) Same as microphotograph C, but under RL. E) Occurrence of sericite with carbonate accompanied by sulphides. F) Mi-crophotograph 50X showing some differences in the polished that suggest a previous early event of pyrite.Mag: 5xXPL+RLMag: 10xPL+RL0.4mm Mag: 5xXPL+RL0.8mm0.4mm<Car<Qtz Ser>Sample ID: SMA_AL_1602_JM_016E FMag: 20xXPL+RL0.2mm Mag: 50xXPL+RLXPL + RL FOV~ 1094μm (Length)<Chl0.08mm<Chl<CarPPL + RL FOV~ 2.18mm (Length)PPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)XPL + RL FOV~ 2.18mm (Length)XPL + RL FOV~ 441μm (Length)<Ab<Tita<Car<Ccp<Ab<Car<Qtz Ser><Chl<Chl<Ab<Tita<Car<Ccp<Ab<Qtz Ser><Sph<Ab<Py<Car<Ccp<Ab <Qtz<Py<Ccp Chl><Qtz Ser><Sph<Ab<Py<Car<Ccp<Ab <Qtz<Py<Ccp Chl><Sph<Py2?<Py1?<Ccp<Ccp<Qtz Ser><Py<Ccp<Qtz<Py<Ccp<Py1?<CcpPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD008@159El Alacran SMA_AL_1602_JM_018Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section corresponds to a lapilli tuff pervasively altered to albite and carbonate. Massive-destructive alter-ation in the sample is characterized by crystals of anhedral to euhedral (<0.5mm) albite. Relict titanite occurs as pinkish to brownish disseminates patches in hand sample and are replaced by carbonates, albite and very fine rutile aggregate. Sulphides occur in minor amounts and comprise mostly chalcopyrite. Chalcopyrite occurs as patchy anhedral aggregates with pitted texture after the replacement by albite, sericite and chlorite. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1602_JM_018Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Comments•Rutile possibly appeared during the carbonate event after albite and titanite. •Sericite shows fracture in-fill occurrence, no related or accompanied by chlorite and albite, then both phases are not in equilibrium in this sample. Sericite seems to be related with a latter phase event. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD008@159 in the El Alacran Deposit Unit 2 and the TufF litho-facies. This sample corresponds to a pale-grey albite + silica with minor amounts of unknowm (up to 3mm) pale pink mineral (rutile?). The sample also displays a pale brownish alteration superimposed to the white pervasive albite?+calcite alteration and it is accompanied of chlorite - chalcopyrite after mafic minerals. In the brownish alteration, calcite is associated with some selective fragments replacement, whereas, sericite occurs in fractures. The goal with this sample is to characterize the pervasive albite+rutile+carbonate alteration in the lithofacie TufF. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsAlbite 45.0% Very fine-grained (<0,01mm) aggregates pervasive destructive texture altered by carbon-ate and sericite.Very fine-grained aggregates (<25μm), selectively replacement and patchy areas of sub rounded shapes possibly replacing previous lapillies(?). Carbonate is locally cut by seric-ite and intergrowing with chlorite.25.0%Sericite 15.0% Fine-grained (70μm) flaky aggregates. Pale-green to colourless and iron-stained. Sericite is occurs as fracture in-fill and a selectively replacement after albite, chlorite and locally after carbonate. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationAlbite Chlorite SericiteCarbonatesIlliteTitaniteRutile MineralizationPyrite Chalcopyrite SphaleriteCarbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%CarbonateSample ID: SMA_AL_1602_JM_018Medium-grained patchy aggregates, colourless, highly-pitted and markedly rimmed by rutile. Optically, titanite displays a high relief, medium to dark grey in birefringence, opaque mineral. 7.0%Titanite Undefined Distribution??MineralizationChalcopyrite Tr Medium-grained (1.5mm) relictic texture of anhedral chalcopyrite, presents a highly pitted texture of replacing/intergrowing? with sericite.Very fine-grained aggregates, replacing albite? Corresponds to the stained coloration in the hand sample. 5.0%IlliteVery fine-grained, irregular aggregates of reddish brown, dusty texture rimming after titanite and related with carbonate. Light-grey birefringence, opaque mineral. 2.0%RutileFine-grained (>100μm), flaky, occurs as isolated crystals and minor a fracture in-fill. 2.0%ChloriteAMag: 20xXPL+RL0.2mmCBDPhotomicrographsA) Representative microphotograph 20X showing the distribution of the rock major minerals. Note sericite cutting carbonate and albite rimming? around carbonate. B) Representative microphotograph showing sericite as fracture in-fill cutting carbonate. C) microphotograph showing the pitted chalcopyrite and carbonate rimmed by sericite + chlorite D) Same as microphotograph C, but under XPL. E) Microphotograph showing the titanite+rutile and chalcopyrite pitted by carbonate, sericite and chlorite. F) Same as micropho-tograph C, but under RL. Mag: 5xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm0.2mmXPL FOV~ 1094 μm(Length) XPL FOV~ 1094 μm(Length)PPL + RL FOV~ 2.18mm (Length) XPL + RL FOV~ 2.18mm (Length)<Ser fracture infill<Car<AbSample ID: SMA_AL_1602_JM_018E FMag: 5xXPL+RL0.8mm Mag: 5xRLXPL + RL FOV~ 4.35mm (Length) RL FOV~ 4.35mm (Length)<Chl0.8mm<Ser<Car<Car Ser><Chl<Ser<Car<Ccp<Chl<Chl<Car<Car<Tita+ Rut<Chl<Car<Chl<Ab<Car<Ab<Ser Ser fracture infill><Car<Ccp<Chl<Chl<Car<Car<Ser Ser fracture infill><Ccp<Tita+ Rut<Chl<Car<Chl<CcpPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD001@42.5El Alacran SMA_AL_1608_JM_080Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This sample correspods to a brecciated, poorly sorted, monomictic, fragments-supported rhyolite with flow-banding texture. Fragments vary from 0.3mm to 3mm in size. The predominate texture in the sample is microphorphiritic with relictic plagioclase, K-feldspar and quartz microphenocrysts set in a microcrystalline groundmass. Flow bands are defined by cryptocrystalline concentrations of microlites highlighted by brown iron staining. K-feldspar microphenocrysts, <0.5 mm, are variably partly replaced by very fine-grained seric-ite and chlorite aggregate. Quartz microphenocrysts (up to 2mm) are anhedral to rounded, commonly with resorption textures. Tabular forms, typically 0.5 mm, possibly former plagioclase microphenocrysts, are re-placed by chlorite. Some larger irregular forms occur partly replaced with chlorite, sericite, carbonate ± rutile, ± quartz and locally ± sulphides and likely represent clusters of mafic phenocrysts. The groundmass consist of a finely microcrystalline quartz-feldspathic mosaic.PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_080Comments •FeOx Stain occurs along fractures associated with chlorite in contact with carbonate.•Given the occurrence of former quartz, it is difficult to distinguish a secondary quartz that accompany chlo-rite, however given that it has been observed in other samples of this same lithological unit, it is likely that also occurs in the sample.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase 3.0% Fine-grained (<0.4mm), occurs as microphenocrysts, partially replaced by sericite and chlorite.Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Quartz 1.0% Very fine to fine grained, phenocrysts and microphenocrysts , partially replaced by seric-ite and chloriteGroundmass 50.0% Very fine-grained, quartz-feldspathic mosaic with abundant microcrystalline chlorite aggregates and minor sericite alteration: comprises groundmass of auto breccia and groundmass of breccia fragments, weakly iron-stained concentrations of microlites define a flow banding. K- Feldspar 20.0% Fine-grained (<0.5mm), occurs as microphenocrysts, partially replaced by sericite. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD001@42.5 in the Unit 1, lithofacie TufR of the El Alacran deposit and analyzed previously by Dunne K, 2016. The initial goal consisted on defining the paragenesis of the green and brown minerals verify the occurrence of skarn silicates in the sample. This corresponds to a rhyodacite tuff with remnant rounded glassy Qtz crystals. Sample has fine-medium grained pale green alteration (?diop-side) with some small patches of darker green mineral (? Fe-rich cpx). The current goal with this sample is to stablish the paragenesis of the albite + Chlorite+ ?Biotite in the TufR lithofacie. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 15.0% -Very fine-grained, patchy replacement of matrix and fragments -Fine-grained (<0.2mm), anhedral aggregates, occurs as patchy replacement of pla-gioclase and tabular forms. Very fine-grained, partially replaces fine-grained tabular forms, likely former mafic phe-nocrysts, partially replaces plagioclase phenocrysts and replacing irregular forms and/or cavity infill.7.0%Sericite 2.0% Very fine-grained, occurs with chlorite and locally with carbonate, rutile as patchy re-placement of irregular forms. This replaces Chlorite.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationCarbonate15%Chlorite 7%Sericite 2%Rutile 1FeOx StainQuartz MineralizationPyriteChalcopyrite Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%Chlorite Sample ID: SMA_AL_1608_JM_080 Undefined Distribution??Very fine-grained, anhedral grains and aggregate, occurs with carbonate, chlorite sericite as replacement of irregular forms. 1.0%RutileOccurs as very fine-grained aggregates associated with chlorite and sericite. TrFeOx StainMineralizationPyrite TrChalcopyrite TrVery fine-grained (<0.1mm), euhedral grains, occurs disseminated, locally enclosed by chalcopyrite. Fine to medium-grained (<2mm), patchy anhedral aggregates, occurs commonly with chlorite, sericite and/or carbonate aggregates and locally encloses euhedral pyrite????AMag: 10xPL+RL0.4mmCBDPhotomicrographsA) Representative microphotograph 10X showing some evidences of chlorite altered to sericite and chlorite altered to carbonate. Note the clastic texture of the rock and the carbonate vein related with the FeOx stain distribution. B) Same as microphotograph A, but under RL. C) Microphotograph showing another couple of evidences of sericite + carbonate ± chalcopyrite after Mg-rich chlorite D) Microphotograph 50X showing the distribution of the FeOx stain in the groundmassMag: 10xXPL+RLMag: 10xXL+RL0.2mm Mag: 50xPL+RL0.08mm0.4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Sample ID: SMA_AL_1608_JM_080<Car<Chl altered to Ser<CarPPL FOV~ 441 μm (Length)<Chl altered to Car<Car<Chl altered to Ser<Car<Chl altered to Car<FeOx Stain<Car<Chl altered to Ser<Car<Chl altered to Car<Ccp<Chl altered to Ser<FeOx Stain<MgChl<MgChlPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD001@165El Alacran SMA_AL_1608_JM_081Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section comprises semi massive (70%) pyrrhotite and pyrite replacement that is embedding fine- to me-dium-grained radiated crystals of actinolite, chlorite, and carbonate. These alterations minerals are formed from a parental microdiorite? where crystals of tabular and zoned plagioclase and amphibole are still pre-served. The section shows some carbonate as fracture in-fill that cuts either the plagioclase or the pyrrhotite. Traces of titanite and illmenite are also present.Chalcopyrite occurs as a later sulphide event, cutting and embedding pyrrhotite and pyrite. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_081Comments•The albite seems to be a former mineral rather than an alteration mineral in this plate. •Pyrrhotite seems to be close in formation with pyrite, but pyrite show some textures that suggest that a least one of the pyrite stages is earlier than pyrrhotite. •Chalcopyrite seem to be related with pyrrhotite, however also exhibits some evidences of crosscutting. •Carbonate is the late phase in the sample. Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Plagioclase 20.0% Fine to medium grained (0.2 to 4mm), tabular, commonly zoned, composition An 17-35 (Oligoclase-Andesine, based on 4 estimates), occurs intergrowing with amphibole par-tially replaced to carbonate, albite and amphibole. Amphibole 5.0% Possible Hornblende and actinolite?. Some relictic textures with 45 cleavage. 350μm in length. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD001@165 in the Unit 2, from an unknown lithofacie of the El Alacran Deposit and analyzed previously by Dunne K, 2016. The initial goal consisted on verifying the occur-rence of skarn silicates in the sample and age relationship between magnetite, pyrrhotite, pyrite and chalco-pyrite. This sample corresponds to a medium to dark-green altered rock with abundant (15-20%) magnetic pyrrhotite and trace occurrence of pyrite and chalcopyrite crystals and blebs. The goal with this sample is to stablish the paragenesis of albite+pyrrothiteMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 6.0% Present fine-grained, (up to 100mμ), colourless to pale brown aggregates that selectively replaces apatite. Also, in veins occurs as very fine-grained aggregates cutting pyrrhotite and plagioclase. In some parts, it is accompanied by silica in the margin of Py crystals.Displays acicular habit in aggregates 1mm to 2.5 mm in length that intergrow with quartz after apatite. Actinolite is partially replaced by chlorite. Optically, displays pleocroism from pale-green to yellowish brown.10.0%Chlorite 5.0% Fine-grained aggregates replacing mostly amphibole (Hb or actinolite)*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationApatiteActinoliteCarbonate ChloriteSphaleriteQuartzMineralizationPyrrhotitePyriteChalcopyrite Act-Qtz-Po? Stage 3 Stage 4>20%10-20%1-10%<1%Actinolite Sample ID: SMA_AL_1608_JM_081 Undefined Distribution??Fine to very fine –grained (<0.8mm), occurs interstitial to amphibole and semi-massive pyrrhotite3.0%QuartzMedium-grained (2mm) euhedral to subhedral aggregates , pale yellow to colour-less , replaced by actinolite –quartz and cut by carbonate and chalcopyrite 2.0%ApatiteMineralizationPyrite 10.0%Chalcopyrite TrEuhedral up to 1mm in length, occurs as inclusions in pyrrhotite? However present some (low occurrence) of cutting relationship in the Po. Always related to Po occurrence. Irregular shapes, up to 0.3m in diameter, locally encloses pyrrhotite and pyrite Occurs as isolated crystals, colourless, intergrowing with plagioclase. Also, present alter-ation to colourless acicular mineral (anatase?)TrTitaniteSphalerite Tr Fine-grained aggregates intergrowing with carbonate, chlorite. Optically presents high anisotropy and internal reflectionsPyrrhotite 50.0% Pale pinkish grey, subhedral crystals up to 3mm in length. Intergrowing with quartz and actinolite after apatite. Carbonate veins cut it. This also encloses pyrite and presents some flames exolutions of pyrite. ????AMag: 10xPL+RL0.4mmCBDPhotomicrographsA) Representative microphotograph 10X showing pyrrhotite + quartz after actinolite?. Note also the chloritization of actinolite in the low left corner. B) Same as microphotograph A, but under XPL. C) Microphotograph showing some evidences of early apatite occurrence cut by chalcopyrite and replaced? by actinolite + quartz. Note also the enclosed pyrite in pyrrhotite and the quartz + carbonate cross-cutting veins. D) Same as microphotograph C, but under XPL. D) Microphotograph 10X showing hematite after amphibole? occurring with carbonate + pyrite + actinolite Mag: 10xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm0.4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length) PPL FOV~ 2.18mm (Length)Sample ID: SMA_AL_1608_JM_081<Car<Tita<QtzXPL FOV~ 1.28 mm (Length)<ActE FMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Qtz<Chl after Act<Ccp<Tita<Qtz<Act<Qtz<Chl after Act Po Po Po Po<CcpAp<Act<Ap<Py Po Po <Py<Py<Qtz<Qtz<CcpAp<Act<Ap<Py Po Po <Py<Py<Qtz<QtzCcp>Plagioclase<ActIlmenite<PyTitaCar<Car<CarPo>Plagioclase<ActIlmenite<PyTitaCar<Car<CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD009@162.5El Alacran SMA_AL_1608_JM_088Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This thin section comprises massive pyrite-chalcopyrite-pyrrhotite aggregates associated with intense chlo-rite-clay and sericite-clay-rutile gange. Apatite occurs as elongate prismatic crystals that have been fractured and infilled by Pyrite. Traces of former titanite grains, partly replaced by rutile aggregates, occur disseminated. Sulphide minerals comprise over 90% of the section as pyrrhotite, pyrite and chalcopyrite aggregates. Semi-massive pyrrhotite occurs as fine to medium-grained anhedral aggregates partly replaced by euhedral pyrite and patchy very fine-grained poorly crystalline aggregates of relict pyrite. Pyrrhotite is partially altered to traces to intermediate sulphide. Chalcopyrite is in patches with interstitial very fine-grained chlorite-clay aggregate. Traces of Fe Ox partly replaces pyrrhotite margins and stain the chlorite-clay and clay. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_088Comments• No clear evidences of pyrrhotite cutting apatite, possibly related to the same stage. • No magnetite in the sample.Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD009@162.5m in the Unit 2, from un unknown lithofacie of the El Alacran Deposit . The initial goal consisted on verifying the occurrence of skarn silicates and sulfides paragen-esis. This sample corresponds to an ore zone with magnetite(?) and chalcopyrite rich ore with possibly some pyrrhotite and minor pyrite. Chalcopyrite appears to be younger and overgrows the magnetite. The current goal with this sample is to characterize the Po+Act+Ab association and relation to magnetite. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite-Clay 7.0% Very fine-grained, occurs with pyrite and pyrrhotite patches, partly stained red-brown by oxidation of pyrrhotite. Fine to medium-grained (<2mm), euhedral aggregates, fractured and infilled by sulphi-des 1.0%Carbonate 1.0% Fine to coarse-grained aggregates (<7mm) as fracture –infills *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationApatite Chl-Clay Carb Sericite Fe-Ox Clay Rutile MineralizationPyrrhotitePyriteChalcopyrite Int productAct-Qtz-Po? Carbonate-Sericite? Late Calcic Veins>20%10-20%1-10%<1%ApatiteSample ID: SMA_AL_1608_JM_088 Undefined Distribution??Fine-grained (<0.3mm), radiating aggregates, occurs with chlorite-clay and clay alter-ation. TrSericiteVery-fine grained replaces margins of pyrrhotite aggregates, as patchy stain on chlo-rite-clay and sericite TrFe-OxMineralizationChalcopyrite 30.0%Pyrrhotite 10.0%Fine to coarse-grained (<7mm), anhedral grains and aggregates, encloses and infills fractured pyrrhotite Fine to medium-grained (<4mm), anhedral aggregates, partly altered to intermediate product, margins party replaced by Fe-Oxide Fine-grained (<0.5mm), relict wedge shaped forms, disseminated. Rutile: Very-fine grained, anhedral aggregates that replace titaniteTrTitanite/RutileIntermediate product Tr Aphanitic aggregates, replacement of pyrrhotite by a very fine-grained pyrite-marcasite product. Pyrite 50.0% Fine-grained (0.1-0.6mm), eu-subhedral aggregates and very fine grained, poorly crystal-line aggregates of relictic pyrite, replacing pyrrhotite, pitted, infills fracture chalcopyrite, occurs as fracture infill cutting chalcopyrite. ????Cryptocrystalline aggregates, brown, occurs with chlorite-clay TrClay ??AMag: 2xXPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 2X showing some pyrrhotite altered to an intermediate product related to the occurrence of Ccp + Chl-Clay after apatite. B) Representative microphotograph 2X showing some carbonates filling at the sample bottom and some veinlets at the lower right side. C) Microphotograph showing alteration of the pyrrhotite to pyrite around the crystals borders D) Distribution of the sericite replacing some former clasts? and intergrowing with pyrrhotite?Mag: 2xXPL+RLMag: 5xPL+RL0.8mm Mag: 5xXPL+RL0.8mm2mmXPL+RL FOV~ 11mm (Length) XPL+RL FOV~ 11mm (Length) PPL FOV~ 4.35mm (Length)Sample ID: SMA_AL_1608_JM_088<Chl+Clay<TitaXPL FOV~ 4.35 mm (Length)<CcpPo<Ccp<Tita<Car Veinlets<Ap<Int ProductCcp+Chl-Clay Po Po Po Po<Ccp Car Veinlets>CcpPy Po<Car Car> PoPo<Chl+Clay Ser><CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD016@139.2El Alacran SMA_AL_1608_JM_091Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description Pervasively chlorite-quartz-albite, selectively sericite-titanite-(pyrite) and patchy carbonate altered former fragmental volcanic rock. The matrix is very fine-grained to cryptocrystalline and comprises? felted pla-gioclase, partly replaced by albite, quartz, sericite and patchy carbonate. Some fragments have relict fine-grained granular texture partly replaced by sericite, chlorite, and carbonate. Other fragments are markedly chlorite altered with patchy titanite, chlorite carbonate ± sericite alteration. Carbonate in the thin section occurs as irregular patches and is colourless and likely mostly calcite (based on sample reaction to cold, dilute HCl). Traces of secondary apatite and ragged epidote occur disseminated. Minor fine to medium-grained subhedral pyrite occurs disseminated and as aggregates associated with chlo-rite, titanite, carbonate and an unknown reactive mineral (see below). Chlorite and carbonate occur as infill to cavities with pyrite. A known mineral reacted with epoxy/water during the section separation leaving trace cavities in the section. This mineral was likely a mixed layer clay, zeolite or sulphate (after Dunne, 2016). PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_091Conclusions: • No clear evidences of pyrrhotite cutting apatite, possibly related to the same stageMineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD016@139.2 in the Unit 2, from the lithofacie TufF of the El Alacran Deposit. This sample correspods to a pervasive- altered fragmental volcanic rock with an ash-rich groundmass in 0.7cm-lenght lapillies. The sample displays a pervasive alteration to dark-green chlorite and albite(?). The goal is to verify the occurrence of retrograde skarn silicates (tremolite-actinolite, and diopside). Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 30.0% Fine to very fine-grained (<0.4mm), anhedral aggregates, occurs as irregular patchesFine to very fine-grained (<0.2 mm), spheroidal to ragged spheroidal aggregates, occurs associated with sericite, titanite carbonate and clay in fragments and occurs within matrix.25%Quartz 15.0% Fine to very fine-grained aggregates (<0.1mm), occurs with albite replacing felted pla-gioclase matrix.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationPlag - AlbiteApatiteChloriteQuartzEpidoteCarbonateSericiteTitaniteClay-SmectiteMineralizationPyriteChloritic Carbonate-Sericite? Stage 4>20%10-20%1-10%<1%ChloriteSample ID: SMA_AL_1608_JM_091 Undefined Distribution??Very fine-grained felted, occurs with quartz as matrix, variably replaced by sericite and quartz?. 15.0%Plagioclase- AlbiteVery fine-grained, flaky occurs partly replacing plagioclase in matrix and fragments 7.0%SericiteClay (Smectite?) 1.0%Apatite TrCryptocrystalline aggregates, brown clusters of anhedral aggregates partially plucked from the section, associated with chlorite, sericite and carbonate alteration. Fine to medium-grained (<1.5mm), partly replaced by carbonate, occurs disseminated.Fine to medium-grained (< 1.5mm), ragged grains and aggregates, some wedge shapes, associated with chlorite and carbonate alteration5.0%Titanite/RutileEpidote Tr Fine-grained (0.6mm), anhedral grains , disseminated ??MineralizationPyrite 1.0% Fine to medium-grained (<1.5mm), eu-subhedral grains and aggreagte, pitted, occurs dis-seminated, can occur with spheroidal chlorite, titanite and carbonate as infill.??AMag: 10XPPL+RL0.4mmCBDPhotomicrographsA) Representative microphotograph 10X showing some relictic apatite partially altered to carbonate + titaniteB) Same as microphotograph A, but under XPL + RLC) Microphotograph showing a dominant quartz alteration accompanied by chlorite, cut and replaced by sericite + carbonate patchy and veins. D) Same as microphotograph C, but under XPL + RLMag: 10xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm0.4mmPPL+RL FOV~ 2.18mm (Length) XPL+RL FOV~ 2.18mm (Length) PPL FOV~ 2.18mm (Length)Sample ID: SMA_AL_1608_JM_091<ApXPL FOV~ 2.18 mm (Length)<Tita<Chl Car Veinlets> Car><Car<Chl<Car<Ap<Clay<Ap<Tita<Chl Car Veinlets><Car<Chl<Car<Ap<Clay<Qtz<Tita<Ser<Car<Chl<Car Vein<Py<Qtz<Tita<Ser<Car<Chl<Car Vein<PyPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD018@55.6El Alacran SMA_AL_1608_JM_093Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description Pervasively altered chlorite-quartz-carbonate (titanite) altered fine-grained rock adjacent to thinly banded magnetite-sulphide band. In the section, the fine-grained rock has relict granular texture (0.1-0.5mm) with fine former interstitial quartz (<0.2mm). The granular texture is virtually completely replaced by chlorite-car-bonate-clay –titanite aggregate and overprinted by disseminated pyrite and magnetite. A patch of fine to medium-grained quartz aggregate occurs adjacent to the altered fine rock which then grades into the magne-tite-sulphide band. The Magnetite-sulphide band changes from fine to very fine quartz-carbonate-chlorite ± (apatite, sericite) with patchy magnetite-chalcopyrite- pyrite to dominantly magnetite-pyrite-quartz-chlorite with progressively more carbonate alteration, sericite and loss of chalcopyrite. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_093Comments•More apatite occurrence (~5%) in comparison with previous descriptions (e.g. Dunne,2016)•Alteration of magnetite + quartz + apatite + dark-chlorite replaced by the occurrence of carbonate + sericite and Py + Ccp.•No visible Albite•Ccp in some places has in-fill textures in quartz (same stage?). There is a zoning form this infill centers from a proximal magnetite + quartz towards an apatite – chloriteMineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD018@55.6m in the Unit 2, from the lithofacie TufF of the El Alacran Deposit. The initial goal consisted on verifying the occurrence of retrograde skarn silicates (dark gar-net). This sample corresponds to a pale green, fine-grained ash tuff with thick layers and small-disseminated crystals of magnetite and large (0.6cm) blebs and crystals of pyrite. The current goal with this sample is to characterize the paragenesis of fine magnetite replacement in relation with pyrite + chlorite.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsMagnetite 30.0% Fine-grained (<2mm), anhedral grains and aggregates, ragged, locally encloses pyrite, occurs in bandsFine to very fine-grained (<1mm), anhedral aggregates, occurs as irregular network of overprinting alteration in patches and bands. 25%Chlorite 25.0% Fine-grained (0.1mm), radiating aggregates, occurs replacing former fine-grained rock and within bands of quartz-carbonate aggregate and magnetite bands. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationMagnetite30Carbonate. 25Chlorite 25Quartz 7Apatite 1Sericite 2Titanite TrMineralizationPyrite3Chalcopyrite7Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%CarbonateIncludes calciteSample ID: SMA_AL_1608_JM_093 Undefined Distribution??Fine to very fine-grained (<1mm), typically eu-subhedral forms, occurs as bands and patches with carbonate, chlorite locally cloud 7.0%Quartz Fine to very fine-grained (<0.1mm), flaky, locally radiating aggregates, occurs with car-bonate in quartz and magnetite-dominant bands. 2.0%SericiteTitanite Tr Fine to very fine-grained (0.1-1mm), euhedral grains, occurs as single crystals or in anhe-dral clusters, locally replacing radiating forms, occurs disseminated within bands. Fine to very fine-grained (~0.1 to 1.1mm), eu-subhedral aggregates, within magne-tite-chalcopyrite bands, overprinted by carbonate. 1.0%ApatiteMineralizationChalcopyrite 7.0% Fine-grained (< 1mm), anhedral ragged grains and aggregate, occurs as in-fill to pyrite and magnetite, occurs in bands??Pyrite 3.0% Fine-grained (< 1.6mm), anhedral grains and aggregate, occurs enclosed by magnetite in bands, inclusions of chalcopyrite and lees commonly pyrrhotite. AMag: 2xPPL+RL2mmCBDPhotomicrographsA) Representative microphotograph 10X showing some relictic apatite partially altered to carbonate + titaniteB) Same as microphotograph A, but under XPL + RL. C) Microphotograph showing a dominant quartz alteration accompanied by chlorite, cut and replaced by sericite + carbonate patchy and veins. D) Same as microphotograph C, but under XPL + RLMag: 10xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm2mmPPL+RL FOV~ 11mm (Length) XPL+RL FOV~ 11mm (Length) PPL FOV~ 2.18mm (Length)Sample ID: SMA_AL_1608_JM_093XPL FOV~ 2.18 mm (Length)<Qtz<Chl<Car<Chl<Car<Ccp<Qtz<Qtz<Chl<Car<Chl<Car<Ccp<Qtz<QtzMag<Car<Chl<Car<Ccp<Qtz<PyMag<Ser<QtzMag<Car<Chl<Car<Ccp<Qtz<PyMag<SerPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@102.4El Alacran SMA_AL_1801_JM_125Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This unit is a brecciated, poorly sorted, clast supported andesite to dacite. The matrix constitutes 30% of the sample and it is composed by very fine-grained (<0.1mm) aggregates of former feldspar (?) pervasive al-tered to sericite. Fragments of quartz (5-20%) are fine-grained (0.7mm), anhedral and angular with multiple embayments. This very fine-grained fraction is difficult to separate from hydrothermal quartz. Traces of pla-gioclase occur as fine-grained (~0.5mm) tabular relictic crystals pervasively altered to sericite and carbonate.Alteration intensity is strong and corresponds to Very-fine grained, flaky aggregates of sericite (~25%) inter-growing with fine-grained (~0.4mm) carbonate and titanite that replace feldspar (plagioclase) and chlorite.Quartz also occurs in the sample as fine to medium-grained (~0.4-1mm), anhedral aggregates accompanied by carbonate and titanite, however it is difficult to separate this from the primary quartz. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_125Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Quartz 20% -Very fine-grained, anhedral, colorless aggregates (15%), homogenously distributed and difficult to separate from secondary origin.-Fine-grained (0.7mm), colorless, anhedral, angular with come em-bayments. (5%) This has a primary origin.Matrix 30% Very fine-grained , anhedral, colorless aggregates altered to sericite. It is composed by very fine-grained (<0.1mm) aggregates of former feldspar.Plagioclase Tr Fine-grained (0.5mm), colorless, tabular relictic minerals pervasively altered to sericite and carbonate. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@102.4 within the Unit 1, TufR lithofacie in the El Alacran Deposit. This corresponds to fine to medium-grained, pale-green rock with some microphenocrysts of quartz and some lapillies partially altered to plagioclase. This sample correspond to a dacite tuff. The goal with this sample is to characterize one representative unaltered specimen of the TufR lithofacie. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSericite 25.0% Very fine-grained, colorless, flaky aggregates intergrowing with carbonate and selectively replacing feldspar (plagioclase). Fine-grained (~0.4mm), colorless, anhedral aggregates, occurring with titanite, replacing selectively feldspar and chlorite15.0%Chlorite 7.0% Very fine-grained (<0.1mm), pale green, with selective replacement after former miner-als, tabular, elongated (hornblende?). *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%CarbonateSample ID: Undefined Distribution??-Fine- to medium-grained (~0.4-1mm), colorless, anhedral to euhedral aggregates occur-ring with Car and Tita. 2.0%Quartz MineralizationPyrite+Sph Tr Very fine grained- (<0.05mm), anhedral, aggregates disseminated.SMA_AL_1801_JM_125AMag: 5xPPL+RL0.8mmCBDPhotomicrographsA) Microphotograph 5x, showing the former clast with some embayments , as well as chl + car alteration after fomer horn-blende? . B) Same as microphotograph A, but under XPL + RLC) Microphotograph 5X, showing the breccia distribution and clastic occurence of quartz . D) Same as microphotograph C, but under XPL + RL. Note the carbonate cutting the qtz fragment. E. Microphotograph 10X showing selective replacemen of carbonate and sericite after former feldspar crystal. F) Same as micro-photograph E, but under XPL + RLMag: 5xXPL+RLMag: 5xPL+RL0.8mm Mag: 5xXPL+RL0.8mm0.8mmPPL+RL FOV~ 4.35mm (Length) XPL+RL FOV~ 4.35mm (Length) PPL FOV~ 4.35 mm (Length)Sample ID:XPL FOV~ 4.35 mm (Length)E FMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Qtz<Car<Chl<Car<Ser<Car<Qtz<Tita<Chl<Qtz<Car<Chl<Car<Ser<Car<Qtz<Tita<Chl<Qtz<Qtz<Qtz<Qtz Embayment<Ser +Car<Ser +Car<Qtz<Qtz<Qtz<Qtz Embayment<Ser +Car<Ser +Car<Chl <Chl<Ser +Car<Qtz <Chl<Qtz<Chl<Ser +Car<Qtz <Chl<QtzSMA_AL_1801_JM_125PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@126.50El Alacran SMA_AL_1608_JM_126Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section is a breccia, poor sorted, clast supported, and monomictic unwelded andesite tuff. With a mi-crocrystalline groundmass (20%) composed of very fine-grained (<0.1mm) aggregates of quartz traces of pla-gioclase. This rocks is mostly composed by medium to coarse-grained (>5mm) , glassy ash fragments, sub tab-ular, elongated with some incipient welding textures. This section exhibits some perlite texture that overprints some subtle flow banding orientation. The vitroclasts in the sample exhibit devitrification process to quartz. Alteration intensity is relatively low and is dominated by the occurrence of fine to medium-grained (~0.4-1mm), anhedral aggregates of carbonate (~7%) that selective replaces apatite. Also by very-fine grained, flaky aggregates of sericite (~7%) that selectively replaces feldspar and devitrified vitroclasts. Chlorite (5%) occurs as very fine grained- (<0.1mm), aggregates that selective replacement of the glass shards (vitroclasts)Mineralization occurs as traces of chalcopyrite, sphalerite and pyrite, accompanied by carbonate, sericite, titanite and quartz. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1608_JM_126Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Quartz 20.0% -Very-fine grained , anhedral, colorless aggregates as crowded tex-ture in the rock groundmass (20%).-Very fine grained- anhedral, with highly irregular contact (con-sertal texture) rimming or nucleating some clay? minerals and grading to a dusty clored quartz that intergrows with acicular mineral. This occurs mostly in some clasts.Also occurs as fine grained (0.3mm), colorless, anhedral, sur-rounded aggregates as free crystals. Vitriclasts 60.0% Medium to coarse-grained (>5mm), pale ember, glassy ash frag-ments, subtabatular, elongated with some incipient welding tex-tures. Exhibit some perlite texture that over-prints some subtle flow foliation. Also the vitriclasts exhibits some variations in the devitrificaion state and products from glass to quartz. The fragments are auto-clastic in nature. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@126.50 within the Unit 2, TufL lithofacies in the El Alacran Deposit. This corresponds to a pale-green, poorly altered monomictic clast supported volcanic breccia, com-posed of 0,5mm length clasts of volcanic rock. This rock does not present an orientation and has been classi-fied as a lithic Tuff. The goal with this sample is to characterize one representative unaltered specimen of the TufL lithofacies. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 7.0% -Fine to medium-grained (~0.4 - 1mm), colorless, anhedral aggregates, replacing selec-tively apatite. Car intergrows with chalcopyrite, Shp, Py , titanite and Qtz-Very fine grained, colorless, flaky aggregates intergrowing with carbonate and selective-ly replacing feldspar and devitrified vitroclasts.7.0%Chlorite 5.0% Very fine grained- (<0.1mm), pale brown, with selective re-placement of the glass shards.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%SericiteSample ID: Undefined Distribution??-Fine to medium-grained (~0.4-1mm), colorless, anhedral to euhedral aggregates occur-ring with Car and Tita,2.0%?Quartz Fine grained <0.2 -colorless, prismatic, aggregates enclosed by glassy material, this is replaced by Ser and CarTrApatiteMineralizationSphalerite Tr Fine-grained 0.7-0.5, anhedral, occurs with Qtz and Tita and close to sericite (sericite later). Occurs disseminated and as veining accompanied by Car and Py +QtzPyrite Tr Fine grained 0.7 , anhedral , accompanied of ShpSMA_AL_1608_JM_126AMag: 2xPPL+RL2mmCBDPhotomicrographsJM126. A) Microphotograph 2X, showing the breccia texture in the rock. Note the clasts composition dominated by vitroclasts and recrystallized quarzt. . B) Same as microphotograph A, but under XPL + RL, Note the dusty clored quartz that intergrows with acicular mineral (clay). C) Microphotograph 10X, showing unwelded vitroclasts altered to chlorite. D) Same as microphotograph C, but under XPL + RL. E) Sample JM126. Microphotograph 10x, showing devitrification evidences and recrystallization to quartz and clay minerals . Note the occurrence of circular perlite textures in the glass. F) Same as microphotograph C, but under XPL + RLMag: 2xXPL+RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm2mmPPL+RL FOV~ 11mm (Length) XPL+RL FOV~ 11mm (Length) PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)E FMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Perlite <Qtz+Clay<Plag<Vitroclast<Glass<Perlite <Qtz+Clay<Plag<Vitroclast<Glass<Glass<Qtz+Clay<Chlorite<Qtz<Tita<Tita<Ap<Ap<Glass<Qtz+Clay<Chlorite<Qtz<Perlite <Perlite <Chl<CloredQtz<CloredQtz<Perlite <Perlite <Chl<Glass <Chl+ClaySMA_AL_1608_JM_126PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@133.8El Alacran SMA_AL_1801_JM_127Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This section shows that rocks correspond to a poorly-sorted, matrix supported monomictic and partially weld-ed andesite breccia. The sample displays a cryptocrystalline (<0.05) matrix (~50%) composed by recrystallized glass with a slight flow banding texture. The clasts in the sample correspond to coarse-grained (>5mm), elon-gated juvenile volcanic clast (fiammes) (~15%) associated with partial welding after compaction. Additionally, fine-grained (0.2-0.4mm) aggregates of plagioclase and quartz (~ 1%) occurs as free crystals. Alteration has low-intensity and it is produced by the occurrence of chlorite (3%) replacing the fiammes. Car-bonate occurs after feldspar accompanied by titanite and traces of quartz. Carbonate also occurs with very-fine grained, flaky aggregates of sericite and as veinlets. Mineralization is not observed in this sample. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Fiamme/Vitriclasts 15% Coarse-grained (>5mm), pale green to yellowish, lenticular, elongated juvenile volcanic clast (fiammes), associated with partial welding after compaction. This is altered to chlorite.Matrix 50% Cryptocrystalline (<0.05mm), brownish amber coloration, composed of recrystallized? glassy ash that presents a slight flow banding.SMA_AL_1801_JM_127Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@133.8m within the Unit 2, TufD lithofacies in the El Alacran Deposit. This corresponds to a pale-green volcanic rock showing a fine-grained matrix with some elongated (0.5mm length) lapilli clasts, that exhibit a certain degree of welding. This lapillies are selectively replaced to chlorite. The goal with this sample is to characterize one representative unaltered specimen of the TufD lithofacies.Plagioclase 5% Fine grained (0.2-0.4mm) sub tabular, colorless aggregates, as free crystals and phe-nocrysts. They are partially to pervasively alter to Car and Ser, some of the crystals present twinning. Quartz 1% Fine to very fine-grained (0.1), sub-rounded, angular, aggregates as free crystals.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 3.0% Very fine-grained (<0.1mm), pale green, with selective replacement after the vitriclasts (Fiammes)-Fine-grained (~0.4), colorless, anhedral aggregates, replacing selectively feldspar. This intergrows with titanite and traces of quartz. It is also observed along veinlets2%Sericite 1% -Very fine-grained, colorless, flaky aggregates intergrowing with carbonate and selective-ly replacing feldspar.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-Sodic Carbonate-Sericite Stage 3 Stage 4>20%10-20%1-10%<1%CarbonateSample ID: Undefined Distribution??Fine-grained (0.4mm), colorless, high-relief, anhedral to subhedral aggregates intergrow-ing with carbonate and sericite and also along some veinlets in the this minerals along with quartz. TrTitaniteSMA_AL_1801_JM_127ACBDPhotomicrographsA) Microphotograph 10X, showing the groundmass dominated texture with some relicitic plagioclase crystals partially replaced to carbonate and sericite. B) Same as microphotograph A, but under XPL + RLC) Microphotograph 10X showing the rock components. Note the matrix supported texture composed mostly of glass. D) Same as microphotograph C, but under XPL + RL. Note the partially welded vitroclasts altered to chlorite.Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)<Welded VitroclastMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Plag<Plag<Car +Ser<Glass<Chl<Ser<Chl<Fiamme<Clay<Glass<Plag<Plag<Car +Ser<Glass<Chl<Ser<Chl<Fiamme<Clay<Glass<Welded Vitroclast<Car<Chl<Car<Welded Vitroclast<Welded Vitroclast<Car<Chl<Car<GlassSMA_AL_1801_JM_127PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@141.00El Alacran SMA_AL_1801_JM_128Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This is a matrix supported, poorly transported, hybrid rock composed of microcrystalline glassy ash matrix and bioclasts. The matrix is composed of fine-grained (0.1mm), anhedral to surrounded aggregates of carbonate (~40%) and vitroclasts (20%). Bioclasts (~15%) correspond to coarse-grained (>10mm) bivalves formed by fine-grained (0.3mm) carbonate crystals. Plagioclase (5%) occurs also in the matrix as free crystals accompa-nied by quartz traces.Alteration is weak in intensity and corresponds to fine to very fine-grained (~0.09), aggregates, carbonate, sericite and titanite that selectively replaces feldspar and bioclasts. Chlorite occurs as selective replacement of the vitriclasts. Mineralization occurs as traces of very fin-grained (<0.05mm), anhedral aggregates of sphalerite, chalcopyrite and pyrite that nucleate glass. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Conclusions: Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Glass 20% Fine-grained (0,1mm), composed, brownish amber coloration, surrounded vitroclasts (sperulites?) that conforms he rock matrixCarbonate 40% Fine-grained (0.1mm), colorless, to dusty coloration, anhedral to surrounded aggregates that occurs as part of the matrix with the vitroclasts. This is also observed as veinlets SMA_AL_1801_JM_128Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@141.0m within the Unit 2, Lim lithofacies in the El Alacran Deposit. This corresponds to a fine to very fine-grained grey mudstone with some white fossiliferous relicts of 3cm length. The fossils corresponds to bivalves that constitutes 40% of the sample. This rock is a Marlstone. The goal with this sample is to characterize one representative unaltered specimen of the Lim lithofacie. Bioclasts 15% Coarse-grained (>10mm), colorless, bivalves clasts, formed by fine grained (0.3mm) carbonate materialPlagioclase 5% Fine-grained (0.1-0.3), colorless, subhedral, tabular aggregates that occur as free crystals in the matrix. These are replaced to sericite and carbonateQuartz Tr Fine-grained (0.1mm), colorless, anhedral, aggregates that occurs as isolated crystals in the groundmassMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChorite 3.0% Very fine-grained (<0.1mm), pale green, with selective replacement after the vitriclasts (fiammes)Very-fine grained, colorless to pale green, flaky aggregates intergrowing with, clay car-bonate and selectively replacing feldspar2.0%Carbonate 2.0% Fine to very fine-grained (~0.09), colorless, anhedral aggregates, replacing selectively feldspar and bioclasts. The carbonate percentage is difficult to obtain given the parental rock composition*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%Sericite+ClaySample ID: Undefined Distribution??Very fine-grained, colorless , flaky aggregates intergrowing with carbonate and selective-ly replacing feldspar1.0%Sericite Fine-grained (0.4mm), colorless, high relief, anhedral to subhedral aggregates intergrow-ing with carbonate and sericite. Also it is observed along some veinlets accompanied of Qtz TrTitanite MineralizationShp+Ccp Tr Very fine grained (<0.05mm), anhedral aggregates nucleating after glass, accompanied of CarbonateSMA_AL_1801_JM_128ACBDPhotomicrographsJM128. A) Microphotograph 10X, showing the distribution of the vitriclasts and carbonate as part of the matrix. B) Same as microphotograph A, but under XPL + RL.C) Microphotograph 10X showing the occurrence of bivalves fragments embedde by glassy material. D) Same as microphotograph C, but under XPL + RL. Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Car<Chl<Car<Glass<Car+Ser<Fossil< Vitriclast<Fossil<Car<Chl<Car<Glass<Car+Ser<Fossil< Vitriclast<Fossil<Plag<Chl<Car<Glass< Vitriclast<Fossil<Car+SerCcp><Plag<Chl<Car<Glass< Vitriclast<Fossil<Car+SerCcp>SMA_AL_1801_JM_128PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA037@112El Alacran SMA_AL_1709_JM_076Country: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE Polished Thin section Description This thin section corresponds to an ore-bearing hydrothermal breccia composed of medium-grained, bladed magnetite (40%) embedding euhedral Qtz, and accompanied by inclusions and exolutions? of pyrite and chalcopyrite. Quartz occurs in two populations: 1) Very fine-grained (silica alteration) that selective replaces former frag-ments (30%). 2) A late? medium-grained euhedral prismatic quartz, growing from the silica clasts toward the zone with magnetite occurrence (5%) and occurs with apatite traces. Mineralization is dominated by pyrite (15%) that occurs as medium to coarse-grained (up to 5mm), euhedral aggregates that intergrows with magnetite. Chalcopyrite occurs as exolutions in bladed magnetite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. SMA_AL_1709_JM_076Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA037@112m in the Unit 1, lithofacie RBx of the El Alacran Depos-it. It corresponds to hydrothermal highly- mineralized breccia that presents silica clasts embedded in a mag-netite + pyrite matrix. The clasts are bigger than 5cm and present banded textures marked by the occurrence of fine magnetite + rutile. The groundmass is composed of bladed magnetite (mushketovite) that intergrows (and locally cut) some 5mm-length, euhedral to subhedral crystals of pyrite. The groundmass is about 70% of the samples, where sulphide constitutes 15-20% of this. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsMagnetite 40.0% Medium-grained, bladed, dark brown, not anisotropic mostly as euhedral crystals embedding euhedral Qtz, and accompanied by inclusions and exolutions? of Pyrite and chalcopyrite. This is also embedded by carbonateTwo populations: -Very fine-grained (<0.01mm), brownish dusty coloration. Occurs as selective replace-ment of fragments. It is cut by carbonate veinlets.-Medium-grained (2mm), euhedral prismatic quatz, growing from the silica clasts toward the zone with magnetite occurrence. This seems to predate the magnetite and occurs with Ap traces. 35%Pyrite 15.0% Medium to coarse-grained (up to 5mm), subhedral to euhedral aggregates locally cut by bladed magnetite, but in overall coexistent phases. It is cut by secondary hematite-filling fractures.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Calc-SodicAlterationSilica/QuartzApatite ManetiteCarbonateMineralizationPyriteChalcopyriteCBM Mag Stage 3 Stage 4>20%10-20%1-10%<1%Quartz Sample ID: Undefined Distribution??Fine grained (0,8mm) intergrowing and as inclusions in magnetite.2.0%ChalcopyriteMineralizationSMA_AL_1709_JM_076Occurs in 2 populationsFine-grained (0,2mm), colourless, euhedral, crystals, related to secondary hematite occurrence (siderite)?1%CarbonateACBDPhotomicrographsM076. A) Microphotograph 2X, showing the differences in the quartz faces . Note the intergrowth of bladed magnetite and Quartz.. B, Same photo A, but under XPL + RL. C) Microphotograph 10X showing the occurrence of carbonate accompanied by magnetite and pyrite and siderite + hematitie late event. D) Same as microphotograph C, but under XPL + RLMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)Mag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)<Py< Bladed Mag<Qtz<Mag<Qtz<PySMA_AL_1709_JM_076CMag: 50xPL+RL0.4mm RL+PL FOV~ 441Um (Length)<CcpMag<Py<QtzMag<Qtz<Py< Bladed Mag<Qtz<Qtz<Qtz<Siderite?Hematite<Car<Car<Mag<Qtz<Py <Qtz<Siderite?Hematite<Car<CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@152.4El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_129Polished Thin section Description This sample is a microcrystalline, massive, relatively well-sorted monomictic mafic tuff (SiO2%~51 wt.%). It is mostly composed of fine to medium-grained (0.5-0.8mm) anhedral devitrified vitriclasts with recrystallization to plagioclase, chlorite and quartz. In addition, glass shards (~10%) are observed as fine to medium-grained (0.5-0.8mm), anhedral clasts with some sperulites textures. Crystals occurs as fine-grained (0.2-0.4m) sub tabular, free phenocrysts of plagioclase (~15%)Alteration intensity in the sample is low to intermediate and it is related to the occurrence of fine- to me-dium-grained (~0.4-1mm), anhedral carbonates (10%) that occurs with very fine-grained sericite (4%) and chlorite (5%). This mineralogy selectively replaces feldspar and devitrified vitriclasts. Apatite is also observed as very fine-grained (<0.1) overgrowth by carbonate and replaced by sericite. Mineralization in the sample is represented by very fine-grained <0.1mm pyrrhotite as exolutions of carbonatePETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Plagioclase 15% Fine-grained (0.2-0.4) sub tabular, colorless to brown dusty colored aggregates that occur as free crystals and as phenocrysts. Plagioclase is partially to pervasively altered to Car, and Ser. Some of the crystals still preserve their twinning.Devitrified vitriclasts 45% Fine to medium-grained (0.5-0.8mm), pale amber, anhedral clasts with recrystallization to lattice, flaky Plag? Qtz? and Chl?SMA_AL_1801_JM_129Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@152.4 within the Unit 2, TufC lithofacies in the El Alacran Deposit. This sample corresponds to a medium to fine-grained, pale-grey, weakly banded lapilli tuff, with two different compositional banding. The lapillies/fragments are anhedral to surrounded, randomly distributed and with a nominal diameter of 1mm. The goal with this sample is to characterize one representative unal-tered specimen of the TufC lithofacie. Vitroclasts 10% Fine to medium-grained (0.5-0.8mm), dark amber, and anhedral clasts with some speru-lites textures.Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 10.0% -Fine to medium-grained (~0.4-1mm), colorless, anhedral aggregates, replacing selective-ly feldspar. This intergrows with sericite and occurs as in-fill, accompanied of apatite and traces of pyrrothite. Very fine-grained, colorless, flaky aggregates intergrowing with carbonate and selectively replacing feldspar and devitrified vitroclasts.4%Pyrrhotite Tr Very fine grained <0.1mm -yellow with a brownish tint, that intergrows with Car (as exolutions) *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%SericiteSample ID: Undefined Distribution??MineralizationVery fine grained- (<0.1mm), pale brown, with selective replacement after devitrified clasts.5%ChloriteSMA_AL_1801_JM_129Apatite Tr Very fine grained <0.1 -colorless, that is overgrowth and replaced by sericiteC DPhotomicrographsJM129. A) Microphotograph 10X, showing the major constitutes of the rock. Note the sperulites texture of the glassy material B, Same photo A, but under XPL + RL.C) Microphotograph 10X, showing the major alteration minerals carbonate and sericite and their relation with the Cu-sulphides D, Same photo C, but under XPL + RL.Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)SMA_AL_1801_JM_129A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Car<Sperulites<Ser<Car<Ser<Glass<Devitrified Vitriclasts<Vitriclasts<Chl<Ser<Ser<Car<Sperulites<Devitrified Vitriclasts<Vitriclasts<Chl<Ser<Ser<Ep<Ser<Car<Ser<Glass<Ep<Pyrrhotite <PyrrhotitePETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD075@207El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_109Polished Thin section Description This unit is a brecciated, poorly-sorted, clast-supported dacite breccia. It comprises two facies with the same phenocrysts mineralogy and marked variations in their matrix crystallinity. The matrix in both facies constitutes their 30%. The Facie 1 (the dark grey) is composed by very fine-grained to cryptocrystalline, anhedral glass. Whereas the other rock matrix (pale grey) is composed of fine to very fine-grained (up to 0.1mm) aggregates of angular plagioclase and quartz.The major phenocrysts in both facies correspond to fine-grained (0.4mm) tabular plagioclase (~70%). Some of the crystals do not present twining and can corresponds to possible K-Felds?. Qtz fragments occur as fine-grained, anhedral to sub rounded distributed homogenously in the sample (~3%).The alteration is relatively weak, and it is composed by fine to medium-grained (up to 1mm), anhedral aggre-gates of carbonate (~7%), very-fine grained sericite and very-fine grained (up to 0.05mm) titanite that selec-tively replace former plagioclase crystals. Albite (~5%) occurs as fine-grained (0.4mm) mineral in the pale rock facie. Chlorite occurs as pale-green fine grained (up to0.5mm), selective replacement after tabular minerals possible former hornblende. Mineralization is very week, just restricted to some sphalerite traces occurrence. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Plagioclase 70% Fine-grained (0.4mm), colorless, tabular weakly to pervasively altered to sericite and carbonate. Some of the crystals do not present twining, possible K-Felds?Matrix 30% Matrix 10% 2 types:1: Very-fine grained to cryptocrystalline, anhedral, brownish , glassy matrix2: Fine to very fine-grained (up to 0.1mm), composed of aggregates of anhedral, angular plagioclase and quartz. SMA_AL_1801_JM_109Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD075@207m within the Unit 1, RBx lithofacies in the El Alacran Deposit. This sample corresponds to a clast-supported, monomictic breccia composed of angular, medium grey-colored fragments of two cms length. It is embedded by a leucocratic matrix with visible medium-grained irregular quartz and possibly albitized plagioclase. The goal with this sample is to characterize the the samples for U/Pb age dating in zircons.Quartz 2-3% Fine grained, anhedral, surrounded to sub angular, colorless , homogenously distributed in the sample. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 7% Fine to medium-grained (up to 1mm), colorless, anhedral, replacing selectively former plagioclase crystals. Carbonate is accompanied by Tita, Ser, Rut and Sph traces.Very fine-grained, colorless, flaky aggregates intergrowing with carbonate and selectively replacing feldspar (plagioclase).2%Sphalerite Tr Very-fine grained, disseminated in the sample*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%SericiteSample ID: Undefined Distribution??MineralizationFine-grained (<0.5mm), pale-green, anhedral, with selective replacement after tabular minerals posibly hornblende TrChloriteTitanite Tr Veryfine-grained (up to 0.05mm), colorless, high-relief, euhedral aggregates intergrowing with CarSMA_AL_1801_JM_109Albite 5% Fine-grained (0.4mm), colorless, defined in the phaneritic matrix facies. It is observed as ondulatory extinction in former plagioclase aggregates. C DPhotomicrographsJM109. A) Microphotograph 10X, showing the major constitutes of the rock. Note the marked differences in matrix component in the different facies. B, Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the breccia texture and the former quartz fragments with some embayments. D, Same photo C, but under XPL + RL. E) Microphotograph 20X, showing the distribu-tion of the alteration mineralogy. Note the euhedral titanite embedded in carbonateMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Car<PlagioclasePale-grey facie<Albitizedclast<Chl<Ser<SerSMA_AL_1801_JM_109EMag: 10xXPL+RL0.4mm XPL FOV~ 2.18mm (Length)<Ser<Car<Ser<Glass<TitaDark-grey facie<Car<PlagioclasePale-grey facie<Albitizedclast<Chl<Ser<SerDark-grey facie<Car <PlagioclasePale-grey facie<Qtz<SerDark-grey facie<Glass<Qtz<Car <PlagioclasePale-grey facie<Qtz<SerDark-grey facie<Qtz<FeldsPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@51El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_073Polished Thin section Description This section corresponds to a pervasive altered volcanic rock, with destructive alteration of the former miner-als. Relictic quartz occurs as fine-grained (<0.4mm), sub angular shapes partially replaced by carbonate. The main alteration mineral correspond to fine to medium-grained (1mm), patchy carbonate (~35%) and titanite locally replacing fine-grained (up to 0.3mm) flaky radiated chlorite (~18%) that intergrows with very fine-grained (<0.05-0.1mm) aggregates of sericite (~25%).Apatite occurs in 2 generations: Ap1) Fine- to medium-grained (1mm), relictic texture after a tabular shape, possible associated with early albite/quartz. Ap1 is altered to sericite + carbonate. Ap2) Very fine-grained (0.07mm), euhedral elongated intergrowing with Car. Ab/Qtz occurs as a patchy alteration possibly earlier than the sericite-carbonate.Sericite is not altered to a later phase. The brownish stain correspond to Fe-Ox, associated with py that locally stains sericite and carbonate.Mineralization is close to 8%, and corresponds to medium-grained (2mm) aggregates of pyrite (8%), inter-growing with chalcopyrite (3%), and carbonate.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Quartz 2% Fine-grained (up to 0.4mm), colorless, anhedral, with sub angular shapes. Optically is anomalous Uniaxial - . It is partially replaced by CarbonateSMA_AL_1709_JM_073Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD025@171m in the Unit 1, RBx lithofacies of the El Alacran De-posit.This unit corresponds to a medium- to coarse-grained rhyolite/dacite breccia highly altered to sericite, chlorite and calcite. More than 60% of the sample is altered to a very fine-grained (<0.5mm) sericite possibly inter-growing with albite? (harder than usual). This seems to be replaced/cut by a medium to dark brown in color, fine-grained (<0.5mm) mineral possible biotite? that seems to be associated with the occurrence of sulphides. The sericite is also surrounded by fine (up to 1 mm in diameter) crystal aggregates of chlorite + chalcopyrite + pyrite and lesser rutile + Fe carbonate. Chlorite is rimmed by fine calcite aggregates. There is an irregular veinlet of pyrite + chalcopyrite cutting the sericite alteration. No magnetite or visible crys-tals quartz are observed. The goal with this sample is to date the sericite alteration using Ar-Ar. Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 35% Fine to medium grained (1mm), colorless, anhedral, patchy locally replacing ChlVery fine-grained (<0.05-0.1mm), pale green to colorless, flaky aggregates intergrowing with albite/qtz or scapolite? and carbonate. Appendix D2 shows the EDS composition of this specimen.25%Py+Ccp 8% Medium-grained (2mm), subhedral to anhedral aggregates, intergrowing with chalcopy-rite (3%) and carbonate.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%SericiteSample ID: Undefined Distribution??MineralizationFine-grained (up to 0.3mm), pale-green to brownish green, flaky radiated aggregates in-tergrowing with sericite and carbonate (carbonate late phase), showing some re growing rims. Appendix D2 shows the EDS composition of this specimen.18%ChloriteTitanite Tr Fine-grained (up to 0.2mm), amber dark color, euhedral , cubic shapes, intergrowing with carbonateSMA_AL_1709_JM_073Albite-Qtz 15% Fine to very fine-grained (up to 0.1mm) colorless, anhedral, to euhedral, patchy, low to medium relief, with BR higher than 1st order to lower 2nd order. Seem to be the earliest stage of mineralization. Apatite Tr Two generations. -Fine to medium-grained (1mm), colorless, high relief, relictic tex-ture after a tabular shape. This altered to sericite + car -Very fine-grained (0.07mm), colorless, euhedral elongated shape possibly intergrowing with Car. Fe-Ox 1% Cryptocrystalline aggregates staining sericite and chloriteAlterationSericite Qtz/AbChloriteCarbonateApatiteTiataniteFe-OxMineralizationPyrite??C DPhotomicrographsJM073. A) Microphotograph 10X, showing the extensive sericite alteration with chlorite replacing apatite B, Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the occurrence of carbonate with euhedral titanite accompanied of sericite and chlorite. D) Same photo C, but under XPL + RL. E) Microphotograph 5X, showing some former quartz fragments. Note some local alteration of chlorite by carbonate and sericite. F, Same photo C, but under XPL + RL.Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Chl<Relictic Ap<Ser<SerSMA_AL_1709_JM_073EMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)FMag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Chl<Relictic Ap<Ser<Ser<Chl<Relictic Ap<Ser+Car<Ser Car> <Tita<Chl<Relictic Ap<Ser+Car<Ser Car> <Tita<Chl<Former Qtz<Ser+Car<Ser Car><Tita<Former Qtz<Chl<Former Qtz<Ser+Car<Ser Car><Tita<Former QtzPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@106.30El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_043Polished Thin section Description This sample corresponds to a pervasive altered, texturally destructive sample. This is dominated by the oc-currence of fine to coarse grained (0.2 to >5mm length), acicular aggregates of actinolite (~50%) that inter-grows with fine-grained (~0.6mm), prismatic to subhedral aggregates of quartz (~10%) and fine-grained (0.2-0.6mm), pale brownish, radiated aggregates of brown chlorite (V-Mica). Carbonate (~30%) occurs as coarse grained (>5mm), anhedral aggregates that seems to be later in the sequence, but part of the same event. This intergrows with sulphides and overgrows actinolite. Traces of apatite shows evidences of being formed in an earlier stage. Mineralization is low (~3%) and dominated by medium grained (2mm) pyrite and fine to medium-grained (<1mm) aggregates of chalcopyrite with in-fill textures around Qtz. Ccp intergrows with traces of fine to very fine-grained (0.2-0.06mm) anhedral to acicular(?) aggregates of ilmenite and carbonate.Pyrite also occurs as veinlets with accompanied of quartz and carbonate. All these minerals seems to be formed during a same event with difference in precipitation timing. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD036@106.30m in the El Alacran Deposit Unit 2 and lithofacie (TufF). This sample corresponds to a fine to medium-grained volcanoclastic rock, highly-altered and miner-alized to pyrite and actinolite. The actinolite occurs in a radiated cluster up to 2cm in length. This is cut and replaced by fine-grained aggregates of amorphous, powder-like pyrite and by carbonate veins that possible accompany the occurrence of Py+Po+Ccp. The actinolite is also cut by a pinkish to reddish mineral that re-sembles to rutile and has some reddish tints that suggest some amounts of hematite. This mineral is cut by pyrite. Actinolite is not a common mineral in the deposit. This sample is intended to understand the relation of actinolite with the mineralization, preferentially with the pyrrhotite mineralization. SMA_AL_1704_JM_043Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsActinolite 50% Fine to coarse grained (0.2 to >5mm length), olive green, euhedral, acicular, aggregates, intergrowing (?) and as inclusion in Qtz. This intergrows with biotite-like mineral? And it is partially replaced by chlorite (lesser than 10%). Locally actinolite is cut by Qtz+Sulp+-CarFine-grained (0.6mm), colorless, euhedral to subhedral aggregates occurs as prismatic shapes and with variable inclusions of Act. Act seems to be latter and in other places occurs as relictic mineral. Also it is present as veinlets accompanied by Ccp + Py cutting 10%Pyrite 3% Medium grained (2mmm), anhedral aggregates , intergrowing Act and locally cutting it, along some veinlets with Qtz + Car*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4Quartz Sample ID:MineralizationCoarse grained (>5mm), colorless, anhedral, with well-developed cleavage, this inter-grows with sulphides, and over grows actinolite. 30%CarbonateZeolites Tr Very fine-grained (<0.1mm), colorless, radiated aggregates filling open spaces, accompa-nied by sulphides and Act. V-Mica 3% Fine-grained (0.2-0.6mm), pale brownish, radiated, striated, semicircular aggregates, with inclusions of Act and locally intergrowing with this mineral. V-Mica occurs with Car +sulphidesApatite Tr Fine to medium-grained (up to 1mm), colorless, anhedral to subhedral aggregates with inclusions? (3d effect?) of actinolite. However, actinolite seems to be later.SMA_AL_1704_JM_043Illmenite Tr Fine to very fine-grained (0.2-0.06mm), anhedral to acicular aggregates intergrowing with Ccp , Py and Qtz and CarChalcopyrite 2% Fine to medium grained (<1mm), anhedral , aggregates with acute infill textures around Qtz, this intergrows with Magnetite (mushketovite) AlterationIllmeniteActinoliteQuartzCarbonateV-MicaApatiteZeolitesMineralizationPyriteChalcopyrite??C DPhotomicrographsJM043. A) Microphotograph 10X, showing the relation of actinolite and quartz. Note that actinolite crosses the quartz boundar-ies. B, Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the occurrence of actinolite overgrowth by carbon-ate + chalcopyrite D, Same photo C, but under XPL + RL. E) Microphotograph 2X, showing the sizes of the actinolite crystals and some cross cutting relationship of quartz +pyrite veinlets. F, Same photo C, but under XPL + RL.Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Qtz<Act<CarEMag: 2xPL+RL2mm PPL FOV~ 11mm (Length)FMag: 2xXL+RL2mm XPL FOV~ 11mm (Length)<ChlCar<Act Car><CcpSMA_AL_1704_JM_043<Act<Py<Qtz<Act<Car<Act<Py<Act<ChlCar<Act Car><Ccp<Act<Py+Qtz Veinlet<Act Qtz><Act<Ap<Py+Qtz Veinlet<Act Qtz><Act<ApPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@106.70El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_042Polished Thin section Description This sample corresponds to a hydrothermal breccia with clasts of relictic bedded rock replaced to very fine-grained (<0.0.5mm), anhedral aggregates of quartz.This breccia is cut by two stages of quartz + sulphides bearing events. 1) Fine to medium-grained (0.3mm-1mm), sub to euhedral, with prismatic shapes as local infill textures accompanied of pyrite, chalcopyrite and fine-grained (0.7mm), chlorite (~4%). 2) Fine grained (~0.3mm), anhedral quartz with multiple inclusions of brown chlorite and very fine-grained (<0.05mm), semi acicular mineral (actinolite?) that produces as dusty coloration in the quartz . This seems to be the later event. This lies in the central part of the infill and seems to be related with the apatite occurrence. Carbonate occurs as medium to coarse-grained (~7mm), as patchy and local infill with sphalerite, pyrite and chalcopyrite as local infill and patchy in the rock. This also occurs as replacement of apatite (2%). Mineralization is dominated by chalcopyrite that occurs as medium-grained (~2mm), anhedral aggregates accompanied by carbonate and sphalerite. Occurs as the latest stage as infill texture in euhedral to prismatic Qtz and infilling some euhedral pyrite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD036@106.70m in the El Alacran Deposit Unit 2. This sample corresponds to a fine-grained volcanoclastic rock (possibly lapilli tuff) highly altered and miner-alized. The sample presents crosscutting relationships of some silice-altered clasts from a mineralized matrix. The matrix consist of an altered to biotite? FeOx tarnish? aggregates cut by carbonate. The clasts display a re-action borders from gray sericite+silica or smoky silica? to pyrite to Ccp, and cut and embedded by calcite pos-sibly with chlorite. Also chlorite veinlets are observed cutting calcite. Pyrite consists of irregular wide patchy crystals and aggregates. The ratio Ccp/Py is 60/40. The goal with this sample is to stablish the paragenesis of Py+Ca mineralization crosscutting silica-replaced clasts. SMA_AL_1704_JM_042Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 50% 3 populations -Very fine-grained (<0.0.5mm), anhedral aggregates as selective replacement of former clasts. -Fine to medium grained -grained (0.3mm-1mm), sub to euhedral, exhibit some prismat-ic shapes as local infill textures accompanied of pyrite, chalcopyrite anhedral aggregates intergrowing with fine chlorite and with inclusions of very fine-grained chlorite.-Fine grained (~0.3mm), anhedral, dusty coloration produced by multiple Chl inclusions, the borders are highly-irregular compared to the rest of quartz generation. Medium to coarse-grained (7mm), colourless aggregates that occur with sphalerite, chalcopyrite as local infill and patchy in the rest of the rock cutting and replacing apatite crystals.8%Pyrite 10% Medium-grained (4mm), subhedral aggregates occurs as infill in quartz grain boundaries and intergrowing with chalcopyrite. It present some inclusions of sphalerite. *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4CarbonateSample ID:MineralizationFine-grained (0.7mm), pale green to brown anhedral aggregates exhibiting some radiat-ed shapes. Intergrows mostly with the euhedral quartz phase. This mineral was identified in other samples and classified as V-rich mica. 4%Brown ChloriteAcicular Mineral 1% Very fine grained (<0.05mm), pale green, semi acicular in shape, occurs as inclusions in quartz.Apatite 2% Medium-grained (1mm), colorless, Euhedral to subhedral, shapes related with the occur-rence of Qtz + Chl as inclusions. This also is embedded and replaced by carbonate and SMA_AL_1704_JM_042Chalcopyrite +Sphalerite 25% Medium-grained (~2mm), anhedral aggregates that occurs with carbonate and sphaler-ite. Occurs as the latest stage as infill texture in euhedral to prismatic Qtz and embedding AlterationQuartzApatiteCarbonateChlorite (V-Mica)Actinolite(?)MineralizationChalcopyritePyriteSphaleriteCryptocrystalline Dusty-Incl of Act+V-Mica PrismaticC DPhotomicrographsJM042. A) Microphotograph 5X, showing the paragenetic relation of the different quartz events. B, Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the occurrence of cockade quartz with CBM mineralogy (Carbonate –Sphalerite-Chalcopy-rite). D. Same photo C, but under XPL + RL.E) Microphotograph 5X, showing brecciated pyrite embedded by carbonate and brownish chlorite. Note the alteration of Apatite by carbonate. F, Same photo C, but under XPL + RL.Sample ID:A BMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)EMag: 2xPL+RL2mm PPL FOV~ 11mm (Length)FMag: 2xXPL+RL2mm XPL FOV~ 11mm (Length)SMA_AL_1704_JM_042<Ccp<Qtz1<Py<Qtz2<Py<Ccp<Qtz1<Py<Qtz2<Py<Ccp<Qtz1<Py<Qtz3<Py<Car<Ccp<Qtz1<Py<Qtz3<Py<Car<Ccp<Ap<Py<Qtz3<Py<Car<Car<Ap<Ccp<Ap<Py<Qtz3<Py<Car<Car<ApMag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Ap Ap><Ap<SphPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@113.4El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_041Polished Thin section Description This sample corresponds to an ore-bearing vein composed of more than 60% of coarse-grained (~8mm) Fe-rich sphalerite that intergrows and locally crosscuts fine to medium-grained (up to 1mm), anhedral aggregates of chalcopyrite (15%) and medium-grained (up to 3mm) anhedral aggregates of carbonate (~20%). These three minerals together are embedding some euhedral pyrite traces.Small amounts of chlorite (~1%) occurs as very fine-grained (<0.1mm) flaky aggregates accompanied by very fine-grained (0.04mm) aggregates of molybdenite. Neither gold nor quartz, sericite-titanite were observed in the sample. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the drillhole ACD036@113.4m in the El Alacran Deposit Unit 2. The hostrock con-sists in a diorite dike (Sill 1) that host the calcite + sphalerite + VG vein (more than 5kg /ton Au). This sample corresponds to an ore vein of sphalerite 60% Ccp 30% and carbonate. This vein has an open space texture with a general growing from wall to within the vein. As initial mineral was chalcopyrite then it was filled and cut in the vein center by sphalerite and lately a carbonate + chlorite in-fill that concordantly cut the previous minerals. A 9/1 proportion of Ccp/Py. The goal with this sample is to define the paragenesis of the visible gold generation. SMA_AL_1704_JM_041Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSphalerite 60%Coarse-grained (8mm), dark grey (Fe-rich sphalerite) with multiple IR, associated to the crystals growth. This intergrows and locally cross-cuts the chalcopyrite Medium-grained (up to 3mm), anhedral aggregates intergrowing with sphalerite and embedding some euhedral pyrite traces.20%*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4Carbonate Sample ID:MineralizationFine to medium-grained ( up to 1mm), anhedral aggregates inter-growing with sphalerite and embedding some euhedral pyrite traces15%ChalcopyriteChlorite 1% Fine to very fine-grained (<0.1mm) medium green to pale, flaky aggregates that occurs in the vein along with Car + sulphides SMA_AL_1704_JM_041Pyrite Tr Very fine-grained (<0.1mm) , euhedral , embedded in the carbonate vein.AlterationCarbonateChloriteMineralizationChalcopyritePyriteSphaleriteMolybdeniteArsenopyrite/ Cobaltite?Arsenopyrite/ Cobaltite? Tr Very fine-grained (40 μm) , euhedral , embedded in the carbonate vein. This locally altered by sphalerite. (See Appendix D2). This present anomalous Sb, and Ni content. C DPhotomicrographsJM041. A) Microphotograph 10X, showing the chalcopyrite disease texture in sphalerite. B. Intergrowing of chlorite, chalcopyrite, sphalerite and carbonate. C) Microphotograph 2X, showing the zoned composition of the sphalerite that produce differences in the internal reflections. Note also some late stage of car cutting the sphalerite. D. Same photo C, but under XPL + RL. E) Micro-photograph 50X under XPL + RL, showing the distribution of the molybdenite in relation to the chlorite. Sample ID:A BMag: 10xXPL+RL0.4mm XPL FOV~ 2.18mm (Length)EMag: 2xPL+RL2mm PPL FOV~ 11mm (Length) Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length)Mag: 10xXPL+RL0.4mm XPL FOV~ 2.18mm (Length)Mag: 50xXPL+RL0.08mm XPL FOV~ 441Um (Length)<Ccp<CarSph<Chl<MoSMA_AL_1704_JM_041<Ccp<Ccp<CarSph<Ccp<Chl<Car<Sph<Fe-rich Sph<Car<Car<Sph<Fe-rich Sph<Car<SphPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD055@130.40El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_105Polished Thin section Description This sample corresponds to a highly altered rock dominated by the occurrence of two events of quartz con-trolled by the rock banding. Qtz 1: Corresponds to a fine to medium-grained (up to 2m) anhedral with multiple inclusions of an acicular amphibole? . This intergrows with medium-grained (~2mm), brown chlorite(?) and medium-grained (up to mm), euhedral apatite. Amphibole and apatite are selectively replaced by carbonate. Qtz 2: Corresponds to a very fine grained (<0.05mm) to fine grained (0.2mm) anhedral to prismatic aggregates with no inclusions, accompanied of medium to coarse-grained (up to 5mm) pyrite, chalcopyrite, sphalerite and carbonate (~10%). No sericite is observed in this samplePETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD055@130.40m within the Unit 2, in an unknown lithofacie (Pos-sibly TufC) of the El Alacran Deposit. This sample corresponds to high-grade zone with a banded structure. One of the bands is composed of Py80%/Ccp10% and apatite aggregates. Other band comprises silica + carbonate ± ?Biotite (oxided sericite+chlorite?). Within this band, a light pink carbonate occurs with the silica. The silica seems to be postdate the Py crystals. The goal with this sample is to verify the occurrence of biotite? and its relation to the bladed magnetite.SMA_AL_1801_JM_105Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 35% -Qtz1: Fine to medium-grained (up to 2m), colorless, anhedral aggregates that contain inclusions of an acicular amphibole-Qtz2: Very fine-grained (<0.05mm) to fine-grained (0.2mm) anhedral to pris-matic, non-inclusions aggregates, accompanied of Py, Ccp, and Shp . The contact with Qtz1 , seems to be controlled by banding composition.Pyrite 20% Medium grained to coarse-grained (up to 5mm), anhedral aggregates intergrows after Qtz 2, accompanied by Ccp*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4Sample ID:MineralizationV-Mica 5% Medium-grained (2mm), brown to pale yellow, non pleocroic, striated to flaky , with BR of 1st order. This is replaced selectively by Car. This phase has been identified as V-mica in other samples (JM065 Appendix D2)Apatite 1% 2 generations1: Medium-grained (up to 1mm), colorless, euhedral aggregates, intergrowing with V-Mi-ca-Qtz1+Amph. It is replaced by a Fe-stained? Carbonate 2. Very fined-grained, colorless, euhedral, as inclusion of Qtz 1SMA_AL_1801_JM_105Carbonate 10% Coarse-grained (>5mm), colorless, anhedral aggregates, replacing AmphiboleAmphibole 2% Fined o medium grained up to 1m, pale green to colorless (Actinolite-Tremolite?), acicu-lar elongated crystals that crosses the Qtz 1 borders. They are selectively replaced to Car. This mineral was tested under EDS, and obtained a Mg-Fe-Si composition (Appendix D2.)Chalcopyrite Tr Medium grained (1.2mm), anhedral , intergrowing with Sph and Car Sphalerite Tr Fine to very fine grained (<0.1mm), anhedral , intergrowing with Ccp AlterationQuartzAmphiboleVa-MicaApatiteCarbonateMineralizationPyriteChalcopyriteSphaleriteC DPhotomicrographsJM105. A) Microphotograph 10X, showing the inclusions of acicular actinolite (?) in the carbonate and quartz 1. B, Same photo A, but under XPL + RL.C) Microphotograph 10X, showing the occurrence of V-Mica in relation to the occurrence of Qtz 1. Note the euhedral crystalline phase of apatite as inclusion D, Same photo C, but under XPL + RL.E) Microphotograph 5X, showing the contrast between the quartz 1+ apatite + V-Mica with the quartz 2 + sulphides. F, Same photo C, but under XPL + RL.Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length)Sample ID:XPL FOV~ 2.18 mm (Length)A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Py<Relictic Ac?<CarEMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)FMag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)SMA_AL_1801_JM_105<Qtz1<Py<Relictic Ac?<Car<Qtz1<Py<Relictic Ac?<Car<QtzAp>Ap><V-Mica<Py<Relictic Ac?<Car<Qtz1Ap>Ap><V-Mica<Py<Qtz1Ap>Ap><Brown Chl<Qtz2<Sph<Py<Qtz1Ap>Ap><Brown Chl<Qtz2<SphPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA017@158El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1705_JM_063Polished Thin section Description This sample corresponds to a highly-altered, banded rock with two populations of quartz (~35%): 1) Fine-grained (<1mm), dusty colored anhedral aggregates with multiple mineral inclusions of acicular elongated mineral (actinolite?). This intergrows with fine to medium-grained (1.2mm) apatite and fine-grained (up to 1mm), flaky to radiated brown chlorite (V-Mica) (~30%). 2) Medium-grained (1-2mm), euhedral, prismatic aggregates that intergrows with fine to medium-grained (1mm) carbonate.Mineralization is mostly related to the second event of quartz. This is dominated by fine to medium-grained (up to 1mm), pyrite (3%) and 1% of fine-grained (0.9mm), anhedral chalcopyrite and fine-grained (0.2-0.5mm) sphalerite. This occurs with carbonate that replaces apatite and chlorite suggesting this event is the later.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA017@158m in the Unit 2, TufC lithofacies of the El Alacran Depos-it. This correspond to a pervasively altered and partially mineralized sample that exhibit some relictic texture of coarse laminated tuff.The sample presents at least eight <1cm-width bands. The bands corresponds to calcite separated one from another by some dark-green to reddish minerals with well formed hexagonal shapes. Although this hexagonal minerals are distributed in all the sample, they tend to be located in the layers bound. Pyrite is the dominant mineral and it is mostly distributed in one of the bands. The goal is to characterize the nature of this mineral that resembles to almandine garnet. SMA_AL_1705_JM_063Mineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsQuartz 35% Occurs in 2 populations.-Qtz1: Medium-grained (1-2mm), colorless, euhedral, prismatic aggregates imbedded in carbonate.-Qtz 2: Fine-grained (<1mm), dusty colored, anhedral aggregates, with multiple mineral inclusions of prismatic elongated mineral (Act?), this intergrows with apatite and V-MicaPyrite 3% Fine to medium-grained (up to 1mm), anhedral to subhedral aggregates that occur as Qtz 2 interstices in-fill.*Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4Sample ID:MineralizationV-Mica 5% Fine grained (up to 1mm), pale to dark brown (pleocroic), flaky to radiated aggregates, possibly intergrowing with quartz? (given some mineral inclusions in Qtz . Also it is seen formed in the periphery of reddish sperulites chloriteChlorite 25% Fine-grained (up to 1mm), pale to dark brown, flaky to radiated aggregates, intergrowing with Qtz2? And locally cut by carbonate. Present Lower 1st order interference.Carbonate 25% Fine to medium-grained (1mm), colourless, cleavage observed, intergrowing with pris-matic Qtz, and replacing apatite. This is concentrated in 2 banded in the samplesChalcopyrite Tr Fine-grained (0.9mm), anhedral aggregates that occurs as interstices in-fill in quartz. This encloses some euhedral traces of pyrite. Sphalerite Tr Fine-grained (0.2-0.5mm), dark grey with multiple IR, , anhedral aggregates intergrowing with CcpSMA_AL_1705_JM_063Apatite 2% Fine to medium-grained (1.2mm) length, colorless, aggregates, texturally destructive altered to car.AlterationCarbonateQuartzV-MicaChloriteApatiteMineralizationPyriteChalcopyriteSphalerite??C DPhotomicrographsJM063. A) Microphotograph 10X, showing the alteration evidences of carbonate+titanite after Qtz1+Ap+V-Mica. B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the occurrence Qtz2 accompanied by pyrite and overgrowing apatite and Qtz1. D) Same photo C, but under XPL + RL. E) Microphotograph 5X, showing the radiated brownish mineral. Note the border composition differes to the central part. Note also the intergrowth textures with the surrounding Qtz 1. F) Same photo C, but under XPL + RL.Sample ID:A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<CarEMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)FMag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Py<Relictic Ac?<Car<Qtz2Ap>Ap><Qtz2<Qtz1 Bio?>Car>SMA_AL_1705_JM_063Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Qtz1<Ap<Car<Car<V-Mica<Qtz1<Ap<Car<Qtz1<Py<Relictic Ac?<Car<QtzAp>Ap><Qtz1Ap><Qtz1 Bio?>Car><Qtz2 V-Mica V-Mica<V-Mica<V-Mica <V-MicaV-Mica V-MicaPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD079@81.20El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_108Polished Thin section Description This sample corresponds to a fine holocrystalline rock, with porphyritic texture. The groundmass constitutes about 70% of the sample, the preserved phenocrysts corresponds to fine-grained (0.5-1mm) euhedral to sub-hedral plagioclase (~5%).The sample alteration intensity is medium to low, defined by the occurrence of fine-grained (~0.1-0.2mm) (quartz >> albite) in intergrowth with fine-grained (>0.2mm) pale-green chlorite (8%). Chlorite also inter-grows with fine to medium-grained (1mm) anhedral aggregates of apatite that is replaced by fine-grained carbonate (3%). This carbonate also intergrows with zoisite and epidote and minor chlorite. Carbonate is also present as veinlets up to 0,1mm width, accompanied of titanite and traces of chalcopyrite. Mineralization occurs as fine to medium-grained (<1mm) isolated aggregates of pyrite (2%) accompanying chlorite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD079@81.20m within the Unit 2, in the Sill 2 in the El Alacran Deposit. This corresponds to a pale-green, altered micro-diorite. This present a groundmass pervasively al-tered to albite and minor carbonate. Some mafic minerals up to 2mmm in length are altered to chlorite and pyrite. Pyrite seems to be rimming chlorite but in some places shows a opposite relation. A Medium to dark brown mineral occurs as fractures filling that cut the rock. . The goal with this sample is to characterize the Ab+Chl+brownish alteration in Sill2Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase (Phenocrysts)70.0%5.0%Fine-grained (0.1mm) groundmass composed mostly of Plagioclase and minor quartzFine to medium-grained (0.5-1mm) dusty-brownish coloration, euhedral to subhedral tabular phenocrysts. In some crystals, the twining has disappeared for the intensity of the alteration. This is altered to chlorite, Alb and minor QtzPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_108Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 3.0%-Fine-grained (0.1-0.2mm) colourless, anhedral aggregates replacing plagioclase and quartz. It intergrows with zoisite and epidote minerals. -Veinlets up to 0,1mm width, accompanied of Tita and traces of Ccp UknownM - Very fine grained (<0,05mm) cryptocrystalline clay as product of alteration of plagioclase and albite. No distinguish optic properties. (This displays a FeOx Staining)Titanite Tr Fine-grained (<0.1mm), colourless, anhedral aggregates with high relief and accompa-nied by carbonate. Apatite Tr Fine to medium-grained (1mm), colorless, anhedral, aggregates , replacing Plag, accom-panied of Chl and embedded by CcpPyrite 2% Fine to medium-grained (<1mm) anhedral, isolated aggregates accompanying chlorite and with elongated minerals inclusions (possibly Ap).* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Chlorite12.0%8.0%Fine-grained (~0.1-0.2mm), colourless, sub-rounded aggregates in intergrowth with chlorite and disseminated in the rock groundmass.Fine-grained (>0.2mm) anhedral, pale green, anhedral aggregates with a random distri-bution in the sample. It replaces plagioclase and inter-grows with titanite and apatiteSMA_AL_1801_JM_108QuartzC DPhotomicrographsJM108. A) Microphotograph 10X, showing the distribution of the former rock minerals. Also the occurrences of Ep-Zoisite Chlorite associated with carbonate. B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing former plagioclase altered to chlorite. Note the Chl+Qtz+Ab alteration in the rock groundmass. D) Same photo C, but under XPL + RL. E) Microphotograph 10X, showing former plagioclase altered to chlorite and dusty brownish alteration (UknownMin). F) Same photo E, but under XPL + RL.Sample ID:A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)E FMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<QtzSMA_AL_1801_JM_108Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Zoisite<Epidote<Car<Chl<Plag<Qtz<Zoisite<Epidote<Car<Chl<Plag<Qtz <Chl<Plag<Plag<Qtz<Chl<Plag<Plag<Qtz<Chl<Plag<Plag<UknowMin<Qtz<Chl<Plag<Plag<UknownMinPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD054@257.7El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_116Polished Thin section Description This sample corresponds to a well-sorted, fine to coarse-layered (up to 6mm) chemical sedimentary rock with minor occurrences of vitriclasts. Layers are exclusively composed of fine to very fine-grained (1mm-0.05mm), euhedral carbonate (~97%) with primary granoblastic texture. Crystals sizes vary from layer to layer and pres-ent some local FeOx staining along the layers boundaries. Traces of fine-grained (up to 0.1mm), elongated shards are Interlayered with the carbonate.Alteration is weak to absent and occurs as fine-grained (0.1-0.2mm width) carbonate veinlets bearing fine to very fine-grained sphalerite, chalcopyrite and pyrite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD054@257.7m ontop of the Unit 2, MudSil lithofacies in the El Alacran Deposit. This corresponds to a fine-grained grey-pale to dark brownish, fine-laminated siltstone. To date this sample is the least altered sample collected from the MudSil lithofacies that is suggested to be the protolith of the banded magnetite replacement at the El Alacran Deposit. The goal with this sample is to char-acterize by petrography of unaltered laminated Mudsil specimen.Mineral Modal Textural and Mineral DistributionRock-forming mineralsCarbonateVitriclasts97.0%TrFine to very fine-grained, colorless, euhedral, granoblastic texture (primary). The size varies from layer to layer. This is stained in some layers by Fe-Ox Fine-grained (up to 0.1mm), amber colored, elongated shards? Interlayered with the carbonate.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_116MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsSphalerite + Ccp 1% Fine to very fine-grained, anhedral aggregates, showing intergrow-ing and exolutions textures (Disease) in the Sph. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite 1% Fine-grained (0.1-0.2mm width), colorless, euhedral aggregates occurring as a veinlet bearing Sph +Py+Ccp. Carbonate C DPhotomicrographsJM116. A) Microphotograph 2X, showing the rock layered structure and the differences in gran size. Not the carbonate + sphaler-ite veinlet crosscutting the sequence. B, Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the some occur-rences of welded (?) vitriclasts and some disseminations of sphalerite. D, Same photo C, but under XPL + RL. Sample ID:A BMag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)<Sph+Ccp<Car<Vitriclast<SphSMA_AL_1801_JM_116Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)Very Fine-grained CarFine-grained Car<Sph+Ccp<CarVery Fine-grained CarFine-grained CarVery Fine-grained CarFine-grained Car<Vitriclast<SphVery Fine-grained CarFine-grained CarPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD034@269El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_115Polished Thin section Description This section corresponds a contact zone between a porphyritic, amygdaloidal basalt and a fine to very fine-grained sandy-pyroclastic material. The crystalline phase presents a fine to very fine-grained groundmass (~25%) composed of plagioclase and rutile. Whereas, phenocrysts include fine to medium-grained (up to 1mm length) plagioclase (~25%).Alteration intensity is medium to strong, and it is dominated by he occurrence of very fine-grained (<0,01mm) aggregates of albite (~25%) intergrowing with very fine-grained quartz and chlorite. Chlorite (~15%) occurs as fine-grained (0.1mm), patchy, selective replacement after former euhedral crystals and amygdals-filling in the basaltic material, whereas it intergrows albite, quartz and rutile in the sandy-pyroclastic material. Rutile (~10%) occurs as very fine-grained, irregular aggregates rimming titanite associated with medi-um-grained aggregates (<2mm) carbonate (~3%) and sericite that selective replaces plagioclase. Mineralization occurs as traces of very fine-grained disseminated pyritePETROGRAPHY REPORTv. APRIL 2018Sample ID:Mineral Modal Textural and Mineral DistributionRock-forming minerals Percentages do not add to 100% as primary minerals are almost completely Replaced. Percentages shown to estimate relative percentages of primary crystals. Groundmass 25% Fine to very fine-graine groundmass, composed of plagioclase and rutile.Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD034@269 within the Unit 3, lithofacie TufA in the El Alacran De-posit. This corresponds to a green to pale green, peperite. It is composed of coherent lava phase with irregular amygdals that are replaced to chlorite. These intergrows with sericite, calcite, and traces of pyrite. A brownish mineral rims the chlorites. The fine-grained phase corresponds to Chl+Sericite in the rock. This probably was a fine tuff or tuffaceous sediment. The goal with this sample is to define the paragenesis of sericite + chlorite alteration in peperite.SMA_AL_1801_JM_115Phenocrysts Plagioclase25% Fine to medium grained (up to 1mm) , brownish dusty colored, with twnining evidence. This is if partially to pervasive altered to Car and SerMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsAlbite 25% Very fine-grained (<0,01mm) aggregates pervasive destructive texture, intergrowing with very fine-grained quartz? and chlorite. It presents ondulatory extinction and lower relief compared with Qtz. Also it is dusty colored. This occurs mostly in the very fine-grained rocks and it is altered to carbonate and sericite.Pyrite Tr Very fine-grained aggregates disseminated in the sample *Size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Po= Pyrrhotite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1%Sample ID: Undefined Distribution??MineralizationRutile 10% Very fine-grained, irregular aggregates of reddish brown, dusty texture rimming after titanite and related with carbonate. Light grey birefringence, opaque mineral. Carbonate 3% Medium-grained aggregates (<2mm), selectively replacement after plagioclase. Also as infill in the rock vesicles. This is mostly associated with crystalline rock associated with sericite and titanite traces. Chlorite 15% Fine-grained (0.1mm), pale-green, anhedral occurs as patchy and as selective replace-ment after rock-former euhedral crystals (Crystal Tuff?). In the fine-grained phase chlo-rite intergrows with Ab+Qtz+Rut, whereas, it is pervasive replacing/filling rock cavities. Carbonate locally altered the chlorite. Sericite Tr Fine-grained (0.1μm) pale-green to colourless, flaky aggregates associated with carbon-ate and replacement after plagioclase. SMA_AL_1801_JM_115C DPhotomicrographsJM115. A) Microphotograph 10X, showing the major components of the basaltic material. Note the brown dusty, pervasive alter-ation in plagioclase. B, Same photo A, but under XPL + RL.C) Microphotograph 5X, showing the contact zone that define the peperite texture between the basaltic material and the fine grained sandy-pyroclastic material. D, Same photo C, but under XPL + RL.Sample ID:A BMag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)<Plag<Chl?Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Ser<Car <Gmass<Chl?SMA_AL_1801_JM_115< amygdal<Plag<Chl?<Ser<Car <Gmass<Chl?< amygdal<Plag<Chl?<Ser<CarBasalt<Chl?< amygdalSandy-Pyroclasticmaterial<Plag<Chl?<Ser<CarBasalt<Chl?< amygdalSandy-PyroclasticmaterialPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA11@43.11El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_038Polished Thin section Description This section corresponds to a tuffaceous rhyodacite rock, composed of fine-grained k-feldspar (~30%), fine to very-fine grained sub-angular aggregates of quartz (~2%) and fine-grained plagioclase aggregates.Alteration is dominated by fine to very fine-grained dark-green chlorite that is locally replaced by patchy carbonate (20%), fine-grained sericite (8%) and traces of very fine-grained titanite. Fine to very fine-grained remnants of bladed magnetite (mushketovite) crystals replaced by carbonate and locally by pyrite. Also is ob-served as syngenetic inclusions in pyrite that possibly defines another stage of Py rich in magnetite.The mineralization in this sample corresponds fine-grained (<1mm), euhedral aggregates of pyrite that occurs with carbonate chlorite and quartz replacing the magnetite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA11@43.11m in the El Alacran Deposit Unit 2 and TufC lithofacies. This sample corresponds to a fine to medium-grained crystal tuff, mostly with plagioclase crystals embedded in a fine chlorite alteration. The alteration it is mostly consists of fine grains of chlorite and minor biotite(?) in the groundmass. There is an acicular mineral probably rutile that replaced previous bladed mineral (mush-ketovite?) since there are some reddish relictic material around this. In addition, this bladed mineral occurs along with carbonate, and cubic pyrite and the sample also has sericite accompanied chlorite and albite. Min-eralization, consist principally of pyrite up to 1,5cm-size intergrowing with calcite. The goal with this sample is to Identify via petrography if the rutile is replacing relictic mushketovite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase 50.0%30.0%Very fine-grained composed of acicular amphibole, pyrrhotite and very fine-grained brownish aggregates (biotite?)Fine-grained (0.3mm), with a pale-brown dusty coloration, tabular shapes, subhedral to anhedral replaced to sericite and carbonate. The 20% of the crystals/fragments exhibit twining. Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Quartz 2.0% Fine-grained (0.8mm), irregular, sub angular to sub-rounded aggregates that occurs as microphenocrysts SMA_AL_1704_JM_038Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 20%Fine-grained aggregates (0.3-0.5mm), colorless, anhedral patchy aggregates altering pla-gioclase, bladed magnetite and locally chlorite it is accompanied by titanite. Also occurs as infill in chloritePyrite 3% Fine-grained (<1mm), euhedral aggregates occurs with carbonate chlorite and quartz replacing the magnetite* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Sericite35%8%Fine to very fine-grained (<0.5mm), flaky, dark-green, selectively replacement the rock groundmass and locally replaced by carbonate and sericiteVery fine-grained (<0.05mm) flaky aggregates. Pale green to colourless, selective replace-ment after former plagioclase and k-feldspar?. Occurs with carbonate.ChloriteSMA_AL_1704_JM_038Titanite TrFine to very fine grained (0.1mm), subhedral to euhedral grains, , occurs within frag-ments as patchy alteration accompanied by carbonate Magnetite TrFine to very fine grained (<0.1mm) , anhedral remnants of a bladed crystals replaced by carbonate and locally by pyrite. Also is observed as inclusions in Py that possibly defines another stage of Py rich in MagnetiteAlterationChloriteSericiteCarbonateTitanite MagnetiteQuartzMineralizationPyriteC DPhotomicrographsJM038. A) Microphotograph 5X, showing a relictic bladed magnetite (mushketovite) replaced by carbonate and pyrite. B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the selective replacement of chlorite in the groundmass and the quartz rich breccia texture of the former rock. D) Same photo C) but under XPL + RL. E) Microphotograph 10X, showing the selec-tive replacement of primary plagioclase by carbonate and sericite. F) Same photo E, but under XPL + RL.Sample ID:A BE FMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Musk<Car<Py<Plag<Py<PlagSMA_AL_1704_JM_038Mag: 10xPL+RL0.4mm Mag: 10xXPL+RL0.4mm PPL FOV~ 2.18mm (Length) XPL FOV~ 2.18 mm (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Chl<Musk<Car<Py<Plag<Py<Plag<Chl<Chl<Car<Py<Qtz<Py<Py<Chl<Plag<Chl<Car<Py<Qtz<Py<Py<Chl<Plag<Chl<Car<Py<Py<Chl<Plag<Musk<Chl<Car<Py<Py<Chl<Plag<Musk<Ser<SerPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD009@62.2El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_039Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD009@62.2m in the El Alacran Deposi Unit 2 and MudSil litho-facies. This sample corresponds to a fine-grained, highly chloritized tuff. This rock hosts a carbonate, rutile, sphalerite and chalcopyrite vein up to 1,5 cm wide. From wallrock to within the vein, the sample displays a white sericite halo with minor chlorite, probably intergrowing with apatite, sphalerite and chalcopyrite. In a later stage, it was reopened to introduce calcite, since all the minerals are cut and embedded by calcite. Some isolated crystals of rutile accompanied by sericite and chlorite. The goal with this sample is to define the par-agenesis of a CBM vein with sericite? Halo that is not common in the deposit. The mineralization in this sample corresponds Fine-grained (<1mm), euhedral aggregates of pyrite that occurs with carbonate chlorite and quartz replacing the magnetite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Polished Thin section Description This section corresponds to a fine-grained tuffaceous rock, with no evince of primary mineral occurrence. The sample is cut by a quartz carbonate sulphide vein.The vein and host rock alteration is dominated by quartz, which occurs in two different populations: 1) Medi-um-grained prismatic aggregates as filling vein. 2). Fine-grained anhedral aggregates that present local alter-ation of sericite in the host rockCarbonate occur also along the vein as coarse-grained crystals that intergrow with Ccp + Shp and as (0.1mm) width veining that cut all the vein mineralogy. Fine to very fine-grained, dark amber titanite occurs with car-bonate, and sericite. Mineralization is dominated by chalcopyrite (~30%), that intergrow with carbonate, sphalerite and pyrite. The sphalerite displays a exsolution of chalcopyrite (disease texture). Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1704_JM_039Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 4%Fine-grained (0.2mm), pale green, anhedral, radiated aggregates intergrowing with Qtz 2. This is cut and locally replaced by carbonate. This occurs as a patchy aggregates in the hostrock and minor within the vein.Chalcopyrite 30%* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate 40.0%15%2 Populations -(proximal) Medium-grained (up to 2mm), colorless, euhedral prismatic aggregates that denote a cockade growing texture in a carbonate in-fill vein. - Fine-grained (<1mm), dusty coloration, anhedral aggregates that occurs as hostrock alteration. This present replacement of sericiteCoarse-grained (8mm), colorless aggregates with cleavage intergrowing with Ccp + Shp and in-filling Qtz 1. QuartzSMA_AL_1704_JM_039Titanite 2%Fine to very-fine grained (up to 0.1mm) dark amber, euhedral aggregates accompanied by carbonate, cutting Qtz 2, accompanied by sericite and carbonate.Sericite TrVery fine-grained (<0.1mm) pale-green, flaky aggregates accompanied by carbonate, replacing Qtz.Sphalerite 10%Pyrite TrCoarse-grained (2cm), anhedral aggregate intergrowing with sphalerite and pyriteCoarse-grained (10mm), anhedral aggregate intergrowing with carbonate and pyrite. It present a texture disease with chalcopyriteMedium to fine grained (1-3mm), sub to euhedral aggregates enclosed by chalcopyrite and cut by Car veinletsAlterationQuartzChloriteCarbonateTitaniteSericiteMineralizationChalcopyriteSphaleritePyrite ??C DPhotomicrographsJM039. A) Microphotograph 2X, showing the open-space texture with prismatic quartz in the center and anhedral quartz in the host rock. Note a late carbonate vein event that cut the sphalerite-bearing vein. B) Same photo A, but under XPL + RL. C) Micro-photograph 5X, showing the dusty coloration in the quartz produced by chlorite inclusions. D) Same photo C, but under XPL + RL. Sample ID:A BMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Car<Car<Ccp<Sph<QtzSMA_AL_1704_JM_039Mag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)<Car<Chl+Ser<Car<Car<Ccp<Sph<Qtz<Car<Chl+Ser<Car<Ccp<Qtz<Qtz<Ser<Chl<Qtz<Py<Car<Ccp<Qtz<Qtz<Ser<Chl<Qtz<PyPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA09@104.87El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_040Polished Thin section Description This section corresponds to a fine-grained crystal (?) tuff rocks with visible subhedral tabular aggregates of plagioclase. This rock is cut by a carbonate + mushketovite + sulphide vein with specularite and hematite host rock alteration. The vein is composed by coarse-grained (>2cm), magnetite with specular habit aggregates embedded in a coarse-grained carbonate. Carbonate also occurs as fine-grained, anhedral aggregates in the hostrock and as destructive alteration after magnetite and flaky radiated chlorite. Chlorite occurs as aggregates that infill the bladed magnetite and is replaced by carbonate. Mineralization occurs as medium to coarse-grained (up to 5mm) aggregates of chalcopyrite (8%) developed along the magnetite margins. This intergrows with fine-grained (up to 1mm), anhedral aggregates of pyrite that also occurs as a late stage accompanied by carbonate. The mineralization in this sample corresponds Fine-grained (<1mm), euhedral aggregates of pyrite that occurs with carbonate chlorite and quartz replacing the magnetite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA09@104.87m in the El Alacran Deposit Unit 2 and TufF lithofacies. This sample corresponds to a fine-grained rock possibly fine-grained tuff highly chloritized (and epidotized?) that hosts a carbonate-mushketovite-chalcopyrite-pyrite vein. The vein halo consist of fine grained crystals of mushketovite replaced by hematite as well as an increase of the carbonate content .There seems to be two calcite events. 1) White calcite, that seems to intergrowth with mushketovite, although possible cut by this one. 2) Pristine veinlets of calcite that cuts the calcite in the mineralization. The sulphides correspond to a 9/1 proportion of Ccp/Py that seems to be cut by the mushketovite in intergrowing with Calcite 1. The goal with this sample is to define the paragenesis of a Musk+Ccp+Ca Vein that is uncommon in the deposit. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPlagioclase Tr Fine-grained (1mm) , dusty colourless, subhedral tabular aggregates in the host rock.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1704_JM_040Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsClay±Chl 7%Very fine-grained (<0.01mm), pale green to brownish green, anhedral aggregates, texturally destructive alteration in the magnetite. This is accompanied by a late stage carbonate. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate40.0%35%Coarse-grained (>2cm), dark grey (magnetite), aggregates embedded in a car vein. This intergrows and is overgrowth by Ccp and Py 3 generations.Car1_Coarse-grained, colorless, with marked cleavage. Intergrows with ccp and pyCar2_fine grained colorless, hosted in veins.Car3_Fine grained, anhedral, dusty colourless, aggregates and in the host rock as de-structive alteration after magnetite and locally after the Chl and clay+chl alteration. Mushketovite (Bladed Magnetite) SMA_AL_1704_JM_040Titanite TrFine grained (>0.1mm), pale green, flaky radiated aggregates that infill the magnetite and is replaced by Car3Chalcopyrite 8%Medium to coarse-grained (up to 5mm), anhedral to subhedral aggregates developed along the magnetite margins and as in-fill in the magnetite blade interstices Pyrite TrFine grained (up to 1mm), anhedral aggregates intergrowing with chalcopyrite and local-ly cutting when accompanied by Car2AlterationMushketoviteChalcopyriteCarbonateClay±ChlChloriteMineralizationPyrite ?? ??C DPhotomicrographsJM040. A) Microphotograph 2X, showing the intergrowing of mushketovite with carbonate and the later replacement by yellow chlorite-clay. B, Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the interstitial intergrowth of chalcopyrite + pyrite and carbonate after the mushketovite crystals. D, Same photo C, but under XPL + RL. Sample ID:A B<Musk <CarSMA_AL_1704_JM_040<Chl+ClayMag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)<Chl+Clay<Chl+Clay<Car<Car<Musk<Musk <Car<Chl+Clay<Chl+Clay<Chl+Clay<Car<Car<Musk<Musk<Car<Py<Chl+Clay<Chl+Clay<Car<Ccp<Musk<Musk<Car<Py<Chl+Clay<Chl+Clay<Car<Ccp<MuskMag: 2xPL+RL2mm Mag: 2xXPL+RL2mm PPL FOV~ 11mm (Length) XPL FOV~ 11 mm (Length)PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA11@96El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_044Polished Thin section Description This sample corresponds to semi-massive ore composed of ~40% of coarse to medium-grained carbonate that occurs as in-fill around very fine to fine-grained anhedral to prismatic quartz (4%). The quartz is accompanied by medium to fine-grained specular hematite (10%) and euhedral crystals of magnetite (5%) locally replaced? by carbonate. Very fine-grained dark-green, radiated chlorite occurs as an early stage that intergrows with magnetite, apatite and it is replaced by carbonate.Mineralization is dominated by pyrite that occurs as subhedral aggregates that is locally cut by fine-grained (0.7mm), anhedral aggregates chalcopyrite. The mineralization in this sample corresponds to a fine-grained (<1mm), euhedral aggregates of pyrite that occurs with carbonate chlorite and quartz replacing the magne-tite.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA11@96m in the El Alacran Deposit Unit 2 and TufL lithofacies. This sample corresponds to semi-massive mushketovite zone intergrowing with calcite and chlorite. Giving the shape of some chlorite selective replacement the possible parental rock corresponds to a medium-grained lithic tuff. In general the mineralization corresponds to a an overgrowth of calcite with fine grained mushke-tovite and chlorite and chalcopyrite 5%. The goal with this sample is to characterize replacement style occur-rence of musketovite.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1704_JM_044Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsMagnetite 5%Fine to medium-grained (1.2mm), dark-grey, euhedral crystals embedded by pyrite and quartz.Pyrite 7% Medium-grained (3mm), subhedral aggregates * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Hematite Specularite40% 10%Coarse to medium grained (up to 7mm), colorless, aggregates as infill in quartz, hematite and as selective replacement of tabular crystals or apatite? Also, carbonate occurs with traces of titaniteMedium to fine-grained (up to 1mm), dark to medium-grey, acicular aggregates embed-ded and locally replaced by carbonate. This intergrows and it is replaced by magnetiteCarbonateSMA_AL_1704_JM_044Quartz 4%Very fine to fine-grained (up to 0.8), colorless, anhedral to prismatic euhedral. Are embedded by carbonate and accompanied by magnetite-hematite association. Quartz seems to corresponds to the earliest formed mineral along with chlorite. Chlorite 2%Very fine-grained (0.08mm), dark green flaky radiated , locally re-placed by carbonate and intergrowing with magnetiteApatite TrFine-grained ( 0.6mm), colorless, anhedral, relictic texture after carbonate replacementChalcopyrite 1% Fine-grained (0.7mm) anhedral aggregates that invades and weakly crosscuts the Mag/He and Py ores. Seems to be associated with CaAlterationCarbonateHematiteMagnetiteQuartzChloriteApatiteMineralizationPyriteChalcopyriteC DPhotomicrographsJM044. A) Microphotograph 5X, showing a relictic bladed magnetite (mushketovite) replaced by carbonate and chlorite. B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the intergrowth of quartz and pyrite with magnetite inclusions. D) Same photo C, but under XPL + RL. E) Microphotograph 10X, showing the selective and patchy replacement of carbonate after mushketovite. F) Microphotograph 20X, showing the coexistence of magnetite (mushketovite) and specularite in a intergrowth with chalcopyrite.Sample ID:A BE FMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Musk<Car<Py<Ap<PySMA_AL_1704_JM_044Mag: 10xXPL+RL0.4mm Mag: 20xXPL+RL0.2mm XPL FOV~ 2.18mm (Length) XPL FOV~ 1094 Um (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Chl<Tit<Ap<Musk<Car<Py<Ap<Py<Chl<Tit<Ap<Mag<Car <Ap<Py <Chl<Qtz<Ap<Mag<Mag<Car<Mag<Car <Ap<Py <Chl<Qtz<Ap<Mag<Mag<Car<Mag<Car <Py<Py<Chl<Specularite<Musk<Car<Ccp<Py<Qtz<Musk<Car<Car<QtzPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA11@105El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_045Polished Thin section Description This sample corresponds to a breccia with an ore bearing matrix that embeds silica-altered clasts. No primary mineralogy is identified. The clasts are selectively replaced to very fine-grained to cryptocrystalline quartz, (< 0.01mm), with a overimposed brownish dusty coloration. The cryptocrystalline clasts are cut by euhe-dral, prismatic, medium-grained quartz aggregates that intergrows with fine-grained (~0,3mm) rounded dark green chlorite (20%). Carbonate occur as fracture filling accompanied by titanite and locally replaces chlorite.Mineralization in the sample is represented by coarse-grained anhedral aggregates of pyrite (5%) intergrow-ing with magnetite and inter- to over-growing quartz. Mineralization is cut by carbonate veinlets.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA11@105 in the El Alacran Deposit Unit 2 and TufL lithofacies. This sample corresponds to volcanoclastic breccia with clasts replaced by silica and a matrix highly altered to chlorite, pyrite, calcite, and apatite(?). The matrix is composed by dark-chlorite with crystal development accompanied by sericite, minor magnetite crystals and cut by calcite with apatite.Pyrite is the dominant sulphide (less than 1 %), it seems to present irregular patchy occurrence when it is with chlorite and medium-grained fine cubic shapes when it is formed within the silica clast. Magnetite cor-responds to less 1mm equidimensional crystals. There seems to be pyrobitumen in some of the silica-altered crystals. The goal with this sample is to characterize the paragenesis of chl+apatite+carbonate in relation with silica alteration.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1704_JM_045Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 10% Coarse to medium-grained (>1mm) crystals, colourless, with marked cleavage, occurring as intergranular and fracture filling accompanied by titanite.Pyrite 5% Coarse-grained (~7mm) anhedral to subhedral patchy aggregates, intergrowing with magnetite and inter?-overgrowing Qtz. It is cut by carbonate veinlets. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Chlorite60.0%20%Fine to medium-grained in 3 different populations: -Qtz1: Euhedral, prismatic, medium grained (up to 1,5mm) aggregates as filling minerals in vein forming cockade textures typical of opens space filling. -Qtz2: Anhedral fine-grained (~0.1mmmm) aggregates as alteration of the wallrock around the vein/stringers zones. This quartz phase intergrows with Chl and present mul-tiple inclusions of chlorite and possible apatite. Also, it presents some relictic textures of an acicular mineral (Act?) that usually is replaced to carbonate. - Qtz3: Very fine-grained to cryptocrystalline size (< 0.01mm), with an over imposed brownish dusty coloration. This quartz phase occurs preferentially as selective replace-ment in clasts surrounded and cut by the coarser phase of quartz. Possibly correspond to Fine-grained (~0,3mm) radiated, rounded, dark green pleocroic. It is growing with Qtz and cut and partially replaced by CaQtzSMA_AL_1704_JM_045Martite? 2%Medium to coarse-grained (~5 mm length) crystals, exhibiting acute angle filling texture in the Qtz crystals. This mostly intergrows with calcite although is some areas is cut by this. It corresponds to the product of martitization of the magnetite and mushketoviteMagnetite TrMedium grained (up to 1mm length) euhedral crystals. Showing some relictic textures of bladed magnetite, this occurs as patchy alteration. This mineral occurs in AlterationQuartzChloriteCarbonateMartite?MagnetiteActinoliteMineralizationPyrite????C DPhotomicrographsJM045. A) Microphotograph 5X, showing the border zone between different populations of quartz. Note the intergrowth of Qtz and Magnetite surrounded by prismatic quartz B, Same photo A, but under XPL + RL. C) Microphotograph 20X, showing relictic texture of acicular mineral possibly actinolite. This is replaced to carbonate .D, Same photo C, but under XPL + RL. E) Microphotograph 5X, showing inclusions of pyrite +chalcopyrite in the euhedral magnetite. F, E) Microphotograph 50X, showing the occurrence of Py intergrowth with Magnetite. This implies a transition zone where the mag-netite coexisted with pyrite.Sample ID:A BE F<Qtz 3SMA_AL_1704_JM_045Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Chl<Qtz1<Mag<Py<Py+Ccp Inclusion<Mag<Py intergrowth with Mag<Qtz 2<Qtz 3<Chl<Qtz1<Mag<Qtz 2<Qtz1<Relictic Act?<Relictic Act?<Qtz1<Qtz1<Relictic Act?<Relictic Act?<Qtz1Mag: 5xRL0.8mm RL FOV~ 4.35mm (Length)<Py+Ccp Inclusion<Mag<Py intergrowth with MagMag: 50xXPL+RL0,08mmXPL FOV~ 441μm (Length)Mag: 20xPPL+RL0,2mmPPL FOV~ 1094μm (Length) Mag: 20xXPL+RL0,2mmXPL FOV~ 1094μm (Length)PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA51@99.60El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1704_JM_049Polished Thin section Description This sample corresponds to a lapilli-tuff, highly altered and mineralized. No evidence of former mineralogy is present in the sample. The dominant alteration of this sample is defined by the occurrence of flaky clay minerals that replaces se-lectively chlorite. Chlorite (25%) occurs as fine-grained (0,2mm), radiated aggregates that Intergrows with medium-grained (~2mm), anhedral quartz (25%) that is locally altered to fine-grained (0.2mm) sericite. Mineralization occurs as medium-grained (~1mm), anhedral aggregates of chalcopyrite that intergrows with traces of sphalerite, ilmenite, pyrrhotite, pyrite, and molybdenite.The alteration mineralogy accompanying mineralization is mostly sericite, quartz and carbonate. Pyrite is also present as late stage veining that cuts all the mineralogy and partly seems to be responsible for the occurrence of clay alteration after chlorite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA51@99.60m in the El Alacran Deposit Unit 2 and TufF lithofacies. This sample corresponds to fine-grained lapilli to ash-tuff altered to chlorite, albite, pyrite, and molybdenite. The alteration consists mainly of fine-grained chlorite and albite 30%, as well as sericite that occurs in the groundmass and as patchy replacement 25% with albite. The mineralization is mostly of irregular Py up to 1cm and corresponds to the 15% of the sample. Pyrite occurs intergrowing mostly with dark? Chl and surrounded and intergrowing with Sericite. Molybdenite occurs as a rims and aggregates around some semicircular areas that contain rutile. Moly seems to be controlled by the distribution of the Rutile. No crosscutting relationship of Py and Moly was observed. In over all the carbonate is mostly absent in this association, as well as the magnetite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1704_JM_049Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsClay 30%Very fine-grained (<0.05mm), flaky aggregates replaces selectively Chl, it is stained by FeOxChalcopyrite 5% Medium-grained (~1mm), anhedral aggregates that occurs with carbonate and pyrrho-tite, as acute infill after Qtz and Chl* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Chlorite25.0%25%Medium-grained (~2mm), coloured by multiple very fine-grained chlorite inclusions , irregular, anhedral intergrowing with chlorite.Fine-grained (0,2mm), pale-green anhedral aggregates exhibiting some radiated shapes. Intergrows with quartz. It is altered to clay and locally to sericite.QuartzSMA_AL_1704_JM_049Sericite 7%Fine-grained (0.2mm),pale green to pale brown flaky aggregates that intergrow with sulphides and Qtz, although locally cut them. Carbonates 4%Medium to coarse -grained (<5mm), colourless that occurs as infill texture after Qtz , accompanied of sulphides and Ser Rutile / titanite TrTitanite: Fine-grained (~0.2mm) , brownish yellow, opaque, euhedral intergrowing with chalcopyrite. Rutile: Fine-grained (0.1mm), brown-reddish, anhedral aggregates associated with clay and Ccp.Sphalerite Tr Very fine-grained (~0.06mm), anhedral aggregates occurs with chalcopyrite and titanite mineralsPyrrhotite Tr Fine-grained (~0.5mm), pinkish metallic colored, highly anisotropic from grey to brown. Intergrows with chalcopyrite and as exolutions with carbonateAlterationQuartzChlorite ApatiteCarbonatesTitaniteMineralizationPyriteChalcopyriteSphaleritePyrrhotiteIlmenite??Molybdenite Tr Very fine-grained (<0.1mm), metallic colored, flaky intergrowing with chalcopyrite and sericite.Illmenite Tr Fine-grained (<0.5mm), dark grey, euhedral to anhedral, occurs with sphalerite and chalcopyriteC DPhotomicrographsJM049. A) Microphotograph 50X, showing the occurrence of molybdenite intergrowing with chalcopyrite and sericite. B) Microphotograph 5X, showing Chl+ anhedral Qtz intergrowth, with some open-space filling texture of quartz +chalcopyrite. C) Microphotograph 20X, showing the occurrence of ilmenite and sphalerite embedding apatite and sulfides. D) Microphotograph 10X, showing evidences of lamellae exolutions of pyrrhotite from carbonate. E) Microphotograph 20X, showing evidence of a later event of pyrite that cruses cuts Ccp +Qtz F) Microphotograph 20X, showing some local and restricted evidences of sericite alteration after chlorite and quartz. Sample ID:A BE F<Qtz SMA_AL_1704_JM_049Mag: 50xPP+RL0.08mm PPL FOV~ 441 μm(Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Chl+Clay<CcpMag: 20xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 1094 μm( (Length) XPL FOV~ 2.18mm (Length)Mag: 20xXPL+RL0,2mmXPL FOV~ 1094μm (Length) Mag: 20xXPL+RL0,2mmXPL FOV~ 1094μm (Length)<Qtz <Ccp<Mo <Ser<Ccp<Qtz <Ccp<Qtz <Chl<Qtz <Po<Ser <Po <Car <Sph<Qtz <Ill <Ser <Ap <Qtz <Chl+-Clay<Ccp<Py<Py <Ser <Qtz <Chl+-Clay<CcpChl> <Ser <Qtz <Chl+Clay<Mo <Clay Mo ><Sph<Ap <Chl+Clay PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA046@181El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1705_JM_065Polished Thin section Description This sample corresponds to a pervasive altered and mineralized breccia. The breccia texture is defined by the occurrence of a silica altered clast with a relictic lamination texture (MudSil lithofacies). These clasts are em-bedded in a matrix composed of a coarse-grained (~7mm), subhedral to euhedral carbonate that selectively replaces the clast. The matrix is also composed of a fine-grained (~0.4mm), brown to pale brown pleocroic Vanadium + potassium mica that intergrows with sericite and sulphides. Mineralization is dominated by fine to medium-grained (up to 1mm), anhedral aggregates of chalcopyrite that displays some sphalerite inclusions and intergrow with sericite after pyrite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ASA046@181m in the transition between Unit 1 and Unit 2 in the El Alacran Deposit (ABx lithofacies). This corresponds to highly altered volcanic?, hydrothermal breccia?, with up to 7 centimeter clasts replaced to silica and highly mineralized matrix. Some of the clasts exhibit a selective al-teration along some rock former bands, from silica, calcite and sericite. The alteration bands present a dissem-inations of a flaky brownish mineral that resembles to biotite. The clasts are embedded and cut? by a matrix of chalcopyrite>>Py, silica? ± carbonate. A later event of carbonate and iron stained oxide mineral, Chlorite? cut the clasts and matrix. The goal with this sample is to determine if the ore correspond to a hydrothermal breccia or a mineralized phase of the Unit 1.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1705_JM_065Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsV-Mica 10%Fine-grained (~0.4mm), brown to pale brown pleocroic, subhedral, flaky aggregates that exhibit micaceous habits. Optically, the interference colors are from the middle 1st order. V-Mica occurs intergrowing with sericite/muscovite accompanied by chalcopyrite and pyrite. In some areas it occurs as radiated mineral intergrowing with carbonate. Under EDS, this mineral shows variable amount of V, K, Mg, Fe, that suggests a Roscoe-lite composition (Appendix D2). Chalcopyrite 15% Fine to medium-grained (up to 1mm), anhedral aggregates that occurs with sericite and along with chalcopyrite occurs in the rock groundmass. It presents some traces of sphalerite. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Quartz30%20%Coarse-grained (~7mm), subhedral to euhedral, pale yellow to colourless aggregates , that occurs as selective replacement after former clasts. This occurs after quartz and after V-Mica1- Fine to very fine-grained (<0.1mm to 0.5mm), euhedral to subhedral aggregates as selective replacement of former clasts. 2- Fine-grained euhedral prismatic that occurs as in-fill occurrence. No clear the cutting relationship with the rest of the sulphides.CarbonateSMA_AL_1705_JM_065Sericite 5% Fine-grained (~0.4mm), colourless, subhedral, flaky aggregates that exhibit micaceous hab-its. Sericite occurs intergrowing with V-mica, sulphides and carbonate.Pyrite 10% Fine to medium-grained (up to 1mm), anhedral to subhedral, surrounded by V-Mica and sericiteAlterationQuartzCarbonateV-MicaSericiteMineralizationPyriteChalcopyriteSphalerite??Sphalerite Tr Fine-grained (up to 0.2 mm), anhedral to subhedral, surrounded by V-mica and sericiteC DPhotomicrographsJM065. A) Microphotograph 2X, showing the breccia texture of some silica altered clast embedded by chalcopyrite, carbonate and V-mica. Note the fine prismatic texture in quartz that denotes open space texture. B) Same photo A, but under XPL + RL. C) Microphotograph 10X showing the occurrence of sphalerite accompanied by chalcopyrite andV-mica D) Same photo C, but under XPL + RL. Sample ID:A BSMA_AL_1705_JM_065<Car<Qtz1<Ccp<Qtz 2Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Py<Car<Qtz1<Ccp<Qtz 2<V-Mica<Ccp<Car<Qtz1<Ccp<Qtz 2<Py<Sph<Ccp<Car<Qtz1<Ccp<Qtz 2<Py<Sph<CcpMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1094µm (Length) XPL FOV~ 1094µm (Length)<Py<V-Mica<V-Mica<V-Mica <V-MicaPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD002@115.9El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_068Polished Thin section Description This sample corresponds to a massive ore composed mostly of medium-grained (1mm) anhedral pyrrhotite that is cut by carbonate and intermediate sulfide (pyrite-marcasite?). Pyrite occurs in 2 phases. 1: Medi-um-grained (up to 1mm) phase that is embedded by the intermediate mineral. 2: Fine-grained intermediate sulfide formed as aggregates along fractures and accompanied by carbonate, chalcopyrite, pyrrhotite, and traces of sphalerite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD002@115.9m in the Unit 2 of the El Alacran Deposit. This sample corresponds to massive pyrrhotite replacement with some circular pre-existent textures that denotes a per-vasive replacement after a lithic tuff (TufL lithofacies?). Some Py veins cut this sample. The main goal with this sample is to characterize the massive mineralization of pyrrhotite and chalcopyrite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1709_JM_068Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionChalcopyrite 3%Medium-grained (up to 3mm), anhedral aggregates intergrowing with Po and also cut and rimmed by carbonate* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite, Pyrrhotite=PoPyrite/Intermediate product 90%5%Medium-grained (1mm), anhedral to subhedral aggregates, rimmed and cut by carbon-ate and an intermediate product/Pyrite. The pyrrhotite displays flames-shaped exolu-tions that under EDS did not indicate to have any nikel content (e.g. Pentlandite flames) -Intermediate sulfide: Fine grained (0.1mm) occurs as rimming alteration mineral accom-panied by carbonate. Texturally presents a low crystallinity and fracturing.- Pyrite: Medium-grained (up to 1mm) fragmental phase surrounded by the intermedi-ate/product. Pyrrhotite SMA_AL_1709_JM_068Sphalerite TrFine-grained (0.2mm), dark grey, internal reflections, anhedral, intergrowing with chalco-pyrite. AlterationCarbonateEpidoteMineralizationPyrrhotite Pyrite/Int. productChalcopyriteSphalerite????C DPhotomicrographsJM068. A) Microphotograph 5X, showing the occurrence of an intermediate product with carbonate that rims pyrrhotite. B)Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the occurrence of sphalerite accompanied by chalcopyrite surrounded by carbonate. D) Microphotograph 20X, showing the occurrence of an intermediate sulfide around pyrrhotite. Note the flames texture. Sample ID:A BSMA_AL_1709_JM_068<PoPy<Po<Int sulfidePy<Ccp+Sph<Car<PoPy<PoPy<Ccp+Sph<Car<PoPy<PoPy<Ccp<Car<Sph <Po<Py flammes<Int sulfide<Ccp+Sph<Car<PoMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 20xXPL+RL0,2mmXPL FOV~ 1094μm (Length)<Int sulfidePETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@192.09El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_069Polished Thin section Description This corresponds to an ore zone with selective replacement along some of the rock-former bedding.The dominant alteration mineralogy corresponds to a mixture of very fined-grained (<0.05mm), pale green to brownish clay + chlorite?, aggregates that occurs with fine-grained (0.1mm) sericite (7%) and carbonate. Carbonate occurs as anhedral aggregates spatially related with apatite and a La-Ce mineral (Lanthanite?). Another clay phase occurs in the sample as iron stained cryptocrystalline mineral. Mineralization is dominated by a fine to medium-grained (1mm), anhedral aggregates of pyrite that intergrow with sphalerite, carbonate and locally cuts cobaltite/arsenopyrite. Carbonate and sericite are the mineral that accompany the mineralization. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD003@192.09m in the El Alacran Deposit Unit 2 and TufC lithofa-cies. This sample corresponds to medium to coarse-grained, coarse-laminated tuff highly altered and mineral-ized Po+Py+Ccp along some pre existent bedding. There are some banding structures where chalcopyrite ± py-rite define a banding zone and are altered/invaded by sericite + chlorite. Pyrrhotite and rutile seem to belong to the same phase of the sericite that replaces the sulphides bands. Some small occurrences of carbonate are present. This is a non-magnetic rock. The goal with this sample is to determine the paragenesis of pyrrhotite + pyrite replacement in banded coarse tuff (TufC). Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1709_JM_069Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4AlterationMineral Modal Textural and Mineral DistributionCarbonate 13% Fine to medium-grained (1mm), colorless, anhedral aggregates spatially related with Ap, but also locally cutting this. Car intergrows with Clay, Ccp, Sph, Py, Ser and titanite* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite, Co= Cobaltite/Co-ArsenopyriteClay 45%23%Very fined-grained (<0.05mm), pale-green to brownish, anhedral aggregates with birefrin-gence of high 1st order this is accompanied by Ccp, Ser, enclosing or rimming syngeneic clay Very-fine to cryptocrystalline brownish with Fe-staining enclosed by Chl + Clay +SerClay –Chl?SMA_AL_1709_JM_069Sericite 7% Fine-grained (0.1mm), pale green, anhedral to flaky aggregates intergrowing with Clay-Chl and rimming ClayApatite 2% Fine to medium-grained (<1mm), colorless, tabular elongated cut by Car and Clay. This mineral correspods to Fluor-Apatite (Appendix D2, sample JM069).Chalcopyrite12%TrFine to medium-grained (1mm), anhedral aggregates intergrow-ing with TiOx, Car and locally cutting cobaltite(?). Py is locally altered to an Intermediate product (Marcasite?)Fine-grained (0.4mm), anhedral, aggregates companied of Ser, and Chl+Clay.PyriteMineralizationCobaltite/Co-ArsenopyriteTr Medium to fine-grained (1mm), pinkish brownish, subhedral, no BR, highly anisotropic from blue to pink. Intergrows with chalcopyrite. The identification was made using EDS (Appendix D2, sample JM069). AlterationClay –Chl?ClaySericiteCarbonateApatiteREE-MineralMineralizationPyriteChalcopyriteCobaltite/Co-ArsenopyriteTi-Ox (V)????REE-Mineral 1% Very-fine grained (0.05mm), pale-green to brownish, anhedral to surrounded aggregates intergrowing with Car and Ccp and cutting and embedding apatite. This mineral contains Ce+La+Cr+Fe, possible (La,Ce)2(CO3)3 · 8H2O Lanthanite.(Appendix D2, sample JM069).C DSample ID:A BSMA_AL_1709_JM_069<Int product<CarPhotomicrographsJM069. A) Microphotograph 10X, showing some a possible relictic pyrrhotite replaced by clay dominated mineralization. Note the differences in clay composition between Clay minerals and a Chl+Clay association. B) Same photo A, but under XPL + RL. C) Mi-crophotograph 10X, showing the distribution of pyrite and Co-rich arsenopyrite?. Note the local occurrences of an intermediate product after pyrite. D) Same photo C, but under XPL + RL. E) Microphotograph 20X, showing 2 generations of apatite. F) Same photo E, but under XPL + RL.E FMag: 20xPPL+RL0,2mmPPL FOV~ 1094μm (Length) Mag: 20xXPL+RL0,2mmXPL FOV~ 1094μm (Length)< Chl+Clay<Ccp<Co<Ser<Clay<Co < Chl+Clay<Ccp<Co<Ser<Py<Clay<Co< Chl+Clay<Ser<Int product<Car<Py<Clay<Co< Chl+Clay<SerCar<Clay<Ap1<Ap1<Ap1<CcpCar<Clay <REE minerals<Ap1<Ap1<Ap1<CcpMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Co<REE mineralsPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD032@89.70El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_074Polished Thin section Description This sample corresponds to a medium to fine-grained basalt with porphyritic texture and a groundmass composed of fine-grained (<0.2mm) plagioclase. The main phenocrysts also correspond to medium-grained (~1mm) plagioclase.Alteration is dominated by chlorite that occurs as very fine-grained (up to 0.1mm) aggregates replacing the rock groundmass. Carbonate occurs as fine-grained (0.4-0.6mm) patchy and cavity in-fill accompanied by a relictic?, acicular mineral (actinolite?). Apatite traces filled the rock cavities and are replaced by chlorite, car-bonate, epidote-zoisite, and actinolite(?).Mineralization occurs as coarse grained, anhedral aggregates of pyrite (~3%) accompanied with epidote, car-bonate ad traces of chalcopyrite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD025@171m in the Unit 3, TufA lithofacies of the El Alacran De-posit. This sample corresponds to a vesicular andesite lava with selective sulfur mineralization. The ground-mass consist of a very fine-grained crystal tuff. There are some very fine irregular crystals of plagioclase, some of them are replaced to carbonate. The groundmass alteration is mostly of chlorite. The amygdales have a calcite halo and are filled with actinolite, epidote and centered by pyrite crystals of up to 1mm. No magnetite was observed. The goal with this sample is to characterize the pyrite mineralization that occurs in the amyg-dales in Unit 3. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase55%3%Fine grained (<0.2mm), phaneritic groundmass composed of tabular to acicular aggre-gates of plagioclase.Medium-grained (~1mm), dusty coloration, anhedral to weakly tabular aggregates that occurs as phenocrysts in the sample. This is saussuritized with traces of epidote.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1709_JM_074Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??AlterationMineral Modal Textural and Mineral DistributionCarbonate 5%Fine-grained (0.4-0.6mm) anhedral aggregates, patchy and as in-fill accompanied by a relictic? cicular mineral (actinolite?)* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite Ep-Zoizite 30%3%Very fine-grained (up to 0.1mm), pale green, pleocroic, anhedral aggregates in the groundmass. Fine to medium grained (up to 1mm), pale yellow dusty aggregates that occur as in-fill of rock cavities. ChloriteSMA_AL_1709_JM_074Apatite TrMedium-grained (1mm), colorless, high-relief, as patchy and cavity filling, local-ly re-placed by car + actinolite and CcpChalcopyrite3%TrCoarse-grained (>5mm), anhedral aggregates, as infill in cavities, accompanied of Ep+ Car+ CcpMedium-grained (up 2mm), anhedral aggregates intergrowing with PyPyriteMineralizationAlterationChloriteCarbonateApatiteEp-ZoisiteAct?-ZeoliteMineralizationPyriteChalcopyrite????C DSample ID:A BSMA_AL_1709_JM_074PhotomicrographsJM074. A) Microphotograph 10X, showing the intergrowth of actinolite, epidote and carbonate replacing plagioclase and embed-ding pyrite. B, Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the distribution of the phaneritic plagioclase groundmass and the selective replacement of apatite, carbonate, titanite and chalcopyrite. D) Same photo C, but under XPL + RL. E) Microphotograph 5X, showing the cavity filling of epidote-zoisite and patchy replacement of carbonate. F) Same photo E, but under XPL + RL.E F<Car<Ep<Plag<Act<ChlPyMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Plag<Car<Ep<Plag<Act<ChlPy<Plag<Tit<Ep<Ap<Ccp<Chl Py<Plag<Ap<Ccp<Chl Py<Plag<Car<Ep+Zoisite<Chl<Plag<Car<Car<Ep+Zoisite<Chl<Car<PlagMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length)Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD055@131.20El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_075Polished Thin section Description This sample corresponds to a brecciated rock highly altered with no evidence of former mineralogy. A major clast in the sample is replaced by cryptocrystalline quartz, Fe-Carbonate and Fe-Oxide. This clast shows some relictic bedding texture (posibly a MudSil lithofacies from Unit2). Another phase of quartz occurs as fine-grained (0.6mm), anhedral to euhedral prismatic, with inclusions of fined grained acicular amphibole possibly actinolite. This intergrows with a medium-grained (2mmm), brown, striated to radiated mineral (V-Mica), carbonate and sulphides. Carbonate occur is three generations: Car1 as very fine-grained with selective replacement along the rock banding. Car2: Fine-grained dusty to reddish (Fe stained? or siderite?) that intergrows with brown the V-Mica. Car3. Fine to medium-grained that overgrows Carb 2. Car3 is accompanied by prismatic quartz, titanite and chalcopyrite. Mineralization includes medium-grained pyrite that replaces relictic acicular structures and is brecciated and cut by prismatic quartz, chalcopyrite and sphalerite PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD055@131.20m in the Unit 1, lithofacie RBx of the El Alacran Deposit. This corresponds to a fine-grained banded or matrix supported volcanic breccia? highly-mineralized. The sample displays silica clasts embedded in a biotite(?) matrix. The interval were this sample was collected yielded high-Au grades. The dominant alteration correspond to a fine-grained brownish mineral (biotite?) that intergrows with silica. This alteration is embedding some >4cm length clasts? pervasive altered to silica. Either the clast and the matrix are cut by rutile veinlets. Rutile is also cut by Py veinlets. The matrix has some relict textures of bladed radial minerals up to 4cm length that seem to be pervasive altered to rutile, silica and chalcopyrite. The goal with this sample is to characterize the biotite(?)alteration and define the origin of the high-Au occurrence. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1709_JM_075Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4AlterationMineral Modal Textural and Mineral DistributionV-Mica 5%Medium-grained (2mmm), brown, non pleocroic, striated, radiated, with BR of 1st order. This occurs with chalcopyrite and Qtz2 as local infill and as veins cutting Qtz1. Also, V-mica shows latter formation relation to the Py.* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite Carbonate 78%10%-Qtz1: (Clast) cryptocrystalline, colorless, anhedral aggregates show a subtle orientation (bedding), with a selective replacement of fine grained carbonate and FeOx-Qtz2: Fine-grained (0.6mm), colorless, anhedral to euhedral prismatic, with some inclu-sions of an acicular mineral. This intergrows with sulphides, car-bonate and V-Mica. Car1. Very fine-grained (<0.05), dusty to black, anhedral aggregates, with selective re-placement following the rock banding. Car2: Fine-grained (up to 0.5mm length), dusty to reddish (Fe-stained?), euhedral. This intergrows with V-MicaCar3: Fine to medium-grained (up to 1mm length) , colorless, anhedral with visible cleav-age this overgrowth Carb 2. It is accompanied by prismatic quartz cut-ting pyrite and locally cutting prismatic quartz. This is accompanied by chalcopyrite and sphalerite. QuartzSMA_AL_1709_JM_075Amphibole. Actinolite? TrFined-grained (up to 0.2mm), pale green to colorless, acicular elongated crystals that crosses the Qtz2 borders.Ccp4%1%Medium-grained to coarse-grained (up to 5mm), anhedral aggregates that grew follow-ing some 1mm-wide acicular? relictic structure. Pyrite is brecciated and locally cut by Qtz2, Car1, Carb 2, and V-Mica, Py also occurs as very-fine grained euhedral disseminat-ed in Qtz 1Fine-grained (0.6mm), anhedral aggregates intergrowing with Sph and locally cut by Car3PyriteMineralizationTitanite TrFine to very fine-grained (up to 0.1mm), pale amber, euhedral , high relief in-tergrowing with Car 3.Tr Fine to very fine-grained (<0.1mm), anhedral aggregates intergrowing with Ccp and carbonate , associated with the FeOx stained occurrence (Car2-3) SphaleriteAlterationQuartzActinolite(?)V-MicaCarbonateMineralizationPyriteChalcopyriteSphaleriteC DSample ID:A BSMA_AL_1709_JM_075PhotomicrographsJM075. A) Microphotograph 10X, showing two different generations of carbonate (Car2 and Car3). B) Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the distribution of Qtz1 and Qtz2, note the vein occurrence of V-mica companied of chalcopyrite. D) Same photo C, but under XPL + RL. E) Microphotograph 2X, showing a possible relictic texture of a bladed mineral replaced by pyrite, quartz 2 and brown mineral. These orientations are discordant with the bedding suggesting an open-space related structures. F) Same photo E, but under XPL + RL.E F<Car2<Ccp<Qtz1PyMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Car3<V-Mica<Car3<Car2<Ccp<Qtz1Py<Car3<V-Mica<Car3<Qtz1Py<Car1<Qtz2<Ccp<Qtz1Py<Car1<Qtz2<Ccp<Qtz1PyPyPy<Qtz2<Qtz1PyPyPy<Qtz2Mag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) Mag: 2xXPL+RL2mm Mag: 2xPPL+RL2mmXPL FOV~ 1,45mm (Length) PPL FOV~ 1,45mm (Length) <V-Mica<V-Mica<V-Mica <V-MicaPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD050@114.40El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_077Polished Thin section Description This sample corresponds to a brecciated rock highly altered with no evidence of former mineralogy. A major clast in the sample is replaced by cryptocrystalline quartz showing some relictic banding. This is cut by me-dium-grained (<3mm), carbonate and with medium-grained (2mm), prismatic quartz and fine-grained flake radiated mg-rich chloriteMineralization is dominated by pyrite that occurs as medium-grained subhedral to euhedral aggregates that intergrowths with prismatic quartz, chlorite, and chalcopyrite. This presents an inclusions of gold and mag-netite.Gold has ~20μm in diameter and was observed just in one spot. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD050@114.40m in the Unit 2, lithofacie MudSil of the El Alacran Deposit. This corresponds to a hydrothermal breccia and replacement with clasts larger than 5cm-length, with relictic banding and completely altered to silica that is cut by pyrite and chalcopyrite veins. The breccia matrix corresponds to a 90% sulphide distributed in at least two pyrite-rich zones and two chalcopyrite-rich. All the zones are intergrowing with coarse chlorite, calcite (pinkish), and sericite (low hardness pristine mineral). This suggest that all belong to the same event. Pyrite constitutes the 60% of the sulphide present in the sample. Neither magnetite nor rutile were observed. The goal with this sample is to characterize Paragenesis of chal-copyrite ores occurring as matrix breccia in Unit1?Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1709_JM_077Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4AlterationMineral Modal Textural and Mineral DistributionCarbonate 3% Medium-grained (<3mm), anhedral, patchy and fracture in-fill occurrence. Car intergrows with chalcopyrite infilling pyrite and prismatic quartz.* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite 35% Two populations: -Very fine-grained (<0.01mm), brownish dusty coloration that occurs as selective replace-ment of former bands. It is cut by Carbonate and Py ±Ccp veinlets.-Medium-grained (2mm), euhedral prismatic quartz, growing from the silica clasts to-ward the zone with sulphides occurrence it intergrows with chlorite. QuartzSMA_AL_1709_JM_077Chlorite 3% Fine-grained (0.3mm), pale green, flake radiated aggregates, occurs as infill accompanied by coarser fraction of quartz and chalcopyrite. Chalcopyrite25%30%Medium-grained (up to 3mm), subhedral to euhedral aggregates that intergrow with coarse-grained quartz and chlorite, and later chalcopyrite. This present inclusions of gold and magnetiteCoarse-grained (>5mm) aggregates that occurs intergrowing and overgrowing quartz and PyriteMineralizationGold Tr Very-fine grained (~20μm in diameter), high reflectance, sub rounded shapes, occurs as inclusion in pyrite (just observed in one spot)Magnetite Tr Very-fine grained,euhedral aggregates that occur as inclusion in pyrite AlterationQuartzChloriteMagnetiteCarbonateMineralizationPyriteChalcopyriteGold??C DSample ID:A BSMA_AL_1709_JM_077PhotomicrographsJM077. A) Microphotograph 2X, showing the contact zone between the silica altered clast (Qtz1) and the matriz composed of prismatic quartz, chalcopyrite and chlorite. B, Same photo A, but under XPL + RL. C, Microphotograph 50X, showing the intergrowth of quart, pyrite and chalcopyrite. Note the magnetite inclusions in the pyrite. D, Microphotograph 50X, showing the shape of gold occurrence in the pyrite. <Py<CcpPy<Qtz1<Qtz2Py<CcpMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) Mag: 50xXPL+RL0,08mm Mag: 50xXPL+RL0,08mmXPL FOV~ PPL FOV~ 441μm (Length) XPL FOV~ PPL FOV~ 441μm <Qtz2<Chl<Car<Py<CcpPy<Qtz1<Qtz2<Chl<Car Mag> Mag>Py Au>PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD081@63.8El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_104Polished Thin section Description This sample corresponds to a semi-massive ore sample composed of coarse-grained radiated magnetite (40%) (mushketovite) that intergrows with medium to fine grained (up to 1mm) quartz. These minerals are over-grown by coarse-grained aggregates of pyrite (~25%), coarse-grained (10mm) anhedral chalcopyrite (30%) and by traces of carbonate. A REE-mineral (Kozoite?) occurs with magnetite. No clear evidences of remnants of actinolite previous in the bladed-shaped mineralogy. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD081@63.8m within the Unit 2, MudSil lithofacies of the El Alacran Deposit. This corresponds to high-grade zone with 40% of mushketovite/magnetite, 30% of chalcopyrite and 25% of Pyrite and lesser silica. It presents some radiated shapes of mushketovite possible formed after actino-lite? This face seems to intergrow with quartz in tabular shapes. The goal with this sample is to verify if there are some remnants of actinolite in the acicular magnetite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_104Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4AlterationMineral Modal Textural and Mineral DistributionCarbonate Tr Medium-grained (3mm), colourless, anhedral aggregates as in-fill in pyrite and magne-tite. Also, Car occurs as later veinlets that cross-cut all the minerals.* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite Quartz40%1%Coarse-grained (7mm), radiated, acicular aggregates intergrowing with Qtz and over-grown by chalcopyrite + pyrite + carbonateMedium to fine-grained (up to 1mm), anhedral aggregates with multiple inclusions of apatite and relictic acicular mineral (actinolite?). This seems to be an earlier phase in relation to the magnetite. Bladed Magnetite (Musketovite)SMA_AL_1801_JM_104Amphibole. Actinolite? TrFine-grained (up to 0.2mm), pale green to colorless, acicular elongated crystals as inclu-sions in quartz. Pyrite 30�25%Coarse-grained (10mm), anhedral aggregates embedding and in-filling crystals of bladed magnetite and embedding pyrite. Also occurs with fine grained, sub rounded radiated aggregates of chlorite Coarse-grained (7mm), subhedral, highly fractured with inclusions of euhedral magne-tite. It is partially embedded by chalcopyriteChalcopyriteMineralizationREE-Mineral Tr Medium-grained (2mm), dark amber to medium yellow, euhedral crystals with prismatic shapes that intergrow? with Mag. This present elevated birefringence. Compositionally it consists of Ca-Fe-La-Ce-Nd, (Appendix D2, sample JM104) Possibly Kozoite(?) (La,Nd)(CO3)(OH)AlterationMagnetite BladedQuartzCarbonateEpidote?ChamositeREE-MineralsMineralizationPyriteChalcopyrite????Chlorite TrVery fine-grained (0.07 mm), dark green, euhedral aggregates as in-fill in pyrite and magnetite. This correspods to Fe-rich specie (chamosite?) defined using EDS. (Appendix D2, sample JM104)C DSample ID:A BSMA_AL_1801_JM_104PhotomicrographsJM104. A) Microphotograph 10X, showing the intergrowth of magnetite and REE mineral (posibly Kozoite?) B) Same photo A, but under XPL + RL. C) Microphotograph 5X, showing the intergrowth of mushketovite and magnetite and traces of chlorite and car-bonate. Chalcopyrite is the latest phase in this association, same photo C) but under XPL + RL. E) Microphotograph 10X, showing the occurrence of anhedral quartz accompanied by actinolite inclusions. F) Same photo E, but under XPL + RL.E FQtzPyMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<REE Mineral Py<MuskPy<CarCcp<Ap<QtzQtzMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)MagMag<MuskPy<Car<Qtz2Ccp<Chl <Acicular InlcusionsIn Quartz<Ap<QtzQtz<Acicular Inlcusions in Qtz<REE MineralQtzQtzMagPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD070@197El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_106Polished Thin section Description This sample corresponds to a semi-massive ore zone composed of 40% of carbonate.Carbonate occurs as two stages of vein generations: 1. Coarse-grained (>5mm), anhedral aggregates that intergrow with fine- to medium-grained (1mm) pyrite (5%), chalcopyrite (1%), euhedral arsenopyrite (35%), and coarse-grained sphalerite (15%). 2. A second generation of carbonate corresponds to a coarse-grained (>5mm), anhedral aggregates with no sulphide association.Carbonate also occurs as fine-grained (0.1 - 0.2mm) replacement of host-rock fragments accompanied by sericite and after chlorite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD070@197m within the Unit 2, Lim lithofacies in the El Alacran Deposit. This sample corresponds to a high-grade zone of a fault-fill vein, exhibiting at least two stages of vein-ing. Vein 1, correspond to a CBM vein composed of chalcopyrite +sphalerite + pinkish carbonate that is cut by a latter phase (Vein 2) of white carbonate bearing arsenopyrite. Both veining phases seems to cut an early pyrite phase. The goal with this sample is to determine the paragenesis of the arsenopyrite-bearing veinMineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_106Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4AlterationMineral Modal Textural and Mineral Distribution* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite. Pent=Pentandite 40% 3 populations:1. Formed by coarse-grained (>5mm), anhedral aggregates intergrowing with Ccp, Shp and Asp.2.Coarse-grained (>5mm) anhedral aggregates, pristine, with no sulphide association.3. Fine-grained (0.1-0.2mm) anhedral, aggregates as replacement of the hostrock. This third generationn intergrows with sericite and after selective replacement of Chl in former rock frag-ments. (2%)CarbonateSMA_AL_1801_JM_106Sphalerite35�15%Medium to coarse-grained (5mm), pale-yellow with a pinkish tint color that occurs as euhedral aggregates with a Sph and Car vein. It is also cut by Car veinlets. Coarse-grained (5mm), dark-grey with internal reflections (Fe-rich variety), anhedral to subhedral aggregates embedded in a carbonate vein intergrowing with sphalerite and cut by a carbonate veinlets. Sphalerite displays Ccp exolutions.ArsenopyriteMineralizationPyrite 5% Medium to coarse-grained (5mm), anhedral aggregates embedded by carbonate vein intergrowing with Sph and cut by Car veinlets. Chalcopyrite 1% Fine to medium-grained (1mm), anhedral aggregates that intergrows with Sph , Aspy, and Py?., also present a s exolutions in SphAlterationCarbonateSericiteChloriteMineralizationPyriteChalcopyriteSphaleriteArsenopyriteC DSample ID:A BSMA_AL_1801_JM_106PhotomicrographsJM106. A) Microphotograph 2X, showing the intergrowth of sphalerite and arsenopyrite cut by a later carbonate event. B, Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the contact zone between the first generation of carbonate bear-ing pyrite and arsenopyrite, in contact with a second event of carbonate poor in sulphides. D., same photo C, but under XPL + RL. SphPy<Aspy<Car2Sph<Car2Sph<Aspy<Car2Sph<Car2Py<Py<Car2<Car1<Car2<Chl altered Py<Py<Car2<Car2<Car1<Chl+Ser altered clastMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) Mag: 2xXPL+RL2mm Mag: 2xPPL+RL2mmXPL FOV~ 1,45mm (Length) PPL FOV~ 1,45mm (Length) <AsPy <AsPyPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD015@166.90El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_112Polished Thin section Description This section corresponds to a mixed rocks between, a mafic crystalline rock with auto-breccia facies and a very fine-grained rock defining a peperite texture. The crystalline volcanic phase corresponds to a hypocrystalline rock composed of a very-fine grained groundmass (60%) with plagioclase phenocrysts (4%) and monomictic, volcanic rock fragments (5%). The fine-grained rocks corresponds to matrix supported poor sorted lapilli tuff?Carbonate is dominant alteration mineral (15%), occurs mostly in the volcanic phase. Epidote and chlorite occurs a selective replacement of plagioclase.The reddish coloration in the sample corresponds to hematite after very-fine grained anhedral aggregates of primary? magnetite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD015@166.90 within the Unit 3, TufA lithofacies in the El Alacran deposit. This sample corresponds to a dark-green and reddish colored peperite. The coherent lave corresponds to a fine to medium-grained amygdaloidal basalt with amygdales up to 2mm of diameter. The amygdales are altered to chlorite and are embedded in a fine-sericite, chlorite and carbonate groundmass. Py occurs as to 2mm euhedral crystals with well-formed shapes. The tuffaceous sediment is characterized by a hematized alteration. The goal with this sample is to revise the nature of the hematized alteration in the lithofacie TuFA. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase60%4%Fine to very fine-grained matrix of glassy material -Very fine grained (<0.1mm) anhedral to subhedral aggre-gates, selectively altered to Ep.-Fine-grained (up to 0.7mm), euhedral aggregates embedding in a carbonate + vitriclasts matrixPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_112Rock fragments 5% Medium-grained (1mm), dusty colored, anhedral fragments of crystalline pla-gioclase-bearing volcanic rock. All the fragments are monomictic and are embedded by carbonateParagenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??SMA_AL_1801_JM_112MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChlorite 17.0% Medium-grained (1.5mm), pale-green, anhedral aggregates that occur as replacement vitriclasts, rock fragments and as amygdales infill. Magnetite 2.0% Very fine-grained (<0.05mm) anhedral to subhedral aggregates, partially altered to he-matite giving the redish coloration to the rock. Epidote Tr Fine-grained (up to 0.4mm), pale yellow high-relief, replacing plagioclase crystalsPyrite Tr Fine-grained (<0.1mm), euhedral aggregates that occur disseminated in the sample accompanied by chlorite* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite, Ep=EpidoteCarbonate 15.0% Medium-grained (1-1.5mm), colorless, anhedral aggregates, embedding rock fragments, vitriclasts and crystals C DSample ID:A BSMA_AL_1801_JM_112PhotomicrographsJM112. A) Microphotograph 10X, showing the contact zone between a volcanic basaltic rock and a fine-grained lapilli tuff. B, Same photo A, but under XPL + RL. C) Microphotograph 50X with conoscopy light, showing the hematite occurrence that tarnish the rock with a red coloration. Note the occurrence of quartz and the selective replacement of plagioclase by chlorite. D, Same photo C, but under XPL + RL. E) Microphotograph 5X with conoscopy light, showing some relictic magnetite altered to hematite.EMag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Lapilli-Tuff<Chl<Chl<Chl<Relictic MagCrystallinePhase<Car<Car<Py<VitriclastLapilli-Tuff<ChlCrystallinePhase<Car<Car<Py<Vitriclast<Glassy Matrix< amygdalesLapilli-Tuff<Chl<He<Plag<Chl<HeLapilli-Tuff<Chl<He<Plag<Chl<He<ChlMag: 50xPPL+RL0,08mm Mag: 50xXPL+RL0,08mmPPL FOV~ PPL FOV~ 441μm (Length) XPL FOV~ PPL FOV~ 441μm Mag: 50xPPL+RL0,08mmPPL FOV~ PPL FOV~ 441μm He>He><QtzPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD030@89.9El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_113Polished Thin section Description This rock corresponds to a contact zone defined by the occurrence of a medium to coarse-grained porphyritic rock fine to very fine-grained (0.05 to 0.1mm) groundmass (~20%) composed of anhedral quartz and euhedral plagioclase. Phenocrysts are dominated by medium-grained (up to 3mm) euhedral plagioclase ( ~15%) accom-panied by medium to coarse-grained (3-5mm), subhedral aggregates of quartz (~5%) A quartz vein cuts the intrusive phase. This vein consists of fine-grained (~0,5mm) anhedral aggregates that cuts and replaces plagioclase borders. The quartz is stained by Fe oxides along some fractures. Mineralization and alteration are dominated by the occurrence of very fine-grained (0.1mm), iron stained carbonate that occurs as fractures and interstices in-filling either the quartz vein or the intrusive rock. Carbon-ate is accompanied by fine-grained (~0.1-1mm) chlorite, fine-grained pyrite and traces of bladed to anhedral magnetite. Pyrite is also present as late stage veining that cuts all the mineralogy and partly seems to be re-sponsible for the occurrence of clay alteration after chlorite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD030@89.9m within the Unit 1 in the El Alacran deposit. This sample corresponds to a medium to coarse-grained porphyritic diorite? composed of anhedral plagioclase of <1mm to 3mm in diameter. This rock contains and isolated quartz crystal (1mm) and a low proportion of mafic minerals relative to the plagioclase content. This diorite displays primary magnetite In the groundmass and selectively replacement of chlorite+sericite+albite? alteration with a fine-graine disseminated, euhedral pyrite and accompanied by carbonate. The diorite is cut by a quartz+hematite veinletwith K-Feldspar (?). The goal with this sample is to define K-Felds? occurrence in the sample and the nature of the quartz fragment. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclase20%15%Fine to very fine-grained (0.05 to 0.1mm) anhedral quartz and chlorite and subhedral to euhedral plagioclase with tabular shapes partially replaced to brown dusty mineral.Medium-grained (up to 3mm) subhedral to euhedral phenocrysts with tabular shapes partially replaced to brown dusty alteration mineral that gives this coloration to the rock. Also, plagioclase is selectively replaced to Car and SerPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Quartz 5% Medium to coarse-grained (3-5mm), colorless, subhedral aggregates as phenocrysts in the intrusive rock. This is cut by the Car+Ch+Mag +Py bearing (Musk) veinsSMA_AL_1801_JM_113Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsPyrite 1% Fine-grained (up to 0.7mm), anhedral aggregates disseminated in the sample either in the intrusive or in the vein. Ccp (Traces)* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Chlorite18.0%3%Fine-grained (~0,5mm) anhedral, disseminated aggregates. Also occurs as alteration product rimming plagioclase. Fine-grained (~0.1-1mm), pale green, anhedral to flaky aggregates that occurs in the groundmass and replacing anhedral former minerals? This occurs also in veinlets accom-panied by CarQuartzSMA_AL_1801_JM_113Magnetite TrVery Fine-grained (<0.1mm) dark grey, anhedral to bladed aggregates, accompanied by carbonate and Chl. Carbonates 4%Very fine-grained (0.1mm), Fe stained colored, anhedral, occurs as fractures infill of the rocks and vein, accompanied by magnetite.C DPhotomicrographsJM113. A) Microphotograph 5X, showing the infill of magnetite + pyrite and chlorite in quartz. B) Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the contact zone between the intrusive rock and the quartz vein. Note the brownish dusty alteration in the intrusive phase. D) Same photo C, but under XPL + RL. E) Microphotograph 10X, showing a late pyrite + carbon-ate dominated veinlets cutting the quartz vein and the intrusive rock. F, Same photo E, but under XPL + RL.Sample ID:A BE F<QtzSMA_AL_1801_JM_113Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Mag<Qtz1<PyCar>Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) <Qtz<Mag<Qtz<Qtz<Mag<PyCar><Qtz<Chl<Qtz<Py<Py<QtzQtz Vein<PyQtz Vein<Py<PlagIntrusive Phase<QtzQtz Vein<PyQtz Vein<Py<PlagIntrusive Phase<Qtz1<PyQtz Vein<Car+Py+Mag<MuskQtz Phenocryst<Qtz1<PyQtz Vein<Car+Py+Mag<MuskQtz Phenocryst<Chl+FeOxPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD034@115.50El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_114Polished Thin section Description This sample corresponds to a fine-grained, coarse-laminated volcanic rock highly altered with no evidences of relictic former mineralogy. The alteration is dominated by the occurrence of very fine-grained albite>>Qtz (~30%) that intergrows with very fine to fine-grained (up to 1mm) Mg-rich chlorite. This assemblage is al-tered to a patchy aggregates of medium grained (3mm) carbonate (~35%) that also replaces apatite. Euhedral titanite occurs with carbonate and sulphides. A FeOx staining overprint event affected albite and minor to chlorite giving to the rock a brownish coloration. Mineralization occurs as traces of pyrite that intergrows with fine to very-fine grained sphalerite and chalco-pyrite and sericite. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD034@115.50m within the Unit 2, TufF lithofacies in the El Alacran Deposit. This corresponds to a pale-green, medium to fine-grained lapilli tuff with coarse (up to 1cm) banding. Those bands are selectively replaced to chlorite + sericite and fine to very fine-grained calcite. There is the occurrence of a brownish mineral that is present also along some of the rock fractures. Very fine-grained eu-hedral pyrite occurs as disseminated in the rock (<0.5%). The goal with this sample is to define the paragenesis of Ab+Chl and brownish alteration mineral in a laminated coarse TufF lithofacie. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_114Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsPyrite + Chalcopyrite 1% Fine-grained (0.4mm), anhedral aggregates intergrowing carbonate , sphalerite and chalcopyrite* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate30.0%35%Very fine-grained (<0,1mm) colorless, anhedral to semi tabular and flaky , aggregates , intergrowing with chlorite and partially replaced by Car and SerMedium-grained (3mm), colorless, anhedral aggregates that occurs as patchy alteration over Ab+Chl. This selectively replaces apatite.AlbiteSMA_AL_1801_JM_114Chlorite 10%Very fine- to fine-grained (up to 1mm), green pale, anhedral to flaky aggregates inter-growing with Ab>>Qtz?. This is replaced by carbonate Apatite 1%Fine to medium-grained (up to 1mm), colorless, high-relief, anhedral aggregates re-placed by Car + TitaTitanite TrVery fine grained (up to 0.1mm), colorless to pale greenish-brownish, high-relief, sub-he-dral to euhedral intergrowing with carbonateFeOx-Staining 20%Very fine-grained (<0.05mm), anhedral aggregates staining albite and chloriteSphalerite 1% Fine-grained (0.2mm), anhedral aggregates intergrowing carbonate and pyrite and traces of chalcopyriteSericite TrVery fine-grained (<0.05mm), anhedral to flaky aggregates after chl and ab AlterationAlbiteChloriteCarbonateApatiteTitaniteFe-StainSericiteMineralizationPyriteChalcopyriteSphalerite??C DPhotomicrographsJM114. A) Microphotograph 20X with conoscopy light, showing the pervasive occurrence of albite ± quartz + chlorite alteration in the rock. Note the local sericite alteration. B) Same photo A, but under XPL + RL. C) Microphotograph 10X, showing a carbonate and sulphide zone replacing previous apatite and selectively the albite zone. D) Same photo C, but under XPL + RL. Sample ID:A BSMA_AL_1801_JM_114Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Qtz<ChlMag: 20xXPL+RL0.2mmXPL FOV~ 1094 Um (Length)Mag: 20xPPL+RL0.2mmPPL FOV~ 1094 Um (Length)<Ab<SerAb+Qtz<Qtz<Chl<Ab<SerAb+Qtz<Ser<ChlAb+QtzCarAp<Tita<Py<Ser<ChlAb+QtzCarAp<Tita<PyPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD068@105.3El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_117Polished Thin section Description This thin section corresponds to amygdalar basalt with destructive albite alteration and minor chlorite occur-rence. Albite occurs as fine-grained (<1mm) anhedral aggregates that replace some rock-former plagioclase. Medium-grained aggregates (<2mm) of carbonate (~25%), very fine-grained titanite (~10%), and sericite alter-ation replace selectively the hydrothermal albite. Chlorite alteration occurs as selective patchy replacement and the amygdalar. Traces of chalcopyrite occurs as infill accompanied by Car and Chl PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD068@105.3m in the Unit 3, TufA lithofacies in the El Alacran Deposit. This sample corresponds to a pale-gray to brownish white, amygdaloidal basalt?. The amygdales sizes varies from 0.3 to 1cm in length. Which are highly-altered to chlorite and calcite. The groundmass is fine to very fine-grained and it is pervasively altered to sericite + carbonate and albite(?). The goal with this sample is to characterize the paragenesis of albite+sulphides in the lithofacie TufA. Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_117Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCcp Tr Very fine-grained aggregates as in-fill accompanied by Car +Chl* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate45.0%30%Fine-grained (<1mm) anhedral aggregates. This phase is difficult to distinguish from the primary plagioclase. Evidences as the undulated extinction, irregular borders and alter-ation to Ser are used as indicative for hydrothermal albite occurrence. Medium-grained aggregates (<2mm), selectively replacing plagioclase. Also as in-fill in the rock vesicles. Carbonate is mostly associated with crystalline rock associated with Ser and titanite traces.Albite - plagioclaseSMA_AL_1801_JM_117Rutile/titanite 10%Very fine-grained, reddish to brown aggregates. Optically, the light-grey birefringence and isotropic (opaque) characterizes the rutile. Rutile intergrows with crystalline, high relief euhedral titanite. Chlorite 10%Fine-grained (0.3mm), pale-green, radiated, sub-rounded, occurs as patchy and as amyg-dales infill intergrowing with Car. Chl is locally altered or replaced to Ser+CarSericite 3%Very fine-grained (<0.1mm) flaky aggregates. Pale-green to colourless mostly associated with carbonate with replacement of the plagioclase and albite. AlterationAlbiteChloriteRutile/titaniteCarbonateSericiteMineralizationChalcopyrite??C DPhotomicrographsJM117. A) Microphotograph 5X, showing the infill occurrence of carbonate and chlorite with carbonate wall rock alteration. B) Same photo A, but under XPL + RL. C) Microphotograph 10X and conoscopy light, showing the selective replacement of sericite and carbonate after former plagioclase and albite. D) Same photo C, but under XPL + RL. E) Microphotograph 10X, showing the local replacement of chlorite by carbonate. Also, note the occurrence of apatite crystals with the carbonate. Sample ID:A BESMA_AL_1801_JM_117Mag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)<Car<Relictic AbCar>Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Chl<Car<Relictic AbCar><Chl<Car+Ser<Relictic AbSer>Mag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length)<Former Plag<Car+Ser<Relictic AbSer><Former Plag<Car+Ser<ApatiteChl>CarbonateAb>PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD081@72.2mEl AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1801_JM_118Polished Thin section Description This sample corresponds to a fine-grained lapilli(?) tuff without evidence of the former mineralogy. Alteration is strong to pervasive composed of fine to very fine-grained anhedral quartz (~55%) with multiple fluid inclusions and mineral inclusions of apatite(?). The quartz intergrows and locally is overgrown by fine to very fine-grained (up to 1mm) magnetite (~20%) that intergrows with fine-grained radiate chlorite (~4%). The magnetite is transformed to hematite (martite) after the contact with pyrite. Mineralization is dominated by medium-grained (<2mm) chalcopyrite (~10%) and pyrite (~8%) that occurs as rock fracture-infill after magnetite. Carbonate veins (~ 1%) also cut the sulphides. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD081@72.2m within Unit 2, MudSil lithofacies in the El Alacran Deposit. This corresponds to a dark, fine-laminated siltstone(?) with banding replacement to silica and mag-netite along stratigraphic planes. This sample displays some crosscutting relationship fine-grained aggregates of pyrite and chalcopyrite, which are accompanied by chlorite, carbonate, and hematite. The goal with this sample is to define if the hematite is a martitized effect produced by the sulphide veins.Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.SMA_AL_1801_JM_118Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsChalcopyrite 10% Medium-grained (2mm), anhedral aggregates occurs as rock infill and patchy, enclosing euhedral Mag and minor Py. * size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Magnetite 55%20% Fine to very fine-grained (0.2mm), colourless, anhedral aggregates with multiple fluid inclusions and mineral inclusions (Ap?), this intergrows and locally is overgrown by magnetite. Fine to very fine-grained (up to 1mm), dark grey, anhedral aggregates that intergrow with quartz and it is embedded by pyrite. QuartzSMA_AL_1801_JM_118Chlorite 4%Fine-grained (0.5mm), dark green, euhedral, radiated aggregates that intergrows with magnetite and are enclosed by Ccp.Martite 2%Fine to very-fine grained (<0.2mm), anhedral, grey with a whiteish tint (properties of hematite), replacing magnetite, after the contact? pyrite. Carbonate 1% Fine-grained (<0.1mm), colorless aggregates that occurs as veinlets after pyrite and also acompanied of radiated chlorite.Pyrite 1% Coarse-grained (1mm), anhedral to subhedral aggregates mostly occurs along a frac-ture-filling vein. This encloses and replaces the magnetite to martite and it is cut by carbonate in a synthetic(?) filling vein.AlterationQuartzMagnetiteChloriteMartiteCarbonateMineralizationChalcopyritePyrite????C DPhotomicrographsJM118. A) Microphotograph 2X, showing the infill of pyrite in a silica altered host rock with a later carbonate event. B) Same pho-to A, but under XPL + RL. C) Microphotograph 10X, showing the some evidences of intergrown of radiated chlorite, magnetite and carbonate. D) Same photo C, but under XPL + RL. E) Microphotograph 50X, showing the transformation of magnetite to hematite (martite). This detail is close to the pyrite vein contact. F) Same photo E, but under XPL + RL.Sample ID:A BE FSMA_AL_1801_JM_118<PyCar>Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<QtzMag: 2xPPL+RL2mm Mag: 2xXPL+RL2mmPPL FOV~ 1,45mm (Length) XPL FOV~ 1,45mm (Length) <Qtz<PyCar><Qtz<Qtz<Chl<ChlCar><Car <Mag<Chl<ChlCar><Car <Mag<Chl<Chl<He (Martite)<Mag<Mag<He (Martite)<He (Martite)<Mag<Mag<He (Martite)Mag: 50xRL0,08mm Mag: 50xRL0,08mmRL FOV~ PPL FOV~ 441μm (Length) RL FOV~ PPL FOV~ 441μm PETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD042@325El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1709_JM_078Polished Thin section Description This sample corresponds to a hypocrystalline rock with a subtle flow-banding and grain gradation. Two differ-ent volcano-clastic lithofacies can be differentiated. One very fine-grained and one fine-grained. The very fine-grained lithofacie corresponds to a poorly sorted matrix supported tuffaceous breccia. The ma-trix is mostly conformed of glass and minor anhedral plagioclase fragment, whereas, the fine-grained lithofa-cie is formed by well-sorted surrounded fragments of basaltic rocks, plagioclase, and pyroxene. Alteration is dominated by chlorite (~20%) that occurs in the groundmass in the very-fine grained lithofacies and as selective replacement of the clast in the coarse lithofacie. Very fine-grained traces of hematite after magnetite (?) are distributed in the sample giving a reddish color-ation to the sample. PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD042@325m in the Unit 3, TufF+TufL lithofacies of the El Alacran Deposit. This corresponds to a fine to medium-grained, coarse-laminated interbedding of fine-grained and lithic tuffs. The tuff banding is composed by very fine-grained chlorite that in some places is locally replaced to hematite. The lithic tuff has up to 1mm altered fragments of chlorite + calcite ± epidote. In some parts of the sample, there are welded lapillies that indicates a weak orientation. The goal with this sample is to character-ize the hematite alteration of Unit 3 that is common in the distal areas of the deposit.Mineral Modal Textural and Mineral DistributionRock-forming mineralsMatrix (Fine-grained facie)Rock fragments60%3%Very fine-grained, brown colored, anhedral aggregates replaced to chlorite and hematite.Fined to medium-grained (up to 1mm), surrounded, colorless fragments of crystalline material possibly basaltic. This fragments area altered to chlorite.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Plagioclase 1% Fine-grained (0.6mm), colorless, tabular aggregates selectively replaced to chlorite. SMA_AL_1709_JM_078Pyroxene Tr Fine-grained (up to 0.7mm), colorless, subhedral, high-relief , show twinning and high birefringence. This is possibly clinopyroxene. Vitriclasts 2% Fined to medium-grained (up to 1mm), surrounded, brownish colored fragments selec-tively altered to chlorite.Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4>20%10-20%1-10%<1% Undefined Distribution??MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration minerals* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate 20%2% Fine-grained (0.4-0.6), pale-green, anhedral, aggregates with patchy replacement in the rock matrix and selectively replacement in the fragments of the coarse-grained facie Fine-grained (up to 0.5mm), pale green to colourless, pleocroic, anhedral aggregates replacing hornblende.Chlorite SMA_AL_1709_JM_078Epidote TrVery fine-grained (<0.1mm), high-relief , yellow to sublte green accompanied of carbon-ate and chloriteHematite/Magnetite TrVery fine-grained (<0.05mm), anhedral, disseminated in the rock matrix. This corre-sponds to primary hematite/magnetite that is being replacing to dusty reddish second-ary hematite. C DPhotomicrographsJM078. A) Microphotograph 50X, showing the chlorite groundmass alteration in the fine-grained facie. Note the alteration of the magnetite to hematite. B) Same photo A, but under XPL + RL. C) Microphotograph 10X, showing the fine-grained fragmental lithofacie with some vitriclasts and free crystal occurrence. D) Same photo C, but under XPL + RL. Sample ID:A BSMA_AL_1709_JM_078Mag: 10xPPL+RL0,4mm Mag: 10xXPL+RL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)<Mag / He<Chl<Chl<PlagCar><Mag / He<Mag / He<Chl<Chl<PlagCar><Mag / He<Chl<Plag<Vitriclast<Plag<Vitriclast<Plag<Chl<Plag<Vitriclast<Plag<Vitriclast<PlagGlassy Matrix>Mag: 50xPPL+RL0,08mm Mag: 50xXPL+RL0,08mmPPL FOV~ PPL FOV~ 441μm (Length) XPL FOV~ PPL FOV~ 441μm PETROGRAPHY REPORT Petrographer: Julian Manco MSc-Candidatev. APRIL 2018Project:SAMPLE LOCATIONSample ID:1 cmCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE San Matias Project Prospect:Location:El Alacran SMA_AL_1704_JM_051Country: ColombiaStained section offcutACD036@106.9SummaryLithology: Porphyritic Px+Hb Gabro (200-250 point-counted)Alteration minerals: Chlorite, Actinolite, EpidoteIntensity of alteration: PervasiveMineralization: Traces of Pyrite Fracture infill: Nv Purpose Characterize this syn-mineral dike to to eventually separate zircons to date by U/PbPolished Thin section Description This sample corresponds to a fine to medium-grained holocrystalline rock with porphyritic texture. Ground-mass constitutes about 60% of the sample and it is composed mostly of plagioclase and amphiboles. The phenocrysts are mostly of medium-grained (up to 2mm), subhedral to anhedral plagioclase (59%), medi-um-grained (1- 3mm length) euhedral pyroxene (4%) and hornblende (35%). Primary magnetite occurs as fine-grained traces of euhedral crystals.Alteration intensity is intermediate to strong and it is produced by the occurrence of fine grained (<1.0mm) striated, aggregates of albite (10%) mostly replacing the fine plagioclase in the groundmass. Also by chlo-rite-zoisite (7%) that occurs as medium to fine-grained (up to 1mm) aggregates, that pervasive replace former tabular shapes of either mafic minerals or plagioclase. This occurs along with fine-grained (~0.2mm) aggre-gates of actinolite (3%) + epidote (tr) + carbonate (7%).Mineralization is occurs a very fined-grained traces of disseminated pyrite. Mineral Modal Textural and Mineral DistributionRock-forming mineralsGroundmassPlagioclaseClinopyroxene>Hornblende 60.0%59.0%4.0%Fine-grained (<0,1mm) groundmass composed of plagioclase and amphibole. Plagioclase is high to pervasive altered to albite The total plagioclase counts the groundmass and phenocrysts: Phenocrysts are medi-um-grained (up to 2mm), subhedral to anhedral partially replaced to chlorite, albite and Medium-grained (1- 3mm length) euhedral, tabular aggregates altered to chlorite and carbonate. It present a fine fibrous texture (alteration?). Possibly some of these crystals corresponds to hornblende, but given the pervasive alteration, it is hard to distinguish between both phases. This phase is defined based on the former crystal morphology ( tabular equidimensional) and some relictic macla in the pyroxene crystals. PETROGRAPHY REPORTv. APRIL 2018Sample ID: SMA_AL_1704_JM_051Hornblende 25.0% Medium to Fine grained (~1.2mm- 2mm) euhedral crystals with tabular shapes and semi hexagonal facets in orthogonal cuts to C axis. It occurs as semi radiated aggregates produced by the nucleation on previous minerals. This is altered to “UknownMineral” 2 described below. Given the pervasive alteration is hard to distinguish pyroxene from hornblende. Optically this clinopyroxene is highly pleocroic with high birefringence, high relief and an angled extinction.Percentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration mineralsCarbonate 7.0%Fine to medium-grained (~1mm), anhedral, colourless, aggregates occurs replacing mafic minerals and locally plagioclase. This also occurs with chlorite-zoisite Chlorite-Zoisite 70% Chlorite-Zoisite 7% Medium to fine grained (up to 1mm) pale green, anhedral aggregates that occur pervasively replacing tabular shapes of pyroxene and hornblende and also plagioclase. This also occurs intergrowing with actinolite. Albite 10.0% Fine-grained (<1mm), striated, semi tabular aggregates mostly replacing the fine pla-gioclase-rich groundmass and some of the phenocrysts?Actinolite 3% Fine-grained (0.2mm) pale green, high relief, acicular aggregates that intergrow with chlorite. Occurs mostly with epidote. Optically present birefringence of Grey and yellow of 1st order. pyrite Tr Very fined-grained traces of disseminated aggregates* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite AMag: 2xPPL+RL2mmCBDPhotomicrographsJM051. A) Microphotograph 5X, showing the selective alteration of Chl after pyroxene and carbonate after pyroxene. B, Same photo A, but under XPL + RL. C) Microphotograph 2X, showing the porphyritic texture of the rocks and the selective alteration of carbonate. D. Same photo C, but under XPL + RL.E) Microphotograph 20X under XPL + RL., showing the Chl + Act intergrowth replacing selectively former crystals. Mag: 2xXPL+RLMag: 5xPPL+RL0,8mm Mag: 5xXPL+RL0,8mm2mmPPL FOV~ 11mm (Length) XPL FOV~ 11mm (Length)XPL FOV~ 4.35mm (Length) XPL FOV~ 4.35mm (Length)<Car<Chl<Ab<ClPxHb?chl<PlagEMag: 20xXPL+RL0,2mmXPL FOV~1094μm (Length)<Car<Chl<Ab<ClPxHb?chl<Plag<Car<Chl<Ab<ClPxHb?<Plag<Chl<Car<Chl<Ab<ClPxHb?<Plag<Chl<Car<Chl<Act<Act<Act<PlagPETROGRAPHY REPORTPetrographer: Julian Manco MSc-Candidatev. July 2018Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD016@128.2El AlacranCountry: Colombia1 cm Slab ScanCrossed-Polarized Light (XPL)Plane-Polarized Light (PPL) HAND SAMPLE SMA_AL_1705_JM_064 Polished Thin section Description This section corresponds to a pervasive altered rock, with no visible former constituents. The dominant alteration corresponds to fine to very fine-grained (up to 0.1mm) sericite (35%) accompanied by coarse grained (>7mm), anhedral carbonate (30%) that occurs as infill minerals accompanied by fine-grained radiated semicircular chlorite (10%) and medium to coarse-grained (up to 5mm) prismatic to anhedral aggregates of Zoisite-Epidote. These minerals occurs with titanite, traces of apatite and prismatic aggregates of quartz. Carbonate and sericite also replaces fine to very fine-grained (up to 0.1mm) albite (20%) that inter-grows with fine-grained, anhedral aggregates of quartz. Mineralization occurs as fine-grained (0.7mm) traces of pyrite embedded in the carbonate + epidote Vein.PETROGRAPHY REPORTv. APRIL 2018Sample ID:Macroscopic Sample DescriptionThis sample was taken from the Drillhole ACD016@128.2m in the Unit 2, TufF lithofacies of the El Alacran Deposit. This sample corresponds to a pale to dark green, banded ash tuff highly altered to chlorite and cut by an actinolite? and carbonate vein. The center band/vein is zoned from a central actinolite crystals of 1.5cm length (25% of the sample) that in-tergrows with calcite. This outwards to a zone of dark fine-grained (<0.5mm) chlorite (10% ) and sericite (7%) ,andcarbonate. Possibly, as part of the vein halo rutile ± epidote crystals (2%) are formed. The outermost zone corresponds to very fine sericite 30% of the sample that intergrows with fine carbonate and fine disseminat-ed chlorite. Pyrite occurs as (1cm in size) subhedral aggregates of Py that are cut by fine-grained sericite and carbonate. At a bigger scale, it seems Py + carbonate + chlorite are cut by very fine sericite + carbonate + rutile association. SMA_AL_1705_JM_064 Mineral Modal Textural and Mineral DistributionRock-forming mineralsPercentages do not add to 100% as primary minerals can be completely replaced. Percentages shown to estimate relative percentages of primary minerals.Paragenetic TableMineral Stage 1 Stage 2 Stage 3 Stage 4MineralizationMineral Modal Textural and Mineral DistributionHydrothermal alteration minerals* size ranges: coarse-grained>5mm; medium-grained 1-5mm; fine-grained 0.05 (50μm) - 1 mm; very fine-grained<0.05mmChl=Chlorite, Qtz= Quartz, Rut=Rutile, Ab=Albite, Ap=Apatite, Car=Carbonate Fe Stain=FeOx stain, Ser=Sericite, Py=Pyrite, Ccp=Chalcopyrite, Sph=S-phalerite, Tita=Titanite, Mag=Magnetite, Mus=Mushketovite Carbonate35.0%30%Fine to very fine-grained (up to 0.1mm),pale green, anhedral to flaky aggregates accom-panied of Car, and as alteration product of albiteCoarse-grained (>7mm), anhedral occurs as infill minerals accompanied by chlorite and prismatic Qtz. Also, Car occurs as patchy with sericite replacing albite, apatite and locally Chl and Qtz.Sericite Albite 20%Fine to very fine-grained (up to 0.1mm), colorless, anhedral, low relief, low BR, diffuse contacts. altered to Sericite and Car Chlorite 10%Fine-grained (0.2mm), pale-green, radiated semicircular, as an early stage of the carbon-ate+titanite ocurrenceZoisite-Epidote 10%Medium to coarse-grained (up to 5mm), pale yellow to green amber, pleocroic , high relief, prismatic to anhedral aggregates intergrowing with carbonate and locally replaced for this.AlterationZoisite-EpidoteQuartzChloriteCarbonateAlbiteSericiteTitaniteApatiteMineralizationPyriteSMA_AL_1705_JM_064 Pyrite Tr Fine-grained (0.7mm), anhedral to subhedral aggregates, embedded in the Car + Epidote vein.Quartz 1%Fine-grained (0.3mm), colorless, euhedral to prismatic aggregates intergrowing as an early phase in the carbonate vein, accompanied by chl. Also occurs as fine-grained, anhe-dral aggregates accompanied by albite Titanite TrFine-grained (up to 0.9mm), amber, with multiple IR, euhedral aggregates accompanied of carbonate and apatite traces. Undefined Distribution??????C DPhotomicrographsJM064. A) Microphotograph 5X showing the occurrence of apatite in carbonate veins. B) Same as microphotograph A, but under XPL + RL. C) Microphotograph 10X, showing the fine-grained association of Ab + Qtz. D) Same photo C, but under XPL + RL. E) Microphotograph 10X showing the local replacement of Car after zoisite+epidote crystals , also note titanite cut by carbonate. F) same as microphotograph E, but under XPL + RL. Sample ID:A BEMag: 5xPL+RL0.8mm PPL FOV~ 4.35mm (Length) Mag: 5xXPL+RL0.8mm XPL FOV~ 4.35mm (Length)Mag: 10xPPL+RL+CL0,4mm Mag: 10xXPL+RL+CL0,4mmPPL FOV~ 2.18mm (Length) XPL FOV~ 2.18mm (Length)Mag: 10xPPL+RL0,4mmPPL FOV~ 2.18mm (Length)<Car<ChlSMA_AL_1705_JM_064 FMag: 10xXPL+RL0,4mmXPL FOV~ 2.18mm (Length)<Tita<Apa<Car<Chl<Tita<ApaAb+QtzCarAb+QtzCar<Chl<Chl<Car<Chl<Ep<Ser<Tita<Ep+Zoisite<Car<Chl<Ep<Ser<Tita<Ep+Zoisite Appendix C : Geochemistry C.1. Whole Rock Geochemistry Database C.2. Lithogeochemistry Plots and Alteration Screening C.3. CIPW Normative mineralogy of the San Matias District intrusions C.1 Whole Rock Geochemistry Database Table 1. Whole rock geochemistry results from the San Matias District samples. SAMPLE BATCH ANALYSIS WEIGHT LOI TOT/C TOT/S SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O MnO TiO2 P2O5 Ba Be Co Cs Ga % % % % % % % % % % ppm ppm ppm ppm ppm SMA_AL_1612_JM_021 VAN17001391 MDRU-LITH17 0.17 3.10 0.07 0.01 54.2 17.8 6.3 6.37 5.82 5.77 0.26 0.12 0.29 0.06 146 1 18.8 0.5 11.9 SMA_AL_1705_JM_022 VAN17001391 MDRU-LITH17 0.17 1.80 0.17 0.02 63.3 16.8 6.64 1.38 2 6.52 1.08 0.09 0.32 0.1 606 1 2.8 0.05 12.4 SMA_AL_1705_JM_023 VAN17001391 MDRU-LITH17 0.18 2.31 0.18 0.03 55.1 15.4 9.18 5.13 6.09 4.69 1 0.15 0.43 0.12 634 0.5 21.6 1.3 11.8 SMA_AL_1705_JM_024 VAN17001391 MDRU-LITH17 0.18 1.75 0.11 0.01 55.9 17.3 8.57 7.88 4.38 2.51 0.76 0.16 0.45 0.1 264 0.5 25.2 0.05 12.4 SMA_AL_1705_JM_025 VAN17001391 MDRU-LITH17 0.18 2.55 0.11 0.07 54.7 18.5 7.73 6.54 4.49 3.08 1.6 0.07 0.33 0.06 194 0.5 9 1.4 12.1 SMA_AL_1705_JM_026 VAN17001391 MDRU-LITH17 0.23 2.27 0.07 0.03 54 18.8 9.15 7.34 4.77 2.35 0.5 0.1 0.33 0.06 65 0.5 18.4 0.4 12.1 SMA_SJ_1705_JM_027 VAN17001391 MDRU-LITH17 0.16 0.94 0.03 0.13 53.4 20.9 7.02 10.7 3.8 2.12 0.68 0.1 0.32 0.08 106 0.5 19.8 1.1 14.5 SMA_SM_1705_JM_028 VAN17001391 MDRU-LITH17 0.19 1.07 0.02 0.04 58.2 17.1 8.1 7.58 4.26 2.59 0.81 0.14 0.42 0.08 179 0.5 20.4 0.4 12.6 SMA_SM_1705_JM_029 VAN17001391 MDRU-LITH17 0.1 1.42 0.03 0.01 53.2 14.3 10.7 8.81 6.34 2.7 0.98 0.17 1.08 0.23 404 2 35.8 0.4 14.6 SMA_SM_1705_JM_030 VAN17001391 MDRU-LITH17 0.14 1.56 0.05 0.26 54.8 18.1 7.94 9.18 4.9 2.3 0.95 0.13 0.39 0.07 217 0.5 24.7 0.05 12 SMA_SM_1705_JM_031 VAN17001391 MDRU-LITH17 0.14 2.12 0.13 0.02 52.8 17.7 9.56 9.56 4.95 2.11 0.45 0.16 0.5 0.07 112 0.5 28.5 0.05 12.8 SMA_SM_1705_JM_032 VAN17001391 MDRU-LITH17 0.18 0.74 0.04 0.62 58.7 17.2 6.73 8.22 3.15 3.6 0.3 0.13 0.96 0.18 213 2 14.2 0.05 16.6 SMA_SM_1705_JM_033 VAN17001391 MDRU-LITH17 0.18 0.91 0.04 0.01 50.6 18.5 10.9 10.5 5.67 1.73 0.45 0.18 0.47 0.06 134 1 33.6 0.05 13.3 SMA_CA_1705_JM_034 VAN17001391 MDRU-LITH17 0.16 1.76 0.10 0.48 61.6 16.5 6.36 6.45 2.65 2.87 1.15 0.09 0.32 0.11 245 0.5 16.7 0.4 11.8 SMA_JA_1705_JM_035 VAN17001391 MDRU-LITH17 0.16 2.39 0.23 0.23 62 16.5 5.89 5.76 2.71 2.89 1.21 0.13 0.32 0.11 357 0.5 17.2 0.5 11.1 SMA_SM_1705_JM_036 VAN17001391 MDRU-LITH17 0.17 7.17 0.83 0.07 48.7 17.3 8.89 8.35 4.39 2.98 1.2 0.15 0.49 0.15 314 0.5 27.4 1.3 11.7 SMA_SM_1705_JM_037 VAN17001391 MDRU-LITH17 0.19 1.27 0.03 0.27 52.8 19.4 8.38 10 5.02 2.22 0.54 0.15 0.39 0.09 150 0.5 24.5 0.05 13.2 SMA_AL_1704_JM_051 VAN17002798 MDRU-LITH17 0.15 3.89 0.55 0.07 53.8 17.3 6.14 6.22 5.94 5.36 0.93 0.11 0.29 0.05 373 0.5 8.5 3 12.2 SMA_AL_1704_JM_051 VAN18000540 MDRU-LITH17 0.09 5.11 0.79 0.05 53.2 17.4 6.16 5.48 5.61 6.01 0.59 0.12 0.29 0.05 218 0.5 7.7 1.8 11 SMA_CA_1705_JM_058 VAN17002798 MDRU-LITH17 0.26 0.52 0.01 0.08 63.7 15.9 6.79 6.3 2.57 3.36 0.29 0.1 0.3 0.1 239 0.5 16.8 0.2 12.4 SMA_ME_1705_JM_059 VAN17002798 MDRU-LITH17 0.23 0.19 0.02 0.03 61 14.5 9.49 4.4 2.44 4.87 1.14 0.13 1.48 0.33 745 1 21.9 0.3 19 SMA_ME_1705_JM_060 VAN17002798 MDRU-LITH17 0.18 1.31 0.06 0.66 73.8 13.6 1.8 2.06 0.8 3.12 3.75 0.01 0.13 0.04 1287 3 10.4 0.3 7.9 SMA_ME_1705_JM_061 VAN17002798 MDRU-LITH17 0.19 0.65 0.01 0.19 62.8 15.2 9.87 5.71 2.06 2.92 0.5 0.11 0.25 0.11 128 0.5 15.3 0.4 13.6 SMA_ME_1705_JM_062 VAN17002798 MDRU-LITH17 0.17 1.39 0.01 0.02 61.8 16.6 6.42 6.83 3.04 2.79 0.93 0.13 0.32 0.1 265 0.5 17.2 0.9 13 SMA_AL_1709_JM_067 VAN17002798 MDRU-LITH17 0.23 4.09 0.12 0.01 48.1 16.1 12.4 6.36 7.94 3.08 0.56 0.15 1.09 0.26 266 0.5 35.1 0.9 17.1 SMA_ME_1612_JM_100 VAN17001391 MDRU-LITH17 0.11 1.16 0.04 0.37 66.4 15.8 4.31 5.09 1.9 3.09 1.48 0.04 0.24 0.09 314 0.5 10.2 0.4 11.5 SMA_AL_1801_JM_125 VAN18000540 MDRU-LITH17 0.02 5.83 0.85 0.09 58.3 16.4 8.45 3.64 2.62 2.1 2.21 0.1 0.25 0.08 195 0.5 6.3 0.4 11.3 SMA_AL_1801_JM_126 VAN18000540 MDRU-LITH17 0.04 4.83 0.14 0.12 52.3 14.9 19.5 1.12 4.44 0.14 0.93 0.16 0.91 0.43 83 0.5 9.6 0.05 16.6 SMA_AL_1801_JM_127 VAN18000540 MDRU-LITH17 0.05 4.75 0.1 0.01 56.9 14.2 13.9 0.96 6.5 1.19 0.73 0.15 0.87 0.36 170 0.5 14.5 0.05 14.6 SMA_AL_1801_JM_129 VAN18000540 MDRU-LITH17 0.03 5.5 0.62 0.1 51.7 18.1 11.3 3.12 3.78 3.51 1.14 0.16 1.18 0.3 251 2 20 0.05 16.4 Continuation of Table 1. SAMPLE Hf Nb Rb Sn Sr Ta Th U V W Zr Y La Ce Pr Nd Sm Eu Gd Tb Dy ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm SMA_AL_1612_JM_021 0.4 0.5 3.2 0.5 355.9 0.05 0.01 0.01 187 0.25 13.1 7.2 1.1 3.1 0.53 2.7 0.78 0.35 1.02 0.18 1.16 SMA_AL_1705_JM_022 0.8 1 12.1 0.5 149.2 0.05 0.01 0.01 60 0.25 27.7 6.9 2.1 4.1 0.66 3 0.88 0.32 1.1 0.18 1.2 SMA_AL_1705_JM_023 1 1.3 10 0.5 312.8 0.05 0.5 0.1 214 0.25 31.1 9.6 3.4 7 1.11 5.3 1.35 0.42 1.44 0.25 1.65 SMA_AL_1705_JM_024 1 1.6 8.4 0.5 215 0.1 0.4 0.2 219 0.25 35.4 10.6 3.3 7.3 1.07 5.2 1.48 0.47 1.6 0.28 1.81 SMA_AL_1705_JM_025 0.5 0.4 33.3 0.5 217 0.05 0.01 0.01 174 0.25 18.1 6.6 1.2 3.2 0.49 2.6 0.71 0.33 0.9 0.16 1.13 SMA_AL_1705_JM_026 0.6 0.4 9.1 0.5 185.6 0.05 0.01 0.1 185 0.25 18 6.3 1 2.8 0.45 2.1 0.64 0.33 0.86 0.15 1.1 SMA_SJ_1705_JM_027 0.5 0.4 13.6 0.5 298.3 0.05 0.01 0.2 188 0.25 16.8 6.5 1.7 4.4 0.68 3.2 0.88 0.39 1.06 0.18 1.2 SMA_SM_1705_JM_028 0.7 0.9 13 0.5 274.9 0.05 0.01 0.01 226 0.25 24.1 8.5 2.3 5.4 0.79 3.7 0.95 0.42 1.32 0.23 1.35 SMA_SM_1705_JM_029 2.1 4.2 15.1 0.5 228.6 0.3 0.8 0.2 301 0.25 78.2 20 6.5 14.4 2.16 10.2 2.65 0.91 3.27 0.56 3.52 SMA_SM_1705_JM_030 1 1.1 19.1 0.5 175.8 0.05 0.4 0.2 207 0.25 34.6 8.2 2.6 5.6 0.79 4 1.1 0.36 1.21 0.22 1.39 SMA_SM_1705_JM_031 0.8 1 6.6 0.5 181.9 0.05 0.3 0.01 258 0.25 26.2 10.3 2.3 5.7 0.89 4.6 1.22 0.47 1.53 0.27 1.8 SMA_SM_1705_JM_032 2.4 4.3 2.9 0.5 189 0.3 0.8 0.4 224 0.25 85.4 17.4 7.1 15.6 2.27 10.6 2.64 0.96 3.05 0.52 3.3 SMA_SM_1705_JM_033 0.5 0.7 8.6 0.5 198.6 0.05 0.3 0.01 378 0.25 18.5 5.3 2 3.5 0.56 2.7 0.71 0.35 0.85 0.15 1.02 SMA_CA_1705_JM_034 1 1.5 21 0.5 249.7 0.1 0.5 0.3 132 1.4 32.1 9.5 4.2 8.2 1.19 5.4 1.39 0.42 1.49 0.24 1.43 SMA_JA_1705_JM_035 1.2 1.7 19.3 0.5 249.2 0.1 0.7 0.3 129 0.25 48.4 9 4.7 9 1.29 5.5 1.38 0.44 1.4 0.24 1.52 SMA_SM_1705_JM_036 0.7 0.4 32.3 0.5 910.8 0.05 0.6 0.3 226 0.25 25.6 7.6 3.6 7.7 1.15 5.3 1.24 0.5 1.25 0.21 1.36 SMA_SM_1705_JM_037 0.6 0.5 8.7 0.5 286.3 0.05 0.01 0.01 230 0.25 18.9 7.3 2.4 4.8 0.69 3.4 0.96 0.41 1.14 0.2 1.29 SMA_AL_1704_JM_051 0.5 0.5 16.2 0.5 267.1 0.05 0.01 0.2 186 0.25 15 8.2 0.9 2.3 0.47 2.9 0.86 0.38 1.27 0.23 1.49 SMA_AL_1704_JM_051 0.3 0.5 9.2 2 235.1 0.05 0.8 0.2 181 0.25 12.9 10.1 1.1 2.7 0.49 3.6 1.26 0.41 1.49 0.25 1.78 SMA_CA_1705_JM_058 1.1 1.6 3.6 0.5 277.9 0.05 0.6 0.2 131 0.25 45.9 9.8 4.3 9.3 1.19 5.6 1.45 0.49 1.55 0.27 1.67 SMA_ME_1705_JM_059 4.3 8.2 21.6 2 232.5 0.6 2.1 0.7 289 0.25 162.6 28 13.8 29.7 3.98 18.6 4.32 1.43 5.47 0.87 5.13 SMA_ME_1705_JM_060 1.9 2.6 31.6 0.5 182.4 0.2 3.2 0.6 34 0.8 72.1 3.1 4.3 6 0.69 2.4 0.52 0.28 0.46 0.08 0.53 SMA_ME_1705_JM_061 0.9 0.5 9.2 0.5 279.5 0.05 0.3 0.01 99 0.25 41.3 6.5 3.4 6.9 0.91 3.8 0.82 0.41 0.97 0.17 0.91 SMA_ME_1705_JM_062 1.4 2 15.9 0.5 309.9 0.1 0.8 0.3 151 0.25 47.7 9.1 4.3 9.5 1.22 5.3 1.34 0.43 1.48 0.25 1.72 SMA_AL_1709_JM_067 1.9 3.9 8.2 0.5 354.9 0.3 0.6 0.4 320 0.25 65.6 18.9 6.8 15 2.07 10.1 2.55 0.81 3.11 0.53 3.21 SMA_ME_1612_JM_100 1.5 2.6 21.5 0.5 250.3 0.2 1 0.5 91 1 60.2 8.1 4.8 9.6 1.27 5.4 1.23 0.38 1.2 0.2 1.31 SMA_AL_1801_JM_125 0.6 1 30.1 0.5 36.1 0.05 0.2 0.1 122 0.9 23.7 5.1 2.3 5.3 0.75 3.7 0.89 0.4 0.86 0.14 0.72 SMA_AL_1801_JM_126 2.7 4.7 12.6 0.5 13.9 0.3 1.7 0.8 167 1.7 92 14.9 9.2 19.2 2.49 11.3 2.56 0.71 2.64 0.39 2.27 SMA_AL_1801_JM_127 2.3 4.4 9.8 0.5 18.8 0.3 1.5 0.4 179 0.5 78.3 12.5 8.5 17.2 2.44 10.7 2.25 0.79 2.43 0.4 2.43 SMA_AL_1801_JM_129 2.8 4.9 15.6 0.5 72 0.3 2 0.5 243 0.5 94.6 23.3 8.1 19.3 2.99 14.1 3.99 1.47 4.69 0.74 4.76 Continuation of Table 1. SAMPLE Ho Er Tm Yb Lu Mo Cu Pb Zn Ni As Cd Sb Bi Ag Tl Se Sc K P Ti ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm SMA_AL_1612_JM_021 0.27 0.89 0.11 0.82 0.12 0.4 39.7 1.7 76 42 2 0.2 1.3 0.05 0.05 0.25 0.5 31 2158.38 261.853 1738.57 SMA_AL_1705_JM_022 0.28 0.75 0.12 0.82 0.14 0.4 10.5 5.1 36 1.6 2 0.05 0.5 0.05 0.05 0.25 0.5 15 8965.59 436.421 1918.43 SMA_AL_1705_JM_023 0.38 1.16 0.16 1.15 0.18 0.3 13.5 1.1 59 24.5 3 0.05 1.2 0.05 0.05 0.25 0.5 37 8301.47 523.705 2577.88 SMA_AL_1705_JM_024 0.38 1.23 0.17 1.16 0.18 0.5 134.6 1.2 81 14 1 0.1 0.1 0.05 0.05 0.25 0.5 30 6309.12 436.421 2697.79 SMA_AL_1705_JM_025 0.25 0.8 0.12 0.79 0.14 0.3 5.2 0.6 40 21.1 2 0.05 0.3 0.05 0.05 0.25 0.5 25 13282.4 261.853 1978.38 SMA_AL_1705_JM_026 0.24 0.78 0.12 0.85 0.13 0.3 122.3 8.4 63 28.2 2 0.05 0.4 0.05 0.05 0.25 0.5 27 4150.74 261.853 1978.38 SMA_SJ_1705_JM_027 0.24 0.72 0.11 0.82 0.11 6.5 73.9 1.3 34 12.8 1 0.1 0.05 0.05 0.05 0.25 0.5 22 5645 349.137 1918.43 SMA_SM_1705_JM_028 0.33 1.04 0.14 0.99 0.16 0.2 13.3 0.8 51 16.2 0.25 0.05 0.05 0.05 0.05 0.25 0.5 32 6724.19 349.137 2517.93 SMA_SM_1705_JM_029 0.76 2.09 0.31 2.05 0.3 0.4 173 1.4 94 70.8 3 0.05 0.1 0.05 0.05 0.25 0.5 35 8135.44 1003.77 6474.69 SMA_SM_1705_JM_030 0.33 0.97 0.15 0.92 0.15 0.4 59.3 0.9 44 17.5 1 0.05 0.05 0.05 0.05 0.25 0.5 33 7886.4 305.495 2338.08 SMA_SM_1705_JM_031 0.39 1.21 0.17 1.08 0.19 0.3 80.3 0.6 61 17 3 0.1 0.2 0.05 0.05 0.25 0.5 38 3735.66 305.495 2997.54 SMA_SM_1705_JM_032 0.71 2.14 0.28 1.9 0.29 0.6 81.8 0.7 29 12.9 1 0.05 0.05 0.05 0.05 0.25 0.5 23 2490.44 785.558 5755.28 SMA_SM_1705_JM_033 0.24 0.59 0.09 0.68 0.11 0.2 11.1 0.6 46 24.1 3 0.05 0.1 0.05 0.05 0.25 0.5 37 3735.66 261.853 2817.69 SMA_CA_1705_JM_034 0.36 1.07 0.15 1.07 0.18 0.4 58.7 1.4 75 7 2 0.7 0.1 0.1 0.05 0.25 0.5 19 9546.69 480.063 1918.43 SMA_JA_1705_JM_035 0.34 1.09 0.15 1.15 0.19 0.5 38.7 1.5 48 7.2 2 0.05 0.1 0.05 0.05 0.25 0.5 17 10044.8 480.063 1918.43 SMA_SM_1705_JM_036 0.29 0.93 0.14 0.86 0.12 0.5 88.8 2 57 21.9 3 0.05 0.1 0.05 0.05 0.25 0.5 29 9961.76 654.632 2937.59 SMA_SM_1705_JM_037 0.28 0.77 0.12 0.79 0.13 1 197.3 0.9 46 21.4 1 0.05 0.05 0.05 0.05 0.25 0.5 28 4482.79 392.779 2338.08 SMA_AL_1704_JM_051 0.3 1 0.14 0.89 0.14 2.8 6.3 3.2 42 21.4 3 0.1 0.3 0.05 0.05 0.25 0.5 30 7720.37 218.211 1738.57 SMA_AL_1704_JM_051 0.36 1.19 0.16 1.14 0.14 0.5 81.9 0.9 52 20 5 0.05 0.2 0.05 0.05 0.25 0.5 23 4897.87 218.211 1738.57 SMA_CA_1705_JM_058 0.39 1.01 0.15 1.21 0.19 0.3 907.9 0.9 60 7.1 0.25 0.1 0.05 0.05 0.3 0.25 0.5 17 2407.43 436.421 1798.52 SMA_ME_1705_JM_059 1.14 3.29 0.45 2.88 0.45 0.6 176.8 1.1 94 10.7 0.25 0.1 0.05 0.05 0.1 0.25 0.5 23 9463.68 1440.19 8872.72 SMA_ME_1705_JM_060 0.11 0.4 0.06 0.45 0.11 3.3 328.1 1.5 12 2.7 0.25 0.05 0.1 0.05 0.05 0.25 0.5 4 31130.5 174.568 779.36 SMA_ME_1705_JM_061 0.21 0.7 0.09 0.67 0.13 0.2 2330.7 0.7 48 5 0.25 0.05 0.05 0.05 0.8 0.25 1 13 4150.74 480.063 1498.77 SMA_ME_1705_JM_062 0.37 1.1 0.15 1.2 0.21 0.5 31.1 2 62 10.7 0.25 0.05 0.1 0.05 0.05 0.25 0.5 19 7720.37 436.421 1918.43 SMA_AL_1709_JM_067 0.71 1.99 0.25 1.89 0.27 0.05 6.9 1.6 81 78.9 0.25 0.05 0.05 0.05 0.05 0.25 0.5 30 4648.82 1134.69 6534.64 SMA_ME_1612_JM_100 0.27 0.96 0.14 1.01 0.18 0.3 302.5 1.1 20 4.5 1 0.05 0.1 0.05 0.05 0.25 1 13 12286.2 392.779 1438.82 SMA_AL_1801_JM_125 0.16 0.59 0.08 0.56 0.1 0.05 1.4 0.5 37 5.6 0.25 0.05 0.2 0.05 0.05 0.25 1 17 18346.2 349.137 1498.77 SMA_AL_1801_JM_126 0.53 1.74 0.25 1.79 0.28 0.6 139.8 164.7 1765 8.3 4 15.9 0.3 0.1 0.3 0.25 0.5 18 7720.37 1876.61 5455.52 SMA_AL_1801_JM_127 0.48 1.47 0.21 1.32 0.22 0.05 23.9 3.4 63 16.6 5 0.1 0.2 0.05 0.05 0.25 0.5 14 6060.07 1571.12 5215.72 SMA_AL_1801_JM_129 0.95 2.54 0.33 2.14 0.31 0.5 176.6 3.3 54 38.3 15 0.4 0.4 0.2 0.2 0.25 0.5 18 9463.68 1309.26 7074.19 C.2 Lithogeochemistry Plots and Alteration Screening QAQC Before shipping to the lab, the rocks were cleaned using rock saw and prepped on the MDRU facilities. For the QAQC purpose in each lab shipment were inserted at least two control samples. The reference material to measure major oxide accuracy correspond to BAS-1 (Figure. 1A) . The BAS-1 is a MDRU certified standard appropriate for basaltic or mafic to intermediate rocks. This standard meets the criteria (> 10 analyses, < 50% of data are outliers, %RSD < 10%, or > 10*DL). The objective with this standard is to ensure that the lab, digestion, and analysis are accurate. Similarly, for reproducibility in lab results, one duplicate control was inserted in every shipment. This control corresponds to a pulp sample with known chemical results from previous lab analysis. A comparison between the previous results on the new result are plotted along a correlation plot (Figure. 1B). The QAC methodology for standards samples consisted in define a warning (2*SD) and failure limits (3*SD) over elements with accepted values. In general, all the elements met the 3*SD criteria in the control samples except for the elements Lu (ppm) and MnO % in one of the control samples (Figure 1A). Analysis Methodology The least altered samples of the intrusive rocks were geochemically analyzed to characterize their compositions. Previous to the analysis major element oxides were normalized to 100% using the IOGAS software. Figure 1. QAQC diagrams for the control samples. A. Analysis of the standard material. B. Analysis of the Duplicates. ALTERATION ANALYSIS LOI Criteria The Loss of Ignition (LOI) can be also used as an indirect measurement of the alteration degree produced by hydration or calcification of mafic minerals (Lecher and Desilets, 1987). For unaltered basaltic, andesitic and rhyodacite rocks the LOI (%) under FeO correction has a LOI mean value of 1.67, 1.85 and 1.13 respectively (Flanagan, 1976). The LOI in the least altered rocks from andesite to rhyodacite can varies between 0.7 and 2.0 (Lecher and Desilets, 1987). Based on the LOI value, 3 categories were assigned to SMD samples. The least altered (0.7%< LOI < 2%), low altered ( 2% < LOI < 3%) and high altered (LOI >3%) (Figure 2A, Table 1). Under this alteration approach the high altered samples (LOI>3%) are from the El Alacrán volcanoclastic sequence (JM067, JM127, JM126, JM125, JM129), with the highest LOI correspond to JM036 from la Capitana area (Figure 2A, Table 1). As previously mentioned, the petrography of these samples shows evidences of glass devitrification with crystallization of clay mineralogy (smectite-palagonite?) (Photo 1. A-B). This syn-volcanic alteration can be in part responsible for the high LOI exhibited in this sample as well as in samples from the El Alacrán sequence. The Alteration Box plot of Chlorite Carbonate Pyrite (CCPI) vs Ishakawa Alteration Index (AI). This measures also the Na depletion associated with Mag (Chlorite) and K (Sericite) gaining (Large et al., 2001). Rocks from the El Alacrán Deposit basement (JM126 and JM127) shows AI values between 75-85 and CCPI greater than 85 (Figure 2B). This is consistent with a chlorite- Figure 2. Alteration Assesment using four different criteria. A. LOI Criteria, B. CCPI vs. AI. (Large, R.R. et al., 2001. C. Molar Element Ratio (K-metasomast criteria) (After Warren I., Simmons S.F., and Mauk J.L. 2007. D. Molar Element Ratio (Na-metasomast criteria) (Davies and Whitehead, 2006 Table 1. Alteration Criteria used in the San Matias District samples. Photo 1. A) Sample JM126. Microphotograph showing devitrification evidences and recrystallization to quartz and clay minerals. B) Same as microphotograph A, but under XPL + RL. C) Sample JM036. Microphotograph showing the breccia- pyroclastic texture of the sample with restricted carbonate alteration. Note the occurrence of hornblende crystals embedded in a glass matrix. D) Same as microphotograph C, but under XPL + RL. pyrite alteration domain. This sample exhibits variable devitrification process and clay recrystallization observed in the samples (Photo 1. A-B). This process may be accompanied by changes in whole-rock composition (Lipman, 1965; Lofgren, 1971; Friedman and Long, 1984) that produces the mafic glass increase the content in Ca-, Fe-, Mg- and Mn and forms minerals such as smectites, phillipsite, oxides and chlorite. (Gifkins, C et al., 2005) Sample JM033 shows alteration close to the carbonate-chlorite trend (Figure 2B). According to this sample petrography, (actinolite 12% and chlorite ≈5%), can explain the calcium-rich values in the sample that produce AI value to ≈35. Although the sample JM022 lies in the unaltered box, petrographically is one of the most altered samples among the analyzed rocks. The reduction on the CCPI (≈50) and AI (≈30), can be explained by a pervasive, mafic minerals destructive Ab+Si alteration that decreases the Fe-Mg in the sample. K Metasomatism Criteria Hydrothermally altered rocks most affected by K metasomatism will be characterized by largest K gains usually in expenses of Na and Ca losses. This has been wide studied in epithermal systems as a vector to mineralized centers (Warren I et al., 2007). The Molar element Ratio K/Al vs (2Ca+Na+K)/Al plot (Figure 2C) shows that samples JM125, JM022, and JM026 are associated with Ca or Na loss and ± K-gain. The increase in K content in the Sample JM125, can be associated with primary composition and sericite occurrence. Rocks from this same lithofacie (e.g. JM080) contains K-feldspar up to 20% in the groundmass (Dunne, 2016). This sample also present carbonate alteration (Ca gaining). The Ca loss in sample JM022 can be associated with the to Ca-rich plagioclase destruction after pervasive albite replacement (Photo 2.C-D) According to this criteria the analyzed samples are consistent with a low K, Na, Ca loss alteration. One exception corresponds to sample JM029 that show a marked Ca-Na gain (Figure 2C). Petrographically calcium gaining in this sample can be explained by protolith rock composition that correspond to a pyroxene-rich diorite in addition to a Ca-bearing hydrothermal/diuretic alteration (~10% zoisite-chlorite). Samples JM126, JM127, JM129 Photo 2. A) Samples JM125 microphotograph showing selective replacemen of carbonate and sericite after former feldspar crystal in a dacite volcanic breccia. B) Same as microphotograph A, but under XPL + RL. C) JM022. Photograph 20X, Representative of the chlorite and albite distribution in the groundmass. D) Same Photo C, but with Parallel Nicolls. Nothe the distribution of the claying mineral and some Fe-Ox in the chlorite in the upper central part. alteration behaviour may be highly influenced by chemistry chances in the rock former glass. The alteration in the glass however, is more likely to be formed during synvolcanic reaction produced by magma-sea water interaction rather than by hydrothermal alteration. Na Metasomatism Criteria The Na/Al vs K/Al Ratio Diagram form Davied and Whitehead (2006) (Figure. 2D) was used to estimate the alteration degree of the analysed samples. This diagram provides a mean for evaluating the degree of K, Ca and Na addition or depletion affecting the analyzed rocks. The composition of the samples can be compared to the composition of the hydrothermal minerals. For each sample was assigned an alteration category e.g. least altered, low altered and highly altered in accordance to the proximity to the zone where the least altered samples plot. (Figure 2D). The major alteration minerals observed under microscope correspond to pervasive albite (Na addition) and minor chlorite. Therefore, an increase or decrease of NA/Al ratio can be properly associated to these minerals occurrence. A Na-gain alteration trend is delineated with the samples JM05, JM021, JM022, JM023, and JM051 of the El Alacrán Deposit sills (Figure 3). The samples with the highest Na gain is JM022 (Figure 2D). This situation is also confirmed by petrography (Photo 1C-D). On the other hand, the sample JM126 shows a marked Na-loss, associated with the occurrence of chlorite + clay minerals that is consistent with the occurrence of clay mineralogy observed in petrography (Photo 2A-B) Sample JM060 shows a marked K-gain, possible associated with K-rich feldspar in the sample. However, K-feldspar occurrence is no properly confirmed by petrography and further work is required to corroborate its presence. Figure 3. Alkalis vs silica diagram for rocks of the San Matías District. Note in the right side the false alkaline composition of the analyzed sill samples. These samples indicate a medium- to pervasive-alteration to albite. In the left side the diagram, indicate that most of the SDM intrusions are low- to medium-k, however rocks from the Unit 1 and Montiel E plot in the high-k field; however, petrography indicate a primary occurrence of K-feldspar rather than K-metasomatism. Left: Subdivision of Subalkalic Rocks using K2O vs SiO2 (Various Authors). Right: Alkaline/Subalkaline Classification Diagram (Irvine and Baragar, 1971). CONCLUSIONS Samples JM022, JM051, JM126 and JM127 matched at least three alteration criteria here used therefore are considered the most altered samples among the analyzed samples. (Table 1). The dominant elemental chemistry alteration in the analyzed samples is characterized by Fe-Mg ± K gaining during syn-volcanic alteration (smectite?), followed by Na ± Ca gain with Fe-Mg loss in the hydrothermal stages. After comparing the alteration methods with the mineralogy observed under microscope, it can be stated that the alteration method that better reflect the alteration mineralogy is the Na- metasomatism criteria (Na/Al vs K/Al) followed by the LOI results (Table 1). C.3 CIPW Normative mineralogy Table 1. Calculation of the CIPW normative mineralogy in samples of the San Matias District SAMPLE SMA_AL_1612_JM_021 SMA_AL_1705_JM_022 SMA_AL_1705_JM_023 SMA_AL_1705_JM_024 SMA_AL_1705_JM_025 SMA_AL_1705_JM_026 SMA_SJ_1705_JM_027 SMA_SJ_1705_JM_028 Normative Minerals Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Quartz 15.9 16.75 5.8 6.34 16.28 17.65 10.63 11.42 16.43 17.99 11.96 12.91 28.47 31.56 Plagioclase 72.76 77.73 62.14 65.85 59.23 64.41 56.26 59.81 59.66 63 56.86 60.93 63.85 67.16 43.82 47.02 Orthoclase 1.77 1.97 6.5 7.09 5.91 6.68 4.73 5.31 9.46 10.51 2.95 3.35 4.14 4.62 4.73 5.42 Corundum 2.75 1.93 0.16 0.12 1.41 1.03 1.44 1.06 Diopside 6.69 5.91 5 4.49 2.97 2.65 4.82 4.28 Hypersthene 10.6 9.39 4.98 4.33 13.38 12.06 9.83 8.8 11.46 10.16 12.2 11.03 7.23 6.44 10.71 9.8 Olivine 0.87 0.77 Rutile 0.19 0.12 0.19 0.13 0.19 0.13 0.29 0.2 Ilmenite 0.21 0.13 0.21 0.13 0.43 0.26 0.43 0.26 0.21 0.13 0.21 0.13 0.21 0.13 0.21 0.13 Hematite 6.5 3.52 6.8 3.61 9.4 5.18 8.7 4.76 8 4.34 9.4 5.2 7.1 3.87 8.2 4.59 Apatite 0.23 0.21 0.23 0.2 0.23 0.21 0.23 0.21 0.23 0.21 0.23 0.21 0.23 0.21 0.23 0.21 Sphene 0.46 0.37 0.43 0.35 0.67 0.55 0.46 0.38 Total 100.09 100 99.7 100.01 99.81 99.98 100.1 100 100 100.02 99.88 100 100 100 98.1 99.99 SAMPLE SMA_SJ_1705_JM_029 SMA_SJ_1705_JM_030 SMA_SJ_1705_JM_031 SMA_SJ_1705_JM_032 SMA_SJ_1705_JM_033 SMA_SJ_1705_JM_034 SMA_SJ_1705_JM_035 Normative Minerals Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Quartz 10.38 11.63 13.1 14.25 13.11 14.42 17.22 18.46 10.53 11.74 23.76 25.13 25.02 26.38 Plagioclase 47.34 52.22 56.12 59.69 56.65 60.84 60.62 64.09 56.3 61.08 53.82 55.97 54 56.04 Orthoclase 5.91 6.85 5.91 6.65 2.95 3.36 1.77 1.97 2.95 3.41 7.09 7.76 7.09 7.74 Corundum 0.18 0.12 Diopside 11.92 10.98 6.09 5.45 6.98 6.32 5.15 4.55 7.05 6.47 1.68 1.46 Hypersthene 10.42 9.63 9.63 8.65 9.47 8.59 5.58 4.94 10.93 10.06 6.44 5.63 6.97 6.07 Olivine Rutile 0.19 0.12 Ilmenite 0.43 0.27 0.21 0.13 0.43 0.26 0.21 0.13 0.43 0.27 0.21 0.13 0.21 0.13 Hematite 10.9 6.16 8 4.39 9.8 5.44 6.8 3.68 11 6.19 6.3 3.36 6 3.19 Apatite 0.46 0.43 0.23 0.21 0.23 0.21 0.46 0.41 0.23 0.21 0.23 0.2 0.23 0.2 Sphene 2.15 1.82 0.71 0.58 0.67 0.56 2.18 1.77 0.67 0.57 0.46 0.37 Total 99.91 99.99 100 100 100.29 100 99.99 100 100.09 100 99.99 100.01 99.89 99.99 Continuation of Table 1 SAMPLE SMA_SJ_1705_JM_036 SMA_SJ_1705_JM_037 SMA_AL_1704_JM_051 SMA_AL_1704_JM_051 SMA_CA_1705_JM_058 SMA_ME_1705_JM_059 SMA_ME_1705_JM_060 SMA_ME_1705_JM_061 Normative Minerals Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Quartz 5.56 6.08 11.21 12.27 26.75 28.35 17.43 18.72 36.35 36.68 29.34 31.46 Plagioclase 59.9 64.49 60.74 64.87 68.41 72.9 73.19 77.93 56.28 58.82 55.78 59.82 36.39 36.62 51.79 54.67 Orthoclase 7.68 8.71 2.95 3.35 5.91 6.55 3.55 3.92 1.77 1.94 6.5 7.23 22.46 23.46 2.95 3.28 Corundum 0.76 0.51 Diopside 7.45 6.71 5.23 4.71 7.72 6.8 5.91 5.19 1.9 1.66 0.56 0.49 Hypersthene 8.26 7.46 10.28 9.29 8.5 7.51 5.26 4.64 5.6 4.9 5.72 5.07 1.99 1.66 5.23 4.63 Olivine 2.36 2.08 4.69 4.12 Rutile 0.09 0.06 0.08 0.05 Ilmenite 0.43 0.26 0.43 0.26 0.21 0.13 0.21 0.13 0.21 0.13 0.21 0.13 0.02 0.01 0.21 0.13 Hematite 9.6 5.31 8.5 4.7 6.4 3.46 6.5 3.5 6.8 3.64 9.5 5.15 1.8 0.92 9.9 5.36 Apatite 0.46 0.42 0.23 0.21 0.23 0.21 0.23 0.2 0.23 0.2 0.7 0.62 0.09 0.08 0.23 0.21 Sphene 0.67 0.56 0.43 0.36 0.46 0.37 0.46 0.37 0.46 0.37 3.4 2.77 0.26 0.21 Total 100.01 100 100 100.02 100.2 100.01 100 100 100 100.01 99.8 100 99.95 100 99.99 100 SAMPLE SMA_ME_1705_JM_062 SMA_AL_1709_JM_067 SMA_ME_1612_JM_100 SMA_AL_1801_JM_125 SMA_AL_1801_JM_126 SMA_AL_1801_JM_127 SMA_AL_1801_JM_129 Normative Minerals Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Weight % Volume % Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Norm Quartz 24.18 25.69 3.75 4.23 30.03 31.14 28.05 30.3 42.62 51.42 38.21 44.56 16.5 18.44 Plagioclase 54.31 56.67 56.78 63.06 51.38 52.53 37.31 39.72 3.53 4.14 12.5 14.61 45.72 50.86 Orthoclase 5.32 5.85 3.55 4.14 8.86 9.51 13.59 15.2 5.91 7.38 4.73 5.71 7.09 8.21 Corundum 0.16 0.11 4.44 3.19 13.47 10.82 11.1 8.62 6.53 4.86 Diopside 1.8 1.57 Hypersthene 6.89 6.04 20.67 19.25 4.73 4.05 6.97 6.22 11.71 11.66 16.94 16.31 9.96 9.19 Olivine Rutile 0.56 0.4 0.15 0.1 0.19 0.13 0.77 0.59 0.67 0.5 1.07 0.76 Ilmenite 0.21 0.13 0.43 0.27 0.09 0.05 0.21 0.13 0.43 0.29 0.43 0.28 0.43 0.27 Hematite 6.5 3.48 12.9 7.34 4.4 2.3 9 4.91 20.6 12.54 14.5 8.54 12 6.77 Apatite 0.23 0.2 0.7 0.65 0.23 0.2 0.23 0.21 1.16 1.16 0.93 0.9 0.7 0.64 Sphene 0.46 0.37 0.76 0.65 Total 99.9 100 100.1 99.99 100.03 99.99 99.99 100.01 100.2 100 100.01 100.03 100 100 Appendix D : Mineral Identification and Modeling D.1 Short-wave infrared (SWIR) analysis D.2 SEM-EDS-BSE analysis D.3 Leapfrog Interpolation Method D.1 Short-wave infrared (SWIR) analysis Introduction Reflectance spectrometry can be used to identify many minerals and mineral groups with molecular (OH, H2O, CO3, and NH4) or cationhydroxyl bonds (Al-OH, Fe-OH, and Mg-OH) and include phyllosilicates (e.g. kaolinite, montmorillonite, illite, chlorite, micas), sorosilicates (e.g. epidote), inosilicates (e.g. actinolite), carbonates (e.g. calcite,ankerite, and siderite), sulfates (e.g. alunite, jarosite, and gypsum), aswell as ammonium-bearing minerals (e.g. NH4-illite/tobelite, NH4-feldspar/buddingtonite and NH4-alunite). However, it is not possible to detect minerals lacking these molecular or cation-hydroxyl bonds (e.g. quartz, adularia, albite, and anhydrite) (Hunt, 1979; Hunt and Ashley,1979; Clark et al., 1990; Clark, 1999; Thompson et al., 1999). White Mica absorption features Compositional variations due to the substitution of octahedral Al3+ by other cations such as Fe2⁺ and Mg2⁺ have been recognized in micas using short-wave infrared spectroscopy. In general, micas have a deep and diagnostic spectral absorption feature between 2,185 and 2,230 nm (the 2,200 nm absorption feature), which is related to the combination of Al-OH bending and OH stretching vibration modes (Clark et al., 1990). The wavelength position of this absorption feature varies as a function of the Al3⁺ content in the octahedral sheets and has been used to define the different mineralogical species (Swayze et al., 1992; Duke, 1994). Micas with high content of octahedral Al3⁺ and interlayer Na⁺ (e.g., paragonites) are characterized by shorter-wavelength Al-OH absorptions, generally between 2,185 and 2,196 nm. Conversely, micas with relatively lower octahedral Al3⁺ and higher Si4⁺, Fe²⁺, or Mg2⁺ (e.g., celadonites) produce Al-OH absorptions in longer wavelengths, typically between 2,211 and 2,225 nm (Post and Noble, 1993). White micas such as aluminoceladonites and muscovites are characterized by the Al-OH wavelength from 2,196 to 2,211 nm (Graham et al., 2018). Hereafter, white mica with an absorption centered at wavelengths between 2,180-2,190 nm are called paragonites (Al-rich and Si-poor (NaAl₂[(OH)₂|AlSi₃O₁₀); Micas with 2,190-2,200 nm are called paragonite-muscovite; Micas with 2,200-2,210 are called muscovite or Illites; between 2210-2216 are called muscovite-phengite and longer than 2,216 are called phengites (K(AlMg)2(OH)2(SiAl)4O10). Compositional changes in white micas are manifested in the wavelength position of the Al-OH absorption feature, which shifts toward shorter wavelengths as the Al content of the octahedral sites of the mineral increases, and the opposite effect, or a shift toward longer wavelengths when the Mg and Fe contents of the octahedral sites increase (Post and Noble, 1993; Duke, 1994). High temperatures favor a decrease in the Mg and Fe content and an increase in the Al content of white mica (Duke, 1994). Chlorite absorption features Chlorite group minerals (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6 have an Fe-OH absorption feature near 2,260 nm (Hunt and Salisbury, 1970). The Fe-OH absorption feature is also present in biotite in the same wavelength region (Post and Noble, 1993). Chlorite also present a absorption feature near 2350 nm, however carbonates can also show this absorbency feature making out the chlorite response. Similarly, the hydroxyl absorption features of biotite and chlorite shift toward shorter wavelengths with increasing Mg, and toward longer wavelengths with increasing Fe (Bassett, 1960; McLeod et al., 1987). Fe contents of chlorite and biotite can increase with formation at higher temperatures (Miyashiro and Shido, 1985; Cathelineau, 1988). The distribution and mode of occurrence of these substitutions into the structural formula of phyllosilicates in porphyry systems has been proposed to be controlled by a number of factors, including temperature, chemistry of the protoliths, and the oxidation state and pH of the fluids (Shikazono and Kawahata, 1987). This report presents a short review of the spectral response using ASD Terraspec of samples from the El Alacrán Deposit with emphasize in sericite and chlorite wavelength 2200nm and 2250nm - 2350nm absorption features, respectively. The distribution of the spectral response of the samples were evaluated at deposit scale and within three detailed cross-sections along the deposit. Chlorite and sericite are widely distributed in the El Alacrán Deposit. In hand sample chlorite present marked variations in color that seem to be spatially distributed (darker chlorite in the south and pale-green chlorite in the northern part (Figure 1A). Similarly, brownish to purple colored white mica seem to be restricted to the middle to northern part of the deposit. This colored micas have been named “Illite” whereas the pale mica as been classified as sericite. However, non-chemical or spectral analyzes have been executed to support this mica differences. Applying Short Wave Infrared (SWIR) can help to correlate core-scale properties such as coloration in chlorite and white micas with their composition. Additionally, chlorite composition and white mica crystallinity can be useful to detect proximal zones to fluid feeders. Figure 1. Spectral analysis in chlorites from the El Alacrán Deposit. A. Plan map of the samples distribution. B1. Dark-green chlorite representative sample. B2 Brown Chlorite representative sample. B3. Pale green chlorite representative sample. C. 2260 vs 2350 nm absorption feature of the analyzed chlorites. D. 2260 vs 2350 nm absorption feature for the chlorites from different mineral assemblages. E. Deposit Scale distribution of the 2350 nm absorption feature found in the chlorite samples. F. Deposit Scale distribution of the 2250 nm absorption feature found in the chlorite samples. Metodology A total of 103 short wavelength infrared spectra (SWIR) were collected from hand specimens using the ASD Terraspec instrument at MDRU, University of British Columbia. Two to three analyses were performed on each sample and a record kept of the analysis position and target (e.g halo, clast etc). Spectra were interpreted using The Spectral Geologist Professional© (TSG) version 5.0 and Specwin softwares by comparison to a reference database. SWIR data are provide in Table 1 and Figure 1. For each measurement, it was obtained the depth, width and maximum absorption peak in nanometers of the in wavelengths W2200nm, W2250nm, W2350nm in addition to the depth of the water absorption peak (hdq1900, Table 1). Crystallinity Index (CI) was obtained using the depth of the 2200 absorption peak (hdq2200) by the depth of the water absorption peak (hdq1900). This Index is inversely proportional to the water content of the white mica. Each obtained spectra was revised and compared with their respective sample petrography for qualitative calibration of the acquired data. Results After a spectra data validation, 61% of the measurements (63 out of 103) are consistent with the observed mineralogy in their respective thin section. Similarly, 35% of the samples (36 of out 103) barely apply to the observed mineralogy (at least one of the mineral obtained SWIR was observed in the petrography). 4% (5 out of 103) of the measurements do not show spectral response to the mineralogy observed in the petrography (Table 1). Table 1. SWIR analysis results for samples from the El Alacrán Deposit Sample Host rock Terraspec Sample W2200 hqd2200 width2200 W2350 hdq2350 width2350 W2250 hqd2250 width2250 hdq1900 Crystallinity Index White Mica Color in this section Chlorite Color in this section Petrography SMA_AL_1602_JM_010 g Unit 2 TufL JM0010_00000.asd.sco 2196.21 0.0499 19.145 2352.04 0.181 34.8 2262.99 0.206 18.22 0.0779 0.64 Pale Chl 25%, Ser 3%, Kaolinite after Ab? SMA_AL_1602_JM_010 g Unit 2 TufL JM0010_00001.asd.sco 2351.77 0.229 38.133 2260.33 0.269 20.32 Pale Chl 25%, Ser 3%, Kaolinite after Ab? SMA_AL_1602_JM_001 f Unit 2 TufD JM001_00001.asd.sco 2206 0.147 22.494 2345.87 0.303 37.851 2255.98 0.308 20.928 Brown NO TS Chl, Ser, Illite SMA_AL_1602_JM_001 f Unit 2 TufD JM001_00002.asd.sco 2206.2 0.14 22.465 2346.46 0.293 38.11 2256.2 0.297 20.962 Brown NO TS Chl, Ser, Illite SMA_AL_1602_JM_002 i Unit 2 TufF JM002_00000.asd.sco 2203.24 0.332 22.388 2350.76 0.298 38.118 2255.93 0.284 19.071 0.243 1.37 Pale Pale Car 30%, Ser 30%, Chl (Mg) 10% SMA_AL_1602_JM_002 i Unit 2 TufF JM002_00001.asd.sco 2203.6 0.357 22.604 2341.61 0.34 39.962 2255.55 0.329 19.675 0.272 1.31 Pale Pale Car 30%, Ser 30%, Chl (Mg) 10% SMA_AL_1704_JM_045 e Unit 2 MudSil JM0045_00000.asd.sco 2212.13 0.0241 16.445 2339.6 0.119 38.87 2259.26 0.119 20.034 0.0968 0.25 Dark FeChl 20% SMA_AL_1602_JM_004 e Unit 2 MudSil JM004_00000.asd.sco 2334.52 0.0842 41.086 2257.6 0.107 20.498 0.037 Pale MgChl 25% SMA_AL_1602_JM_004 e Unit 2 MudSil JM004_00001.asd.sco 2343.7 0.0832 37.739 2257.58 0.104 20.911 0.0372 Pale MgChl 25% SMA_AL_1602_JM_005 j Unit 2 Sill 1 JM005_00000.asd.sco 2339.89 0.297 38.265 2254.36 0.299 21.953 0.206 Brown Pale MgChl 20%, Ser-Illite 8% SMA_AL_1602_JM_006 b Unit 1 RBx JM006_00000.asd.sco 2208.31 0.157 13.803 2342.61 0.282 38.679 2254.17 0.28 21.382 0.219 0.72 Pale Pale MgChl 10% Ser 1% SMA_AL_1602_JM_007 b Unit 1 RBx JM007_00000.asd.sco 2207.03 0.197 16.289 2344.17 0.224 38.675 2255.76 0.2 21.234 0.293 0.67 Pale Pale MgChl 8% Ser 15% SMA_AL_1602_JM_007 b Unit 1 RBx JM007_00001.asd.sco 2206.85 0.175 17.455 2345.19 0.153 39.975 2255.93 0.131 20.746 0.242 0.72 Pale Pale MgChl 8% Ser 15% SMA_AL_1602_JM_008 f Unit 2 TufD JM008_00001.asd.sco 2186.02 0.286 23.938 2331.35 0.0937 41.911 0.61 0.47 Brown Sericite-Illite 25%, , Ab 50% SMA_AL_1602_JM_008 f Unit 2 TufD JM008_00002.asd.sco 2187.08 0.281 21.272 2333.84 0.12 39.361 2237.17 0.0127 11.011 0.488 0.58 Pale Sericite-Illite 25%, , Ab 50% SMA_AL_1602_JM_008 f Unit 2 TufD JM008_00003.asd.sco 2211.46 0.337 21.2 2342.89 0.326 38.51 2251.12 0.254 20.988 0.295 1.14 Pale Sericite-Illite 25%, , Ab 50% SMA_AL_1602_JM_009 i Unit 2 TufF JM009_00000.asd.sco 2347.5 0.283 38.99 2256.78 0.321 21.515 NO TS NO TS Chl, Ser Tr SMA_AL_1602_JM_011 m Unit 2 Sill 2 JM011_00000.asd.sco 2196.53 0.121 22.382 2344.58 0.121 40.074 2253.77 0.121 20.234 0.368 0.33 Pale Pale Ab 70%, MgFe10%, Ser3% SMA_AL_1602_JM_011 m Unit 2 Sill 2 JM011_00002.asd.sco 2202.15 0.116 20.47 2345.71 0.112 39.695 2254.54 0.103 20.532 0.276 0.42 Pale Pale Ab 70%, MgFe10%, Ser3% SMA_AL_1602_JM_012 i Unit 2 TufF JM012_00000.asd.sco 2349.48 0.111 41.055 2257.76 0.132 20.67 0.0628 Pale MgChl 45% SMA_AL_1602_JM_012 i Unit 2 TufF JM012_00001.asd.sco 2348.36 0.06 41.471 2257.21 0.0781 20.588 0.0495 Pale MgChl 45% SMA_AL_1602_JM_015 g Unit 2 TufL JM015_00000.asd.sco 2334.58 0.163 41.046 2257.12 0.185 22.072 Pale MgChl 25% SMA_AL_1602_JM_016 k Unit 2 TufC JM016_00000.asd.sco 2208.22 0.119 18.512 2336.96 0.306 34.779 2253.04 0.299 22.107 #DIV/0! Pale Pale Ab 40%, MgChl 25%, Ser 4% SMA_AL_1602_JM_019 g Unit 2 TufL JM019_00000.asd.sco 2208.38 0.167 20.923 2348.93 0.241 38.128 2256.04 0.24 20.612 0.123 1.36 Brown Pale Ser 15%, Illite 12%, MgChl 10% SMA_AL_1602_JM_019 g Unit 2 TufL JM019_00001.asd.sco 2335.86 0.0876 35.152 2255.72 0.109 21.772 Brown Pale Ser 15%, Illite 12%, MgChl 10% SMA_AL_1704_JM_039 i Unit 2 TufF JM039_00000.asd.sco 2193.94 0.0743 22.113 2341.31 0.0555 35.93 2253.61 0.0309 18.072 0.125 0.59 Pale Pale MgChl 4%, Ser Tr SMA_AL_1704_JM_039 i Unit 2 TufF JM039_00001.asd.sco 2194.42 0.0942 21.666 2334.16 0.0503 39.34 2255.92 0.0362 17.269 0.131 0.72 Pale Pale MgChl 4%, Ser Tr SMA_AL_1704_JM_043 e Unit 2 MudSil JM043_00000.asd.sco 2206.67 0.00283 14.366 2320.84 0.17 39.376 0.158 0.02 Act 50%, Bio3%, Car30% SMA_AL_1704_JM_043 e Unit 2 MudSil JM043_00001.asd.sco 2323.04 0.159 38.573 2258.11 0.0357 20.698 0.142 Act 50%, Bio3%, Car30% SMA_AL_1705_JM_063 e Unit 2 MudSil JM063_00000.asd.sco 2341.03 0.117 36.63 2256.33 0.127 20.885 Brown Brown Chl SMA_AL_1705_JM_064 i Unit 2 TufF JM064_00000.asd.sco 2201 0.297 20.246 2341.86 0.149 40.029 0.361 0.82 Pale Ser 35%, SMA_AL_1705_JM_064 i Unit 2 TufF JM064_00001.asd.sco 2200.46 0.166 20.746 2344.04 0.0707 39.281 0.193 0.86 Pale Ser 35%, SMA_AL_1705_JM_064 i Unit 2 TufF JM064_00002.asd.sco 2205.69 0.15 22.791 2339.82 0.455 39.732 2254.52 0.282 20.686 0.296 0.51 Pale Ser 35%, Epidote 10% SMA_AL_1705_JM_064 i Unit 2 TufF JM064_00003.asd.sco 2199.83 0.17 21.371 2339.17 0.0647 38.388 0.237 0.72 Pale Ser 35% SMA_AL_1709_JM_072 e Unit 2 MudSil JM072_00000.asd.sco 2192.59 0.254 21.462 2343.32 0.198 39.01 2253.18 0.137 18.423 0.372 0.68 NO TS Chl, Ser SMA_AL_1709_JM_072 e Unit 2 MudSil JM072_00001.asd.sco 2198.59 0.274 20.999 2345.19 0.215 39.518 2251.68 0.133 19.699 0.364 0.75 NO TS Chl, Ser SMA_AL_1709_JM_072 e Unit 2 MudSil JM072_00002.asd.sco 2195 0.163 21.32 2338.87 0.186 39.182 2253.61 0.107 19.097 0.221 0.74 NO TS Chl, Ser SMA_AL_1709_JM_073 e Unit 2 MudSil JM073_00000.asd.sco 2203.23 0.219 22.279 2343.2 0.214 35.676 2252 0.102 15.308 0.151 1.45 Pale Pale Ser 25%, Carb 35%,MgChl 18% SMA_AL_1709_JM_073 e Unit 2 MudSil JM073_00001.asd.sco 2202.89 0.184 21.549 2345.28 0.108 38.682 0.0844 2.18 Brown Pale Ser 25%, Carb 35%,MgChl 18% SMA_AL_1608_JM_080 a Unit 1 TufR JM080_00000.asd.sco 2208.22 0.156 21.654 2350.33 0.189 38.101 2257.63 0.176 19.526 0.117 1.33 Brown Pale Chl 7%, Ser 2% Continuation of Table 1 Continuation of Table 1 Sample Hostrock Terraspec Sample W2200 hqd2200 width2200 W2350 hdq2350 width2350 W2250 hqd2250 width2250 hdq1900 Crystallinity Index White Mica Color in this section Chlorite Color in this section Petrography SMA_AL_1608_JM_081 i Unit 2 TufF JM081_00000.asd.sco 2320.86 0.227 40.047 2256.88 0.0812 21.509 0.0971 Pale Chl 5% SMA_AL_1608_JM_081 i Unit 2 TufF JM081_00001.asd.sco 2322.84 0.0619 31.577 2251.4 0.0587 18.827 0.0334 Pale Chl 5% SMA_AL_1608_JM_082 n Unit 3 TufM JM082_00000.asd.sco 2206.15 0.357 22.636 2347.16 0.223 38.094 0.263 1.36 Pale Pale Ill-Ser, Chl SMA_AL_1608_JM_082 n Unit 3 TufM JM082_00001.asd.sco 2207.06 0.377 22.318 2346.85 0.229 38.377 0.244 1.55 Pale Pale Ill-Ser, Chl SMA_AL_1608_JM_084 g Unit 2 TufL JM084_00000.asd.sco 2196.55 0.0871 19.411 2347.74 0.218 39.186 2258.59 0.222 20.673 0.0947 0.92 Brown NO TS Chl, Ser SMA_AL_1608_JM_084 g Unit 2 TufL JM084_00001.asd.sco 2195.43 0.0719 19.777 2347.17 0.192 39.339 2257.94 0.2 20.856 0.0836 0.86 Brown NO TS Chl, Ser SMA_AL_1608_JM_086 e Unit 2 MudSil JM086_00000.asd.sco 2186.49 0.179 18.471 2349.59 0.154 39.615 2258.25 0.147 20.782 0.337 0.53 Purple-Brown Dark-Pale Ser, MgChl , FeChl SMA_AL_1608_JM_086 e Unit 2 MudSil JM086_00001.asd.sco 2189.05 0.109 19.214 2335.51 0.0614 39.032 2256.39 0.0599 20.604 0.193 0.56 Purple-Brown Dark-Pale Ser, MgChl , FeChl SMA_AL_1608_JM_086 e Unit 2 MudSil JM086_00002.asd.sco 2351.96 0.119 37.919 2257.88 0.126 21.105 0.315 Purple-Brown Dark-Pale Ser, MgChl , FeChl SMA_AL_1608_JM_086 e Unit 2 MudSil JM086_00003.asd.sco 2187.32 0.168 18.252 2358.18 0.166 38.861 2257.71 0.186 21.206 0.338 0.50 Pale Ser, MgChl , FeChl SMA_AL_1608_JM_087 e Unit 2 MudSil JM087_00000.asd.sco 2186.19 0.245 19.607 2334.53 0.0957 42.403 2257.43 0.0172 17.92 0.443 0.55 Pale Ser, MgChl , Ab-Clay SMA_AL_1608_JM_087 e Unit 2 MudSil JM087_00001.asd.sco 2187.35 0.0913 18.566 2338.35 0.0549 40.649 2254.71 0.0548 21.111 0.188 0.49 Brown Ser, MgChl , Ab-Clay SMA_AL_1608_JM_087 e Unit 2 MudSil JM087_00002.asd.sco 2185.56 0.191 19.424 2339.45 0.0699 41.247 2255.02 0.0446 20.519 0.381 0.50 Brown Ser, MgChl , Ab-Clay SMA_AL_1608_JM_091 k Unit 2 TufC JM091_00000.asd.sco 2202.08 0.0674 18.863 2324.29 0.0305 27.832 0.0997 0.68 Pale Chl 25%, Ser 7%, Clay(Smec) 1% SMA_AL_1608_JM_091 k Unit 2 TufC JM091_00001.asd.sco 2200.49 0.0619 19.784 2340.7 0.0563 32.269 2251.61 0.0717 20.363 0.0874 0.71 Pale Chl 25%, Ser 7%, Clay(Smec) 1% SMA_AL_1608_JM_092 k Unit 2 TufC JM092_00000.asd.sco 2193.2 0.223 23.068 2341.55 0.172 39.864 2253.32 0.123 19.779 0.282 0.79 Dark FeChl, Ser SMA_AL_1608_JM_092 k Unit 2 TufC JM092_00001.asd.sco 2202.51 0.107 21.858 2337.04 0.0415 39.3 0.0869 1.23 Pale FeChl, Ser SMA_AL_1608_JM_093 k Unit 2 TufC JM093_00000.asd.sco 2346.1 0.224 36.505 2259.76 0.232 20.44 Pale Dark FeChl 25%, Ser 2% SMA_AL_1608_JM_094 e Unit 2 MudSil JM094_00000.asd.sco 2188.26 0.128 19.195 2337.12 0.201 39.228 2252.96 0.193 22.071 0.292 0.44 Pale Dark Ill 20%, FeChl20% SMA_AL_1608_JM_094 e Unit 2 MudSil JM094_00001.asd.sco 2187.35 0.0948 18.838 2335.2 0.155 38.96 2252.9 0.148 21.433 0.197 0.48 Pale Dark Ill 20%, FeChl20% SMA_AL_1608_JM_095 k Unit 2 TufC JM095_00000.asd.sco 2332.66 0.174 40.753 2252.28 0.163 21.406 0.151 Brown NO TS Act, Crytocrystalline Brown SMA_AL_1608_JM_095 k Unit 2 TufC JM095_00001.asd.sco 2200.96 0.00644 15.148 2323.96 0.0638 38.872 2251.99 0.0562 20.242 0.193 0.03 Brown NO TS Act, Crytocrystalline Brown SMA_AL_1608_JM_097 g Unit 2 TufL JM097_00000.asd.sco 2205.05 0.058 22.568 2350.67 0.0819 37.47 2257.61 0.0751 19.251 0.0623 0.93 NO TS Dark Ser , FeChl SMA_AL_1608_JM_097 g Unit 2 TufL JM097_00001.asd.sco 2209.68 0.0399 19.605 2357.69 0.0929 37.929 2257.65 0.0938 20.311 0.0785 0.51 Dark Ser , FeChl SMA_AL_1608_JM_098 e Unit 2 MudSil JM098_00000.asd.sco 2338.33 0.0422 39.072 2254.63 0.0453 17.146 0.06 Dark FeChl, MgRich SMA_AL_1608_JM_098 e Unit 2 MudSil JM098_00001.asd.sco 2211.89 0.0206 18.477 2334.73 0.0482 37.036 2255.52 0.0561 20.307 0.0346 0.60 Dark FeChl, MgRich SMA_AL_1608_JM_099 e Unit 2 MudSil JM099_00000.asd.sco 2353.05 0.0971 32.461 2253.52 0.0927 19.374 0.0912 Dark FeChl SMA_AL_1801_JM_108 m Unit 2 Sill 2 JM108_00001.asd.sco 2208.62 0.0511 17.877 2346.08 0.0558 39.148 2252.12 0.0428 19.401 0.219 0.23 Brown Pale Crypto brown, MgChl SMA_AL_1801_JM_114 e Unit 2 MudSil JM114_00000.asd.sco 2329.08 0.0403 31.824 2251.99 0.0544 17.417 0.0568 Pale MgChl 10% Ser Tr SMA_AL_1801_JM_114 e Unit 2 MudSil JM114_00001.asd.sco 2332.9 0.139 33.78 2252.95 0.143 21.569 0.0642 Brown MgChl 10% Ser Tr SMA_AL_1801_JM_115 n Unit 3 TufM JM115_00000.asd.sco 2335.19 0.127 37.764 2255.44 0.124 22.354 0.0966 Pale MgChl 15% Ser Tr SMA_AL_1801_JM_118 e Unit 2 MudSil JM118_00000.asd.sco 2211.06 0.0557 22.184 2336.48 0.0616 34.426 2250.81 0.0782 19.924 0.161 0.35 DON’T USE SMA_AL_1801_JM_121 m Unit 2 Sill 2 JM121_00000.asd.sco 2196.49 0.0039 17.23 2255.52 0.00777 17.123 0.452 0.01 Pale NO TS SMA_AL_1801_JM_121 m Unit 2 Sill 2 JM121_00001.asd.sco 2200.43 0.00275 10.995 2255.46 0.0228 18.767 0.432 0.01 Pale NO TS SMA_AL_1801_JM_125 a Unit 1 TufR JM125_00000.asd.sco 2200.55 0.273 20.973 2348.05 0.218 39.444 2254.79 0.187 17.19 0.319 0.86 Pale Pale Ser 25% MgChl7% SMA_AL_1602_JM_017 i Unit 2 TufF Jm017.001.sco 2186.2 0.168 23.564 2344.39 0.154 39.371 2257.14 0.18 20.389 0.544 0.31 SMA_AL_1602_JM_017 i Unit 2 TufF Jm017.000.sco 2200.55 0.0328 19.92 2319.47 0.021 33.376 2261.79 0.0334 16.106 0.06 0.55 Dark SMA_AL_1602_JM_022 m Unit 2 Sill 2 Jm022.000.sco 2347.51 0.272 38.504 2257.27 0.263 20.733 0.115 Pale SMA_AL_1602_JM_023 j Unit 2 Sill 1 Jm023.000.sco 2201.57 0.0296 21.055 2329.68 0.0743 36.059 2256.92 0.0448 18.213 0.0924 0.32 Pale SMA_AL_1602_JM_024 a Alacrán Oeste Jm024.000.sco 2208.43 0.0765 13.571 2325.45 0.0792 26.608 2244.62 0.078 16.611 0.121 0.63 Pale Continuation of Table 1 Sample TSA_S Mineral1 TSA_S Weight1 TSA_S Mineral2 TSA_S Weight2 TSA_S Error Petrographic validation Validation Comments Re-definition after Spectral revision Min 1 Re-definition after Spectral revision Min 2 WM_Name_Based in WL SMA_AL_1608_JM_081 Hornblende 64% IntChlorite 36% 46.41 Possibly Apply Act in that sample Hornblende IntChlorite SMA_AL_1608_JM_081 IntChlorite 100% 252.35 Possibly Apply Chl-Clay in TS IntChlorite SMA_AL_1608_JM_082 Illite 71% IntChlorite 29% 35.929 Possibly Apply Why pale Illite? Illite IntChlorite Illite SMA_AL_1608_JM_082 Illite 71% Phengite 29% 47.944 Possibly Apply Why pale Illite? Illite IntChlorite Illite SMA_AL_1608_JM_084 FeChlorite 100% 20.157 Apply Mg Chlorite Illite Paragonitic-muscovitic Illite SMA_AL_1608_JM_084 FeChlorite 1 19.404 Do not Apply Don’t pick the brown Mg Chlorite Illite Paragonitic-muscovitic Illite SMA_AL_1608_JM_086 FeChlorite 69% Paragonite 31% 40.9 Possibly Apply Paragonite Purplish Clay Mg Chlorite Illite Paragonitic Illite SMA_AL_1608_JM_086 FeChlorite 59% Paragonite 41% 62.509 Possibly Apply Paragonite Purplish Clay Mg Chlorite Illite Paragonitic Illite SMA_AL_1608_JM_086 FeChlorite 72% Paragonite 28% 34.64 Possibly Apply Paragonite Purplish Clay Mg Chlorite Illite SMA_AL_1608_JM_086 FeChlorite 75% Paragonite 26% 34.474 Possibly Apply Paragonite Purplish Clay Mg Chlorite Illite Paragonitic Illite SMA_AL_1608_JM_087 Paragonite 57% Montmorillonite 43% 123.68 Possibly Apply Paragonite Purple-brown Clay Mg Chlorite Illite-Smectite Paragonitic Illite SMA_AL_1608_JM_087 FeChlorite 60% Paragonite 40% 98.168 Possibly Apply Paragonite Purple-brown Clay Mg Chlorite Illite-Smectite Paragonitic Illite SMA_AL_1608_JM_087 Paragonite 55% Opal 45% 153.43 Possibly Apply Paragonite Purple-brown Clay Mg Chlorite Illite-Smectite Paragonitic Illite SMA_AL_1608_JM_091 Illite 1 1219.44 Barely Apply Why pale Illite?, Ab in TS Illite Illite SMA_AL_1608_JM_091 IntChlorite 67% Illite 33% 163.23 Apply IntChlorite Illite Illite SMA_AL_1608_JM_092 IntChlorite 52% Illite 48% 72.252 Apply IntChlorite Illite Paragonitic-muscovitic Illite SMA_AL_1608_JM_092 Illite 1 124.42 Barely Apply Why pale Illite?, Illite Illite SMA_AL_1608_JM_093 FeChlorite 100% 11.415 Apply FeChlorite SMA_AL_1608_JM_094 IntChlorite 76% Paragonite 24% 71.628 Possibly Apply Dark Chl IntChlorite Paragonite Paragonitic Illite SMA_AL_1608_JM_094 IntChlorite 75% Paragonite 25% 61.719 Possibly Apply Dark Chl IntChlorite Paragonite Paragonitic Illite SMA_AL_1608_JM_095 IntChlorite 1 61.329 Do not Apply same situation with JM001. Do not pick the brown color IntChlorite Uknown SMA_AL_1608_JM_095 IntChlorite 61% Palygorskite 39% 86.043 Possibly Apply Palygorskite as the brown min IntChlorite Uknown Illite SMA_AL_1608_JM_097 FeChlorite 82% Illite 18% 41.848 Apply FeChlorite Illite Illite SMA_AL_1608_JM_097 FeChlorite 100% 35.442 Apply FeChlorite Illite SMA_AL_1608_JM_098 FeChlorite 100% 307.06 Apply FeChlorite SMA_AL_1608_JM_098 IntChlorite 100% 424.07 Possibly Apply IntChlorite Muscovitic-phengitic Illite SMA_AL_1608_JM_099 FeChlorite 100% 395.5 Apply Unknown SMA_AL_1801_JM_108 Montmorillonite 72% Epidote 28% 304.52 Possibly Apply Montmorillonite the brown Min Illite IntChlorite Illite SMA_AL_1801_JM_114 IntChlorite 100% 219.42 Possibly Apply IntChlorite SMA_AL_1801_JM_114 IntChlorite 1 36.441 Barely Apply Don’t pick the brown IntChlorite SMA_AL_1801_JM_115 IntChlorite 100% 70.971 Possibly Apply IntChlorite SMA_AL_1801_JM_118 IntChlorite 0.671 Illite 0.329 136.68 Do not Apply Bad referenced IntChlorite Illite Muscovitic-phengitic Illite SMA_AL_1801_JM_121 Palygorskite 84% Gypsum 16% 365.84 Possibly Apply Palygorskite Paragonitic-muscovitic Illite SMA_AL_1801_JM_121 Palygorskite 100% 406.42 Possibly Apply Palygorskite Illite SMA_AL_1801_JM_125 FeChlorite 0.642 Illite 0.358 35.467 Barely Apply Palegrren Chl, and Ser in TS FeChlorite Illite Illite SMA_AL_1602_JM_017 FeChlorite 0.655 Montmorillonite 0.345 42.401 Paragonitic Illite SMA_AL_1602_JM_017 SMA_AL_1602_JM_022 FeChlorite 1 12.29 SMA_AL_1602_JM_023 IntChlorite 1 362.31 SMA_AL_1602_JM_024 Continuation of Table 1 Sample Hostrock Terraspec Sample W2200 hqd2200 width2200 W2350 hdq2350 width2350 W2250 hqd2250 width2250 hdq1900 Crystallinity Index White Mica Color in this section Chlorite Color in this section SMA_AL_1602_JM_026 a Alacrán Norte Jm026.000.sco 2209.42 0.037 18.09 2335.78 0.143 40.414 2252.74 0.0908 20.494 0.312 0.12 Pale Pale SMA_AL_1704_JM_038 b Unit 1 RBx Jm038.000.sco 2202.4 0.0769 21.116 2352.49 0.148 37.572 2259.16 0.124 19.651 0.117 0.66 Dark SMA_AL_1704_JM_051 j Unit 2 Sill 1 Jm051.000.sco 2211.8 0.192 19.284 2324.19 0.25 38.393 2250.21 0.174 20.587 0.483 0.40 Pale Pale SMA_AL_1704_JM_052 b Unit 1 RBx JM052.000.sco 2204.7 0.251 22.627 2345.61 0.249 39.014 2255.43 0.227 19.781 0.121 2.07 Pale Pale SMA_AL_1709_JM_074 m Unit 3 TufA Jm074.000.sco 2197.94 0.0783 23.31 2313.64 0.0816 32.948 2259.81 0.0897 19.994 0.109 0.72 Pale SMA_AL_1709_JM_075 b Unit 1 RBx Jm075.000.sco 2214.66 0.0176 18.466 2313.81 0.0639 40.265 0.0679 0.26 Brown SMA_AL_1709_JM_078 p Unit 3 TufL Jm078.000.sco 2204.64 0.0348 17.271 2332.72 0.0959 32.015 2252.9 0.0746 21.324 0.128 0.27 Dark SMA_AL_1608_JM_090 i Unit 2 TufF JM090.000.sco 2195.25 0.12 21.823 2341.98 0.108 38.569 2254.27 0.0752 19.865 0.203 0.59 Pale Dark SMA_AL_1801_JM_107 b Unit 1 RBx JM107.000.sco 2205.03 0.181 22.228 2347.8 0.217 37.241 2256.37 0.168 19.126 0.096 1.89 Pale Pale SMA_AL_1801_JM_109 a Unit 1 TufR Jm109.000.sco 2203.25 0.152 20.215 2346.68 0.244 37.756 2256.24 0.267 20.9 0.367 0.41 Pale Pale JM019 g Unit 2 TufL Jm109.001.sco 2202.77 0.146 21.07 2347.49 0.262 38.857 2256.63 0.282 20.948 0.349 0.42 Pale Pale SMA_AL_1801_JM_113 b Unit 1 RBx JM113.001.sco 2352.77 0.191 35.517 2259.92 0.182 19.382 0.0775 Pale SMA_AL_1801_JM_113 b Unit 1 RBx JM113.002.sco 2214.27 0.0218 15.858 2352.34 0.16 34.593 2259.44 0.153 19.485 0.084 0.26 Pale SMA_AL_1801_JM_113 b Unit 1 RBx JM113.003.sco 2352.13 0.128 34.579 2258.94 0.131 19.532 0.0629 Pale SMA_AL_1801_JM_116 e Unit 2 MudSil Jm116.000.sco 2203.29 0.006 14.863 2339.61 0.138 37.236 0.0418 0.14 SMA_AL_1801_JM_126 g Unit 2 TufL Jm126.000.sco 2201.25 0.117 20.884 2352.85 0.219 36.141 2257.78 0.224 20.054 0.213 0.55 Pale Pale SMA_AL_1801_JM_127 f Unit 2 TufD Jm127.000.sco 2347.61 0.313 38.707 2256.35 0.335 21.194 0.161 Pale Pale SMA_AL_1801_JM_128 h Unit 2 Lim Jm128.000.sco 2203.8 0.0383 20.277 2341.29 0.122 33.847 2256.55 0.0861 19.689 0.0772 0.50 Pale Pale SMA_AL_1801_JM_129 k Unit 2 TufC JM129.000.sco 2197.44 0.156 20.579 2347.38 0.215 35.701 2259.16 0.218 19.448 0.172 0.91 Pale Pale SMA_AL_1808_JM_133 i Unit 2 TufF Jm133.000.sco 2344.57 0.116 41.397 2255.75 0.073 19.478 0.501 Dark SMA_AL_1808_JM_132 b Unit 1 RBx Jm134.000.sco 2209.28 0.0135 15.604 2257.07 0.0771 20.19 0.0605 0.22 Dark Sample TSA_S Mineral1 TSA_S Weight1 TSA_S Mineral2 TSA_S Weight2 TSA_S Error Petrographic validation Validation Comments Re-definition after Spectral revision Min 1 Re-definition after Spectral revision Min 2 WM_Name_Based in WL SMA_AL_1602_JM_026 IntChlorite 0.748 Illite 0.252 112.52 Illite SMA_AL_1704_JM_038 FeChlorite 1 36.552 SMA_AL_1704_JM_051 IntChlorite 0.604 Illite 0.396 117.58 Muscovitic-phengitic Illite SMA_AL_1704_JM_052 IntChlorite 0.598 Muscovite 0.402 45.552 Illite SMA_AL_1709_JM_074 Siderite 1 1039.17 SMA_AL_1709_JM_075 Siderite 0.701 Diaspore 0.299 23.672 SMA_AL_1709_JM_078 MgChlorite 1 678.8 SMA_AL_1608_JM_090 IntChlorite 0.59 Illite 0.41 78.953 Paragonitic-muscovitic Illite SMA_AL_1801_JM_107 FeChlorite 0.746 Illite 0.254 21.054 Illite SMA_AL_1801_JM_109 FeChlorite 0.824 Illite 0.176 27.532 Illite JM019 FeChlorite 0.837 Illite 0.163 26.408 Illite SMA_AL_1801_JM_113 FeChlorite 1 9.148 SMA_AL_1801_JM_113 FeChlorite 1 21.696 SMA_AL_1801_JM_113 FeChlorite 1 14.15 SMA_AL_1801_JM_116 Calcite 1 157.82 SMA_AL_1801_JM_126 FeChlorite 0.836 Illite 0.164 9.594 Illite SMA_AL_1801_JM_127 FeChlorite 1 17.881 SMA_AL_1801_JM_128 FeChlorite 0.787 Calcite 0.213 89.042 SMA_AL_1801_JM_129 FeChlorite 0.796 Illite 0.204 15.132 Paragonitic-muscovitic Illite SMA_AL_1808_JM_133 Paragonite 1 240.44 SMA_AL_1808_JM_132 FeChlorite 1 32.098 Figure 1. Reflectance spectra results from (Terraspect) on white mica and chlorite from El Alacrán Deposit. Chlorite Analysis Analyzed chlorites present a wide range of the W2250 feature from 2250.21nm to 2262.99nm and W2350 from 2320.86 nm to 2358.18nm. This suggest marked variations in Fe/Mg chlorite composition. However, no clear correlation is observed between the chlorite color and their respective spectra (Figure 1C). Figure1D shows that chlorites associated with the calc-sodic alteration present a wide variation range of their spectral response suggesting marked variations in Fe/Mg ratio content associated with this mineral assemblage. On the other hand, chlorites associated with the carbonate-sericite assemblage present a higher W2250/W2350 and a narrower spectral variation range (Figure 1D). This suggests that the chlorites from this later mineral assemblage are dominantly higher in Fe/Mg than the ones from the chlorite alteration. Plan map of the 2250-2350nm distribution shows that the highest wavelength results for chlorite samples are mostly localized in the southern part of the El Alacrán deposit (Figure 1E-F). This is expected since the highest Fe/S in the deposit is associated with the magnetite - quartz assemblage that occurs preferentially in the southern El Alacrán Deposit. Figure 2A-B-C shows three detailed cross sections in different segments of the deposit (855750m N, 855540m N, 855050m N). In the northern section, the highest 2250nm values are observed in samples from the CBM assemblage (JM010) and (?) Chl-Car-Musk alteration (JM113). This later unit is restricted to the Unit 1 lithofacie RBx. (Figure 2A). White Mica Analysis According to the spectral response and notable water feature in the 1900nm in all the analyzed samples (Figure 1), the white mica that occurs in the El Alacrán deposit corresponds to Illite that varies in composition from paragonitic-Illite to muscovite-phegite Illite. The W2200 presents a big variation from 2185.56 nm – 2211.46 nm that is related with differences in the white mica composition (Figure 1). The brown coloration in the white mica does not reflect differences in the type of mica composition (Figure 3 A-B-C). This is also confirmed by petrography where the brownish coloration seems to be related with a Fe-staining process over imposed to the mica, rather to the mica itself. The purple-colored mica, however, show a narrower field presenting the lowest W2200 and crystallinity index values (Figure 3C) and can be classified as paragonitic-Illite. Figure 2. Representative cross-section of the El Alacrán Deposit showing the distribution of the defined alteration mineral assemblages and the analyzed chlorite samples. A. Northern Alacrán 855750m N. B Middle Alacrán 855540 m N. C. Southern Alacrán 855050. Figure 3. Spectral analysis in white micas from the El Alacrán Deposit. A. Plan map of the samples distribution. B1. Brown-colored white mica representative sample. B2 Purple-colored white mica representative sample. B3. Pale white mica representative sample. C. Crystallinity Index vs W2200 absorption feature of the analyzed white micas. D. Crystallinity Index vs W2200 absorption feature for white micas associated with different mineral assemblages. E. Deposit scale distribution of the crystallinity index found in the white micas samples. F. Deposit scale distribution of the W2200 nm absorption feature found in the white mica samples. When comparing the obtained spectral data with their mineral assemblage (Figure 3D), it shows that white mica from the carbonate-sericite presents the highest W2200 values and crystallinity index values (CI) among the alteration assemblages. The terraspec detected white mica occurrence within the samples associated with the chlorite alteration (Figure 3D). This white mica presents low CI and 2200nm values in comparison to white mica from the carbonate-sericite alteration. This can suggest another type of white mica occurrence associated with the chlorite alteration. However, based on the El Alacrán Deposit paragenesis, not other sericite event has been defined in the deposit. This suggest instead, that the white mica from the carbonate-sericite that overgrown over minerals from the chlorite and calc sodic alterations present lower crystallinity and higher Na values (more paragonitic). Plan map of the W2200 and CI values distribution shows that the northwestern part of the deposit present the higher crystallinity values (Figure 3C-E) with variable composition mostly associated with Illite (Wavelengths > 2200nm) (Figure 3CF). In the northern part of the deposit (section 855750m N, Figure 4A) the CI values exhibit a westward zoned distribution towards higher crystallinity white micas in the transition between Unit 1 and Unit 2. Similarly, in section 855540m N the highest CI values are located in the proximity of the recently defined intrusion breccia (Figure 4B). In the southern part, however, no major CI variations are observed along the 855050m N section. In relation to the white mica composition, the northern part of the deposit (section 855750m N) shows a zoned distribution from paragonite-Illite towards Illite in the west (Figure 5A). In the middle part of the deposit (Figure 5B) there is not a conclusive zoned pattern of the white mica composition. In the southern Alacrán (section 855050, Figure 5C) paragonitic mica is associated with the chlorite and calc-sodic alteration, whereas Illite mica occurs associated to the carbonate-sericite assemblage. Figure 4. Representative cross-sections of the El Alacrán deposit showing the distribution of the crystalline index associated to white mica samples. In the background the defined mineral assemblages. A. Northern Alacrán 855750m N showing some interpreted limits of the crystallinity index zonation. B Middle Alacrán 855540 m N. showing the higher crystallinity index concentration C. Southern Alacrán 855050m N. Figure 5. Representative cross-sections of the El Alacrán deposit showing the distribution of the white mica composition based in their spectral W2200 absorption feature. In the background the defined mineral assemblages. A. Northern Alacrán 855750m N showing some interpreted limits of a zonation pattern. B Middle Alacrán 855540 m N. C. Southern Alacrán 855050m N. Conclusions • W2250 and W2350 spectral data suggest that the coloration observed core scale samples is not directly related to the Fe/Mg values in the chlorite. Similarly, the brown coloration observed in the white micas is not a feature of the mica composition. • The host rock lithofacies in the El Alacrán Deposit control the alteration mineral assemblages distribution (e.g. Lithofacies TufD, TufL, TufF from Unit 2 and RBx lithofacie from Unit 1 are preferentially altered to group II mineral assemblage with chlorite spectral values in the 2255.76-2258.59 nm range. • Marked W2350-W2250 differences in the chlorite observed in northern El Alacrán Deposit supports the existence of one additional alteration mineral assemblage associated with the occurrence of Fe-rich chlorite+carbonate+mushketovite that occurs exclusively associated with Unit 1. • The white mica that occurs at the El Alacrán Deposit corresponds to Illite with variations to paragonitic-Illite and muscovite-phegite Illite. The Illite composition varies depending on the pre-existent alteration mineralogy. (e.g. Micas formed after pre-existent minerals from group I and II present lower crystallinity and a paragonitic composition). • The northwestern part of the deposit exhibit a zonation to low Na-composition and to high-illite crystallinity. This zonation pattern can be related with higher formation temperature of the white mica and serve as a proxy for a higher temperature fluid source in that part of the deposit. D.2 SEM-EDS-BSE analysis Begins on following page… SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD012@51.76El AlacranCountry: ColombiaSMA_AL_1602_JM_019 1A1b1cD1Highlights1A. Takes the composiiton of the Albite1b. This is Apatite (Fluor Apatite)1c. Albite Conclusions:The brownish colored mineral correspond to Albite.Albite intergrows with ApatiteSEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD012@51.76El AlacranCountry: ColombiaSMA_AL_1602_JM_019 21D2Highlights1. Correspond to a Clay mineral2. Posible altred clayConclusions:Fe occurrences is not clearly identified bu the EDS as the alter-ation of the clay mineral SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD012@51.76El AlacranCountry: ColombiaSMA_AL_1602_JM_019 D3Highlights1. Chlorite2. Albite3. QuartzConclusions:Quartz Chlorite embbeding Albite-altered fragments . EDS doesnt recognize Fe in the Albite as potential alteration123SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: Artisanal TunnelEl AlacranCountry: ColombiaSMA_AL_1612_JM_021 2D1Conclusions:The alteration in hornblende is characterized by a loss of Na-Al-Siand a enrichment of Fe and Si13D1SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: Artisanal TunnelEl AlacranCountry: ColombiaSMA_AL_1612_JM_021 2D1Conclusions:The dusty coloration is an effect overimposed in Albite, that seems not to be related with Fe. 13D16SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@113.4lEl AlacranCountry: ColombiaSMA_AL_1704_JM_041 D1Conclusions:Arsenopyrite occurrs as an early stage of Sphalerite + Carbonate +Pyrite +Chlacopyrite. This Arsenopyrite is anomalous in Co, Sb and Ni0D1 SphAspyPySphCarSEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA046@181El AlacranCountry: ColombiaSMA_AL_1705_JM_065 12D1Highlights1A. Potassic Mica1b. Chloritic Mica Conclusions:The composition of minerals analyzed in D1, show evidences of border alteration of a K-mica into a Mg phyllosilicate.12D1SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA046@181El AlacranCountry: ColombiaSMA_AL_1705_JM_065 1D1Conclusions:There is a mixture and aggregates occurrence of a chlorite-like composition brown mineral that intergrow with calcite and is being altered/intergrowing by a pale mineral which shows a gaining of Al -Si and slightly Fe loss. K is not picked by the EDS23312D2D3D2(1)SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA046@181El AlacranCountry: ColombiaSMA_AL_1705_JM_065 D1Highlights:4. V-bearing mica 5. V-bearing mica with lower Fe content compared to 4. 6. CalciteConclusions: The variations in color seems to be related with varia-tions in Fe coentent of the V-rich mica. 466D2D3D2(2)5SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ASA046@181El AlacranCountry: ColombiaSMA_AL_1705_JM_065 D1Highlights:1. Sphalerite2. Posible chlorite similar to the other analyzed spots, however the EDS does not pick the K and V 2D2D3 D3112SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@192.09El AlacranCountry: ColombiaSMA_AL_1709_JM_069 01D1D110Highlights:0. REE mineral, (Possible Monazite)1. Fluor ApatiteConclusionsApatite in the paragenesis occurs with hydrothermal REE-rich miner-al possibly monaziteSEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@192.09El AlacranCountry: ColombiaSMA_AL_1709_JM_069 1D1D2Highlights:1. Cobalt Iron Arsenic Sulfide. CobaltiteD21SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD003@192.09El AlacranCountry: ColombiaSMA_AL_1709_JM_069 1D1D3Highlights:1. V-Cr-Fe-Sc, Ti -Oxide 2. Cr, Ti OxideD21D3 2SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD081@63.8El AlacranCountry: ColombiaSMA_AL_1801_JM_104 1D1D1Highlights:1.Fracture infill material composed of Fe-S and variable amounts of Mg and AlD21D3SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD081@63.8El AlacranCountry: ColombiaSMA_AL_1801_JM_104 1D1D2Highlights:3 measurements in different areas of the crystals that exhibit zona-tion. All the results are consistent and no variations are observed. The mineral corresponds to a REE-bearing Ca-Fe silicate.D21D323SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD081@63.8El AlacranCountry: ColombiaSMA_AL_1801_JM_104 1D1D3Highlights:2 measurements in different crystals. All the results are consistent and no variations are observed. The Mineral corresponds to Fe-Rich specimenD21D3 2SEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@51El AlacranCountry: ColombiaSMA_AL_1709_JM_073 1D1D3Chlorite CompositionD21D32Sericite CompositionChloriteSericiteSEM RESULTSAnalyzer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD055@130.40El AlacranCountry: ColombiaSMA_AL_1801_JM_105 D2Posible Fe- CarbonateD41Mg-Fe silicate embeeded in quartz possibly actinolite. D211D4BSE - ResultsPetrographer: Julian Manco MSc-Candidatev. February 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD050@114.40El AlacranCountry: ColombiaSMA_AL_1709_JM_077EDS results from Au as inclusion in PyriteD4EDS results from Au (Electrum) as fracture infill after Pyryte. D1-0D1-2,3D1-0D1-2,3D1-0D1-2,3D1-0D1-2,3BSE - ResultsPetrographer: Julian Manco MSc-Candidatev. August 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: ACD036@ 113.4mEl AlacranCountry: ColombiaSMA_AL_1704_JM_041Element At. No. NettoMass[%]Mass Norm.[%]Atom[%]abs. error [%](1 sigma)rel. error [%](1 sigma)Gold 79 238928 60.01063 74.4417 48.12225 2.2700713.782782Silver 47 53309 17.6592 21.9058 25.85762 0.5836363.304998Carbon 6 3202 1.761389 2.184959 23.16254 0.3256518.48826Zinc 30 755 1.183046 1.467539 2.857592 0.0891777.537889Sum 80.61427 100 100Element At. No. NettoMass[%]Mass Norm.[%]Atom[%]abs. error [%](1 sigma)rel. error [%](1 sigma)Gold 79 252892 54.78175 72.27296 43.83254 2.0741373.786183Silver 47 60500 17.51025 23.10108 25.58309 0.5779693.300747Carbon 6 4344 2.066409 2.726191 27.1138 0.35705717.27909Zinc 30 913 1.439991 1.899764 3.470576 0.0990026.875208Sum 75.7984 100 100Highlights:Free gold intergrown with sphalerite (Au3). This gold grain was tested directly under EDS. The photo corresponds to a back scattered image (BSE). The EDS results come from 2 different spots within the Au crystal. D1D2BSE - ResultsPetrographer: Julian Manco MSc-Candidatev. August 2019Project:SAMPLE LOCATIONSample ID:San Matias Project Prospect:Location: Buenos Aires mineBuenos Aires Country: ColombiaSMA_BA_1801_JM_111Highlights:Breccia hydrothermal of chalcopyrite, pyrrhotite and ilmenite with La-Ce, Ca, Fe mineral, before misclassified as tourmaline in hand sample. This mineral intergrows with apatite and the sulfides. Eventhough the mineral is highly zoned the EDS showed a consistent chemistry. Mag: 10x 0,4mmXPL FOV~ 2.18mm <Ccp<ApCcp> <La+Ce<La+CeElement At. No. NettoMass[%]Mass Norm.[%]Atom[%]abs. error [%](1 sigma)rel. error [%](1 sigma)Oxygen 8 61298 34.2675 38.00666 54.25634 4.005381 11.68856953Silicon 14 89899 14.19847 15.74776 12.80652 0.617482 4.348935596Calcium 20 46046 11.13415 12.34908 7.037574 0.361192 3.243999235Aluminium 13 63100 10.00306 11.09456 9.391567 0.491237 4.910867047Iron 26 10085 7.581731 8.409025 3.439064 0.263799 3.479402007Carbon 6 4693 5.558507 6.165033 11.72332 0.905423 16.28896262Cerium 58 8369 4.608927 5.111838 0.833243 0.169647 3.680833543Lanthanum 57 5433 2.809483 3.116044 0.512364 0.117058 4.166530669Sum 90.16184 100 100Ce+La MineralChalcopyrite D.3 Leapfrog Interpolation Method Appendix E : Geochronology E.1. U-Pb Geochronology Data E.2. Ar-Ar Geochronology Data E.3. Re-Os Geochronology Data E.1 U-Pb Geochronology Data Table 1. Petrography of the recovered zircons Sample Grain Colour External Shape Detail External Shape General Internal Texture L (Um) W(Um) L/W Notes SMA_BT_1801_JM_122 MDRU19-7-2-21 Translucent Euhedral Equant Oscillatory zoning. Periphery sector zoning 120 80 1.5 SMA_BT_1801_JM_122 MDRU19-7-2-8 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis 175 40 4.4 Inclusion SMA_BT_1801_JM_122 MDRU19-7-2-25 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Sector zoning 200 65 3.1 SMA_BT_1801_JM_122 MDRU19-7-2-18 Translucent Euhedral to prismatic Prismatic Sector zoning parallel to c-axis 200 70 2.9 SMA_BT_1801_JM_122 MDRU19-7-2-11 Translucent Euhedral Prismatic Unzoned 140 70 2.0 SMA_BT_1801_JM_122 MDRU19-7-2-17 Translucent Euhedral Pyramidal convolute zoning, recristallized zoning 180 80 2.3 SMA_BT_1801_JM_122 MDRU19-7-2-3 Translucent Euhedral, one pyramid well developed Pyramidal external zoning rim parallel to c-axis to unzoned 190 120 1.6 SMA_BT_1801_JM_122 MDRU19-7-2-22 Translucent Euhedral, pyramidal to prismatic Pyramidal Homogenous unzoned 160 50 3.2 SMA_BT_1801_JM_122 MDRU19-7-2-16 Translucent Euhedral Broken piece Pyramidal Homogenous unzoned with thin growth zoning parallel to c-axis 120 70 1.7 SMA_BT_1801_JM_122 MDRU19-7-2-12 Translucent Euhedral Broken Pyramidal Irregular zoning Inherited core? 130 70 1.9 SMA_BT_1801_JM_122 MDRU19-7-2-9 Translucent Euhedral, one pyramid well developed Pyramidal Oscillatory zoning parallel to c-axis 175 80 2.2 SMA_BT_1801_JM_122 MDRU19-7-2-14 Translucent Euhedral Pyramidal Oscillatory zoning parallel to c-axis. Outter Rim (Magmatic?) 160 80 2.0 SMA_BT_1801_JM_122 MDRU19-7-2-24 Translucent Euhedral, pyramidal to prismatic Pyramidal Oscillatory zoning parallel to c-axis. Sector zoning 170 60 2.8 SMA_BT_1801_JM_122 MDRU19-7-2-15 Translucent Euhedral Pyramidal Sector and Oscillatory zoning. 160 80 2.0 SMA_BT_1801_JM_122 MDRU19-7-2-4 Translucent Euhedral Pyramidal Sector, and Oscillatory growth, no inherited core 200 120 1.7 SMA_BT_1801_JM_122 MDRU19-7-2-5 Translucent Euhedral Pyramidal Sector, and Oscillatory zoning parallel to c-axis 200 120 1.7 Inclusion SMA_BT_1801_JM_122 MDRU19-7-2-6 Translucent Euhedral Pyramidal Sector, and Oscillatory zoning parallel to c-axis 260 180 1.4 Continuation of Table 1. Sample Grain Colour External Shape Detail External Shape General Internal Texture L (Um) W(Um) L/W Notes SMA_SJ_1709_JM_066 MDRU19-7-5-15 Translucent Subhedral Prismatic Prismatic Fine Oscillatory zoning parallel to c-axis. 280 60 4.7 SMA_SJ_1709_JM_066 MDRU19-7-5-10 Translucent Subhedral Prismatic Prismatic Homogenous thin zonation parallel to c-axis 150 50 3.0 SMA_SJ_1709_JM_066 MDRU19-7-5-7 Translucent Prismatic, broken edges Prismatic Homogenous unzoned 250 60 4.2 SMA_SJ_1709_JM_066 MDRU19-7-5-20 Translucent Euhedral Pyramidal Pyramidal Oscillatory zoning 200 60 3.3 SMA_SJ_1709_JM_066 MDRU19-7-5-19 Translucent Subhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 150 50 3.0 SMA_SJ_1709_JM_066 MDRU19-7-5-21 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 230 50 4.6 SMA_SJ_1709_JM_066 MDRU19-7-5-6 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 300 50 6.0 SMA_SJ_1709_JM_066 MDRU19-7-5-1 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 400 50 8.0 SMA_SJ_1709_JM_066 MDRU19-7-5-18 Translucent Subhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 180 60 3.0 SMA_SJ_1709_JM_066 MDRU19-7-5-2 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 300 70 4.3 SMA_SJ_1709_JM_066 MDRU19-7-5-3 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Magmatic resorbed? 300 65 4.6 SMA_SJ_1709_JM_066 MDRU19-7-5-4 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Magmatic resorbed? 350 80 4.4 SMA_SJ_1709_JM_066 MDRU19-7-5-9 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Sector zoning 180 60 3.0 SMA_SJ_1709_JM_066 MDRU19-7-5-12 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Sector zoning, resorbed borders 300 60 5.0 SMA_SJ_1709_JM_066 MDRU19-7-5-5 Translucent Euhedral Prismatic with one pyramid Prismatic Oscillatory zoning parallel to c-axis. Small overgrown border 200 60 3.3 SMA_SJ_1709_JM_066 MDRU19-7-5-8 Translucent Subhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. Small overgrown border 250 60 4.2 SMA_ME_1705_JM_061 MDRU19-7-6-1 Translucent Anhedral Equant crystal Equant Sector zoning 230 200 1.2 SMA_ME_1705_JM_061 MDRU19-7-6-2 Translucent Anhedral Equant crystal Equant Sector zoning 200 150 1.3 SMA_ME_1705_JM_060 MDRU19-7-7-19 Translucent Euhedral Pyramidal Pyramidal Sector+oscillatory growth zoning parallel to c-axis 100 40 2.5 SMA_ME_1705_JM_060 MDRU19-7-7-10 Translucent Euhedral Pyramidal Pyramidal Oscillatory zoning, sector zoning 167 70 2.4 SMA_ME_1705_JM_060 MDRU19-7-7-13 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 250 70 3.6 SMA_ME_1705_JM_060 MDRU19-7-7-18 Translucent Euhedral Prismatic Prismatic Sector+oscillatory growth zoning parallel to c-axis 250 80 3.1 SMA_ME_1705_JM_060 MDRU19-7-7-1 Translucent Anhedral Equant crystal Equant Sector zoning 150 100 1.5 Continuation of Table 1. Sample Grain Colour External Shape Detail External Shape General Internal Texture L (Um) W(Um) L/W Notes SMA_ME_1705_JM_060 MDRU19-7-7-15 Translucent Subhedral, equant broken edges Equant Sector+oscillatory growth zoning 150 100 1.5 SMA_ME_1705_JM_060 MDRU19-7-7-12 Translucent Euhedral Pyramidal Pyramidal Sector+oscillatory growth zoning, no inherited core 200 100 2.0 SMA_ME_1705_JM_060 MDRU19-7-7-14 Translucent Euhedral Pyramidal to equant Pyramidal Sector+oscillatory growth zoning, resorb border 150 110 1.4 SMA_ME_1705_JM_060 MDRU19-7-7-17 Translucent Subhedral, equant crystal Equant Sector+oscillatory growth zoning, resorb border, inherited core 150 120 1.3 SMA_ME_1705_JM_060 MDRU19-7-7-16 Translucent Subhedral, equant crystal Equant Sector+oscillatory growth zoning, no inherited core 200 125 1.6 SMA_JA_1704_JM_057 MDRU19-7-9-13 Translucent, pinkish Euhedral Equant Equant Sector Zoning 117 70 1.7 SMA_JA_1704_JM_057 MDRU19-7-9-20 Translucent Eubhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis and sector zoning 130 38 3.4 SMA_JA_1704_JM_057 MDRU19-7-9-1 Translucent Euhedral Prismatic Prismatic Oscillatory zoning parallel to c-axis. 200 40 5.0 SMA_JA_1704_JM_057 MDRU19-7-9-17 Translucent Eubhedral Prismatic Prismatic Thin Oscillatory zoning parallel to c-axis 200 50 4.0 SMA_JA_1704_JM_057 MDRU19-7-9-15 Translucent Eubhedral Prismatic Prismatic Thins Oscillatory zoning parallel to c-axis 200 50 4.0 SMA_JA_1704_JM_057 MDRU19-7-9-19 Translucent Eubhedral Prismatic, broken edge Prismatic Unzoned to weak sector zoning 170 40 4.3 SMA_JA_1704_JM_057 MDRU19-7-9-6 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning 183 60 3.1 SMA_JA_1704_JM_057 MDRU19-7-9-9 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning 183 60 3.1 SMA_JA_1704_JM_057 MDRU19-7-9-24 Translucent Subhedral Pyramidal, one pyramid well developed Pyramidal Oscillatory zoning and sector zoning 200 100 2.0 SMA_JA_1704_JM_057 MDRU19-7-9-22 Translucent Subhedral Pyramidal, one pyramid well developed Pyramidal Oscillatory zoning and sector zoning, no inherited core 100 38 2.6 SMA_JA_1704_JM_057 MDRU19-7-9-12 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning parallel to c-axis. 160 66 2.4 SMA_JA_1704_JM_057 MDRU19-7-9-2 Translucent Subhedral Pyramidal, one pyramid well developed Pyramidal Oscillatory zoning parallel to c-axis. 150 67 2.3 SMA_JA_1704_JM_057 MDRU19-7-9-5 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning, sector zoning 180 50 3.6 SMA_JA_1704_JM_057 MDRU19-7-9-7 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning, sector zoning 183 60 3.1 SMA_JA_1704_JM_057 MDRU19-7-9-4 Translucent Subhedral Pyramidal Pyramidal Oscillatory zoning, sector zoning, border intergrown 180 50 3.6 SMA_JA_1704_JM_057 MDRU19-7-9-16 Translucent Euhedral Equant Pyramidal Unzoned to weak sector zoning 120 100 1.2 Low luminescence Table 2. QAQC of the recovered and analyzed zircons Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_BT_1801_JM_122 MDRU19-7-2-3R Rim Same area SMA_BT_1801_JM_122 MDRU19-7-2-3C Core Same area SMA_BT_1801_JM_122 MDRU19-7-2-4C Core Core SMA_BT_1801_JM_122 MDRU19-7-2-4R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-5R Rim Mixed Inclusion identified with Ca, Va, Sc, Ti SMA_BT_1801_JM_122 MDRU19-7-2-5C Core Mixed- Inclusion Excluded SMA_BT_1801_JM_122 MDRU19-7-2-6C Core Mixed SMA_BT_1801_JM_122 MDRU19-7-2-6R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-8R Rim Mixed Inlcusion, reflected in High Ca and La, Va, Ce, Pr, Nd SMA_BT_1801_JM_122 MDRU19-7-2-8C Core Mixed-Inclusion Excluded SMA_BT_1801_JM_122 MDRU19-7-2-9C Core Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_BT_1801_JM_122 MDRU19-7-2-11C Core Mixed Inclusion Excluded SMA_BT_1801_JM_122 MDRU19-7-2-11R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-12R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-14C Core Inherited Core SMA_BT_1801_JM_122 MDRU19-7-2-15C Core Partially Mixed SMA_BT_1801_JM_122 MDRU19-7-2-16C Core Same area SMA_BT_1801_JM_122 MDRU19-7-2-16R Rim Same area SMA_BT_1801_JM_122 MDRU19-7-2-17R Rim Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_BT_1801_JM_122 MDRU19-7-2-18R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-18C Core Mixed SMA_BT_1801_JM_122 MDRU19-7-2-21C Core Mixed SMA_BT_1801_JM_122 SMA_BT_1801_JM_122 MDRU19-7-2-22C Core Border SMA_BT_1801_JM_122 MDRU19-7-2-24C Core Homogenus SMA_BT_1801_JM_122 MDRU19-7-2-24R Rim Mixed SMA_BT_1801_JM_122 MDRU19-7-2-25R Rim Border, mixed SMA_BT_1801_JM_122 MDRU19-7-2-25C Core Homogenus SMA_SJ_1709_JM_066 MDRU19-7-5-1C Core Border, mixed The TE is consistent SMA_SJ_1709_JM_066 MDRU19-7-5-1R Rim Fracture? Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_SJ_1709_JM_066 MDRU19-7-5-2R Rim Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-2C Core Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-3C Core Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-3R Rim Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-4R Rim Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-4C Core Mixed, same area, border SMA_SJ_1709_JM_066 MDRU19-7-5-5C Core Mixed, same area SMA_SJ_1709_JM_066 MDRU19-7-5-5R Rim Mixed, same area, border SMA_SJ_1709_JM_066 MDRU19-7-5-6R Rim Homogenus SMA_SJ_1709_JM_066 MDRU19-7-5-6C Core Mixed SMA_SJ_1709_JM_066 MDRU19-7-5-7C Core Same are, homogenus SMA_SJ_1709_JM_066 MDRU19-7-5-7R Rim Same are, homogenus Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_SJ_1709_JM_066 MDRU19-7-5-8R Rim Mixed, border SMA_SJ_1709_JM_066 MDRU19-7-5-8C Core Mixed SMA_SJ_1709_JM_066 MDRU19-7-5-10C Core Homogenus SMA_SJ_1709_JM_066 MDRU19-7-5-10R Rim Homogenus partially mixed SMA_SJ_1709_JM_066 MDRU19-7-5-12R Rim Mixed SMA_SJ_1709_JM_066 MDRU19-7-5-12C Core Core SMA_SJ_1709_JM_066 MDRU19-7-5-15C Core Same area, mixed SMA_SJ_1709_JM_066 MDRU19-7-5-15R Rim Same area, mixed SMA_SJ_1709_JM_066 MDRU19-7-5-18R Rim Mixed SMA_SJ_1709_JM_066 SMA_SJ_1709_JM_066 MDRU19-7-5-19C Core Mixed SMA_SJ_1709_JM_066 Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_SJ_1709_JM_066 MDRU19-7-5-20C Core Mixed, highly heterogenus The TE is consistent SMA_SJ_1709_JM_066 MDRU19-7-5-20R Rim Mixed, highly heterogenus The TE is consistent SMA_SJ_1709_JM_066 MDRU19-7-5-21R Rim Mixed, same are SMA_SJ_1709_JM_066 MDRU19-7-5-21C Core Mixed, same are SMA_ME_1705_JM_061 MDRU19-7-6-1C Core Homogenous SMA_ME_1705_JM_061 MDRU19-7-6-1R Rim Homogenous SMA_ME_1705_JM_061 MDRU19-7-6-2R Rim Mixed SMA_ME_1705_JM_061 MDRU19-7-6-2C Core Homogenous SMA_ME_1705_JM_060 MDRU19-7-7-1C Core Homogenous SMA_ME_1705_JM_060 MDRU19-7-7-1R Rim Mixed SMA_ME_1705_JM_060 MDRU19-7-7-10C Core Mixed, Fracture? SMA_ME_1705_JM_060 MDRU19-7-7-10R Rim Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_ME_1705_JM_060 MDRU19-7-7-12R Rim Homogenous SMA_ME_1705_JM_060 MDRU19-7-7-12C Core Mixed SMA_ME_1705_JM_060 MDRU19-7-7-13C Core Mixed SMA_ME_1705_JM_060 MDRU19-7-7-13R Rim Mixed SMA_ME_1705_JM_060 MDRU19-7-7-14R Rim Mixed Excluded High Vanadium SMA_ME_1705_JM_060 MDRU19-7-7-14C Core Mixed -Dilution High Sc SMA_ME_1705_JM_060 MDRU19-7-7-15C Core Homogenous SMA_ME_1705_JM_060 MDRU19-7-7-16C Core Mixed SMA_ME_1705_JM_060 MDRU19-7-7-16R Rim Homogenous SMA_ME_1705_JM_060 MDRU19-7-7-17R Rim Inlusion Excluded SMA_ME_1705_JM_060 MDRU19-7-7-17C Core Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_ME_1705_JM_060 MDRU19-7-7-18C Core Mixed SMA_ME_1705_JM_060 MDRU19-7-7-18R Rim Mixed SMA_ME_1705_JM_060 MDRU19-7-7-19C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-1C Core Mixed with Epoxy SMA_JA_1704_JM_057 MDRU19-7-9-1R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-2R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-2C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-4C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-5C Core Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_JA_1704_JM_057 MDRU19-7-9-6C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-6R Rim Mixed+Fract? TE consistent SMA_JA_1704_JM_057 MDRU19-7-9-7R Rim Mixed Excluded TE relative consistent, differences in Va and Sn SMA_JA_1704_JM_057 MDRU19-7-9-7C Core Homogenous SMA_JA_1704_JM_057 MDRU19-7-9-8C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-8R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-12R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-12C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-13C Core Mixed SMA_JA_1704_JM_057 SMA_JA_1704_JM_057 MDRU19-7-9-15C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-15R Rim Mixed Continuation of Table 2. Sample Zircon ID Location Note CL RL Conclusion (TE) Chemistry SMA_JA_1704_JM_057 MDRU19-7-9-16C Core Homogenous SMA_JA_1704_JM_057 MDRU19-7-9-16R Rim Homogenous SMA_JA_1704_JM_057 MDRU19-7-9-17R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-17C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-19C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-19R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-20R Rim Mixed Fracture? SMA_JA_1704_JM_057 MDRU19-7-9-20C Core Mixed Fracture? Excluded TE consitent, high Va, Sn core SMA_JA_1704_JM_057 MDRU19-7-9-22C Core Mixed SMA_JA_1704_JM_057 MDRU19-7-9-22R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-24R Rim Mixed SMA_JA_1704_JM_057 MDRU19-7-9-24C Core Mixed Table 3. U-Pb LA-ICP-MS data from the recovered zircons Sample ID Zircon ID Location External Shape 206/238 Age 2σ 207Pb/235U 2σ 206Pb/238U 2σ EC U (ppm) 2σ Th (ppm) 2σ Pb (ppm) 2σ U/Th 2σ JM-122 MDRU19-7-2-3R Rim Pyramidal 75.4 3.6 0.074 0.013 0.01177 0.00057 0.01000 614 40 723 49 88.6 7 0.835 0.018 JM-122 MDRU19-7-2-3C Core Pyramidal 80.4 6.6 0.067 0.023 0.0126 0.001 0.01000 363 68 338 72 40.9 9.5 1.46 0.13 JM-122 MDRU19-7-2-4C Core Pyramidal 72.7 4 0.077 0.016 0.01135 0.00062 0.01000 337 17 263 16 32.7 4.7 1.29 0.029 JM-122 MDRU19-7-2-4R Rim Pyramidal 75.4 2.8 0.065 0.016 0.01177 0.00044 0.01000 409 46 355 42 43.2 6.5 1.134 0.026 JM-122 MDRU19-7-2-5R Rim Pyramidal 72.3 3.3 0.064 0.014 0.01129 0.00052 0.13248 405 30 345 27 37.7 4.4 1.183 0.018 JM-122 MDRU19-7-2-6C Core Pyramidal 73.8 5.4 0.054 0.02 0.01152 0.00085 0.01000 200 16 109.9 9.8 14.1 2.1 1.852 0.035 JM-122 MDRU19-7-2-6R Rim Pyramidal 78.9 4.6 0.068 0.016 0.01231 0.00073 0.01000 300 21 222 15 24.6 3.3 1.359 0.027 JM-122 MDRU19-7-2-8R Rim Prismatic 72.5 3.6 0.082 0.018 0.01131 0.00057 0.30099 354 15 238.2 7.5 27.4 3.3 1.497 0.028 JM-122 MDRU19-7-2-9C Core Pyramidal 73.2 3.9 0.062 0.015 0.01143 0.00062 0.01000 359 29 257 27 30.3 4.6 1.49 0.055 JM-122 MDRU19-7-2-11R Rim Prismatic 84.2 3.9 0.09 0.02 0.01315 0.00061 0.15503 357 37 274 20 34.9 5.1 1.274 0.042 JM-122 MDRU19-7-2-12R Rim Pyramidal 68.9 2.2 0.0655 0.009 0.01074 0.00034 0.01000 1340 190 1490 260 162 28 0.999 0.039 JM-122 MDRU19-7-2-14C Core Pyramidal 71.1 3.6 0.074 0.018 0.0111 0.00056 0.22052 456 28 396 22 46.8 5.1 1.158 0.02 JM-122 MDRU19-7-2-15C Core Pyramidal 75 3.2 0.059 0.013 0.0117 0.00051 0.09362 497 31 370 28 38.3 4.8 1.371 0.033 JM-122 MDRU19-7-2-16C Core Pyramidal 78.7 6.1 0.057 0.027 0.01229 0.00095 0.01000 116.2 3.8 57 4.1 5.8 1.5 2.12 0.13 JM-122 MDRU19-7-2-16R Rim Pyramidal 71.7 5.4 0.062 0.025 0.01118 0.00085 0.01000 202 22 117 11 14.2 2.7 1.699 0.048 JM-122 MDRU19-7-2-17R Rim Pyramidal 73.1 3 0.092 0.022 0.01141 0.00047 0.01000 1210 150 716 86 83 13 1.677 0.04 JM-122 MDRU19-7-2-18R Rim Prismatic 73.5 2.1 0.0661 0.0092 0.01147 0.00034 0.01000 873 17 950 20 105.8 8.9 0.926 0.014 JM-122 MDRU19-7-2-18C Core Prismatic 74.2 3.1 0.071 0.012 0.01158 0.00048 0.01000 721 33 705 33 83.3 6.9 1.025 0.015 JM-122 MDRU19-7-2-21C Core Equant 77.6 3.5 0.086 0.018 0.01211 0.00056 0.08246 406 38 265 28 31.4 4.6 1.569 0.028 JM-122 MDRU19-7-2-22C Core Pyramidal 75 3.1 0.074 0.012 0.0117 0.00049 0.01000 860 130 810 120 92 14 1.063 0.017 JM-122 MDRU19-7-2-24C Core Pyramidal 73.4 2.9 0.089 0.014 0.01145 0.00045 0.07869 665 14 620 13 68.1 5.3 1.077 0.02 JM-122 MDRU19-7-2-24R Rim Pyramidal 71.9 2.9 0.095 0.013 0.01121 0.00046 0.01000 754 36 753 38 86.1 7.2 1.012 0.025 JM-122 MDRU19-7-2-25R Rim Prismatic 68.4 2.2 0.077 0.011 0.01066 0.00034 0.01000 1320 71 1048 42 115.1 7.8 1.251 0.03 JM-122 MDRU19-7-2-25C Core Prismatic 71.7 2.2 0.0779 0.0093 0.01118 0.00034 0.12793 1344 59 1122 62 130.4 7.5 1.196 0.026 JM-066 MDRU19-7-5-1C Core Prismatic 71.3 2.9 0.077 0.015 0.01113 0.00045 0.01000 705 22 358 18 43.6 4.9 2.0 0.076 JM-066 MDRU19-7-5-1R Rim Prismatic 73.1 3.7 0.086 0.019 0.01141 0.00057 0.04641 383 25 169 13 23.6 3.2 2.4 0.11 Continuation of Table 3. Sample ID Zircon ID Location External Shape 206/238 Age 2σ 207Pb/235U 2σ 206Pb/238U 2σ EC U (ppm) 2σ Th (ppm) 2σ Pb (ppm) 2σ U/Th 2σ JM-066 MDRU19-7-5-2R Rim Prismatic 77.3 2.5 0.091 0.012 0.01206 0.00039 0.16140 1210 150 990 100 122 12 1.2 0.026 JM-066 MDRU19-7-5-2C Core Prismatic 73.5 3.2 0.075 0.014 0.01146 0.00051 0.28574 583 19 294.3 8.6 33.4 3.5 2.0 0.036 JM-066 MDRU19-7-5-3C Core Prismatic 76.7 3.2 0.082 0.016 0.01196 0.0005 0.00287 557 34 276 24 32.9 4.1 2.1 0.12 JM-066 MDRU19-7-5-3R Rim Prismatic 73.9 2.7 0.068 0.014 0.01154 0.00043 0.30596 528 41 223 17 26.5 3.4 2.4 0.073 JM-066 MDRU19-7-5-4R Rim Prismatic 71.1 2.8 0.075 0.014 0.01109 0.00045 0.01000 489.4 9.4 221.5 5.3 26.4 2.7 2.2 0.036 JM-066 MDRU19-7-5-4C Core Prismatic 74.7 3.1 0.077 0.015 0.01165 0.00048 0.14213 486 12 229.2 7.8 29.5 3.8 2.1 0.041 JM-066 MDRU19-7-5-5C Core Prismatic 72.7 3.2 0.07 0.015 0.01134 0.0005 0.19492 488 35 214 19 29.2 4.7 2.3 0.1 JM-066 MDRU19-7-5-5R Rim Prismatic 73.1 2.7 0.091 0.016 0.01141 0.00042 0.17069 498 24 262 25 35.5 6 2.0 0.12 JM-066 MDRU19-7-5-6R Rim Prismatic 74.9 2.3 0.0695 0.0092 0.01169 0.00036 0.01000 1063 34 842 89 98 12 1.5 0.15 JM-066 MDRU19-7-5-6C Core Prismatic 74.7 2.5 0.072 0.01 0.01166 0.0004 0.14424 957 35 675 77 79 10 1.6 0.14 JM-066 MDRU19-7-5-7C Core Prismatic 72.8 3.1 0.079 0.011 0.01136 0.00049 0.05972 771 33 558 22 65.4 6 1.4 0.052 JM-066 MDRU19-7-5-7R Rim Prismatic 77.4 3.8 0.074 0.016 0.01207 0.0006 0.01000 508 41 306 37 34.6 5.3 1.8 0.11 JM-066 MDRU19-7-5-8R Rim Prismatic 73.7 2.5 0.0764 0.0096 0.01149 0.00039 0.01000 1159 71 1126 75 130 10 1.0 0.018 JM-066 MDRU19-7-5-8C Core Prismatic 72.9 3.1 0.068 0.011 0.01137 0.00049 0.24806 725 34 355 26 38 3.8 2.1 0.045 JM-066 MDRU19-7-5-10C Core Prismatic 74.1 3.3 0.066 0.01 0.01156 0.00052 0.01000 792 58 448 53 57.5 9 1.9 0.11 JM-066 MDRU19-7-5-10R Rim Prismatic 77.7 3.3 0.068 0.014 0.01213 0.00052 0.01000 557 54 370 57 49.7 7.4 1.9 0.16 JM-066 MDRU19-7-5-12R Rim Prismatic 75.1 2.8 0.078 0.011 0.01173 0.00044 0.06953 927 30 712 27 79.5 6.3 1.3 0.062 JM-066 MDRU19-7-5-12C Core Prismatic 69.9 2.5 0.068 0.011 0.0109 0.00039 0.19473 765 17 358 14 35.5 4.4 2.2 0.066 JM-066 MDRU19-7-5-15C Core Prismatic 73.1 3.1 0.073 0.011 0.0114 0.00049 0.06444 825 57 416 32 37 4.1 2.0 0.06 JM-066 MDRU19-7-5-15R Rim Prismatic 77.1 3.4 0.08 0.012 0.01203 0.00053 0.15962 668 48 282 22 26.1 3.1 2.4 0.042 JM-066 MDRU19-7-5-18R Rim Prismatic 73.6 2.8 0.0691 0.0084 0.01149 0.00044 0.01000 1016 82 399 34 35.1 3.7 2.5 0.062 JM-066 MDRU19-7-5-19C Core Prismatic 82.1 4 0.108 0.02 0.01282 0.00062 0.03012 448 51 180 22 19.2 3.7 2.5 0.093 JM-066 MDRU19-7-5-20C Core Pyramidal 75.3 2.8 0.079 0.013 0.01175 0.00044 0.01000 888 62 265 10 26.2 3.2 3.5 0.25 JM-066 MDRU19-7-5-20R Rim Prismatic 78.6 3 0.101 0.017 0.01227 0.00047 0.32828 1018 74 299 43 38.1 6.3 4.0 0.28 JM-066 MDRU19-7-5-21R Rim Equant 74.2 2.2 0.0691 0.0091 0.01158 0.00034 0.01000 1371 82 1052 61 86.9 5.2 1.3 0.014 JM-066 MDRU19-7-5-21C Core Equant 74.7 2.3 0.0648 0.0092 0.01165 0.00035 0.12749 1066 49 830 23 64.5 3.7 1.3 0.039 Continuation of Table 3. Sample ID Zircon ID Location External Shape 206/238 Age 2σ 207Pb/235U 2σ 206Pb/238U 2σ EC U (ppm) 2σ Th (ppm) 2σ Pb (ppm) 2σ U/Th 2σ JM-061 MDRU19-7-6-1R Rim Equant 68.5 7.5 0.052 0.031 0.0107 0.0012 0.01000 58.5 1.6 14.19 0.5 0.96 0.38 4.15 0.14 JM-061 MDRU19-7-6-2R Rim Equant 69.5 8.8 0.061 0.033 0.0109 0.0014 0.09359 65.7 3.6 23 1.9 1.79 0.63 2.94 0.16 JM-061 MDRU19-7-6-2C Core Equant 76.3 9 0.05 0.028 0.0119 0.0014 0.03394 68.5 1.6 26.47 0.9 1.4 0.55 2.568 0.069 JM-060 MDRU19-7-7-1C Core Equant 72.9 9 0.063 0.046 0.0114 0.0014 0.01000 50.2 3.8 11.73 0.89 1.42 0.61 4.25 0.16 JM-060 MDRU19-7-7-1R Rim Equant 74 13 0.054 0.045 0.0115 0.0021 0.05360 42.2 2.8 9.86 0.81 0.38 0.33 4.22 0.24 JM-060 MDRU19-7-7-10C Core Pyramidal 70.9 6.5 0.047 0.027 0.0111 0.001 0.01306 95.6 8.5 31.5 3.7 3.7 1.2 3.1 0.13 JM-060 MDRU19-7-7-10R Rim Pyramidal 74.2 4.9 0.084 0.023 0.01158 0.00078 0.01000 262 30 110 14 14.8 2.6 2.55 0.14 JM-060 MDRU19-7-7-12R Rim Pyramidal 73 10 0.052 0.036 0.0115 0.0016 0.26460 68.1 6.4 27.9 3.1 2.28 0.94 2.488 0.084 JM-060 MDRU19-7-7-12C Core Pyramidal 79 11 0.061 0.04 0.0124 0.0017 0.00981 51.1 4.4 14 1.3 1.66 0.66 3.66 0.13 JM-060 MDRU19-7-7-13C Core Prismatic 75.9 7.2 0.069 0.025 0.0119 0.0011 0.02143 132 13 71.3 9.8 8.5 2 2.04 0.11 JM-060 MDRU19-7-7-13R Rim Prismatic 73 5.8 0.04 0.019 0.01139 0.00092 0.01000 141 12 83.2 9.5 9.7 2.3 1.795 0.084 JM-060 MDRU19-7-7-14C Core Pyramidal 75.9 6.9 0.073 0.032 0.0119 0.0011 0.14272 91.5 3.5 30.9 1.9 3.7 1.3 3.01 0.1 JM-060 MDRU19-7-7-15C Core Equant 79.3 7.3 0.074 0.029 0.0124 0.0011 0.02862 95.9 2.9 30 1.7 3.16 0.9 3.22 0.12 JM-060 MDRU19-7-7-16C Core Equant 66 13 0.132 0.087 0.0104 0.002 0.26434 30.1 2.6 7.56 0.73 -0.17 1.39 4.14 0.22 JM-060 MDRU19-7-7-16R Rim Equant 66.1 7.9 0.063 0.027 0.0103 0.0012 0.01000 72.4 5.6 27.5 2.3 2.22 0.88 2.685 0.092 JM-060 MDRU19-7-7-17C Core Equant 74.6 7.6 0.02 0.018 0.0116 0.0012 0.01000 77.8 2.5 28.4 1.2 3 1.1 2.72 0.076 JM-060 MDRU19-7-7-18C Core Prismatic 70.7 9.3 0.081 0.049 0.011 0.0015 0.07909 43.8 2.3 15.93 0.74 1.54 0.63 2.76 0.12 JM-060 MDRU19-7-7-18R Rim Prismatic 76.3 9.6 0.063 0.039 0.0119 0.0015 0.02849 52.7 1.6 19 1.2 2.67 0.83 2.81 0.14 JM-060 MDRU19-7-7-19C Core Pyramidal 70.7 6.4 0.118 0.037 0.011 0.001 0.01000 126 14 73.1 9.1 8.8 1.9 1.88 0.1 JM-057 MDRU19-7-9-1C Core Prismatic 76.8 6.3 0.106 0.022 0.012 0.001 0.01000 255 11 177 11 25.8 4.1 1.442 0.053 JM-057 MDRU19-7-9-1R Rim Prismatic 75.7 4.6 0.076 0.019 0.01182 0.00072 0.42376 260 15 196 19 23.3 3.6 1.396 0.079 JM-057 MDRU19-7-9-2R Rim Pyramidal 72.9 4.4 0.125 0.02 0.01138 0.0007 0.01000 545 64 368 50 54.7 6.9 1.574 0.07 JM-057 MDRU19-7-9-2C Core Pyramidal 76.1 5 0.072 0.019 0.01188 0.00079 0.01000 290 11 222 15 26.4 3.4 1.324 0.056 Continuation of Table 3. Sample ID Zircon ID Location External Shape 206/238 Age 2σ 207Pb/235U 2σ 206Pb/238U 2σ EC U (ppm) 2σ Th (ppm) 2σ Pb (ppm) 2σ U/Th 2σ JM-057 MDRU19-7-9-4C Core Pyramidal 74.8 4.8 0.066 0.017 0.01167 0.00075 0.13626 373 23 273 21 29.7 3.6 1.362 0.055 JM-057 MDRU19-7-9-5C Core Pyramidal 75.6 5.3 0.073 0.018 0.0118 0.00083 0.01000 314 36 255 33 29.2 4.3 1.339 0.073 JM-057 MDRU19-7-9-6C Core Pyramidal 72.1 3.4 0.078 0.018 0.01124 0.00053 0.11439 417 34 281 28 31.3 4.6 1.538 0.056 JM-057 MDRU19-7-9-6R Rim Pyramidal 73.7 7.5 0.06 0.031 0.0115 0.0012 0.07996 294 49 184 39 24.8 6.4 1.698 0.084 JM-057 MDRU19-7-9-7C Core Pyramidal 84.7 8.2 0.205 0.068 0.0132 0.0013 0.50784 341 22 196 11 37 11 1.77 0.13 JM-057 MDRU19-7-9-8C Core Pyramidal 72 3.2 0.067 0.019 0.01124 0.0005 0.01000 347 14 224 16 29.4 3.5 1.582 0.076 JM-057 MDRU19-7-9-8R Rim Pyramidal 78.9 5.3 0.111 0.033 0.01232 0.00083 0.37334 214 12 123 10 23.5 3.6 1.744 0.055 JM-057 MDRU19-7-9-12R Rim Pyramidal 81 6.4 0.098 0.032 0.0127 0.001 0.00069 163 13 75.1 7.2 13 2.4 2.204 0.083 JM-057 MDRU19-7-9-12C Core Pyramidal 77 4.6 0.073 0.02 0.01202 0.00072 0.00278 255 14 178.2 7.4 19.9 2.9 1.418 0.062 JM-057 MDRU19-7-9-13C Core Equant 72.8 4.1 0.071 0.023 0.01136 0.00064 0.01000 348 27 294 33 31.6 4.9 1.262 0.071 JM-057 MDRU19-7-9-15C Core Prismatic 72.8 4.1 0.081 0.02 0.01136 0.00064 0.05241 318 43 209 28 27.1 3.6 1.556 0.067 JM-057 MDRU19-7-9-15R Rim Prismatic 76.5 4.9 0.061 0.018 0.01194 0.00077 0.01000 295 33 220 26 24.4 3.5 1.393 0.067 JM-057 MDRU19-7-9-16C Core Pyramidal 73.7 3.1 0.071 0.012 0.0115 0.00048 0.00136 876 42 858 52 108.7 9.8 0.998 0.034 JM-057 MDRU19-7-9-16R Rim Pyramidal 78.7 2.5 0.0815 0.0096 0.01229 0.0004 0.11233 1351 90 1870 180 234 22 0.73 0.02 JM-057 MDRU19-7-9-17R Rim Prismatic 94.5 7.2 0.28 0.066 0.0148 0.0011 0.59318 233 18 147 12 44.4 6.2 1.597 0.041 JM-057 MDRU19-7-9-17C Core Prismatic 75.9 5.8 0.091 0.03 0.01185 0.0009 0.04022 137 14 73.6 7.8 9.5 1.9 1.92 0.057 JM-057 MDRU19-7-9-19C Core Prismatic 72.7 4.6 0.068 0.022 0.01135 0.00073 0.01000 250 21 143 16 17.1 3 1.826 0.068 JM-057 MDRU19-7-9-19R Rim Prismatic 75.6 4.7 0.068 0.017 0.0118 0.00073 0.01000 260 13 150.6 7.7 17.4 2.6 1.734 0.044 JM-057 MDRU19-7-9-20R Rim Prismatic 113 13 0.73 0.2 0.0178 0.002 0.82874 214 25 118 18 74 15 1.957 0.081 JM-057 MDRU19-7-9-22C Core Pyramidal 74.1 3 0.082 0.012 0.01157 0.00048 0.08166 695 44 796 47 89.8 6.9 0.865 0.016 JM-057 MDRU19-7-9-22R Rim Pyramidal 71.2 2.2 0.0742 0.0083 0.01111 0.00034 0.03204 1580 100 2560 200 289 21 0.622 0.012 JM-057 MDRU19-7-9-24R Rim Pyramidal 72.9 3.9 0.082 0.015 0.01138 0.00061 0.12565 613 37 536 24 58.7 5.1 1.123 0.024 JM-057 MDRU19-7-9-24C Core Pyramidal 72.1 4.7 0.079 0.017 0.01125 0.00074 0.11046 315 20 167.7 8.9 19.9 2.6 1.829 0.058 E.2 Ar-Ar Geochronology Data Table 1.Ar-Ar geochronology results in actinolite from the El Alacrán Deposit (sample SMA-AL-JM-043). March 2019 SMA-AL-JM-043 Actinolite Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2σ 2.30 44.21 9.74 0.14 0.131 0.023 0.005 0.0032 0.0029 0.002 1.24 5.62 0.55 2.484 16.66 ± 254.01 2.80 135.31 4.37 0.43 0.019 0.007 0.000 0.0032 0.0001 0.061 0.19 5.50 42.77 7.452 49.54 ± 26.97 3.00 57.88 6.05 0.16 0.022 0.017 0.002 0.0027 0.0003 0.018 0.39 18.21 16.25 10.549 69.74 ± 30.42 3.30 74.47 2.54 0.22 0.015 0.013 0.000 0.0029 0.0002 0.019 0.49 13.10 17.88 9.765 64.65 ± 25.88 3.70 67.89 3.40 0.20 0.012 0.015 0.001 0.0029 0.0001 0.052 0.07 14.12 22.55 9.636 63.81 ± 14.73 J = 0.00368130 ± 0.00000736 Volume 39ArK = 0.093 x E-13 cm3 NPT Integrated Date = 62.33 ± 10.80 Ma Plateau age = 62 ± 11 Ma (2s, including J-error of .4%) MSWD = 0.33, probability=0.85 Includes 100% of the 39Ar steps 1 through 5 Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 5 points Age = 76 ± 29 Ma Initial 40Ar/36Ar =289 ± 18 MSWD = 0.079 Probability = 0.97 Analysis by Janet Gabites Pacific Centre for Isotopic and Geochemical Research, Dept Earth and Ocean Sciences, The University of British Columbia, Vancouver, BC., Canada Table 2.Ar-Ar geochronology results in actinolite from the El Alacrán Deposit (sample SMA-AL-JM-043). July 2019 SMA-AL-JM-043 Actinolite Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2s 2.30 50.53 0.33 0.16 0.00 0.020 0.000 0.0031 0.0000 0.115 0.90 8.13 18.31 4.112 27.50 ± 3.90 2.60 311.90 2.00 0.94 0.01 0.003 0.000 0.0030 0.0000 0.154 0.10 10.45 3.07 32.722 208.20 ± 21.14 2.90 194.29 1.64 0.56 0.01 0.005 0.000 0.0029 0.0000 0.129 0.09 13.60 6.02 26.538 170.62 ± 13.23 3.20 250.17 1.51 0.83 0.02 0.004 0.000 0.0033 0.0001 0.091 0.04 2.10 2.34 5.306 35.41 ± 34.08 3.60 178.62 3.03 0.59 0.01 0.006 0.000 0.0033 0.0000 0.078 0.06 1.48 4.84 2.667 17.89 ± 15.68 3.90 207.32 2.87 0.67 0.02 0.005 0.000 0.0032 0.0001 0.000 0.05 4.68 5.16 9.788 64.79 ± 28.28 4.20 109.89 0.93 0.34 0.01 0.009 0.000 0.0031 0.0000 0.129 0.06 8.81 4.42 9.747 64.53 ± 9.15 4.70 97.53 0.76 0.316 0.006 0.010 0.000 0.0032 0.0001 0.046 0.05 5.84 6.27 5.744 38.30 ± 12.04 5.20 52.47 0.45 0.164 0.003 0.019 0.000 0.0030 0.0001 0.361 0.06 10.44 6.29 5.515 36.79 ± 5.54 5.70 50.67 0.39 0.163 0.004 0.020 0.000 0.0031 0.0001 0.031 0.05 8.36 4.67 4.268 28.53 ± 7.97 6.40 27.73 0.22 0.082 0.003 0.036 0.000 0.0027 0.0001 0.027 0.06 18.63 8.00 5.199 34.70 ± 5.95 7.10 22.00 0.14 0.060 0.004 0.045 0.000 0.0025 0.0002 0.015 0.07 25.53 6.10 5.649 37.67 ± 8.64 8.00 19.04 0.15 0.052 0.003 0.052 0.000 0.0024 0.0001 0.055 0.07 27.50 7.85 5.266 35.15 ± 5.52 9.00 14.13 0.09 0.036 0.003 0.070 0.000 0.0023 0.0002 0.019 0.09 31.84 5.78 4.518 30.20 ± 5.14 10.00 12.24 0.07 0.028 0.003 0.081 0.000 0.0021 0.0002 0.007 0.10 38.25 4.86 4.700 31.40 ± 5.92 11.50 12.76 0.08 0.028 0.003 0.078 0.000 0.0020 0.0002 0.011 0.11 40.65 6.03 5.205 34.74 ± 5.36 J = 0.00368130 ± 0.00000736 Volume 39ArK = 0.610 x E-13 cm3 NPT Integrated Date = 37.19 ± 1.76 Ma Plateau age = 33.8 ± 2.1 Ma (2s, including J-error of .4%) MSWD = 0.92, probability=0.50 Includes 55.8% of the 39Ar steps 8 through 16 Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 14 points Age = 30.8 ± 6.4 Ma Initial 40Ar/36Ar =301.6 ± 6.3 MSWD = 5.4 Probability = 0 Analysis by Janet Gabites Pacific Centre for Isotopic and Geochemical Research, Dept Earth and Ocean Sciences, The University of British Columbia, Vancouver, BC., Canada Table 3.Ar-Ar geochronology results in sericite from the El Alacrán Deposit (sample SMA-AL-JM-073). June 2019 SMA-AL-JM-073 Sericite Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2σ 2.30 13.68 0.18 0.0178 0.0009 0.073 0.001 0.00130 0.00006 0.011 23.97 61.21 4.02 8.371 55.08 ± 1.76 2.60 12.05 0.14 0.0063 0.0003 0.083 0.001 0.00052 0.00002 0.022 24.08 84.39 11.06 10.170 66.70 ± 0.93 2.90 11.53 0.14 0.0045 0.0002 0.087 0.001 0.00039 0.00002 0.036 9.86 88.38 20.73 10.190 66.84 ± 0.89 3.20 11.58 0.14 0.0048 0.0003 0.086 0.001 0.00041 0.00002 0.034 7.26 87.68 11.25 10.157 66.62 ± 0.97 3.70 11.93 0.14 0.0050 0.0002 0.084 0.001 0.00042 0.00001 0.063 27.43 87.43 32.77 10.431 68.39 ± 0.87 4.00 11.87 0.14 0.0153 0.0031 0.084 0.001 0.00129 0.00026 0.005 5.82 61.62 5.98 7.312 48.20 ± 6.04 4.40 14.13 0.18 0.0269 0.0056 0.071 0.001 0.00190 0.00039 0.003 3.25 43.22 2.35 6.109 40.36 ± 10.89 5.20 12.76 0.16 0.0420 0.0035 0.078 0.001 0.00329 0.00027 0.013 3.03 1.87 4.10 0.239 1.59 ± 6.84 6.20 11.81 0.14 0.0351 0.0063 0.085 0.001 0.00297 0.00053 0.005 2.63 11.40 5.63 1.346 8.97 ± 12.44 7.20 13.58 0.20 0.1251 0.0144 0.074 0.001 0.00920 0.00105 0.034 0.96 -174.60 2.10 23.714 -165.69 ± 31.29 J = 0.00364940 ± 0.00000730 Volume 39ArK = 1.499 x E-13 cm3 NPT Integrated Date = 65.90 ± 0.44 Ma Plateau age = 66.73 ± 0.60 Ma (2s, including J-error of .4%) MSWD = 0.056, probability=0.95 Includes 43% of the 39Ar steps 2 through 4 Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 4 points Age = 67 ± 17 Ma Initial 40Ar/36Ar =281 ± 520 MSWD = 5.4 Probability = 0 Analysis by Janet Gabites Pacific Centre for Isotopic and Geochemical Research, Dept Earth and Ocean Sciences, The University of British Columbia, Vancouver, BC., Canada Table 4.Ar-Ar geochronology results in sericite from the El Alacrán Deposit (sample SMA-AL-JM-073). March 2019 SMA-AL-JM-073 Sericite Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2s 2.30 13.68 0.18 0.0178 0.0009 0.073 0.001 0.00130 0.00006 0.011 23.97 61.21 4.02 8.371 55.08 ± 1.76 2.60 12.05 0.14 0.0063 0.0003 0.083 0.001 0.00052 0.00002 0.022 24.08 84.39 11.06 10.170 66.70 ± 0.93 2.90 11.53 0.14 0.0045 0.0002 0.087 0.001 0.00039 0.00002 0.036 9.86 88.38 20.73 10.190 66.84 ± 0.89 3.20 11.58 0.14 0.0048 0.0003 0.086 0.001 0.00041 0.00002 0.034 7.26 87.68 11.25 10.157 66.62 ± 0.97 3.70 11.93 0.14 0.0050 0.0002 0.084 0.001 0.00042 0.00001 0.063 27.43 87.43 32.77 10.431 68.39 ± 0.87 4.00 11.87 0.14 0.0153 0.0031 0.084 0.001 0.00129 0.00026 0.005 5.82 61.62 5.98 7.312 48.20 ± 6.04 4.40 14.13 0.18 0.0269 0.0056 0.071 0.001 0.00190 0.00039 0.003 3.25 43.22 2.35 6.109 40.36 ± 10.89 5.20 12.76 0.16 0.0420 0.0035 0.078 0.001 0.00329 0.00027 0.013 3.03 1.87 4.10 0.239 1.59 ± 6.84 6.20 11.81 0.14 0.0351 0.0063 0.085 0.001 0.00297 0.00053 0.005 2.63 11.40 5.63 1.346 8.97 ± 12.44 7.20 13.58 0.20 0.1251 0.0144 0.074 0.001 0.00920 0.00105 0.034 0.96 -174.60 2.10 23.714 -165.69 ± 31.29 J = 0.00364940 ± 0.00000730 Volume 39ArK = 1.499 x E-13 cm3 NPT Integrated Date = 65.90 ± 0.44 Ma Plateau age = 66.73 ± 0.60 Ma (2s, including J-error of .4%) MSWD = 0.056, probability=0.95 Includes 43% of the 39Ar steps 2 through 4 Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 4 points Age = 67 ± 17 Ma Initial 40Ar/36Ar =281 ± 520 MSWD = 5.4 Probability = 0 Analysis by Janet Gabites Pacific Centre for Isotopic and Geochemical Research, Dept Earth and Ocean Sciences, The University of British Columbia, Vancouver, BC., Canada Table 5. Ar-Ar geochronology results in sericite from the Mina Cocos (La Jagua) prospect sample SMA-JA-JM-048). July 2019 SMA-JA-JM-048 Sericite non-mag 0.6-1.0 amp Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2σ 2.30 16.03 0.11 0.0229 0.0037 0.062 0.000 0.00132 0.00023 0.010 0.10 60.73 1.04 9.773 63.99 ± 7.10 2.60 14.69 0.10 0.0147 0.0014 0.068 0.000 0.00096 0.00009 0.023 0.29 71.31 2.54 10.487 68.58 ± 2.68 2.90 12.86 0.10 0.0087 0.0003 0.078 0.001 0.00062 0.00002 0.119 0.28 81.39 6.37 10.483 68.55 ± 0.83 3.20 11.96 0.08 0.0048 0.0001 0.083 0.001 0.00034 0.00001 0.073 0.27 89.71 11.45 10.747 70.25 ± 0.56 3.40 11.83 0.09 0.0042 0.0001 0.084 0.001 0.00030 0.00001 0.100 0.29 91.08 10.44 10.788 70.51 ± 0.65 3.60 11.51 0.07 0.0034 0.0002 0.087 0.000 0.00023 0.00002 0.019 0.24 93.24 8.17 10.750 70.26 ± 0.60 3.90 11.58 0.06 0.0039 0.0003 0.086 0.000 0.00028 0.00003 0.006 0.26 91.70 8.22 10.635 69.53 ± 0.68 4.20 10.96 0.07 0.0015 0.0002 0.091 0.001 0.00010 0.00001 0.015 0.48 97.05 7.87 10.645 69.59 ± 0.52 4.60 10.95 0.07 0.0014 0.0002 0.091 0.001 0.00012 0.00002 0.007 1.79 96.53 6.81 10.575 69.14 ± 0.61 5.10 10.66 0.07 0.0002 0.0003 0.094 0.001 0.00001 0.00003 0.001 3.40 99.63 6.71 10.622 69.44 ± 0.77 5.80 10.68 0.07 0.0009 0.0004 0.094 0.001 0.00008 0.00004 0.007 3.64 97.52 8.99 10.419 68.14 ± 0.86 6.60 10.51 0.06 0.0011 0.0004 0.095 0.001 0.00010 0.00004 0.005 2.85 97.02 6.72 10.202 66.75 ± 0.80 7.50 10.43 0.07 0.0005 0.0002 0.096 0.001 0.00004 0.00002 0.008 2.84 98.85 6.29 10.308 67.43 ± 0.57 8.50 10.56 0.06 0.0035 0.0002 0.095 0.001 0.00032 0.00002 0.029 1.41 90.41 5.63 9.546 62.53 ± 0.59 9.50 12.05 0.08 0.0087 0.0005 0.083 0.001 0.00072 0.00004 0.031 2.21 78.65 2.74 9.479 62.10 ± 0.98 J = 0.00364030 ± 0.00000728 Volume 39ArK = 2.225 x E-13 cm3 NPT Integrated Date = 68.32 ± 0.18 Ma Plateau age = no plateau Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 10 points Age = 68.83 ± 0.78 Ma Initial 40Ar/36Ar =293 ± 34 MSWD = 3.5 Probability = 0.004 Analysis by Janet Gabites Pacific Centre for Isotopic and Geochemical Research, Dept Earth and Ocean Sciences, The University of British Columbia, Vancouver, BC., Canada Table 6.Ar-Ar geochronology results in sericite from the Mina Cocos (La Jagua) prospect (sample SMA-JA-JM-048). March 2019 SMA-JA-JM-048 ser Laser Isotope Ratios Power(%) 40Ar/39Ar 2σ 36Ar/39Ar 2σ 39Ar/40Ar 2σ 36Ar/40Ar 2σ Rho K/Ca %40Ar rad f 39Ar 40Ar*/39ArK Age 2s 2.30 17.39 0.41 0.0383 0.0023 0.0574 0.0013 0.00215 0.00014 0.283 0.21 35.80 4.94 6.238 41.05 ± 4.98 2.60 13.23 0.28 0.0208 0.0013 0.0755 0.0016 0.00154 0.00009 0.080 0.54 53.95 12.42 7.142 46.92 ± 2.64 2.80 12.29 0.20 0.0171 0.0007 0.0812 0.0013 0.00133 0.00005 0.166 0.27 60.22 15.92 7.413 48.68 ± 1.58 3.00 11.74 0.16 0.0163 0.0010 0.0850 0.0012 0.00133 0.00008 0.032 0.26 60.28 16.81 7.090 46.58 ± 2.03 3.20 11.32 0.15 0.0144 0.0007 0.0882 0.0012 0.00123 0.00006 0.061 0.44 63.19 15.74 7.162 47.06 ± 1.46 3.50 10.15 0.15 0.0106 0.0005 0.0985 0.0014 0.00103 0.00005 0.082 1.22 69.20 18.29 7.024 46.16 ± 1.28 3.80 11.72 0.14 0.0146 0.0010 0.0853 0.0010 0.00125 0.00008 0.029 5.60 62.81 5.75 7.362 48.35 ± 1.99 4.20 11.23 0.20 0.0158 0.0040 0.0891 0.0016 0.00140 0.00036 0.044 2.46 58.24 4.80 6.538 43.00 ± 7.86 6.00 13.91 0.16 0.0410 0.0034 0.0719 0.0008 0.00294 0.00025 0.014 1.30 12.26 5.34 1.706 11.32 ± 6.74 J = 0.00363560 ± 0.00000727 Volume 39ArK = 1.548 x E-13 cm3 NPT Integrated Date = 46.69 ± 0.67 Ma Plateau age = 47.16 ± 0.71 Ma (2s, including J-error of .4%) MSWD = 1.5, probability=0.17 Includes 89.7% of the 39Ar steps 2 through 8 Inverse isochron (correlation age) results: Model 1 Solution (±95%-conf.) on 8 points Age = 46.8 ± 4.8 Ma Initial 40Ar/36Ar =294 ± 49 MSWD = 2.5 Probability = 0.022 E.3 Re-Os Geochronology Data Appendix F : Mineral Chemistry Analyses in Magnetite INTRODUCTION This appendix presents the results of the mineral chemistry analyses in magnetite from the El Alacrán Deposit and other prospects within the San Matias District. These results come from a directed study developed by the author under the direction of Dr. Craig Hart at The University of British Columbia (UBC) Why Magnetite? Magnetite (Fe3O4) is one of the most abundant oxide minerals in the continental crust and a common accessory mineral in igneous rocks. It is also a common mineral in deposits that form in different geological conditions (e.g. Porphyry Cu, Iron Oxide-Copper Gold (IOCG), Iron Oxide Apatite (IOA), skarn deposits) and incorporates a wide range of minor and trace elements (Buddington and Lindsey 1964). Consequently, magnetite is a useful tool for petrogenetic interpretations and fingerprinting mineral deposit types. In the literature, attempts to consolidate a diagram to discriminate for deposits using magnetite chemistry have been widely documented (e.g. Dupuis and Beaudoin, 2011). However, the available studies in magnetite chemistry are scarce and in many cases, lack a detailed micro- to district-scale geological characterization. The lack of detailed characterization decreases the possibility to establish fundamental parameters to be incorporated into a discriminant diagram that can be applied effectively to most geological environments. The San Matías District offers an exciting opportunity to analyze the behaviour in the magnetite chemistry signature because a large proportion of the mineral occurrences in the district contain magnetite in different stages and mineralization styles. Similarly, since the El Alacrán Deposit paragenesis comprises various magnetite phases, the chemical signature of these individual phases can elucidate some of the physical-chemical conditions of the ore-forming fluid. This study uses petrographic analysis in polished thin sections combined with a Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Electron Microprobe Analysis (EMPA) in selected magnetite grains. The objective is to obtain and compare the chemical signature of igneous magnetite from the holocrystalline intrusions and host rock with hydrothermal magnetite from the Cu-Au porphyries and strata bound replacement deposit (El Alacrán Deposit). The results are aiming to identify the elements that characterize the different magnetite generations of the SMD and provide information about the physical-chemical evolution of the mineral fluid either at deposit or district scale. These results can also support the establishment of discrimination diagrams to fingerprint mineral deposits effectively. Recent Developments in Magnetite Chemistry Magnetite from hydrothermal ore deposits can contain up to tens of thousands of parts per million (ppm) of elements such as Ti, Si, V, Al, Ca, Mg, Na which are preferentially structurally incorporated into growth and sector zones or form mineral micro-to nano-sized particles (Deditius et al., 2018). (Deditius et al., 2018) defined six types of crystalline nanoparticles (NPs) using transmission electron microscopy (TEM) in trace element zones from various magnetite from Los Colorados Deposit, Chile. The types of NPs include diopside, clinoenstatite, amphibole, mica, ulvöspinel and Ti-rich magnetite which represent supersaturation in the hydrothermal fluid and subsequent entrapment in the growth surfaces of the magnetite. V in magnetite has been used as a monitor of fO2 where V4+ is preferentially incorporated into the inverse spinel relative to V3+ (Deditius et al., 2018). Given the complexity of trace elements during growth, Deditius et al. (2018) suggested to be cautious for interpretation of the micron-scale chemical data from magnetites. Among the possible geological controls, temperature plays a significant role on trace element incorporation into magnetite. Huang and Beaudoin (2019) used Scanning Electron Microscope (SEM) and Electron Probe Microanalyzer (EPMA) data from magnetites from five IOCG deposits (Igarape Bahia, Alemao, Sossego, Salobo, and Candelaria) and from El Romeral Kiruna-type iron oxide-apatite (IOA). They identified three mechanisms responsible for the distribution of textures and trace elements in the analyzed magnetites: 1) oscillatory zoning 2) oxy-exsolutions 3) recrystallization, and 4) Coupled Dissolution and Reprecipitation Reactions (CDR). 1) The oscillatory zoning is interpreted to have formed from the crystal growth during changes in the fluid composition rather than from variation in temperature and oxygen fugacity. 2) These authors attributed the oxy-exsolution of ilmenite in magnetite to increase of oxygen fugacity and decreasing temperature with alteration and mineralization, which produced magnetite with lower Ti and higher V contents. 3) Recrystallization consisted of a process where magnetite anneals due to high temperature by retaining primary compositions. 4) Concerning CDR processes, two different types were recognized by the authors according to differences in textures and compositions of the CDR products. CDR 1 is more extensive and corresponds to the transformation of first-generation magnetite (Mag-1) with abundant fluid inclusions and trace elements to a second-generation magnetite rim (Mag-2) which is fluid inclusion-poor and trace element-poor. During the CDR 1 process Si, K, Ca, Mg, Al and Mn in magnetite are excluded, whereas the Fe content increases. Mag-1 indicate some igneous-origin features, whereas Mag-2 is hydrothermal in the Sossego IOCG and El Romeral IOA. This was used by Huang and Beaudoin (2019) as a piece of evidence to support the transition between the IOA and IOCG deposits. The CDR process was interpreted to have formed by the changes in the fluid composition or decreasing in temperature during progressive alteration and ore formation. These authors remark that CDR 1 process has been recognized in skarn deposits, however, do not provide further information about it. CDR 2 is more restricted and consists of the transformation of second-generation magnetite rim (Mag-2) which is fluid inclusion-poor and trace element-poor to the third generation of magnetite (Mag-3) inclusion-poor but trace element-rich, along some veins and indicate an increase of Si, K, Ca, Mg, Al and Mn. This process was interpreted by Huang and Beaudoin (2019) as the product of a post-ore replacement due to a new pulse of magmatic-hydrothermal fluids. Huang and Beaudoin (2019) demonstrated that magnetite is susceptible to textural and compositional re-equilibrium during high-temperature magmatic and magmatic-hydrothermal process. The re-equilibrated magnetite after a CRD process has geochemical patterns that may be different from its precursor, complicating the application of discrimination plots for genetic interpretation (e.g. Dupuis and Beaudoin, 2011). Iron oxide trace element for fingerprinting mineral deposits Many authors have tried to distinguish some mineral deposits based on the composition of their associated magnetite. Dupuis and Beaudoin (2011) proposed the use of a diagram based on the use of [Ti + V] vs. [Al + Mn + Ca] and [Ni/Cr+Mn] vs. [Ti + V], based on EMPA data, to distinguish magnetites from porphyries from another magmatic-hydrothermal deposit. Various authors have demonstrated and supported the decrease of the Ti +V reflect a decreasing temperature and increase in the oxygen fugacity respectively, (Nadoll et al., 2014, 2015; Canil et al., 2016; Huang and Beaudoin, 2019) and were effective to elucidate the genesis of the Gushan Deposit in China as Kiruna-Type deposit (Sun et al., 2019). Nadoll et al. (2015) studied magnetite from porphyry and skarn deposits in western USA, proposed the use of [Al + Mn] vs. [Ti + V] to discriminate between the two deposit types. They suggested the boundary of these deposits is transitional. These authors found that Mg, Al, Ti, V, Mn, Co, Zn and Ga are the best overall discriminators for the composition of magnetite from the examined porphyry and skarn deposits and their igneous host rocks. These elements are incorporated into magnetite at levels above their Limit of Reporting (LOR) indicating significate variations among the different deposits (Nadoll et al., 2015). Low Ti and V in combination with high-induced fluid-rock interaction produced and enrich Mn and Mg in magnetite from skarn deposits, whereas Ti, V, Mn, Co, and Zn, display higher concentrations in the porphyry Cu deposits. This study also concludes that in comparison to igneous magnetite, the magnetite from porphyry and skarn deposits are depleted in V, Mn, Co and Ga concentrations. Canil et al. (2016) used PCA (Principal Components Analysis) using Ti, Al, and V contents in magnetite to distinguish between highest-temperature magmatic magnetite, intermediate-temperature hydrothermal porphyry magnetite and low-temperature skarn magnetite. Huang and Beaudoin (2019) questioned the use of PCA analysis in magnetite and applied effectively PLS-DA (Partial least squares-discriminant analysis) in PMA and LA-ICP-MS data to distinguish between W-Mo Au-Cu porphyries from Cu-Mo, Cu-Au, and Mo-Au porphyry deposits. The possibility of distinguishing different types of porphyry deposits is related to the composition of the host rock that is reflected in the magnetite composition (Huang and Beaudoin, 2019). These authors also concluded that magnetite from porphyry Cu, skarn and IOCG and IOA deposits can not be adequately separated using PLS-DA analysis. However, some critical trace elements contributions are recognized that can serve as a basis to differentiate each type of deposit. For example, porphyry Cu deposits indicate a positive correlation and contribution in the order of decreasing importance for Ti, V, Zn, and Al, whereas IOCG can be discriminated by a positive contribution of V, Ni, Ti and Al (Huang and Beaudoin, 2019). Similarly, V, Ti and Mg are higher for IOAs, and Mg, Mn, Ca, and Zn are the elements with higher contributions in skarn deposits. This is consistent with the importance of Mg and Mn recognized previously in skarn deposits (e.g. Nadoll et al. 2015). The higher Ni content in magnetites from IOCGs deposits relative to skarn and porphyry Cu is interpreted by Huang and Beaudoin (2019) as a chemical effect of the mafic composition of the diorites associated with the IOCG intrusions. Similarly, these authors state that because porphyry Cu are sulphide-rich deposits relative to IOCGs, it is likely that Ni partitions into the sulphides and the magnetites remain as a Ni-poor phase. Therefore, Ni in magnetite seems to have significate use in the IOCG deposits recognition. METHODOLOGY We analyzed a suite of 15 samples representing the variety of host rocks, and mineralizations associated with porphyry Cu-Au prospects and Fe-rich strata bound replacement deposits in the San Matías District. Polished thin sections were studied petrographically to document the mineral assemblages and to help to discriminate the different hydrothermal magnetites from magmatic magnetites. Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) data were collected using the Hitachi SU-70 field emission SEM fitted with an Oxford AZtec XMax80 EDS system at the University of British Columbia (UBC), Vancouver, Canada. The SEM and EDS data were used to establish textural and compositional differences in the analyzed magnetites. Electron-probe micro-analyses (EMPA) of the magnetites (n= 123) were done at UBC on a fully automated CAMECA SX-50 instrument, operating in the wavelength-dispersion mode with the following operating conditions: excitation voltage, 15 kV; beam current, 20 nA; peak count time, 40 s (20 s for Ti, Fe, Mn); background count-time, 20 s (10s for Ti, Fe, Mn); spot diameter, 5 µm. Data reduction was done using the 'PAP' φ(ρZ) method (Pouchou and Pichoir, 1985). For the elements considered, the following standards, X-ray lines and crystals were used: synthetic magnesiochromite, MgKα, TAP; gahnite, AlKα, TAP; synthetic rhodonite, SiKα, PET; diopside, CaKα, PET; rutile, TiKα, PET; V element, VKα, LIF; synthetic magnesiochromite, CrKα, LIF; synthetic rhodonite, MnKα, LIF; hematite, FeKα, LIF; synthetic Ni2SiO4, NiKα, LIF. RESULTS Textures Magmatic magnetites texture in the holocrystalline intrusions show some features. The quartz diorites display euhedral magnetites either with ilmenite exsolution or homogeneous (Figure 1). The magnetite in the analyzed tonalite rocks are euhedral homogenous, whereas the magnetite in the diorite samples display a complex and fine-laminated ilmenite exsolution (Figure 1). Complex exolutions of ilmenite have been recognized in igneous magnetites in IOCG deposits (e.g. Sossego IOCG, Brazil; Huang and Beaudoin, 2019; Figure 2) The magnetite in the SMD porphyry prospects show anhedral shapes with mineral inclusions along the crystals growth borders (Figure 3) and do not exhibit the ilmenite exsolution recognized in some porphyry deposits (e.g. Bajo de la Alumbrera Cu-Au Porphyry, Argentina; Figure 2). In the El Alacrán Deposit, five different textures are observed among the different paragenetic stages of the Calc-Silicate group alteration. Ca, P, Si and Al, seem to be diagnostic to distinguish the different magnetite generations. The Magnetite – Quartz Assemblage: in this stage, the magnetite 1 (Mag 1) displays euhedral shapes, dark-gray coloration and multiple apatite inclusions (Ap) (Figure 4 A-B). The apatite inclusions are indicated by the distribution of Ca and P in the EDS elemental mapping (Figure 4 C-F). The magnetite 2 (Mag 2) corresponds to unzoned euhedral crystals of light-gray coloration that lack apatite inclusions (Figure 4 A-F). Mag 1 and Mag 2 resemble some of the textures recognized in IOCG and IOA deposits in Chile (e.g. Candelaria and El Romeral respectively, Figure 2E-F). The magnetite 3 (Mag 3) corresponds to bladed magnetite (mushketovite variety) with multiple oscillatory and sector zoning from light gray to dark-gray areas (Figure 5 A-B). The EDS elemental mapping indicates enrichment of Ca and P in the Mag 3 (Figure 5 C-D). The Fe Chlorite Assemblage: in this stage, the magnetite 4 (Mag 4) exhibit subhedral to euhedral shapes with oscillatory zoning from outer dark-gray zones to lighter zones inwards (Figure 6 A-B). The EDS elemental mapping in Mag 4 generation exhibit enrichment in Al, relative to Ca, P and Si (Figure 6 C-F). Texturally Mag 4 resembles the magnetite (X magnetite phase) defined in the Los Colorados, IOA deposit (Figure 2 A). The Mushketovite-Pyrite Assemblage: in this stage, the magnetite 5 (Mag 5) corresponds to unzoned bladed magnetite (mushketovite variety) with evidence of relictic hydrothermal hematite (specularite) (Figure 7 A-B). The EDS elemental mapping does not indicate an association to Ca, P, Si, and Al (Figure 7 C-F). Figure 1. Magmatic magnetite textures in SMD intrusions. A. Photo showing the different types of intrusions in the SMD district. B. magmatic magnetite intergrowing with quartz plagioclase and biotite from the San Jorge Quartz Diorite Intrusion. C. Backscattered electron (BSE) image of the magnetite from photo B, showing the occurrence of lamellae exolutions of ilmenite. D. Euhedral magnetite with no ilmenite exolutions. San Jorge Quartz Diorite. E. Microphotograph 2X under RL + PPL of the Alto San Pedro Diorite. F. Backscattered electron (BSE) of the magnetite of photo E. Note the fine-laminated exolutions of ilmenite from the magnetite. The red dots indicate the location of the Micro Probe analysis. Figure 2. Backscattered electron (BSE) images of different textures documented in various deposits types. A. Image of the magnetite X from Los Colorados IOA Chile. (Deditius et al., 2018). B. Two generations of magnetite in sample 080 from the Sossego IOCG Brazil, displaying different textures. The first magnetite with exsolution lamellae of ilmenite in the core (Mag-1) was replaced by dark-gray, inclusion-rich magnetite (Mag-3) (Huang and Beaudoin, 2019). C. Hydrothermal magnetite in a magnetite-quartz vein from the Bajo de la Alumbrera Cu-Au Porphyry, Argentina. Quartz inclusions and minor ilmenite exsolutions lamellae are observed in magnetite (Huang et al., 2019). D. Microphotograph of magnetite-sulfide vein from the Chino Skarn, USA. The magnetite (mt) displays martitization (hematite-hm) along spinel planes, rims, and fissure. E. Sample 367A from the Candelaria IOCG deposit, Chile showing two generations of magnetite. The first generation of magnetite (Mag-1) is dark gray and inclusion rich and was replaced by smooth, inclusion poor magnetite (Mag-2) (Huang and Beaudoin, 2019). F. Three generations of magnetite in the El Romeral IOA deposit, Chile showing different textures. The primary magnetite (Mag-1) is inclusion rich and replaced by secondary magnetite (Mag-2). Mag-2 is further replaced by dark-gray magnetite (Mag-3) along the grain boundary or fractures (Huang and Beaudoin, 2019). Figure 3. Magnetite textures in the Cu-Au porphyry prospects of the SMD. A. Montiel East and Costa Azul Cu-Au porphyry prospects with B-type veins (quartz + magnetite ± chalcopyrite) and tardi-magmatic veinlets. B. Microphotograph 5X under RL + XPL of the showing the magnetite replacement after hornblende crystals in the early stage of the Montiel E porphyry (PxHe). C. Backscattered electron (BSE) of a B-type vein from the Montiel E porphyry. D. Zoom to the magnetite in the photo C, showing the very-fine grained mineral inclusions pattern along the magnetite crystal-growing margin. Figure 4. Backscattered electron (BSE) BSE and Energy-dispersive X-ray spectroscopy (EDS) mapping images from the El Alacrán Deposit magnetites (Mag 1 and Mag 2). A. Sample from the alteration assemblage 1A (Magnetite – Quartz) showing the two generations of magnetite (Mag 1 and 2). B. Same photo A with the distribution of the elemental mapping for Ca, P, Si and Al. Note the apatite-rich inclusions in the Mag 1 generation versus and the lighter color and lack of inclusions in the Mag 2 generation. C - F EDS chemical mapping images for Ca, P, Si and Al, respectively. Figure 5. Backscattered electron (BSE) BSE and Energy-dispersive X-ray spectroscopy (EDS) mapping images from the El Alacrán Deposit magnetites (Mag 3) A. Microphotograph 20X under RL + XPL of one representative sample of the Assemblage IC (Fe- Chlorite). B. BSE image showing the trace element (TE) -rich zonation in the Mag 3. C- E. EDS chemical mapping images for Ca, P, Si and Al, respectively. Note the elevated Al values that coincides with the TE-rich zones. Figure 6. Backscattered electron (BSE) BSE and Energy-dispersive X-ray spectroscopy (EDS) mapping images from the El Alacrán Deposit magnetites (Mag 4) A. BSE image showing the location of the microprobe analyses and the trace element (TE) -rich zonation in the Mag 3. C- E. EDS chemical mapping images for Ca, P, Si and Al, respectively. Note the elevated Al values that coincide with the TE-rich zones. Figure 7. Backscattered electron (BSE) BSE and Energy-dispersive X-ray spectroscopy (EDS) mapping images from the El Alacrán Deposit magnetites (Mag 3) A. Microphotograph 20X under RL + XPL of one representative sample of the Assemblage IC (Fe- Chlorite). B. BSE image showing the trace element (TE) -rich zonation in the Mag 3. C- E. EDS chemical mapping images for Ca, P, Si and Al, respectively. Note the elevated Al values that coincide with the TE-rich zones. Chemistry Magnetite Chemistry Summary statistics for magnetite from individual deposits and regional units from SMD are listed in Error! Reference source not found.. Cr could only be detected in 11 measurements and Ni in 68 measurements out of 123 analyses. The analyzed samples from the volcanic basement yielded an extreme Ti content (>30% Ti) consistent with ilmenite rather than with magnetite. Therefore, magnetite from the volcanic basement is not used for the current analysis. There are marked differences in the magmatic magnetite from the holocrystalline intrusions. On average, the quartz-poor tonalites present higher content of Al, Mn, Ti, and Cr and the lowest Fe content among the holocrystalline intrusions (Figure 8). The magmatic magnetite from the diorites also show an equivalent compositional behaviour with the quartz-poor tonalites, except for the Al and Mn content and a marked high Ca content (Figure 8). The magnetites from the quartz diorites display the highest V average content among the analyzed samples (Figure 8). Comparison between the chemical signatures of hydrothermal magnetite from the porphyry prospects with the magmatic magnetite from holocrystalline rocks indicates a positive correlation between the chemistry of the magnetite in porphyry prospects with the magnetite from the quartz-rich tonalites group. The chemical correlation is reflected in the high-Fe and low V and Ca content in the analyzed magnetite (Figure 8). The chemical signature of the hydrothermal magnetite from the El Alacrán Deposit show to be consistent with the magnitude of the hydrothermal magnetite associated to the porphyries and with the magmatic magnetite from the quartz-rich tonalites Figure 8. However, the hydrothermal magnetite phase from El Alacrán Deposit show significant variations in their chemistry that will be analyzed below: Table 1. Average of the minor and trace element concentration (EMPA) in magnetites from the SMD in weight percent (wt %) Figure 8. Box and whisker plots for magmatic, hydrothermal magnetites from the SMD host rock and mineralizations. The Mag 1 from the Quartz – Magnetite Alteration Assemblage of the El Alacrán Deposit displays the highest Al, Si, Ca and Mg and the lowest Fe content relative to the rest of analyzed magnetites of this deposit (Figure 9). The high Ca content in the Mag 1 is consistent with the results of the EDS elemental Map analysis with is associated with the multiple apatite inclusions (Figure 4). Mag 1 exhibits an elemental behaviour similar to the Mag 4 of the Fe-Chlorite Assemblage, especially (in decreasing order) from Al, Si, Ca, Mg (Figure 9) Figure 9. Box and whisker plots for hydrothermal magnetites from the El Alacrán Deposit Calc-Silicate alteration stage. Although Mag 2, Mag 3, and Mag 5 are hydrothermal magnetite from different paragenetic stages, these magnetite display similar element content, especially in the Si, Ca, and Fe (Figure 9). The Mag 3, however, contains the highest V content among the El Alacrán Deposit magnetite (Figure 9) Discussion Comparison of the magmatic (Holocrystalline Intrusions) and hydrothermal magnetites (Porphyry) The igneous magnetites from the holocrystalline intrusions of the San Matias District exhibit two compositional groups relative to the [Ca+Al+Mn] and [Ti+V]content (Figure 10A). Group I includes samples from the Quartz Diorites (e.g. San Jorge) and quartz-rich tonalites (e.g Costa Azul) and exhibit a low Ca+Al+Mn and Ti+V. The ilmenite exsolution occurrence in the Quartz Diorites reduces the Ti content in the magnetite by 50%, whereas enriching the magnetite in V by 200% (Table 1). This fractionation in the V content generated by the ilmenite exsolution produces that the V + Ti factor increase and surpass the 1% (Figure 10A) which is a practical limit to differentiate between magmatic (Fe-Ti, V field) and hydrothermal magnetite (e.g. Porphyry field; Figure 10A). Group II includes the Diorites (e.g. Alto San Pedro) which display ilmenite exsolutions and the quartz-poor tonalites (e.g. El Alacrán Oeste) which lack ilmenite exsolution. Group II display extremely high Ca+Al+Mn and high Ti+V content. The occurrence of ilmenite exsolution does not produce a marked difference in the Ti+V content as observed in Group I. However, a subtle shift towards lower Ti+V is indicated by the magnetite in the Diorite relative to the quartz-poor tonalites. Petrographically, both intrusive units contain the clinopyroxene augite (Ca, Na)(Mg, Fe, Al) (Al, Si)2O6 that is reflected in the high Al and Ca in the magnetite chemistry (Figure 8, Figure 10Error! Reference source not found.) suggesting a marked control in the magnetite chemistry associated to the parental magma composition. The Costa Azul Tonalite magnetites cluster within the Costa Azul Porphyry magnetites and exhibit a lesser dispersion than the Montiel E porphyry magnetites (Figure 10A). The dispersion displayed by the magnetites from the Montiel E porphyry cannot be associated with textural changes observed at a microscopic scale. However, mineral inclusions (possibly of amphibole and mica) are recognized in some of the Montiel E porphyry magnetites (Figure 3D). Nano-sized particles of amphibole or mica (which are common in magnetites, Deditius, 2018) associated with the mineral inclusions might have entered as contamination in the analysis. The magnetites from the SDM holocrystalline intrusions and porphyries prospects display a decreasing temperature gradient or trend from high temperature (> 500 °C) magmatic magnetites in the intrusions with clinopyroxene (Group I) towards intermediate temperature (300 °C – 500 °C) associated with the Quartz Diorites, Tonalites (Group II) and porphyry prospects (Figure 10B). Since, ilmenite likely exsolved from the host magnetite as a result fO2 increase with a decrease in temperature (Deditius et al., 2018) the proposed trend might also reflect the increase of the fO2 in the intrusions of the SMD. Figure 10. Distribution of the SMD magnetites in the [Ca+Al+Mn] vs [Ti+V] diagram (Dupuis and Beaudoin, 2011). The diagram shows the Group I and Group II of magnetites from the SMD holocrystalline intrusions. Note that: (1) the magnetites from the porphyry prospects are mostly consistent with the field defined for porphyries by Dupuis and Beaudoin (2011). (2) The shift from Fe-Ti, V deposits field to porphyry deposits field when the magnetites lack of ilmenite exolutions. (3) The earliest magnetite in the El Alacrán Deposit (Mag 1) clusters in the skarn field. Figure 11. Temperature diagrams in magnetite showing tow possible cooling trends one trend consistent with magmatic (> 500 C) towards hydrothermal temperature values in the El Alacrán Deposit magnetites (200 – 300 C). An alternative decreasing temperature pattern in the El Alacrán Deposit is indicated by the earliest magnetite generation (Mag 1) towards the formation of the later magnetite generations. Diagrams A and B modified after Dupuis and Beaudoin (2011) and Nadoll et al. (2015), respectively). Comparison of the magnetites from the El Alacrán Deposits concerning the mineral paragenesis Trace-element rich magnetites (e.g. Mag 1 and Mag 4) cluster in narrower areas than the trace-element poor (unzoned, light gray-coloured) magnetites (e.g. Mag 2) which show a large variation in their chemistry (Figure 10A). Paragenetically, the trace-element poor magnetites indicate to be associated with open space infill-overgrowth (?) (e.g. Mag 2) and later pseudo morphing processes such as magnetite formed after specular hematite (e.g. Mag 3 and Mag 5) suggesting to have undergone major modifications or chemical redistributions in relation to the initial composition that prevails in the earliest trace-element rich magnetites. The paragenesis of the El Alacrán Deposit indicates that the magnetite-bearing stages (e.g. calc-silicate alteration) formed at an early stage among the rest of the assemblages. The marked variability in the chemistry in the El Alacrán Deposit magnetites especially in Mag 2 and Mag 5 might reflect (to some extent) a late hydrothermal overprint (e.g. sericitic Alteration; Manco et al., 2018) that obscured the primary geochemical signatures. The El Alacrán Deposit magnetites define a trend from Mag 1 at high temperature 300 – 500 °C, consistent with the skarn deposits field (Figure 10-11) towards a lower temperature (< 300 °C) in Mag 4 and Mag 2 and 3 inadequately consistent with the IOCG field (Figure 10-11). The proposed cooling trend for the El Alacrán Deposit magnetite seem to follow a different trend than the indicated by the magnetite from the holocrystalline intrusions and porphyry prospects (Figure 10) Conclusions • We illustrate chemical variations in the igneous and hydrothermal magnetites of holocrystalline intrusions and porphyries from the San Matías District in Northern Colombia. The magnetites from holocrystalline intrusions display a low Fe and high Al, Mn, Ti, V and Cr content reflecting higher formation temperatures (>500 °C), whereas the porphyry magnetites have a high-Fe, low V and Ca contents that reflect intermediate to high temperature (300 – 500 °C) and possibly associated with a fO2 increase. • Five textures of magnetites (Mag 1 to Mag 5) in the El Alacrán Deposit calc-silicate alteration stage are recognized. The Mag 1 and Mag 4 corresponds to trace elements-rich species that have on average higher Al, Si, Ca and Mg and low Fe content relative to the trace elements-poor magnetites (Mag 2, Mag 3, and Mag 5). • Linking the mineral chemistry in magnetites of this study to the deposit paragenesis (Manco et al., 2018) we suggest that the iron oxide-forming fluid from the calc-silicate alteration evolved from an intermediate - high-temperature (300 – 500 °C) fluid that formed trace-element rich, zoned, euhedral magnetites with variable amounts of apatite inclusions. This fluid(s) cooled down (<300 °C) to form trace-element poor, unzoned magnetites that display marked variability in their geochemical signature even at crystal-scale. From this study, we conclude that to characterize the primary chemistry on the magnetites from strata bound replacement deposit similar to El Alacrán Deposit, trace element-rich specimens should preferentially be used over trace-element poor specimens. Appendix G : Cu-Au Fertility Analyses Fertility Analysis: zircon geochemistry approach Introduction High Field Strengths Elements (HFSE) such as Ti and Zr, as well as the chondrite-normalized REE ratios (La/Sm)N, (La/Yb)N, and (Dy/Yb)N from whole-rock geochemistry analysis have served as a proxy to estimate the fractionation degree of magmatic suites (e.g. Richards et al., 2012). Similarly, adakite-like criteria elements (e.g. Sr/Y and Eu anomaly Eu*= (𝐸𝐸𝐸𝐸 √𝑆𝑆𝑆𝑆 × 𝐺𝐺𝐺𝐺 2⁄ )N) have been used to indicate the oxidation conditions of the magmas and porphyry-related deposits fertility (e.g. Richards et al., 2012). However, weathering and hydrothermal alteration can affect whole-rock Sr/Y and Eu* anomaly (Lu et al., 2016). Therefore, the use of additional oxidation proxies (e.g. zircon geochemistry) are required for a more robust interpretation. The validity of using only whole-rock geochemistry to understand the evolution of a particular magmatic suite has been questioned in the literature (e.g. Shen et al., 2015). This is due to zircons crystallize late during the solidification of the magmas and tend to contain REE (usually Heavy Rare Earth Elements - HREEs) that can be missed from a whole-rock analyses. Zircons can also have minute inclusions of REE-bearing minerals such as apatite, titanite, monazite, and allanite that can bias a whole-rock analysis for porphyry deposits fertility (Shen et al., 2015). In general, granitic magmas with modest alkali contents (Al/Na+K) >1.25 requires ~200 ppm Zr concentrations for zircon saturation (at 800°C; Watson and Harrison, 1983). These values are realistic because the Zr content of bulk continental crust rocks is 100 ppm (Shen et al., 2015). Zr values close to 50 ppm in magmatic rocks have been interpreted to crystallize at low-temperature with high dissolved H2O contents to depress the zircon solubility into 50-ppm range. These conditions are not usually attained to upper crustal pressures (R. Loucks, pers. comm., 2019). The Ti content in zircon has been used widely to evaluate the crystallization temperatures of igneous rocks (Ti-in-zircon temperature). Ti content in zircon is controlled by temperature, activities of oxides (TiO2 and SiO2) and pressure (Shen et al., 2015). In many porphyry-related systems zircon grains, likely crystallized over a limit of pressures range (<1 - 2 kbars) under these conditions the effect of pressure can be neglected from the temperature estimation (Shen et al., 2015). Given the occurrence of magmatic quartz and the lack of rutile in the analyzed samples from SMD, the Ti-in-zircon temperature estimation assumes activities of 1 and 0.70 for SiO2 and TiO2, respectively (Le Maitre, 1976). In this study, we calculated the crystallization temperatures of representative samples of the magmatic suites following the Ti-in- zircon thermometer of Ferry and Watson, (2007). Fertility Analysis: zircon geochemistry approach Introduction A persistent spatial association between oxidized calc-alkaline intrusions and magmatic-hydrothermal Cu ± Au deposits suggest a genetic link (Ballard, 2002). From a mineral exploration perspective, this association means that the oxidation state of the intrusion can be used as an empirical criterion to identify fertile vs non-fertile magmatic-hydrothermal systems (Ballard, 2002). Unfortunately, quantitative oxygen barometers based on Fe-Ti oxides usually are reset during slow cooling of the intrusive rocks, and empirical redox indicators (e.g. whole-rock Fe3+/Fe2+ ) can be highly modified by hydrothermal alteration. Zircon is a geochemically robust and resistant mineral to hydrothermal alteration and weathering. Zircons also record the late stages of crystallization and chemical composition of the parental magma, which is related to its volatile content hydrothermal alteration evolution (Dilles et al., 2015). Zircon is a sensitive indicator of the magmatic oxidation state via the Ce and Eu contents (Dilles et al., 2015). Zircon preferentially incorporates Ce4+ into the Zr4+ site of its structure (Shen et al., 2015). Ce3+ has a partitioning coefficient that is generally considered to be less than 1; however, Ce4+ may be in the order of ~1000 (Trail et al., 2012). Relative to trivalent REE, Ce4+ is preferentially incorporated, and Eu+2 is excluded (Hoskin and Schaltegger, 2003). Zircon Ce4+/Ce3+ ratios are affected by not only oxygen fugacity but also the melt compositions and temperature at which zircon crystallized (Shen et al., 2015). In mineralized intrusions zircons are associated with high-calculated Ce4+/Ce3+ ratio (larger Ce anomaly (Ce*=(Ce/(La*Pr)^1/2))). It is, however, difficult to estimate Ce4+/Ce3+ ratios reliably for the following reasons. The first, being that the La and Pr elements are near the detection limits of LA-ICP-MS (Lu et al., 2016). Secondly, The Ce4+/Ce3+ ratio, the whole-rock concentration is assumed to be the same as the melt Ce concentration when the zircon crystallized (Ballard et al., 2002) which is highly questioned in the literature (e.g. Dilles et al., 2015). And lastly, the direct measurement of the Ce4+/Ce3+ ratio (e.g. by Ce LIII-edge X-ray 445 absorption near-edge structure) yields significantly different ratios from those Ce anomalies estimated for example with the lattice-strain method (Ballard et al., 2002, Lu et al., 2016). Similar to Ce4+, the trivalent europium (Eu3+) is preferentially incorporated into the zircon structure relative to Eu2+. Although small negative Eu anomalies in zircons can be created by early plagioclase fractionation in anhydrous magmas (Eu2+ depletion in the magma), Dilles et all, (2005) argued that the water content and related lack or presence of plagioclase suppression do not adequately explain the observed Eu anomalies in mineralized porphyries. Therefore, small Eu anomalies would reflect oxidation instead in the magma due to SO2 degassing, where the Eu and Fe are oxidized from the magma due to the reduction of magmatic sulphate (S6+) to SO2 (S4+). Ore-forming granites have relative small negative europium anomalies (Eu* > 0.4 Dilles et al., 2015; Eu* > 0.3 Lu et al., 2016) and Larger Ce anomalies (Ce*>300, Ballard et al., 2002, Lu et al., 2016). The hafnium content and Hf/Zr ratio of zircon increase as the titanium content and Ti-in-zircon model crystallization temperature decrease (Dilles et al., 2015). In mineralized granitoid suites, the normalized negative Eu anomaly of zircon becomes more pronounced with the increase of Hf content; this has been used as a proxy for the decrease in models temperature. In hydrous melts, hornblende crystallizes at an early stage and shows a Y depletion in the residual melt. Yttrium is usually included in the calculation and analysis because its geochemical behaviour is very similar to that of heavy REE (HREE). Also, Y concentration in zircon is always higher than the calculation of REE in whole-rock, which makes it favorable to lower the uncertainty associated with the calculation of the Ce3+ (Shen et al., 2015). Method and Samples Trace element analyses were performed using a quadrupole mass analyzer Q-ICP-MS at a repetition rate of 5 Hz and spot sizes of 34µm. Energy density on the sample was 1.8 J/cm2. Helium served as carrier gas and was admixed with N2 for signal enhancement. This study followed the methodology defined by Lee and Amini M. (2019). The standards G_NIST612, G_NIST610, and G_BCR2G were used for QAQC purposes (Figure 2). Trace element geochemistry was obtained in zircons from representative samples of the SMD magmatic suites (defined in section 2.3). The samples included zircons from the San Matías-La Jagua Suite, such as PxHe and QFPx phases of the Montiel E Porphyry and la Jagua Tonalite. Samples from the Jorge and Betesta-Mina Escondida magmatic suites included zircons from the San Jorge Quartz Diorite and the Betesta Quartz Diorite, respectively. Given the lack of zircon recovery in samples from the El Alacrán Norte and Alto San Pedro magmatic suites, no zircon geochemistry data was obtained in these rocks. The trace element geochemistry acquisition is described in section 1.3.9. For the SMD samples, the estimation of the Cerium anomaly (Ce*) included Nd and Sm as proposed by Loader et al. (2017) (e.g. (Ce*=CeN/((NdN^2)/SmN). Results The minor and trace-element concentrations from zircons are listed in Table 1 and the chondrite-normalized REE pattern is shown in Figure 1. The obtained Ce/Ce* values from the SMD display a good correlation with the Ce/Nd ratio (Figure 2A), which is a feature recognized in other provinces (e.g. Lu et al., 2016). The samples from SMD display relatively constant Ce anomalies (from 6.69 to 228.94, Figure 2B), which are usually interpreted in the literature as an indication of either hydrous or oxidized magmatic systems (Lu et al., 2016). The samples from SDM show a ‘break” in the Eu anomaly around Eu*=0.4, where the rocks from the Montiel E Porphyry and Betesta Quartz-Diorite display the more significant Eu anomalies (Eu*>0.4), On the other hand, the La Jagua Tonalite and the San Jorge Quartz Diorite have Eu*< 0.4. (Figure 2B). The Ce anomaly does not seem to vary among the quartz diorites rocks, but in the La Jagua Tonalite, the Ce anomaly exhibits two different subgroups (Figure 2C-F). One group comprises Ce anomaly values Ce*> 75 and is dominated by pyramidal morphology zircons, whereas, a second group displays Ce*< 75 associated with prismatic-shaped zircons. The granodiorite sample from the QFPx phase for the Montiel E displays the most significant variation both in the Ce anomaly (< 10 - >225) and Eu anomaly from Eu*= 0.3 – Eu*= 0.65). The Quartz Diorite samples show marked differences in the Eu anomalies. The Eu* in the San Jorge Quartz Diorite is consistently lower than Eu*= 0.4, whereas the Betesta Quartz Diorite surpasses the Eu* > 0.55. (Figure 2D). The Dy/Yb ratio is used as an indication of hornblende fractioning degree in a magmatic suite (Richards et al., 2012). The Dy/Yb values in zircons from the SMD intrusions indicate a poor-fractionation degree undergone by the La Jagua Tonalite. In contrast, the Betesta Quartz Diorite samples indicate to represent two generations of zircons with marked differences in their Dy/Yb ratios (Figure 2E). Figure 1. Chondrite-Normalized REE patterns for zircons and whole rock from representative samples of the SDM magmatic suites. Chondrite values from McDonough and Sun (1995). Samples from the El Alacrán Norte and Alto San Pedro suites are omitted in the analysis due to the lack of zircons in the analyzed samples. Note the smooth curves of the whole- rock samples, the significant positive Ce anomalies and small negative Eu anomalies displayed by the zircon chemistry. Discussion The obtained Ce anomalies in the analyzed zircons do not effectively constrain differences in the oxidation state of the SMD magmatic suites. In addition, the Ce anomaly in the analyzed samples is lower than Ce*= 225. This value is marked smaller than the Ce* value recognized in typical porphyry Cu systems (e.g. Ce*>300, Ballard et al., 2002, Lu et al., 2016). However, the Eu* anomaly and Dy/Yb ratios in zircons from the Montiel E porphyry and Betesta Quartz Diorite indicate that these intrusions come from an oxidized magma, along with evidence of hornblende fractionation. The Betesta Quartz Diorite displays two different zircon populations from magmas with different hornblende-fractionation degrees. These two groups, however, suggest to have sourced from oxidized and fertile magma for Cu porphyries (e.g. Eu* > 0.4, Figure 2E). The Hf/Y and Th/U values of the analyzed zircon samples show fractional crystallization patterns from rocks from the Betesta Quartz Diorite towards the porphyries, suggesting that the Betesta Quartz Diorite is likely to be the SMD porphyries precursor (Figure 2G). Conclusion Among the magmatic suites defined in the SMD, the rocks that belong to The San Matías-La Jagua magmatic suite (except for the La Jagua Tonalite) and the Betesta-Mina Escondida magmatic suites indicate to be fertile for porphyry Cu deposits and related mineralization. Figure 1. Trace element geochemistry in zircons from the SMD magmatic suites Ce anomaly (Ce*) was estimated as (Ce*=CeN/((NdN^2)/SmN) (Loader et al.,2017). Eu anomaly (Eu*) was estimated as Eu*= (Ce*=EuN/((SmN^ xGdN)^0.5 (Richards et al., 2012). A. Diagram that indicates the good correlation between the Ce* and the Ce/Nd ratio. The shapes of the samples indicate the external morphology of the analyzed zircons. B. Eu* vs. Ce* indicating the Eu*= 0.4 as the limit to define fertility (Dilles et al., 2015). C-D. Diagrams showing the variation of the Ce* and Eu* anomalies relative to the different SMD rock types. E-F. Diagrams comparing the Eu* and Ce* respectively, with the Dy/Yb ratio that indicates hornblende fractionation (Richards et al., 2012). G. Hf/Y and Th/U diagram useful to indicate the evolution of the studied magmatic suits. The diagram suggests a fractionation crystallization trend from the Betesta Quartz Diorite and the SMD porphyries. Table 1. Trace Element Geochemistry of the SMD zircons Sample ID Zircon ID External Shape Rock Type Sc ppm Ti ppm V ppm Y ppm Nb ppm Mo ppm Sn ppm La ppm Ce ppm Pr ppm Nd ppm Sm ppm Eu ppm Gd ppm Tb ppm JM-122 MDRU19-7-2-3R Pyramidal QtzDiorite 490 9.6 1612 1.68 1.66 0.147 0.0119 9.42 0.119 1.79 3.66 1.95 25 8.95 JM-122 MDRU19-7-2-3C Pyramidal QtzDiorite 481 0.208 1100 1.07 1.55 0.0216 7.3 0.223 3.12 3.87 1.91 18.4 6.5 JM-122 MDRU19-7-2-4C Pyramidal QtzDiorite 479 5.1 1241 1.25 1.87 0.0191 6.88 0.203 2.77 4.12 2.13 21.1 6.81 JM-122 MDRU19-7-2-4R Pyramidal QtzDiorite 483 7.8 1510 1.66 1.78 0.0179 7.81 0.213 3 4.2 2.28 24.3 8.41 JM-122 MDRU19-7-2-5R Pyramidal QtzDiorite 478.7 7.7 0.206 1170 1.35 1.58 0.246 0.0223 7.11 0.15 2 3.27 1.8 18.2 6.39 JM-122 MDRU19-7-2-6C Pyramidal QtzDiorite 415.7 657 0.689 1.95 0.0104 2.89 0.057 0.91 1.78 0.82 9.22 3.12 JM-122 MDRU19-7-2-6R Pyramidal QtzDiorite 428.5 4.8 879 1.04 1.32 4.53 0.037 0.46 0.99 0.653 9.63 3.87 JM-122 MDRU19-7-2-8R Prismatic QtzDiorite 428.1 5.1 954 0.97 1.38 0.087 4.72 0.093 1.46 2.18 1.16 13.46 4.89 JM-122 MDRU19-7-2-9C Pyramidal QtzDiorite 465.4 4.7 987 1.18 1.86 5.69 0.122 1.36 2.63 1.18 12.2 4.48 JM-122 MDRU19-7-2-11R Prismatic QtzDiorite 436.2 9.4 831 1.22 1.44 0.0114 5.26 0.06 1.06 1.82 0.84 10.3 4.03 JM-122 MDRU19-7-2-12R Pyramidal QtzDiorite 528 13 0.37 2040 1.61 2.15 0.202 0.034 19.8 0.151 1.84 3.67 1.29 26.2 10 JM-122 MDRU19-7-2-14C Pyramidal QtzDiorite 529.7 7 0.221 1548 1.53 1.64 0.036 9.37 0.253 3.61 4.6 2.56 25.6 8.61 JM-122 MDRU19-7-2-15C Pyramidal QtzDiorite 502.7 6.5 1067 1.22 1.42 5.93 0.012 0.59 1.15 0.656 10.73 4.52 JM-122 MDRU19-7-2-16C Pyramidal QtzDiorite 395.7 4.5 356 0.588 1.28 0.09 2.2 0.039 0.32 0.8 0.409 4.71 1.77 JM-122 MDRU19-7-2-16R Pyramidal QtzDiorite 417.3 5.9 1.06 573 0.697 1.28 3.3 0.069 0.89 1.31 0.73 8.2 2.93 JM-122 MDRU19-7-2-17R Pyramidal QtzDiorite 386 488 0.598 1.62 0.0066 5.01 0.0224 0.42 0.86 0.236 5.46 2.17 JM-122 MDRU19-7-2-18R Prismatic QtzDiorite 556 7.8 0.258 1855 2.18 1.56 11.23 0.102 1.76 3.21 1.85 27.3 10.04 JM-122 MDRU19-7-2-18C Prismatic QtzDiorite 615 6.5 1982 1.7 0.92 0.041 10.85 0.287 3.92 6.31 3.58 37.4 12.03 JM-122 MDRU19-7-2-21C Equant QtzDiorite 452.8 6 773 1.02 1.36 0.0018 4.18 0.029 0.34 0.86 0.563 7.75 3.3 JM-122 MDRU19-7-2-22C Pyramidal QtzDiorite 592.1 4.9 0.279 2008 1.78 1.1 0.041 9.95 0.245 2.77 5.95 2.9 35 11.69 JM-122 MDRU19-7-2-24C Pyramidal QtzDiorite 569 4.3 0.24 1775 1.46 1.63 0.029 10.15 0.276 3.72 6.82 3.28 32.2 10.64 JM-122 MDRU19-7-2-24R Pyramidal QtzDiorite 599 5.4 0.211 1971 1.57 1.29 0.081 0.039 11.17 0.293 3.99 7.41 3.52 36.3 12.23 JM-122 MDRU19-7-2-25R Prismatic QtzDiorite 503.2 7.1 0.225 1934 1.58 1.42 0.3 0.187 12.07 0.234 2.45 4.63 2.26 30 10.51 JM-122 MDRU19-7-2-25C Prismatic QtzDiorite 556.3 0.214 2270 1.68 1.23 0.293 0.037 14.54 0.151 2.33 5.15 1.94 33.3 12.07 JM-066 MDRU19-7-5-1C Prismatic QtzDiorite 574 5.3 2030 1.98 1.04 0.167 0.085 9.49 0.083 1.55 3.92 1.03 23.9 8.64 JM-066 MDRU19-7-5-1R Prismatic QtzDiorite 545 5.7 0.37 1490 1.54 1.27 0.33 0.015 6.21 0.044 1.04 2.39 0.62 14.7 5.96 JM-066 MDRU19-7-5-2R Prismatic QtzDiorite 664 7.3 0.3 3366 3.1 1.28 0.26 0.031 21.5 0.065 1.55 5.5 1.36 46.1 16.95 JM-066 MDRU19-7-5-2C Prismatic QtzDiorite 676 5.8 2239 2.58 1.17 0.075 9.06 0.048 0.98 2.92 0.77 22.8 9.1 JM-066 MDRU19-7-5-3C Prismatic QtzDiorite 562 1810 1.61 0.7 8.21 0.092 2.06 3.93 0.92 23.9 8.45 JM-066 MDRU19-7-5-3R Prismatic QtzDiorite 563 5.3 1620 1.61 1.23 0.0018 6.9 0.075 1.34 3.18 0.78 18.3 6.94 JM-066 MDRU19-7-5-4R Prismatic QtzDiorite 546.3 7.1 15.2 1587 1.69 0.81 6.53 0.035 0.68 2.3 0.562 15.9 6.33 JM-066 MDRU19-7-5-4C Prismatic QtzDiorite 571 6.3 20.9 1734 1.53 1.33 0.0096 7.2 0.063 1.33 3.43 0.603 18.8 7.37 JM-066 MDRU19-7-5-5C Prismatic QtzDiorite 556 6.9 1510 1.65 1.01 0.02 6.15 0.043 0.82 2.25 0.63 15.6 6.32 Continuation of Table 1 Sample ID Zircon ID Dy ppm Ho ppm Er ppm Tm ppm Yb ppm Lu ppm Hf ppm Ta ppm U ppm Th ppm Pb ppm ∑REE Ti49 ppm Temp C° Hf Ce/Ce* Eu/Eu* JM-122 MDRU19-7-2-3R 128.4 49.7 253.6 63 658 164.3 7260 0.518 614 723 88.6 1367.9009 9.6 776.45 7260.000 24.816 0.620 JM-122 MDRU19-7-2-3C 89 34.9 182 46.6 509 130 6910 0.376 363 338 40.9 1032.8446 0 6910.000 6.693 0.688 JM-122 MDRU19-7-2-4C 95.6 38.4 208 53.5 584 150.6 7640 0.39 337 263 32.7 1174.1321 5.1 716.99 7640.000 8.520 0.695 JM-122 MDRU19-7-2-4R 121.4 47.5 251 64.7 698 173.5 7770 0.477 409 355 43.2 1406.3309 7.8 756.16 7770.000 8.406 0.686 JM-122 MDRU19-7-2-5R 91.3 36.5 193.9 49.5 538 135.5 7330 0.392 405 345 37.7 1083.6423 7.7 754.92 7330.000 13.405 0.709 JM-122 MDRU19-7-2-6C 46.9 19.89 114.1 30.5 350 93.4 7750 0.314 200 109.9 14.1 673.5974 0 7750.000 14.327 0.615 JM-122 MDRU19-7-2-6R 58.5 26.04 147.4 38.8 429 109.7 7560 0.354 300 222 24.6 829.61 4.8 711.64 7560.000 48.879 0.643 JM-122 MDRU19-7-2-8R 71.1 29.57 161.6 40.5 425 112.6 7900 0.39 354 238.2 27.4 868.42 5.1 716.99 7900.000 11.133 0.651 JM-122 MDRU19-7-2-9C 66 29.4 170.6 45.9 498 137.7 7182 0.379 359 257 30.3 975.262 4.7 709.80 7182.000 18.659 0.633 JM-122 MDRU19-7-2-11R 56.1 25.22 137.5 35.7 380 100.2 7400 0.4 357 274 34.9 758.1014 9.4 774.36 7400.000 19.650 0.590 JM-122 MDRU19-7-2-12R 141 61.8 329 82.3 837 203 10010 0.885 1340 1490 162 1717.085 13 807.56 10010.000 49.500 0.400 JM-122 MDRU19-7-2-14C 115 47.8 249.3 65.9 707 184.3 7710 0.47 456 396 46.8 1423.939 7 745.89 7710.000 7.628 0.717 JM-122 MDRU19-7-2-15C 68.8 31.96 181.8 47 505 133.6 7910 0.402 497 370 38.3 991.748 6.5 738.98 7910.000 45.181 0.568 JM-122 MDRU19-7-2-16C 24.9 11.4 63.3 16.9 200 53.6 7720 0.259 116.2 57 5.8 380.348 4.5 706.02 7720.000 39.639 0.641 JM-122 MDRU19-7-2-16R 40.9 17.85 96.3 25.4 292 75.2 7830 0.373 202 117 14.2 565.079 5.9 730.08 7830.000 12.587 0.677 JM-122 MDRU19-7-2-17R 33.5 15.1 84.6 21.8 242 59.7 12760 0.693 1210 716 83 470.885 0 12760.000 56.331 0.331 JM-122 MDRU19-7-2-18R 145.8 60.3 305 72.5 759 177.1 8180 0.684 873 950 105.8 1575.192 7.8 756.16 8180.000 26.839 0.601 JM-122 MDRU19-7-2-18C 162.3 64.3 324 78 838 197.9 7900 0.49 721 705 83.3 1738.918 6.5 738.98 7900.000 10.275 0.709 JM-122 MDRU19-7-2-21C 53.6 24.1 134.1 35.1 398 101.6 7640 0.387 406 265 31.4 763.5238 6 731.62 7640.000 71.717 0.663 JM-122 MDRU19-7-2-22C 160.5 65.4 331 81.2 878 209.4 8150 0.61 860 810 92 1794.046 4.9 713.46 8150.000 17.795 0.611 JM-122 MDRU19-7-2-24C 144.4 59.1 299 73 794 186.7 7770 0.575 665 620 68.1 1623.315 4.3 702.09 7770.000 11.536 0.673 JM-122 MDRU19-7-2-24R 154.8 61.6 329 78.9 836 198.9 8030 0.512 754 753 86.1 1734.152 5.4 722.09 8030.000 11.990 0.653 JM-122 MDRU19-7-2-25R 144.7 59.4 317.5 74.2 788 187.6 9270 0.716 1320 1048 115.1 1633.741 7.1 747.23 9270.000 21.472 0.583 JM-122 MDRU19-7-2-25C 166.8 68.4 371 88.5 939 221.2 9330 0.827 1344 1122 130.4 1924.418 0 9330.000 31.810 0.450 JM-066 MDRU19-7-5-1C 127.9 58.2 347 90.9 997 259 7520 0.592 705 358 43.6 1928.698 5.3 720.41 7520.000 35.710 0.324 JM-066 MDRU19-7-5-1R 87 41.1 253 66.4 757 200 7870 0.531 383 169 23.6 1435.479 5.7 726.95 7870.000 31.647 0.318 JM-066 MDRU19-7-5-2R 240.4 99.1 529.8 128.4 1330 310.4 10110 0.996 1210 990 122 2731.156 7.3 749.85 10110.000 113.513 0.260 JM-066 MDRU19-7-5-2C 137.7 64.9 384 97.8 1081 271.6 8290 0.734 583 294.3 33.4 2082.678 5.8 728.53 8290.000 63.528 0.287 JM-066 MDRU19-7-5-3C 124 53.9 308 80.7 917 230 8190 0.646 557 276 32.9 1761.162 0 8190.000 17.535 0.289 JM-066 MDRU19-7-5-3R 100.7 46.3 280 76.5 885 229 8420 0.658 528 223 26.5 1655.0168 5.3 720.41 8420.000 28.182 0.311 JM-066 MDRU19-7-5-4R 100.7 46.5 274.3 72.5 805 208.7 7799 0.595 489.4 221.5 26.4 1540.037 7.1 747.23 7799.000 74.908 0.283 JM-066 MDRU19-7-5-4C 111.4 50.3 297 77.6 854 220.6 7910 0.631 486 229.2 29.5 1649.7056 6.3 736.09 7910.000 32.198 0.228 JM-066 MDRU19-7-5-5C 92.6 44.1 260 69 760 197 8560 0.579 488 214 29.2 1454.533 6.9 744.54 8560.000 47.461 0.323 Continuation of Table 1 Sample ID Zircon ID External Shape Rock Type Sc ppm Ti ppm V ppm Y ppm Nb ppm Mo ppm Sn ppm La ppm Ce ppm Pr ppm Nd ppm Sm ppm Eu ppm Gd ppm Tb ppm JM-066 MDRU19-7-5-5R Prismatic QtzDiorite 563 8.6 0.39 1690 1.52 1.41 0.208 0.029 7.23 0.04 1.46 2.95 0.93 20.8 7.92 JM-066 MDRU19-7-5-6R Prismatic QtzDiorite 594 7.3 0.209 3040 2.92 1.14 0.128 0.0067 18 0.109 2.39 7.5 1.58 48.4 16.6 JM-066 MDRU19-7-5-6C Prismatic QtzDiorite 635 6.2 2860 2.64 1.36 15.3 0.145 2.61 7.6 1.62 44.4 15.2 JM-066 MDRU19-7-5-7C Prismatic QtzDiorite 591 6.6 3480 1.52 0.69 0.029 14.81 0.355 6.5 12.67 2.98 66.1 20.8 JM-066 MDRU19-7-5-7R Prismatic QtzDiorite 478 5.2 2240 1.07 0.96 0.135 0.019 9.5 0.203 3.78 7.6 1.78 40.7 12.7 JM-066 MDRU19-7-5-8R Prismatic QtzDiorite 662 10 0.284 3859 3.63 1.19 0.163 0.0027 21.14 0.098 1.86 8.13 2.1 62 21.52 JM-066 MDRU19-7-5-8C Prismatic QtzDiorite 629.5 3.6 0.151 1900 1.67 0.82 0.144 0.007 7.91 0.07 1.65 3.57 0.83 22 8.49 JM-066 MDRU19-7-5-10C Prismatic QtzDiorite 658 5.8 0.26 2290 2.35 1.02 0.0091 10.4 0.059 1.93 4.37 1.05 27.3 10.2 JM-066 MDRU19-7-5-12R Prismatic QtzDiorite 639 8.6 2960 2.16 1.08 0.082 0.0032 13.85 0.065 1.71 5.81 1.65 42.5 15.1 JM-066 MDRU19-7-5-12C Prismatic QtzDiorite 680 3.9 2147 1.5 1.19 8.82 0.024 1.01 2.99 0.8 20.86 8.42 JM-066 MDRU19-7-5-15C Prismatic QtzDiorite 672 4.9 2150 1.4 1.32 0.0077 9.7 0.062 1.11 2.59 0.68 22.4 8.51 JM-066 MDRU19-7-5-15R Prismatic QtzDiorite 564 1425 0.71 1.32 0.0033 7.29 0.03 0.96 1.97 0.472 14.14 5.54 JM-066 MDRU19-7-5-18R Prismatic QtzDiorite 765 5.9 2360 2.3 1.2 9.53 0.075 1.37 3.35 0.97 23.3 8.87 JM-066 MDRU19-7-5-19C Prismatic QtzDiorite 473 7 0.55 1334 0.9 1.2 0.079 6.06 0.074 1.46 2.5 0.7 18 6.41 JM-066 MDRU19-7-5-20C Pyramidal QtzDiorite 486 3.3 1340 0.87 1.16 0.087 0.04 6.59 0.064 1.41 2.83 0.523 16.3 5.86 JM-066 MDRU19-7-5-20R Prismatic QtzDiorite 422 0.18 1140 0.76 1.11 0.175 0.036 5.92 0.063 1.23 2.78 0.59 16.8 5.91 JM-066 MDRU19-7-5-21R Equant QtzDiorite 626 6.5 3768 2.62 1.01 0.186 0.0196 23.67 0.241 3.56 8.99 1.82 57.8 20.13 JM-066 MDRU19-7-5-21C Equant QtzDiorite 664 6.5 0.268 3540 3.25 1.24 19.45 0.13 3.85 9.97 2.1 58.9 19.67 JM-061 MDRU19-7-6-1C Equant Tonalite Porphyry 309.1 4.2 317.1 0.48 1.08 1.121 0.149 0.43 0.185 3.09 1.334 JM-061 MDRU19-7-6-1R Equant Tonalite Porphyry 342 5.2 482 0.86 1.08 1.69 0.0114 0.181 0.66 0.329 4.84 1.78 JM-061 MDRU19-7-6-2R Equant Tonalite Porphyry 311.9 3.6 566 0.627 1.05 0.101 0.001 1.85 0.043 0.79 1.56 0.583 7.98 2.89 JM-061 MDRU19-7-6-2C Equant Tonalite Porphyry 316.1 4.7 660 0.603 0.87 0.0012 2.1 0.062 0.87 2.27 0.782 10.09 3.3 JM-060 MDRU19-7-7-1C Equant Granodiorite Px 351.9 5.5 312.4 0.452 0.75 1.123 0.0029 0.083 0.45 0.132 3.18 1.35 JM-060 MDRU19-7-7-1R Equant Granodiorite Px 308 5.3 293.8 0.477 0.95 1.14 0 0.17 0.3 0.203 3.01 1.18 JM-060 MDRU19-7-7-10C Pyramidal Granodiorite Px 444.1 6.4 649 0.67 1.11 2.36 0.025 0.35 1.05 0.415 7.61 2.97 JM-060 MDRU19-7-7-10R Pyramidal Granodiorite Px 429.2 7.2 779 1.36 1.14 0.055 0.026 4.03 0.022 0.46 1.17 0.365 8.2 3.28 JM-060 MDRU19-7-7-12R Pyramidal Granodiorite Px 376.4 4.7 602 0.626 1.16 0 1.97 0.043 0.67 1.62 0.547 8.48 2.99 JM-060 MDRU19-7-7-12C Pyramidal Granodiorite Px 378 4.9 400 0.78 1.06 1.59 0.093 0.54 0.236 3.87 1.53 JM-060 MDRU19-7-7-13C Prismatic Granodiorite Px 433.3 5.6 1277 1.09 1.12 4.29 0.09 1.43 2.96 1.07 18.6 6.84 JM-060 MDRU19-7-7-13R Prismatic Granodiorite Px 435 7.1 1510 1.53 1.12 0.074 5.3 0.14 1.89 3.99 1.38 22.8 8.39 JM-060 MDRU19-7-7-14C Pyramidal Granodiorite Px 432.4 7.5 830 1.5 1.16 3 0.0123 0.33 1.03 0.422 7.47 2.97 JM-060 MDRU19-7-7-15C Equant Granodiorite Px 437 6.4 856 1.58 1.08 3.4 0.026 0.33 1.05 0.447 7.3 3.07 JM-060 MDRU19-7-7-16C Equant Granodiorite Px 324.5 4.4 266 0.476 1.24 0.022 1.08 0.083 0.31 0.09 2.61 0.935 Continuation of Table 1 Sample ID Zircon ID Dy ppm Ho ppm Er ppm Tm ppm Yb ppm Lu ppm Hf ppm Ta ppm U ppm Th ppm Pb ppm ∑REE Ti49 ppm Temp C° Hf Ce/Ce* Eu/Eu* JM-066 MDRU19-7-5-5R 113.7 49.5 284 71.7 792 203 8940 0.557 498 262 35.5 1555.259 8.6 765.60 8940.000 23.076 0.361 JM-066 MDRU19-7-5-6R 221 90.9 490 118.9 1238 302 9020 0.84 1063 842 98 2555.3857 7.3 749.85 9020.000 54.506 0.252 JM-066 MDRU19-7-5-6C 200 82.6 461 115 1222 306 9000 0.87 957 675 79 2473.475 6.2 734.62 9000.000 39.367 0.268 JM-066 MDRU19-7-5-7C 273 107.6 566 140 1458 353 7240 0.564 771 558 65.4 3021.844 6.6 740.39 7240.000 10.243 0.313 JM-066 MDRU19-7-5-7R 172 68.5 364 89 950 234 7380 0.355 508 306 34.6 1953.782 5.2 718.72 7380.000 11.654 0.308 JM-066 MDRU19-7-5-8R 291.5 115.2 589 139.4 1436 331.5 7610 0.799 1159 1126 130 3019.4507 10 780.53 7610.000 114.571 0.284 JM-066 MDRU19-7-5-8C 120.8 55.4 328 85.9 984 256.5 7200 0.609 725 355 38 1875.127 3.6 687.04 7200.000 23.921 0.285 JM-066 MDRU19-7-5-10C 153 68.3 388 101.2 1119 289 8150 0.781 792 448 57.5 2173.8181 5.8 728.53 8150.000 28.139 0.292 JM-066 MDRU19-7-5-12R 212 87.6 484 119.9 1279 317 7180 0.823 927 712 79.5 2580.1882 8.6 765.60 7180.000 63.466 0.319 JM-066 MDRU19-7-5-12C 134.6 63 390 101.6 1167 304 6890 0.685 765 358 35.5 2203.124 3.9 693.76 6890.000 59.622 0.308 JM-066 MDRU19-7-5-15C 133 61.4 362 92.9 1053 269 7990 0.745 825 416 37 2016.3597 4.9 713.46 7990.000 47.025 0.271 JM-066 MDRU19-7-5-15R 84.4 40.8 246.6 65.9 770 197.7 8660 0.61 668 282 26.1 1435.8053 0 8660.000 35.938 0.272 JM-066 MDRU19-7-5-18R 135.6 66 414 113.3 1331 357 7340 0.911 1016 399 35.1 2464.365 5.9 730.08 7340.000 39.229 0.334 JM-066 MDRU19-7-5-19C 91.1 40.9 228.6 59.5 662 170.2 8250 0.386 448 180 19.2 1287.583 7 745.89 8250.000 16.391 0.317 JM-066 MDRU19-7-5-20C 88 39.2 225 57.9 647 166 9640 0.471 888 265 26.2 1256.717 3.3 679.84 9640.000 21.634 0.234 JM-066 MDRU19-7-5-20R 79 33.3 176 45 489 123 10200 0.31 1018 299 38.1 978.629 0 10200.000 25.088 0.263 JM-066 MDRU19-7-5-21R 270.9 111.5 587.4 143 1532 362.4 10020 0.957 1371 1052 86.9 3123.4306 6.5 738.98 10020.000 38.723 0.243 JM-066 MDRU19-7-5-21C 264 104.1 537 128.5 1337 313 8970 0.773 1066 830 64.5 2797.67 6.5 738.98 8970.000 30.172 0.263 JM-061 MDRU19-7-6-1C 20.32 9.67 57.4 15.54 180.7 47.8 7310 0.189 32.7 7.39 0.57 337.739 4.2 700.07 7310.000 50.073 0.488 JM-061 MDRU19-7-6-1R 29.3 14.83 90.4 24.5 277 74.6 7220 0.258 58.5 14.19 0.96 520.1214 5.2 718.72 7220.000 78.520 0.560 JM-061 MDRU19-7-6-2R 39.4 17.28 98.9 25.79 284.3 73.4 7520 0.227 65.7 23 1.79 554.767 3.6 687.04 7520.000 10.665 0.502 JM-061 MDRU19-7-6-2C 48.5 20.73 117.6 28.3 315 78.2 7550 0.202 68.5 26.47 1.4 627.8052 4.7 709.80 7550.000 14.525 0.497 JM-060 MDRU19-7-7-1C 20.28 9.43 57.5 15.15 171 45.3 8090 0.207 50.2 11.73 1.42 324.9809 5.5 723.73 8090.000 169.177 0.336 JM-060 MDRU19-7-7-1R 17.76 8.48 53.2 14.67 171.9 46.1 7930 0.2 42.2 9.86 0.38 318.113 5.3 720.41 7930.000 27.292 0.650 JM-060 MDRU19-7-7-10C 42.6 20.3 115.5 30.3 333 86.3 7590 0.238 95.6 31.5 3.7 642.78 6.4 737.54 7590.000 46.652 0.446 JM-060 MDRU19-7-7-10R 51.6 23.6 134.7 34.8 371 93.6 9160 0.647 262 110 14.8 726.853 7.2 748.54 9160.000 51.390 0.358 JM-060 MDRU19-7-7-12R 43.3 18.56 105.6 26.3 290 70.6 8860 0.184 68.1 27.9 2.28 570.68 4.7 709.80 8860.000 16.396 0.449 JM-060 MDRU19-7-7-12C 25 11.75 71.4 19.05 219.2 56.5 8530 0.239 51.1 14 1.66 410.759 4.9 713.46 8530.000 228.945 0.496 JM-060 MDRU19-7-7-13C 95 40.8 221 54.3 591 137.3 8340 0.39 132 71.3 8.5 1174.68 5.6 725.35 8340.000 14.321 0.438 JM-060 MDRU19-7-7-13R 116 47.9 260 62.5 667 156 8620 0.365 141 83.2 9.7 1353.364 7.1 747.23 8620.000 13.653 0.440 JM-060 MDRU19-7-7-14C 50.7 24.3 152.4 40 473 117.5 8590 0.438 91.5 30.9 3.7 873.1343 7.5 752.41 8590.000 65.439 0.463 JM-060 MDRU19-7-7-15C 50.8 25.1 157.3 40.7 475 116.8 8370 0.492 95.9 30 3.16 881.323 6.4 737.54 8370.000 75.604 0.491 JM-060 MDRU19-7-7-16C 16.5 7.38 49.1 12.77 154.2 37.5 9130 0.021 30.1 7.56 -0.17 282.58 4.4 704.07 9130.000 112.082 0.304 Continuation of Table 1 Sample ID Zircon ID External Shape Rock Type Sc ppm Ti ppm V ppm Y ppm Nb ppm Mo ppm Sn ppm La ppm Ce ppm Pr ppm Nd ppm Sm ppm Eu ppm Gd ppm Tb ppm JM-060 MDRU19-7-7-16R Equant Granodiorite Px 348.1 4.7 666 0.601 0.82 1.85 0.037 0.82 1.39 0.6 8.78 3.16 JM-060 MDRU19-7-7-17C Equant Granodiorite Px 404.6 5.7 0.175 839 1.13 0.98 0.056 0.022 2.91 0.031 0.57 1.2 0.469 8.1 3.33 JM-060 MDRU19-7-7-18C Prismatic Granodiorite Px 314.6 5.9 324 0.407 0.93 0 1.55 0.035 0.35 0.87 0.324 4.22 1.53 JM-060 MDRU19-7-7-18R Prismatic Granodiorite Px 324.2 379 0.561 0.89 0.0012 1.73 0.028 0.45 0.65 0.31 5.13 1.61 JM-060 MDRU19-7-7-19C Pyramidal Granodiorite Px 441 6.4 0.152 1205 1.07 0.71 0.0191 4.07 0.096 1.96 3.47 1.02 18.3 6.56 JM-057 MDRU19-7-9-1C Prismatic Tonalite 529 6.9 0.213 2285 2.97 0.85 0.181 0.0057 11.33 0.151 2.18 5.69 1.28 33.2 12.26 JM-057 MDRU19-7-9-1R Prismatic Tonalite 580 6.7 2870 3.7 0.86 0.057 0.0235 14.8 0.202 3.56 8.3 1.73 44.8 16.6 JM-057 MDRU19-7-9-2R Pyramidal Tonalite 713 11 0.53 3270 6.2 0.76 0.47 0.023 20.9 0.068 1.42 3.89 1.29 39.3 15.89 JM-057 MDRU19-7-9-2C Pyramidal Tonalite 679 10.8 2830 3.71 0.75 0.121 0 14.27 0.047 1.25 5.29 1.54 40.7 14.87 JM-057 MDRU19-7-9-4C Pyramidal Tonalite 645 7.3 0.217 3870 4.18 0.88 0.0092 17.8 0.22 4.57 10.26 2.34 62.7 22.2 JM-057 MDRU19-7-9-5C Pyramidal Tonalite 609 4.22 0.19 3430 4.01 1.03 0.0197 17.9 0.258 4.29 10.4 2.54 60.6 20.7 JM-057 MDRU19-7-9-6C Pyramidal Tonalite 804 6.5 0.263 3950 4.31 0.84 0.0109 19 0.218 4.91 10.39 2.73 63.8 21.5 JM-057 MDRU19-7-9-6R Pyramidal Tonalite 764 8.5 0.36 3290 3.73 1.14 0.026 15.3 0.157 3.54 8.5 2.3 51.8 17.6 JM-057 MDRU19-7-9-7C Pyramidal Tonalite 624 5.5 0.35 2480 3.41 1.23 0.0153 11.8 0.097 2.06 5.3 1.25 33.1 12.6 JM-057 MDRU19-7-9-8C Pyramidal Tonalite 669 6 0.247 3430 3.46 0.6 0.0164 15.8 0.233 4.26 10.1 2.3 54.7 19.7 JM-057 MDRU19-7-9-8R Pyramidal Tonalite 547 6.2 2009 2.72 1.21 0.047 9.17 0.106 1.96 4.93 1.04 28.2 10.17 JM-057 MDRU19-7-9-12R Pyramidal Tonalite 449 3.5 1206 1.4 0.57 0.064 0.0031 5.57 0.05 1.1 2.34 0.64 16.2 5.77 JM-057 MDRU19-7-9-12C Pyramidal Tonalite 620 5.6 2680 2.98 0.9 0.0148 13.48 0.144 3.02 8.22 2.09 46.2 15.44 JM-057 MDRU19-7-9-13C Equant Tonalite 592 6.3 0.24 3070 3.45 1.15 0.0079 14.9 0.126 2.4 7.61 1.93 48.2 18 JM-057 MDRU19-7-9-15C Prismatic Tonalite 544 6.4 2560 2.86 1.05 0.0137 13 0.151 3.03 7.22 1.62 42.1 14.4 JM-057 MDRU19-7-9-15R Prismatic Tonalite 542 5.7 0.342 2740 2.88 1.02 0.0172 13.7 0.203 3.54 8.3 1.96 44.8 15.8 JM-057 MDRU19-7-9-16C Pyramidal Tonalite 703 14.4 0.521 5460 11.86 0.9 0.193 37.5 0.078 2.35 9.09 2.48 73.5 28 JM-057 MDRU19-7-9-16R Pyramidal Tonalite 657 13.5 0.399 4967 16.53 1 0.166 0.0049 44 0.133 2.74 9.36 2.43 71.8 26.84 JM-057 MDRU19-7-9-17R Prismatic Tonalite 414.2 7.8 0.167 1684 1.93 1.04 0.027 7.87 0.116 2.1 4.7 0.95 25.2 8.92 JM-057 MDRU19-7-9-17C Prismatic Tonalite 373.1 6.8 1188 1.24 0.9 0.057 5.02 0.064 1.45 3.26 0.67 18.3 6.3 JM-057 MDRU19-7-9-19C Prismatic Tonalite 535 6.2 0.214 1890 2.36 0.87 0.0057 8.33 0.064 1.65 4.55 1.11 26.1 9.53 JM-057 MDRU19-7-9-19R Prismatic Tonalite 515 6.3 1850 2.21 0.81 0.0106 8.13 0.067 1.61 4.29 1.02 25 9.35 JM-057 MDRU19-7-9-20R Prismatic Tonalite 478 6.3 1590 1.69 0.76 0.006 6.44 0.082 1.31 3.45 0.84 20.5 7.5 JM-057 MDRU19-7-9-22C Pyramidal Tonalite 634 14.8 0.509 5095 9.64 0.85 0.089 0.053 33.92 0.1 2.3 8.87 2.38 73.6 27.25 JM-057 MDRU19-7-9-22R Pyramidal Tonalite 700 16.1 0.52 5024 19.28 0.8 0.249 0.0101 50.25 0.159 3.51 11.57 2.67 72.7 27.07 JM-057 MDRU19-7-9-24R Pyramidal Tonalite 706 12.5 0.33 4158 9.23 0.64 0.18 26.73 0.062 1.41 5.27 1.19 44.4 18.49 JM-057 MDRU19-7-9-24C Pyramidal Tonalite 638 6.2 2265 3.46 0.89 0.002 9.03 0.04 1.06 3.13 0.707 24.1 9.54 Continuation of Table 1 Sample ID Zircon ID Dy ppm Ho ppm Er ppm Tm ppm Yb ppm Lu ppm Hf ppm Ta ppm U ppm Th ppm Pb ppm ∑REE Ti49 ppm Temp C° Hf Ce/Ce* Eu/Eu* JM-060 MDRU19-7-7-16R 46.2 20.3 112.7 28.8 309 76.3 8110 0.204 72.4 27.5 2.22 609.937 4.7 709.80 8110.000 8.820 0.522 JM-060 MDRU19-7-7-17C 53.1 24.54 145.9 38.5 421 108.2 8150 0.374 77.8 28.4 3 807.872 5.7 726.95 8150.000 24.787 0.457 JM-060 MDRU19-7-7-18C 22.3 9.43 52.9 14.8 164.6 42.9 8850 0.15 43.8 15.93 1.54 315.809 5.9 730.08 8850.000 25.388 0.514 JM-060 MDRU19-7-7-18R 24.8 10.79 62.7 17.4 199 51.6 8800 0.198 52.7 19 2.67 376.1992 0 8800.000 12.807 0.516 JM-060 MDRU19-7-7-19C 90.7 37.3 200 49.1 516 124 8910 0.346 126 73.1 8.8 1052.5951 6.4 737.54 8910.000 8.478 0.389 JM-057 MDRU19-7-9-1C 175.6 70.5 376 90.8 922 207 9810 0.741 255 177 25.8 1907.9967 6.9 744.54 9810 31.284958 0.2831665 JM-057 MDRU19-7-9-1R 230 92.7 470 110 1102 245 9740 0.844 260 196 23.3 2339.7155 6.7 741.79 9740 22.353534 0.2727879 JM-057 MDRU19-7-9-2R 234.7 99.6 537 125.7 1207 276 9480 1.53 545 368 54.7 2562.781 11 790.19 9480 92.987716 0.317231 JM-057 MDRU19-7-9-2C 212 88.4 473 111 1061 247 8070 0.85 290 222 26.4 2270.367 10.8 788.32 8070 111.42073 0.319119 JM-057 MDRU19-7-9-4C 310 125.1 651 149 1442 321 9470 1.056 373 273 29.7 3118.1992 7.3 749.85 9470 20.167002 0.280521 JM-057 MDRU19-7-9-5C 283 111 569 130 1240 277 9310 0.78 314 255 29.2 2726.7077 4.22 700.48 9310 23.328036 0.3076364 JM-057 MDRU19-7-9-6C 297 122.8 665 154.1 1506 356 8370 1.14 417 281 31.3 3223.4589 6.5 738.98 8370 18.884807 0.3224049 JM-057 MDRU19-7-9-6R 239 101 549 128 1270 307 8010 0.9 294 184 24.8 2693.223 8.5 764.46 8010 23.933721 0.333281 JM-057 MDRU19-7-9-7C 186 79.5 434 99.1 1023 230 9100 0.858 341 196 37 2117.8223 5.5 723.73 9100 33.988329 0.2869559 JM-057 MDRU19-7-9-8C 259 106.7 551 130.2 1326 294 8580 0.887 347 224 29.4 2774.0094 6 731.62 8580 20.279892 0.2975298 JM-057 MDRU19-7-9-8R 143.6 62.2 331 81 833 189.2 9010 0.727 214 123 23.5 1695.623 6.2 734.62 9010 27.140041 0.2681899 JM-057 MDRU19-7-9-12R 82.8 36.4 200.6 50.2 543 127.4 9540 0.513 163 75.1 13 1072.0731 3.5 684.70 9540 24.842315 0.3160615 JM-057 MDRU19-7-9-12C 207 84.9 435 103.8 1058 232.9 8830 0.634 255 178.2 19.9 2210.2088 5.6 725.35 8830 28.019102 0.3260967 JM-057 MDRU19-7-9-13C 235 96.6 497 114 1146 251 8990 0.841 348 294 31.6 2432.7739 6.3 736.09 8990 45.399893 0.3064069 JM-057 MDRU19-7-9-15C 193 78.9 417 100.5 1040 240 8960 0.84 318 209 27.1 2150.9347 6.4 737.54 8960 23.577713 0.2825286 JM-057 MDRU19-7-9-15R 206 83.7 439 101.4 1041 233 8720 0.766 295 220 24.4 2192.4202 5.7 726.95 8720 20.926593 0.3090545 JM-057 MDRU19-7-9-16C 381 161.3 843 193.5 1966 433 9170 1.93 876 858 108.7 4130.798 14.4 818.47 9170 142.35273 0.2917314 JM-057 MDRU19-7-9-16R 379.8 152.3 782 182.9 1775 392.3 8990 2.66 1351 1870 234 3821.6079 13.5 811.56 8990 126.5126 0.285012 JM-057 MDRU19-7-9-17R 130.3 52.2 276 66.8 672 157.5 8800 0.533 233 147 44.4 1404.683 7.8 756.16 8800 19.343737 0.2654187 JM-057 MDRU19-7-9-17C 91.1 37.3 192 46.5 473 112 9140 0.401 137 73.6 9.5 987.021 6.8 743.18 9140 17.951126 0.2637531 JM-057 MDRU19-7-9-19C 137 57.8 311 76.7 791 190 8130 0.686 250 143 17.1 1614.8397 6.2 734.62 8130 32.106643 0.3097092 JM-057 MDRU19-7-9-19R 135.6 57.5 305 75.2 769 187 8700 0.653 260 150.6 17.4 1578.7776 6.3 736.09 8700 31.031479 0.2994736 JM-057 MDRU19-7-9-20R 116 48.5 260 64.2 670 158 8940 0.581 214 118 74 1356.828 6.3 736.09 8940 29.858553 0.3037035 JM-057 MDRU19-7-9-22C 393.1 156 784 182.4 1761 392 9550 1.43 695 796 89.8 3816.973 14.8 821.43 9550 131.16869 0.2832261 JM-057 MDRU19-7-9-22R 379 151.1 778 183.4 1760 392.1 10310 3.45 1580 2560 289 3811.5391 16.1 830.63 10310 108.83324 0.2799203 JM-057 MDRU19-7-9-24R 285.2 124 655 156 1516 342.5 9740 1.5 613 536 58.7 3176.252 12.5 803.43 9740 163.40966 0.2365414 JM-057 MDRU19-7-9-24C 150.5 67.2 375 92.6 932 224.8 9100 0.859 315 167.7 19.9 1889.709 6.2 734.62 9100 58.013189 0.2475117 Figure 1. Difference between the average values obtained in the geochemistry and the preffered value from the used standard (RFS). A. RSF in % of the NIST610 standard. A1. RSF as proportion of the NIST610 standard. B. RSF in % of the NIST612 standard. B1. RSF as proportion of the NIST612 standard. C. RSF in % of the BCR2G standard. C1. RSF as proportion of the BCR2G standard. Appendix H : Pb and S Isotopic Data H.1.Pb isotopes in sulfides H.2. Pb isotopes in feldspars H.3. S isotopes in sulfides H.1 Pb isotopes in sulfides Table 1. Pb isotopes results from sulfide separates of the San Matias District, May 2019 Sample Mineral 206Pb/ Error Error 207Pb/ Error Error 208Pb/ Error Error 207Pb/ Error Error 208Pb/ Error Error Number 204Pb Absolute % 2 sigma 204Pb Absolute % 2 sigma 204Pb Absolute % 2 sigma 206Pb Absolute % 2 sigma 206Pb Absolute % 2 sigma JM058 py 18.6666 0.0082 0.04 15.6549 0.0051 0.03 38.5414 0.0173 0.04 0.8387 0.0002 0.029 2.0647 0.0002 0.009 JM040 py 18.6831 0.0085 0.05 15.5969 0.0051 0.03 38.3734 0.0243 0.06 0.8348 0.0003 0.032 2.0539 0.0009 0.044 JM042 py 18.6493 0.0245 0.13 15.5468 0.0138 0.09 38.5194 0.0613 0.16 0.8336 0.0008 0.097 2.0655 0.0019 0.090 JM048 py 18.7164 0.0073 0.04 15.5826 0.0049 0.03 38.4866 0.0174 0.05 0.8326 0.0002 0.024 2.0563 0.0005 0.023 JM052 py 18.6750 0.0660 0.35 15.5283 0.0489 0.32 38.5512 0.2088 0.54 0.8315 0.0013 0.161 2.0643 0.0085 0.411 JM060 py 18.8808 0.0104 0.05 15.6599 0.0081 0.05 39.8608 0.0225 0.06 0.8294 0.0002 0.018 2.1112 0.0003 0.013 JM061 py 18.5905 0.0337 0.18 15.4677 0.0266 0.17 38.0598 0.0703 0.18 0.8320 0.0005 0.058 2.0473 0.0008 0.037 JM076 py 18.6446 0.0276 0.15 15.5338 0.0224 0.14 38.2146 0.0594 0.16 0.8332 0.0003 0.033 2.0496 0.0010 0.048 JM110 py 19.7143 0.0148 0.08 15.5901 0.0112 0.07 38.4056 0.0289 0.08 0.7908 0.0002 0.023 1.9481 0.0001 0.006 Lead Isotope Analysis of Sulphides from San Matías Project submitted by Julian Manco, May 2019 Analyses by Janet Gabites, Geochronology Laboratory, Department of Earth Ocean and Atmospheric Sciences, The University of British Columbia. Results have been normalized using a fractionation factor of 0.12% based on multiple analyses of NBS981 standard lead, and the values in Thirlwall., 2000. Errors are reported at the 2 sigma level. Minerals analysed: gl = galena, py = pyrite The total procedural blank was 88pg, with composition 206Pb/204Pb 17.71, 207Pb/204Pb 15.22, 208Pb/204Pb 36.54. Table 2. Pb isotopes results from sulfide separates of the San Matias District, July 2019 Sample Mineral 206Pb/ Error Error 207Pb/ Error Error 208Pb/ Error Error 207Pb/ Error Error 208Pb/ Error Error Number 204Pb Absolute % 2 sigma 204Pb Absolute % 2 sigma 204Pb Absolute % 2 sigma 206Pb Absolute % 2 sigma 206Pb Absolute % 2 sigma JM41 sl 18.6919 0.0080 0.04 15.5766 0.0063 0.04 38.3001 0.0171 0.04 0.8333 0.0001 0.014 2.0490 0.0003 0.013 JM41 sl 18.6740 0.0060 0.03 15.5749 0.0044 0.03 38.2602 0.0129 0.03 0.8340 0.0001 0.015 2.0489 0.0002 0.011 JM41 sl 18.6331 0.0277 0.15 15.5330 0.0227 0.15 38.3282 0.0574 0.15 0.8336 0.0003 0.031 2.0570 0.0004 0.019 Lead Isotope Analysis of Sulphides from San Matías Project submitted by Julian Manco, May 2019. Revised 3 July 2019 Analyses by Janet Gabites, Geochronology Laboratory, Department of Earth Ocean and Atmospheric Sciences, The University of British Columbia. Results have been normalized using a fractionation factor of 0.12% based on multiple analyses of NBS981 standard lead, and the values in Thirlwall., 2000. Errors are reported at the 2 sigma level. Minerals analysed: gl = galena, py = pyrite, sl = sphalerite The total procedural blank was 88pg, with composition 206Pb/204Pb 17.71, 207Pb/204Pb 15.22, 208Pb/204Pb 36.54. H.2 Pb isotopes in feldspars Table 1. Pb isotopes LA-ICP-MS (NuAttom) results in feldspars from the San Matias District representative units. (JM057, JM058 JM060) Sample QAQC grains visual inspection Spots Pb206 Pb206 Int2SE Pb207 Pb207 Int2SE Pb208 Pb208 Int2SE TotalPbBeam TotalPbBeam Int2SE Pb8_6 Final Pb8_6 Final Int2SE Pb8_6 Final Prop2SE SMA_JA_1704_JM_057 Good JM057_G1_b 5750 180 4860 160 11960 390 22820 710 2.055 0.034 0.035 SMA_JA_1704_JM_057 Separated, No back up. Some microinclusions of Chl (tested with HCl) JM057_G4_a 3805 84 3254 81 8110 150 15330 260 2.116 0.045 0.046 SMA_JA_1704_JM_057 Separated, No back up. Some microinclusions of Chl (tested with HCl) JM057_G4_b 3636 79 3013 84 7490 130 14360 250 2.038 0.038 0.039 SMA_JA_1704_JM_057 Separated, No back up. Some microinclusions of Chl (tested with HCl) JM057_G6_a 4760 130 3960 110 9830 260 18750 470 2.048 0.036 0.038 SMA_JA_1704_JM_057 Separated, No back up. Some microinclusions of Chl (tested with HCl) JM057_G6_b 3197 64 2733 62 6720 130 12740 200 2.073 0.043 0.044 SMA_JA_1704_JM_057 Separated, No back up. Some microinclusions of Chl (tested with HCl) JM057_G6_c 3590 120 3016 84 7470 210 14240 390 2.062 0.044 0.045 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G2_a 3526 69 2913 58 7380 150 13930 200 2.076 0.045 0.046 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G2_b 5700 2000 4700 1700 11700 4100 22300 7900 2.059 0.039 0.04 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G2_c 3330 140 2790 130 7110 360 13250 540 2.086 0.046 0.047 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G4_a 3370 68 2861 50 7050 100 13390 150 2.077 0.044 0.045 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G4_b 3337 77 2828 81 7130 210 13340 300 2.084 0.037 0.038 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G5_a 3564 82 3076 77 7540 170 14270 240 2.085 0.048 0.049 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G5_b 3603 68 3080 61 7540 150 14390 220 2.079 0.05 0.051 SMA_CA_1705_JM_058 Difficult to separate from Qtz (recognition) JM058_G5_c 3313 65 2854 52 7030 90 13360 170 2.108 0.043 0.044 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G1_a 3716 74 3111 66 7790 160 14820 240 2.081 0.044 0.046 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G1_b 3422 96 2925 87 7160 170 13650 330 2.078 0.037 0.039 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G1_c 3900 280 3310 240 8100 590 15500 1100 2.039 0.043 0.044 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G2_a 7730 120 6520 110 15970 200 30570 360 2.057 0.034 0.036 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G2_b 7970 120 6696 78 16580 170 31600 300 2.064 0.031 0.032 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G2_c 8360 120 7002 92 17530 200 33320 290 2.08 0.031 0.033 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G3_a 1740 160 1470 150 3740 340 6980 640 2.139 0.067 0.068 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G3_b 4016 99 3361 88 8340 190 15900 340 2.059 0.04 0.041 SMA_ME_1705_JM_060 Difficult to separate from Qtz (recognition) JM060_G3_c 1640 320 1600 490 3470 610 6500 1200 2.139 0.08 0.08 Continuation of Table 1 (right side). Sample Pb7_6 Final Pb7_6 Final Int2SE Pb7_6 Final Prop2SE Pb8_6 NoFract Pb8_6 NoFract Int2SE Pb7_6 NoFract Pb7_6 NoFract Int2SE PbFract 86 PbFract86 Int2SE PbFract 76 PbFract 76 Int2SE SMA_JA_1704_JM_057 0.845 0.016 0.018 2.077 0.034 0.848 0.016 0.995 0.018 0.987 0.019 SMA_JA_1704_JM_057 0.856 0.022 0.024 2.139 0.045 0.859 0.022 0.971 0.02 0.978 0.025 SMA_JA_1704_JM_057 0.829 0.023 0.025 2.06 0.038 0.832 0.024 1.004 0.02 1.011 0.028 SMA_JA_1704_JM_057 0.828 0.016 0.018 2.07 0.037 0.831 0.016 1.002 0.018 0.999 0.019 SMA_JA_1704_JM_057 0.854 0.015 0.017 2.095 0.043 0.857 0.015 0.991 0.021 0.976 0.017 SMA_JA_1704_JM_057 0.843 0.02 0.022 2.084 0.044 0.846 0.02 0.993 0.022 0.985 0.022 SMA_CA_1705_JM_058 0.832 0.023 0.024 2.098 0.045 0.834 0.023 0.99 0.021 1.008 0.028 SMA_CA_1705_JM_058 0.834 0.017 0.019 2.081 0.04 0.837 0.017 0.997 0.019 1 0.021 SMA_CA_1705_JM_058 0.838 0.024 0.026 2.109 0.047 0.841 0.025 0.981 0.021 1.001 0.03 SMA_CA_1705_JM_058 0.847 0.023 0.024 2.1 0.044 0.85 0.023 0.985 0.02 0.989 0.027 SMA_CA_1705_JM_058 0.834 0.02 0.022 2.106 0.037 0.837 0.021 0.985 0.018 1.003 0.025 SMA_CA_1705_JM_058 0.858 0.024 0.025 2.108 0.048 0.861 0.024 0.987 0.023 0.977 0.027 SMA_CA_1705_JM_058 0.856 0.022 0.023 2.101 0.051 0.859 0.022 0.991 0.024 0.978 0.025 SMA_CA_1705_JM_058 0.859 0.022 0.024 2.131 0.043 0.861 0.022 0.975 0.02 0.976 0.027 SMA_ME_1705_JM_060 0.837 0.018 0.02 2.103 0.045 0.84 0.018 0.988 0.021 0.993 0.019 SMA_ME_1705_JM_060 0.855 0.019 0.021 2.1 0.038 0.858 0.019 0.988 0.017 0.973 0.021 SMA_ME_1705_JM_060 0.848 0.02 0.022 2.06 0.043 0.851 0.02 1.008 0.021 0.98 0.021 SMA_ME_1705_JM_060 0.846 0.014 0.016 2.079 0.035 0.849 0.014 0.997 0.016 0.985 0.016 SMA_ME_1705_JM_060 0.837 0.015 0.017 2.086 0.031 0.84 0.015 0.993 0.015 0.996 0.017 SMA_ME_1705_JM_060 0.837 0.013 0.015 2.102 0.031 0.84 0.013 0.986 0.015 0.995 0.016 SMA_ME_1705_JM_060 0.844 0.036 0.037 2.162 0.068 0.847 0.036 0.968 0.031 1.007 0.044 SMA_ME_1705_JM_060 0.838 0.022 0.024 2.081 0.04 0.841 0.022 0.997 0.019 1 0.027 SMA_ME_1705_JM_060 0.86 0.038 0.039 2.162 0.081 0.863 0.038 0.973 0.037 0.991 0.045 Table 2. Pb isotopes LA-ICP-MS (NuAttom) results in feldspars from the San Matias District representative units. (JM061, JM066, JM067, 079) Sample QAQC grains visual inspection Spots Pb206 Pb206 Int2SE Pb207 Pb207 Int2SE Pb208 Pb208 Int2SE TotalPbBeam TotalPbBeam Int2SE Pb8_6 Final Pb8_6 Final Int2SE Pb8_6 Final Prop2SE SMA_ME_1705_JM_061 Difficult to separate from Qtz (recognition) JM061_G4_b 1774 50 1501 41 3663 74 7000 110 2.045 0.066 0.067 SMA_ME_1705_JM_061 Difficult to separate from Qtz (recognition) JM061_G4_c 1732 61 1475 47 3602 85 6810 120 2.098 0.077 0.078 SMA_ME_1705_JM_061 Difficult to separate from Qtz (recognition) JM061_G5_a 3378 52 2795 64 7040 110 13320 170 2.066 0.037 0.039 SMA_ME_1705_JM_061 Difficult to separate from Qtz (recognition) JM061_G5_b 3331 49 2807 62 6977 92 13290 140 2.071 0.04 0.042 SMA_ME_1705_JM_061 Difficult to separate from Qtz (recognition) JM061_G6_a 2657 92 2253 89 5710 250 10720 390 2.135 0.066 0.067 SMA_SJ_1709_JM_066 Good JM066_G1_a 3831 87 3325 90 8120 130 15450 260 2.095 0.037 0.039 SMA_SJ_1709_JM_066 Good JM066_G1_b 4761 62 3979 72 9790 110 18730 180 2.044 0.032 0.034 SMA_SJ_1709_JM_066 Good JM066_G1_c 4872 88 4122 77 10110 130 19360 200 2.06 0.042 0.043 SMA_SJ_1709_JM_066 Good JM066_G2_a 3514 63 2995 58 7310 100 13980 160 2.064 0.042 0.043 SMA_SJ_1709_JM_066 Good JM066_G2_b 3358 67 2903 62 7170 120 13580 180 2.111 0.045 0.046 SMA_SJ_1709_JM_066 Good JM066_G2_a_1 4255 99 3566 87 8810 180 16790 330 2.054 0.036 0.037 SMA_SJ_1709_JM_066 Good JM066_G4_a 3399 69 2875 75 7150 130 13540 200 2.087 0.044 0.045 SMA_SJ_1709_JM_066 Good JM066_G4_b 3390 73 2854 57 7110 120 13500 220 2.061 0.036 0.038 SMA_SJ_1709_JM_066 Good JM066_G4_c 3326 82 2831 81 6970 130 13260 240 2.073 0.043 0.044 SMA_SJ_1709_JM_066 Good JM066_G6_a 4778 81 4087 81 10120 140 19210 220 2.104 0.038 0.04 SMA_SJ_1709_JM_066 Good JM066_G6_b 4434 98 3748 99 9430 190 17860 340 2.111 0.039 0.041 SMA_AL_1709_JM_067 Good JM067_G4_b 656 24 565 23 1386 42 2568 74 2.12 0.095 0.095 SMA_AL_1709_JM_067 Good JM067_G5_a 624 40 501 34 1263 55 2380 110 2.05 0.14 0.14 SMA_AL_1709_JM_079 Good JM079_G1_a 1466 91 1210 63 3030 180 5620 260 2.093 0.067 0.068 SMA_AL_1709_JM_079 Good JM079_G1_b 1607 63 1318 59 3250 110 6230 220 2.029 0.055 0.056 SMA_AL_1709_JM_079 Good JM079_G1_c 1415 56 1168 41 2897 88 5510 160 2.049 0.071 0.072 SMA_AL_1709_JM_079 Good JM079_G2_a 1579 41 1320 37 3279 62 6234 97 2.056 0.053 0.054 SMA_AL_1709_JM_079 Good JM079_G2_b 2371 67 2019 66 5010 120 9470 220 2.103 0.056 0.057 SMA_AL_1709_JM_079 Good JM079_G3_b 1218 39 990 31 2471 70 4720 130 2.016 0.056 0.057 SMA_AL_1709_JM_079 Good JM079_G3_c 2710 120 2260 110 5590 230 10650 440 2.053 0.053 0.054 SMA_AL_1709_JM_079 Good JM079_G5_b 1708 57 1404 43 3505 75 6720 140 2.053 0.069 0.07 SMA_AL_1709_JM_079 Good JM079_G6_a 3421 88 2813 76 6990 120 13380 240 2.032 0.047 0.048 SMA_AL_1709_JM_079 Good JM079_G6_b 5290 170 4400 160 11100 330 21030 650 2.083 0.036 0.038 SMA_AL_1709_JM_079 Good JM079_G6_c 2135 65 1806 54 4500 120 8500 210 2.095 0.053 0.054 SMA_AL_1709_JM_079 Good JM079_G7_a 2567 66 2115 58 5270 120 10050 200 2.041 0.05 0.051 SMA_AL_1709_JM_079 Good JM079_G7_c 2920 130 2480 120 6220 280 11760 520 2.078 0.048 0.049 Continuation of Table 2 (right side). Sample Pb7_6 Final Pb7_6 Final Int2SE Pb7_6 Final Prop2SE Pb8_6 NoFract Pb8_6 NoFract Int2SE Pb7_6 NoFract Pb7_6 NoFract Int2SE PbFract 86 PbFract86 Int2SE PbFract 76 PbFract 76 Int2SE SMA_ME_1705_JM_061 0.852 0.031 0.032 2.067 0.067 0.854 0.031 1.005 0.033 0.991 0.036 SMA_ME_1705_JM_061 0.864 0.032 0.033 2.12 0.078 0.867 0.032 0.99 0.034 0.977 0.035 SMA_ME_1705_JM_061 0.827 0.022 0.024 2.088 0.038 0.83 0.022 0.993 0.018 1.013 0.028 SMA_ME_1705_JM_061 0.839 0.021 0.022 2.093 0.041 0.842 0.021 0.992 0.02 0.997 0.025 SMA_ME_1705_JM_061 0.849 0.026 0.027 2.158 0.067 0.851 0.026 0.968 0.027 0.99 0.03 SMA_SJ_1709_JM_066 0.868 0.02 0.021 2.117 0.038 0.871 0.02 0.98 0.018 0.958 0.021 SMA_SJ_1709_JM_066 0.837 0.016 0.018 2.066 0.032 0.84 0.016 1.003 0.015 0.996 0.019 SMA_SJ_1709_JM_066 0.847 0.02 0.021 2.082 0.043 0.849 0.02 0.998 0.021 0.988 0.023 SMA_SJ_1709_JM_066 0.853 0.022 0.024 2.086 0.042 0.856 0.022 0.995 0.02 0.981 0.026 SMA_SJ_1709_JM_066 0.866 0.023 0.024 2.133 0.045 0.869 0.023 0.97 0.022 0.967 0.026 SMA_SJ_1709_JM_066 0.838 0.018 0.02 2.076 0.036 0.841 0.018 0.999 0.017 0.997 0.022 SMA_SJ_1709_JM_066 0.841 0.024 0.026 2.11 0.044 0.844 0.025 0.985 0.02 0.992 0.031 SMA_SJ_1709_JM_066 0.838 0.016 0.018 2.083 0.037 0.84 0.016 0.988 0.018 0.996 0.02 SMA_SJ_1709_JM_066 0.852 0.025 0.026 2.095 0.043 0.855 0.025 0.982 0.02 0.985 0.029 SMA_SJ_1709_JM_066 0.854 0.021 0.023 2.126 0.038 0.857 0.021 0.976 0.018 0.98 0.024 SMA_SJ_1709_JM_066 0.845 0.02 0.022 2.133 0.04 0.848 0.02 0.973 0.018 0.99 0.023 SMA_AL_1709_JM_067 0.875 0.043 0.044 2.143 0.096 0.878 0.043 0.988 0.044 0.962 0.041 SMA_AL_1709_JM_067 0.805 0.042 0.043 2.07 0.14 0.808 0.042 1.031 0.063 1.044 0.053 SMA_AL_1709_JM_079 0.85 0.037 0.038 2.116 0.068 0.853 0.037 0.989 0.032 1 0.044 SMA_AL_1709_JM_079 0.822 0.029 0.03 2.05 0.056 0.825 0.029 1.017 0.028 1.017 0.034 SMA_AL_1709_JM_079 0.836 0.035 0.036 2.071 0.072 0.838 0.035 1.013 0.035 1.004 0.039 SMA_AL_1709_JM_079 0.842 0.032 0.033 2.078 0.053 0.845 0.032 0.997 0.026 1.005 0.039 SMA_AL_1709_JM_079 0.853 0.027 0.028 2.126 0.057 0.856 0.027 0.975 0.024 0.986 0.032 SMA_AL_1709_JM_079 0.819 0.031 0.032 2.038 0.056 0.821 0.031 1.017 0.03 1.031 0.037 SMA_AL_1709_JM_079 0.836 0.027 0.029 2.075 0.054 0.838 0.028 1.005 0.027 1.007 0.032 SMA_AL_1709_JM_079 0.835 0.033 0.034 2.075 0.07 0.838 0.034 1.01 0.035 1.014 0.04 SMA_AL_1709_JM_079 0.824 0.022 0.024 2.054 0.047 0.827 0.023 1.013 0.023 1.017 0.027 SMA_AL_1709_JM_079 0.83 0.016 0.018 2.105 0.037 0.832 0.016 0.985 0.018 1.006 0.02 SMA_AL_1709_JM_079 0.849 0.025 0.026 2.118 0.053 0.852 0.025 0.983 0.024 0.989 0.03 SMA_AL_1709_JM_079 0.825 0.022 0.023 2.063 0.051 0.828 0.022 1.009 0.024 1.015 0.026 SMA_AL_1709_JM_079 0.842 0.025 0.026 2.101 0.048 0.845 0.025 0.985 0.024 0.997 0.029 Table 3. Pb isotopes LA-ICP-MS (NuAttom) results in feldspars from the San Matias District representative units. (JM122, JM123, JM134) Sample QAQC grains visual inspection Spots Pb206 Pb206 Int2SE Pb207 Pb207 Int2SE Pb208 Pb208 Int2SE TotalPbBeam TotalPbBeam Int2SE Pb8_6 Final Pb8_6 Final Int2SE Pb8_6 Final Prop2SE SMA_BT_1801_JM_122 Good JM122_G1_a 3966 73 3367 63 8240 120 15730 220 2.055 0.036 0.037 SMA_BT_1801_JM_122 Good JM122_G1_b 2798 65 2337 49 5865 99 11120 170 2.073 0.039 0.04 SMA_BT_1801_JM_122 Good JM122_G2_a 3420 91 2979 86 7110 200 13660 350 2.062 0.046 0.047 SMA_BT_1801_JM_122 Good JM122_G2_c 2113 66 1729 61 4310 120 8210 220 2.028 0.053 0.054 SMA_BT_1801_JM_122 Good JM122_G4_a 2050 370 1750 330 4510 810 8400 1500 2.128 0.097 0.097 SMA_BT_1801_JM_122 Good JM122_G4_b 2821 76 2371 78 5940 150 11280 260 2.102 0.045 0.046 SMA_BT_1801_JM_122 Good JM122_G4_c 2310 160 1920 140 4680 230 8920 440 2.049 0.065 0.066 SMA_BT_1801_JM_122 Good JM122_G5_a 2502 68 2077 66 5168 93 9800 190 2.065 0.047 0.049 SMA_BT_1801_JM_122 Good JM122_G5_b 1680 210 1420 170 3480 460 6640 840 2.038 0.065 0.066 SMA_BT_1801_JM_122 Good JM122_G5_c 1920 230 1620 200 4050 480 7660 910 2.1 0.062 0.063 SMA_BT_1801_JM_122 Good JM122_G6_a 1614 50 1385 44 3366 85 6340 100 2.101 0.068 0.069 SMA_BT_1801_JM_122 Good JM122_G6_b 1736 52 1436 53 3658 88 6880 160 2.091 0.054 0.055 SMA_BT_1801_JM_122 Good JM122_G6_c 1630 54 1396 53 3339 81 6410 170 2.055 0.061 0.062 SMA_SM_1801_JM_123 Good JM123_G1_a 964 34 824 32 2044 58 3840 110 2.103 0.069 0.07 SMA_SM_1801_JM_123 Good JM123_G1_b 877 36 738 30 1864 56 3471 85 2.11 0.1 0.1 SMA_SM_1801_JM_123 Good JM123_G1_c 870 28 719 30 1790 44 3386 77 2.038 0.07 0.071 SMA_SM_1801_JM_123 Good JM123_G2_a 1028 32 864 28 2132 45 4019 76 2.059 0.07 0.071 SMA_SM_1801_JM_123 Good JM123_G2_b 1016 27 835 30 2168 64 4033 81 2.133 0.088 0.089 SMA_SM_1801_JM_123 Good JM123_G2_c 941 31 798 24 2014 45 3783 69 2.148 0.086 0.087 SMA_SM_1801_JM_123 Good JM123_G5_a 1080 41 895 38 2199 78 4200 130 2.035 0.08 0.081 SMA_SM_1801_JM_123 Good JM123_G5_c 910 36 804 37 1964 64 3700 110 2.165 0.084 0.085 SMA_AL_1808_JM_134 Good JM134_G2_b 1290 160 1080 130 2700 320 5120 610 2.091 0.081 0.082 SMA_AL_1808_JM_134 Good JM134_G2_c 1110 370 1120 460 2250 720 4300 1400 2.048 0.081 0.082 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G3_a 541 29 451 25 1103 45 2099 78 2.08 0.12 0.12 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G3_b 407 25 336 21 801 27 1548 50 2.04 0.14 0.14 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G5_a 630 27 536 26 1288 45 2422 75 2.039 0.099 0.099 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G5_b 594 21 516 20 1249 39 2340 54 2.072 0.09 0.091 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G5_c 818 29 698 29 1705 41 3257 77 2.072 0.081 0.081 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G7_b 435 25 363 21 921 34 1686 57 2.15 0.14 0.15 SMA_AL_1808_JM_134 Micro inclusions of Chl and Mag JM134_G7_c 616 26 504 24 1292 39 2441 74 2.1 0.12 0.12 Continuation of Table 3 (right side). Sample Pb7_6 Final Pb7_6 Final Int2SE Pb7_6 Final Prop2SE Pb8_6 NoFract Pb8_6 NoFract Int2SE Pb7_6 NoFract Pb7_6 NoFract Int2SE PbFract 86 PbFract86 Int2SE PbFract 76 PbFract 76 Int2SE SMA_BT_1801_JM_122 0.854 0.02 0.022 2.077 0.036 0.857 0.02 0.995 0.019 0.979 0.023 SMA_BT_1801_JM_122 0.838 0.024 0.025 2.095 0.039 0.841 0.024 0.987 0.02 1.001 0.029 SMA_BT_1801_JM_122 0.87 0.022 0.024 2.085 0.046 0.873 0.022 0.997 0.021 0.962 0.024 SMA_BT_1801_JM_122 0.82 0.023 0.024 2.05 0.053 0.822 0.023 1.017 0.027 1.023 0.029 SMA_BT_1801_JM_122 0.843 0.027 0.028 2.151 0.098 0.846 0.027 0.988 0.028 0.991 0.036 SMA_BT_1801_JM_122 0.842 0.026 0.027 2.125 0.046 0.845 0.026 0.978 0.02 0.998 0.031 SMA_BT_1801_JM_122 0.822 0.03 0.031 2.071 0.066 0.824 0.03 1.004 0.032 1.026 0.035 SMA_BT_1801_JM_122 0.828 0.023 0.025 2.087 0.048 0.83 0.023 0.997 0.023 1.008 0.03 SMA_BT_1801_JM_122 0.845 0.026 0.027 2.059 0.066 0.848 0.026 1.01 0.035 0.994 0.031 SMA_BT_1801_JM_122 0.848 0.03 0.031 2.122 0.063 0.851 0.03 0.985 0.03 0.995 0.035 SMA_BT_1801_JM_122 0.856 0.031 0.032 2.124 0.069 0.859 0.031 0.986 0.033 0.979 0.036 SMA_BT_1801_JM_122 0.829 0.033 0.034 2.113 0.054 0.832 0.033 0.986 0.026 1.021 0.04 SMA_BT_1801_JM_122 0.862 0.033 0.034 2.077 0.062 0.864 0.033 1.006 0.031 0.982 0.038 SMA_SM_1801_JM_123 0.866 0.043 0.043 2.125 0.07 0.868 0.043 0.979 0.033 0.99 0.05 SMA_SM_1801_JM_123 0.85 0.047 0.048 2.13 0.1 0.852 0.047 0.991 0.049 1.015 0.056 SMA_SM_1801_JM_123 0.833 0.038 0.039 2.06 0.071 0.836 0.039 1.011 0.037 1.025 0.05 SMA_SM_1801_JM_123 0.849 0.035 0.036 2.081 0.071 0.852 0.035 1.001 0.035 0.979 0.034 SMA_SM_1801_JM_123 0.828 0.036 0.037 2.156 0.089 0.831 0.036 0.98 0.042 1.016 0.041 SMA_SM_1801_JM_123 0.86 0.04 0.041 2.171 0.087 0.863 0.04 0.972 0.04 0.992 0.046 SMA_SM_1801_JM_123 0.838 0.039 0.04 2.057 0.081 0.841 0.039 1.025 0.041 1.019 0.05 SMA_SM_1801_JM_123 0.898 0.048 0.049 2.188 0.085 0.901 0.049 0.962 0.037 0.957 0.049 SMA_AL_1808_JM_134 0.846 0.033 0.034 2.113 0.082 0.849 0.033 0.989 0.04 0.992 0.04 SMA_AL_1808_JM_134 0.836 0.038 0.039 2.07 0.082 0.839 0.038 1.001 0.04 0.996 0.054 SMA_AL_1808_JM_134 0.852 0.064 0.064 2.1 0.13 0.855 0.064 1.028 0.061 1.028 0.073 SMA_AL_1808_JM_134 0.859 0.079 0.08 2.06 0.15 0.862 0.08 1.063 0.073 1.06 0.1 SMA_AL_1808_JM_134 0.876 0.064 0.064 2.06 0.1 0.879 0.064 1.023 0.053 1.006 0.067 SMA_AL_1808_JM_134 0.876 0.046 0.047 2.094 0.091 0.879 0.046 1.004 0.05 0.971 0.051 SMA_AL_1808_JM_134 0.852 0.037 0.038 2.094 0.081 0.855 0.037 0.998 0.041 0.991 0.049 SMA_AL_1808_JM_134 0.866 0.063 0.063 2.17 0.15 0.869 0.063 0.99 0.067 1.023 0.075 SMA_AL_1808_JM_134 0.819 0.05 0.051 2.12 0.12 0.821 0.051 0.999 0.056 1.055 0.071 Figure 1. Iolite 3.4 software graphics displaying the distribution of the Pb isotopic ratios using the 204Pb isotope. A. Pb6/Pb4 results in feldspars of the SMD units. A1. Pb6/Pb4 results in the BCR2G standard. A2. Pb6/Pb4 results in the KL2_G standard. B. Pb7/Pb4 results in feldspars. B1. Pb7/Pb4 results in the BCR2G standard. B2. Pb7/Pb4 results in the KL2_G standard. C. Pb8/Pb4 results in feldspars. C1. Pb8/Pb4 results in the BCR2G standard. C2. Pb8/Pb4 results in the KL2_G standard. Figure 2. Iolite 3.4 software graphics displaying the distribution of the Pb isotopic ratios using the 206Pb isotope. A. Pb7/Pb6 results in feldspars of the SMD units. A1. Pb7/Pb6 results in the BCR2G standard. A2. Pb7/Pb6 results in the KL2_G standard. B. Pb8/Pb6 results in feldspars. B1. Pb8/Pb6 results in the BCR2G standard. B2. Pb7/Pb4 results in the KL2_G standard. H.3 S isotopes in sulfides Appendix I : Colombia Geo-tectonic Framework Review I.1 Preliminary Map of the Geological Terranes of Colombia (Etayo-Serna et al., 1983) This publication corresponds to the first attempt to divide the Colombian territory into major geological terranes. It is a publication by the Colombian Geological Survey (former INGEOMINAS) in collaboration with geologists of the United States Geological Survey (USGS) led by Dennis P. Cox and Donald A. Singer, among others. The 23 terranes proposed (Figure 1) are justified on the basis of significant differences in tectono-stratigraphic domains, distinct geological evolution, major suture faults limits and metallogenic domains (An evaluation report of non-fossil mineral resources accompany this report). Under this model, the SMD would lie within the Buriticá Terrane, defined as a series of calc-alkaline plutons and andesitic porphyries that intruded coarse-grained turbidites with serpentine fragments, hemipelagic shales, tuffs, cherts and basaltic flows (Etayo-Serna et al., 1983). The Dabeiba Fault defines the southwest limit of the Buriticá Terrane with the Cañas Gordas Terrane; whereas the Sinú lineament separates the Buriticá Terrane from the Sinú Terrane to the west. The Montelibano Fault marks the northeast limit of the Buriticá Terrane with the San Jacinto Terrane, whereas the Romeral Fault acts as the eastern limit with the Puquí Terrane (Figure 1). The San Jacinto Terrane comprises tick (up to 6 km) hemipelagic and turbiditic sequences with basal intercalations to mafic vulcanites. The Planeta Rica peridotite (Campanian-Maastrichtian) belongs to this terrane. According to the authors, accretion of the San Jacinto Terrane to the continental margin occurred during the lower Paleocene. Figure 1. Location of the SMD and El Alacrán Deposit within the context of the Preliminary Map of the geological terranes of Colombia (Etayo-Serna at al., 1983). The red polygon corresponds to the SMD area. Etayo-Serna et al. (1983) also differentiated the Buriticá and San Jacinto terranes based on the absence of intrusive magmatism in the latter, which, by the time of this publication had not been recognized to the North of the Montelibano fault. Conversely, the Puquí Terrane, to the East of the Buriticá Terrane, includes migmatites, felsic gneisses, amphibolites, granulites, and separated from the San Jorge-Plato Terrane to the north by the Murrucucú Fault (Figure 1). The Cañas Gordas Terrane, to the south of the Buriticá Terrane, comprise calc-alkaline plutons, low-k tholeiitic basalts, fine to coarse-grained turbidites, limestones and mafic volcanoclastics. The Sinú Terrane, to the west of the Buriticá Terrane, includes hemipelagic sediments, turbidites and transitional deposits of Oligocene age that can be as thick as five kilometers (Etayo-Serna et al., 1983). I.2 Suspected Terranes of Colombia (Restrepo and Toussaint, 1988) This model was proposed by Restrepo and Toussaint (1988) and has been later modified in the light of new geological and radiometric data by Toussaint and Restrepo (1994, 1996), Ordoñez and Pimentel (2002) and Restrepo et al. (2009). The terrane and subsequent exotic terrane definition is supported by the metamorphic grade and age recorded in the defined terranes. Seven terranes were proposed: Andaquí, Chibcha, Tahamí, Calima, Cuna, Panzenú and Gorgona, grouped into three major domains: 1) an Autochthonous block, 2) continental crust terranes, and 3) oceanic crust terranes) (Figure 2, Figure 3). The autochthonous block is composed of a Precambrian basement that includes the Mitú Migmatite Complex, and the Garzón Granulite Group, with ages between 1800 and 800 Ma, and associated to the Guiana Shield. Figure 2. Location of the SMD and El Alacrán Deposit within the context of the suspect terranes of Colombia model (Modified from Restrepo and Toussaint, 1988; Ordoñez and Pimentel 2002). The red polygon corresponds to the SMD area. Figure 3. Synthesis summarizing the tectonic evolution and Phanerozoic magmatism of Colombia under the tectonic terrane proposals from Etayo-Serna et al.(1983), Toussaint and Restrepo (1988), Cediel et al. (2003) and Kennan and Pindell (2009). The left side of the diagram indicates the proposed terranes and their respective age as proposed by the authors. The middle-right side of the diagram shows the terrane accretion and evolution proposed by Toussaint and Restrepo (1988) and Cediel et al. (2003). The right part of the diagram shows the distribution of the magmatic events defined by Leal-Mejía (2011). The comments inside the diagram highlight the geological and geochronological evidence presented by the authors to support their interpretations. The Continental Crust Terranes include: 1) The Andaqui Terrane (An), which is conformed by Precambrian (Grenville-age) metamorphic rocks and Paleozoic marine sediments exposed in the Garzón Massif. The accretion of the An Terrane to the autochthonous block probably occurred during the Pre-Cambrian Grenville-age orogenic event (Ordoñez and Pimentel, 2002); 2) The Chibcha Terrane (Ch), which include the Cesar Valley, Serranía de Perijá, Santander Massif, Magdalena Valley, Eastern Cordillera and the majority of the Sierra Nevada de Santa Marta morpho-structural units. The Chibcha Terrane has a Precambrian (~1 Ga) metamorphic basement overlain by pre-Devonian medium-grade metamorphic rocks. The newest metamorphism recorded in this terrane is from the Caledonian Orogeny (490 - 390 Ma). Jurassic magmatism affected the western margin of this terrane (Restrepo and Toussaint, 1988). The accretion of the Chibcha terrane to the continental margin and Andaquí Terrane is considered to be Late Paleozoic (Ordoñez and Pimentel, 2002). 3) The Tahamí Terrane (Ta) has a sialic basement and was formed through a very complex tectonic/metamorphic history starting in the Precambrian and displaying Devonian, Permian/Triassic cretaceous metamorphic and deformational events (Ordoñez and Pimentel, 2002). The Tahamí Terrane is separated from the Panzenú terrane by the Espiritu Santo Fault (Figure 2). The Panzenú terrane is conformed by high-grade metamorphosed tonalites and gneisses (e.g., the Puquí Complex, 315 - 285 Ma. The accretion age between the Panzenú and Tahamí is interpreted to be at ca. 140 - 126 Ma (Ordoñez and Pimentel, 2002). The Oceanic Crust terranes include: 1) The Cauca Romeral Allochthonous Slivers (Cras), which correspond to a mosaic of exotic terranes with oceanic affinity juxtaposed as narrow blocks between the San Jeronimo and Cauca-Almaguer Faults (Figure 2). These exotic terranes were later defined as: Anacona, Quebrada Grande, Amagá-Sinifaná, Heliconia and Arquía (Álvarez et al., 2009; Restrepo et al., 2009a). According to Toussaint and Restrepo (1994, 1996), the Cras block was amalgamated to the Tahamí terrane during Late Jurassic- Early Cretaceous. However, the Tahamí-Cras-Calima composite assemblage joined the Chibcha Terrain in Late Cretaceous times (Restrepo and Toussaint, 1988; Ordoñez and Pimentel, 2002) (Figure 2). The Cauca-Almaguer Fault separates the Cras from the Calima Terrane (Álvarez et al., 2009). The Calima Terrane comprises basalts, flysch-type chemical and siliciclastic sediments and pyroclastic rocks (Restrepo et al., 1991; Ordóñez‐Carmona et al., 2001; Vinasco et al., 2006). The basalts of the Calima Terrane formed as part of Plateau in an equatorial paleo-latitude during the beginning of the Galapagos hot spot (Acton et al., 2000). Desmet (1995) stated that volcano sedimentary sequences of the Calima Terrane formed in insular arcs environments within the former Galapagos Plateau. The Calima Terrane amalgamated to continental terranes as a result of an eastern convergence from an SW paleo-latitude of its current location (Restrepo et al., 1988, 1996). Hincapié-Gómez et al. (2018) using gravimetric and paleo-magnetic data in northwestern Colombia support the idea that the Calima terrane belongs to a high-density block that was formed at southern latitudes in the Pacific Ocean as part of an oceanic plateau and was subsequently accreted, dismembered and rotated along the continental margin. Under the model proposed by Restrepo and Toussaint (1988) the SMD lies in the northern part of the Calima terrane (Ca) (Figure 2). During the Miocene, two more oceanic terranes (Gorgona and Cuna) were accreted to the Andean block. The Gorgona Terrane (Go) is almost entirely composed of mafic and ultramafic rocks, and it is best known for its komatiite late Cretaceous lava flows. This terrane was accreted to the Calima Terrane along the Buenaventura Fault (Figure 2). Stratigraphy suggests that Gorgona may be accreted to before the early Miocene (Restrepo and Toussaint, 1988). The Cuna Terrane (Cu), corresponds to the composite terrane conformed by the Panama-Baudó-Mandé terrane assemblage with a suture located east of the Mandé Batholith. This suture represents the trust of this terrane onto the Calima Terrane during Miocene-Pliocene times along the Dabeiba – Pueblo Rico Fault System (Restrepo and Toussaint, 1988) (Figure 2). The Cuna Terrane collision had a big impact in the Colombia Andes since it produced the Eastern Cordillera uplift (Restrepo and Toussaint, 1988). Calima Terrane Accretion: Some factors such as the abscense of Cretaceous volcanism recorded in the Cretaceous sedimentary sequences on the western margin of South America (Eastern Cordillera) is interpreted by Álvarez et al. (2009), as an indication of pre-accretionary magmatism developed along the composite Tahamí-Calima terrane. This composite terrane may be amalgamated to the western Colombia margin during Late Cretaceous along the Otú-Pericos Fault (Figure 2) as part of the NE movement of the Caribbean plate with respect to South America (Restrepo and Toussaint, 1988; Toussaint and Restrepo, 1996). Other authors (e.g. Rodriguez and Arango, 2013) also suggest an early accretion (before 105 Ma) of the Tahami and Calima Terranes, and proposing the development of a ca. 105 - 88 Ma Sabanalarga-Barroso arc along the suture between both terranes. Similarly, Mora et al. (2017), using Hf isotopic data from a granitoid sample (Bonga Pluton) collected from a borehole (Bonga-1 Well) in the western Lower Magdalena Valley suggest a juvenile component for the ca. 89.2 - 75.4-Ma age intrusion. The limited contamination with older continental crust observed in the Bonga pluton was interpreted by this author as an indication that rocks from the Magangue Arc (Silva et al., 2016) also affected the accreted oceanic terranes (e.g., the Quebrada Grande Complex and San Jacinto/Calima terrane) suggesting that the Panzenú and Calima terranes collided earlier than ca. 89 Ma. A post-collision magmatism can be argued with geochemistry studies from Leal-Mejía (2011) and Hf isotopes analysis from Cardona et al., (2012) who demonstrated marked differences in the Cretaceous magmatism that occurred in each side of the Romeral fault. I.3 Tectonic Assembly of the Northern Andean Block (Cediel et al., 2003; Cediel, 2019) This model identifies and characterizes more than 30 distinct lithotectonic and morpho-structural units including terranes, terrane assemblages, sub-plates, blocks and tectonic realms not only for Colombia, but for the entire Northern Andean Block. The authors support their terrane delimitation proposal based on geochemical, seismic, gravity, magnetic, tomographic and satellite-based data. Under this model, the Northern Andean Block is divided into four major tectonic realms: Guiana Shield Realm (GSR), Maracaibo Orogene Float (MOF, Cediel et al., 2019) or Maracaibo Sub-Plate Real (MSP, Cediel et al., 2003), the Central Tectonic Real (CTR, Cediel et al., 2019) or Central Continental Sub-Plate Realm (CCSP, Cediel et al., 2003), the Guajira – Falcon Composite Terrane (GU-FA), and the Western Tectonic Realm (WTR) which includes the Pacific Terranes (PAT), the Caribbean Terranes (CAT) an the Choco- Panama Arc (CHO) (Figure 4). The Guiana Shield Realm (GSR) comprises the autochthonous Garzón Massif (GA) and the Precambrian basement of the Guiana Shield where 1300 - 900 Ma granulites record a Grenville-age continental collision (Cediel et al., 2003). Central Tectonic Realm (CTR) contains the Paleozoic Cajamarca-Valdivia Terrane (CA-VA), and the Proterozoic Chicamocha Terrane (CHIC) which underlies the Mesozoic San Lucas (sl) and Ibague (ib) blocks which altogether dominate the physiographic Central Cordillera of Colombia (Figure 4). The Chicamocha Terrane was amalgamated to the Guiana Shield during the Orinoco (Grenville) orogeny (Cediel and Caceres, 2000), whereas the Cajamarca-Valdivia terrane (CA-VA) conforms a parautochthonous accretionary prism of Ordovician-Silurian age sutured to the Chicamocha Terrane along the Palestina Fault (Figure 4). The migration path of the Caribbean Plate is defined as the main driver of sequential dextral-oblique accretion of the allochthonous oceanic terranes from the Western Tectonic Realm (WTR) from the Albian through Miocene times (Cediel et al., 2003). The allochthonous terranes proposed by this authors include the Romeral terrane (RO), the Dagua-Pinon (DAP), the San Jacinto terrane (SJ), the Cañasgordas Terrane (CG), the Baudó Terrane (BAU), and the Gorgona Terrane (GO) (Figure 3 and Figure 4). The lithologies that characterize these terranes correspond to the lithologies described by Etayo-Serna et al. (1983), model. The Dagua-Piñón, San Jacinto and Sinú terranes from Cediel et al. (2003) model are broadly equivalent to the single Calima Terrane of the Restrepo and Toussaint (1988). model, which is another remarkable difference between both proposals. Figure 4. Location of the SMD and El Alacrán Deposit within the context of the lithotectonic and morphostructural map of northwestern South America (Cediel et al., 2003). The red polygon corresponds to the SMD area. The oldest recognized sedimentary rocks within the San Jacinto Terrane are Paleocene (Cediel et al., 2003). Pre- and post-evolution for the San Jacinto Terrane accretion during the Andean Orogeny include: 1) Aptian-Albian arrival and accretion of the Romeral Terrane (RO) to the Cajamarca-Valdivia Terrane (CA-VA), 2) Oblique subduction and accretion of the Dagua-Pinon (DAP) and San Jacinto terrane (SJ) during the Paleocene-Lower Eocene, which has been later supported by U-Pb (zircon) geochronology data by Cardona et al. (2012) and Mora et al. (2017), 3) Oblique subduction and accretion of the Gorgona Terrane (GO) during Eocene-Lower Miocene, and 4) Oblique collision of the Sinú Terrane (SN) to the western margin of the San Jacinto Terrane, the frontal obduction of the Cañasgordas Terrane (CG), and later collision of the Baudó Terrane (BAU) during the Miocene. With respect to the accretion of the San Jacinto Terrane, Cediel et al. (2003) explain that the collision and accretion of the San Jacinto and Sinú terranes are difficult to constrain due to the lack of precise radiometric ages. The arrival of the San Jacinto terrane may be recorded by the deposition of turbidite sequences of continental affinity, beginning in the Paleocene (Cediel et al., 2003). Also, erosion surfaces are recorded during the early Eocene suggesting a pre-Oligocene collision. This differs from the Restrepo and Toussaint, proposal for the Calima Terrane accretion during the Late Cretaceous. Paleotectonic reconstructions at ~90 Ma (e.g. Boschman et al., 2014), suggest that the San Jacinto Folded Belt (SJFB) would have been as far as ~1,077 km to the SW of its present location, what is consistent with the interpretation of Cediel et al. (2003) and opposed to the previously described interpretations from Restrepo and Toussaint, 1988; Rodríguez and Arango (2013); and Mora et al. (2017). Besides the differences in the boundaries and definition of the terranes themselves, the model by Restrepo and Toussaint (1988) proposed a late Cretaceous accretion of the Tahamí Terrane (equivalent to CA-VA) to the Chibcha Terrane (equivalent to CHIC). This late Cretaceous accretion implies a dominant allochthonous origin of the Cretaceous magmatism developed along the Central Cordillera (e.g. Antioquia Batholith), which is questioned by the Cediel et al. (2003) and other authors (e.g. Leal-Mejía, 2011; Villagómez et al., 2011). I.4 Major terranes association of the Northern Andes (Kennan and Pindell, 2009) This tectonic model proposed by Kennan and Pindell (2009) based on regional terrane affinities of lithological units and sutures in the Northern Andes, including Colombia, Ecuador and northern Perú (Figure 5). This model proposes a Pacific-origin for the terranes as a result of the relative northeastward migration of the Caribbean Plate and the Caribbean-Andes-Farallon triple junction (trailing edge relative to South America). This model implies that the Caribbean Plate and Panama Arc moved > 1,500 km from west to east with respect to the Americas. According to the authors, five major terranes from east to west include: 1) Parautochthonous to allochthonous continental margin terranes (T1-T2). , 2) “Caribbean Arc” fragments derived from the leading edge of the Caribbean plate, including: back arc ba, 3) “Caribbean LIP fragments”, including plateau basalts episodically accreted from the interior of the Caribbean Plate (T4), and 4) “Greater Panama” island arc fragments derived from the trailing edge of the Caribbean Plate (T5) (Figure 5). The parautochthonous terrane (T1) comprises Paleozoic and Neoproterozoic metasedimentary rocks overlain by an unconformable Cretaceous cover and intruded by middle Jurassic ca. 160 Ma magmatism (e.g. San Lucas, Ibagué in Colombia and Abitagua and Zamora granites in Figure 4. Location of the SMD and El Alacrán Deposit within the context of the Simplified Geological Map of the Northern Andes (Kennan and Pindell, 2009), showing the major terrane associations and sutures from Northern Peru, Ecuador and Colombia. The red polygon corresponds to the SMD area. Ecuador). T1 terrane is equivalent to the Chibcha (Ch) and Chicamocha (CHIC) terranes of Restrepo and Toussaint (1988) and Cediel et al. (2003, 2019) respectively. The Cimarrona Fault (B1) limits this terrane to the east, whereas the Palestina (Colombia) and the Huancabamba (Ecuador) faults (B2) limit this terrane to the west (Figure 5). The Antioquia terrane (T2) in the central cordillera correspond to a displaced South American terrane with Paleozoic metamorphic rocks and Cretaceous granitoids (ca. 95-85 Ma). T2 is equivalent to the Tahamí Terrane (Ta) and the Cajamarca-Valdivia Terrane (CA-VA) of Restrepo and Toussaint (1988) and Cediel et al. (2003, 2019) respectively. Given the occurrence of sheared Mesozoic ultramafic rocks in T2 and the undeformed Antioquia Batholith, Kennan and Pindell (2009) suggested that the accretion of T2 took place in the Cretaceous times prior to the Antioquia Batholith intrusion. This interpretation is consistent with the Cediel et al. (2003) interpretation for the accretion of the Cajamarca – Valdivia Terrane (CA-VA) and differs with the Restrepo and Toussaint (1988) interpretation for the accretion of the Tahamí Terrane (Ta). The San Jeronimo Fault (B3) bounds this T2 Terrane to the west and display an association with ultramafic rock slivers (Kennan and Pindell, 2009) (Figure 5). The T3 terrane corresponds to a mélange zone conformed by a mixture of metasedimentary rocks and Cretaceous Caribbean Arc volcanic rocks (e.g., the Quebrada Grande Complex), blue schists (e.g., the Jambaló Schists) and metasedimentary rocks with Paleozoic-Cretaceous photoliths (e.g., the Arquía (Colombia) and the Chacha (Ecuador) complexes). The Cauca-Almaguer (Romeral) Fault Zone, equivalent to the Pujili mélange zone in Ecuador (B4), bound this terrane in the west (Figure 5). The rocks of the T3 terrane are sheared and accreted fragments of the Trans-American Arc and its successor Caribbean Arc (Kennan and Pindell, 2009). The T4 comprises fault-bounded slivers of oceanic plateau basalts and associated ultramafic rocks and sediments. The high-pressure metabasic rocks (Amaime Fm.), the Bolivar Complex, the Buga Batholith (ca. 91 Ma), and the Caribbean Large Igneous Province (CLIP) Oceanic Plateau Basalts integrate the east portion of T4 (T4a Block). On the other hand, the T4b Block comprises the bulk of the Western Cordillera rocks in Colombia (e.g., Volcanic Fm., Barroso Fm.), the San Jacinto and Sinú accretionary prisms and the Late Cretaceous volcanoclastic rocks of the Guaranda Terrane in Ecuador (Figure 5). The Cauca-Patía Fault Zone (B4b), to the west of the Cauca- Patía basin separates the T4a and T4b blocks (Figure 5). In addition, T4 partially includes the eastern part of the Dagua-Piñón Terrane of Cediel et al. (2003) and is equivalent to the Calima Terrane of Restrepo and Toussaint (1988). This terrane is separated from the T5 Terrane by the Atrato - Urumita Suture (Colombia) and parts of the Pallatanga Fault Zone (Ecuador) (Figure 5). Finally, the T5 terrane that include boninites, tholeiites and calc-alkaline basalts of intra-oceanic island arcs overlaying oceanic plateau basalts, is divided into four blocks: 1) the westernmost block (T5a) includes the Baudo-Choco block (78 - 72 Ma Caribbean Large Igneous Province), the Dabeiba Arc (48 Ma) in Colombia and the Rio Cala Arc (<84 Ma) in Ecuador; 2) The T5b Block includes the Macuchi Arc (Paleogene) and underlying Piñon basement (88 Ma Caribbean Plateau) both in Ecuador (Figure 5); 3) The T5c Block includes the Naranjal and San Lorenzo Arcs (island-arc lavas 86-65 Ma) and overlying volcaniclastic sedimentary rocks (Ecuador) and the Timbiquí Arc (Paleocene, previously accreted CLIP basement). Eocene and younger forearc basins in Colombia; and 4) the T5d block, composed by Gorgona (88? Ma Plateau originated in a paleolatitude ca. 26°S (Kennan and Pindell, 2009). Under this model, the SMD area is located within the T4 Terrane (T4b Block) that comprises fault-bounded slivers of oceanic plateau basalts and associated ultramafic rocks and sediments (Figure 5). T4 Terrane Accretion: Based on field observations by Alfonzo et al. (1994) and Kerr et al. (1998) and unpublished seismic lines data from Ecopetrol, these authors suggested a late Cretaceous through Cenozoic accretion of the T4 Terrane, involved under-thrusting of the Western Cordillera rocks beneath the Central Cordillera rocks. The proposed accretion of the T4 Terrane is consistent with the Restrepo and Toussaint, (1988); Cediel et al. (2003) proposals. The implications for magmatism and mineral occurrence similar to those in the SMD, suggest to be are restricted to the Tb5 which extends from Ecuador (e.g. Guaranda Terane) to the Caribbean Floodplains in Northern Colombia (Figure 3 and Figure 5).
Thesis/Dissertation
eng
Geological Sciences
Vancouver : University of British Columbia Library
Attribution-NonCommercial-NoDerivatives 4.0 International
Graduate
Geology, geochronology and geochemistry of the El Alacrán Deposit, San Matías District, Cordoba-Colombia
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