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Geological characteristics and genesis of the Kemess North porphyry Au-Cu-Mo deposit , Toodoggone district,… McKinley, Bradley Scott Mason 2006

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Geological Characteristics and Genesis of the Kemess North Porphyry Au-Cu-Mo Deposit, Toodoggone District, North-Central British Columbia, Canada by BRADLEY SCOTT MASON MCKINLEY B.Sc. (Hops), University of Waterloo, 2003 A THESIS SUBMITTED FOR PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (GEOLOGICAL SCIENCES) THE UNIVERSITY OF BRITISH COLUMBIA December 2006 © Bradley Scott Mason McKinley,' 20C>6 Abstract The Kemess North porphyry Au-Cu-Mo deposit (300 Mt resource @ 0.30 g/t Au and 0.16% Cu) is situated in the Toodoggone district, along the eastern margin of the Stikinia terrane in British Columbia. Mineralization is genetically related to the ca. 202 Ma, moderately SE-plunging, Kemess North diorite and is also hosted by proximal Takla Group basalt country rock. The nearby 202.7 ± 1.9 Ma Sovereign diorite has a comparable emplacement age, mineralogy, and chemistry to the Kemess North diorite, but is unmineralized. Toodoggone Formation volcaniclastic rocks (199.1 ± 0.3 Ma) crop out as prominent N-trending ridges or as isolated, fault-bounded blocks within Takla Group basalt. The unmineralized, (197.3 + 1.1/0.9 Ma) Duncan pluton intrudes Takla Group basalt. Seven vein types are separated into four stages of formation with respect to Au-Cu-Mo mineralization. Early-stage veins include magnetite stringer veins and later quartz-magnetite-pyrite + chalcopyrite + molybdenite veins. These veins are restricted mainly to the diorite, are associated with locally preserved potassic (biotite) alteration, and resulted in most of the Au-Cu-Mo mineralization at Kemess North. Main-stage quartz-pyrite + chalcopyrite ± molybdenite veins are the most abundant vein type and are present in the diorite and proximal Takla Group basalt. The veins are associated with phyllic (sericite- quartz) alteration and have a Re-Os molybdenite age of 201.8 ± 1.2 Ma. Late-stage pyrite- chalcopyrite and anhydrite ± pyrite ± chalcopyrite veins and associate phyllic (sericite-chlorite- pyrite) alteration occur in diorite and Takla Group country rocks. Lastly, post-mineralization anhydrite and carbonate-zeolite veins cut all rocks. Fluid inclusion studies indicate that early- and main-stage ore fluids deposited Au-Cu-Mo at similar temperatures (about 400°C to 375°C) and pressures (0.9 to 3.0 kbar), corresponding to crustal depths of 3 to 10 km. Sulfur and Pb isotope compositions suggest that metals from the early-stage fluid were derived from the Kemess North diorite; metals in the main-stage fluid were derived from the diorite and probably Takla Group ii country rock and meteoric fluids. An E-striking, steeply S-dipping fault truncates the northern extremity of the ore body. Late NW- to NE-striking normal faults vertically displace the deposit resulting in graben-and-horst block shuffling of the stratigraphy. iii Al 8^•S33N11113.4111 LMHIAIMAO SISIHI c^SAdOlOSI CIVA1 t7SAdOlOSI NEIDAXO and NOMPVD t^SAcIaLOSIlifliinS £ SNOISIMNI (LIMA £^A9OrION0111-130A9 SO-AN Z AIIISIINHDOAD Z^DNIddVIAI TVDIDO-1019 ZA901000H1ghl 1 ^IISOcIA(1 OW-113-11V A2IAHc1110d HJAION SSMA1AN A1-11 NO SAIGILLS DNIISIXa INIOLLDRUONINI IVIIHNIa9 I^I IllicIVHD !!!xINHIAIHIVIS dIHSIlflOHIIIV-03 !!x^simaiNosaalAiotstxpv xS3[111191,4 AO 1S11 x!^SIIIIVI AO ISI1 AlSIN3INIOD AO a'rnvi !!^IDVIIISSIV sjuajuop jo alqui CHAPTER II^ 10 INTRODUCTION 10 REGIONAL GEOLOGY^ 14 KEMESS NORTH LITHOGEOCHEMISTRY AND LITHOSTRATIGRAPHY^ 17 TAKLA GROUP BASALT^  17 KEMESS NORTH PLUTON 26 SOVEREIGN PLUTON^ 32 TOODOGGONE FORMATION VOLCANICLASTIC ROCKS^ 35 DUNCAN PLUTON^ 36 LATE DYKES 39 Mafic Dykes^ 39 Felsic to Intermediate Dykes^ 40 STRUCTURE^ 41 SHEAR ZONES^ 41 VEINS^ 44 FAULTS 44 JOINTS^ 47 VEIN PARAGENESIS AND ASSOCIATED HYPOGENE ALTERATION^ 47 EARLY-STAGE VEINS^ 48 Magnetite stringer veins  48 Quartz-magnetite-pyrite ± chalcopyrite ± molybdenite veins^  51 MAIN-STAGE VEINS^ 56 Quartz pyrite± chalcopyrite ± molybdenite veins^  56 LATE-STAGE VEINS^ 56 Pyrite-chalcopyrite veins  56 Anhydrite ± pyrite + chalcopyrite veins^  58 POST-MINERALIZATION VEINS^  58 Anhydrite veins^  58 Carbonate-zeolite veins^  58 DISTRIBUTION OF DEPOSIT-SCALE ALTERATION^ 59 BIOTITE + POTASS1UM-FELDSPAR (POTASSIC) ALTERATION^ 59 QUARTZ-SERICITE-CHLORITE-PYRITE (PHYLLIC) ALTERATION 62 CHLORITE-EP1DOTE (PROPYLITIC) ALTERATION^ 62 QUARTZ (SILICEOUS) ALTERATION^ 62 GYPSUM-LIMONITE-KAOLINITE ± HEMATITE ALTERATION^ 63 MAJOR CONTROLS ON THE DISTRIBUTION AND GEOMETRY OF THE KEMESS NORTH ORE BODY^ 63 FLUID INCLUSION MICROTHERMOMETRY^ 67 DISTRIBUTION AND PETROGRAPHY OF FLUID INCLUSIONS^ 67 RESULTS^ 71 Freezing results^  71 Heating Results  75 SULFUR ISOTOPE COMPOSITIONS^  76 CARBON AND OXYGEN ISOTOPE COMPOSITIONS^  77 LEAD ISOTOPE COMPOSITIONS^  80 vi PHYSICOCHEMICAL CONDITIONS OF ORE FORMATION^ 82 ORE FLUID COMPOSITION AND TEMPERATURE^ 82 Fluid Salinity^  82 Temperature  86 PRESSURE AND DEPTH ESTIMATES^ 90 CONSTRAINTS ON THE SOURCE OF THE HYDROTHERMAL ORE FLUID^ 92 SULFUR, CARBON, AND OXYGEN STABLE ISOTOPES^ 92 LEAD ISOTOPES^  100 FORMATION OF THE KEMESS NORTH PORPHYRY AU-CU-MO DEPOSIT ^ 108 ASITKA AND TAKLA GROUP COUNTRY ROCK^  108 EARLY-JURASSIC PLUTONISM AND PORPHYRY-STYLE AU-CU-MO MINERALIZATION^ 109 EARLY-JURASSIC VOLCANISM AND DEPOSITION OF THE TOODOGGONE FORMATION ROCKS ^ 113 STRUCTURAL DISMEMBERMENT OF THE KEMESS NORTH DEPOSIT^  115 COMPARISONS WITH THE NEARBY KEMESS SOUTH AU-CU-MO PORPHYRY DEPOSIT^ 118 EXPLORATION IMPLICATIONS^ 118 CONCLUSIONS^ 120 REFERENCES:^ 123 CHAPTER III^ 132 GENERAL CONCLUSIONS^ 132 FURTHER WORK^ 136 APPENDIX A^ 137 vii APPENDIX B^ 145 APPENDIX C 155 viii List of Tables Table 2.1: Representative major-, and trace-element geochemical compositions of the main intrusive and extrusive rocks hosting the Kemess North deposit^  27 Table 2.2: Summary of Re-Os dating from a Kemess North main-stage vein^ ... 57 Table 2.3: Summary of microthermometric results from fluid inclusion assemblages in early-stage veins   72 Table 2.4: Summary of microthermometric results from fluid inclusion assemblages in main-stage veins^  73 Table 2.5: Summary of microthermometric results for CO 2 fluid inclusion assemblages in early-and main-stage veins   74 Table 2.6: Summary of sulfur isotope compositions from Kemess North veins^ 78 Table 2.7: Summary of carbon and oxygen isotope compositions from Kemess North veins^ 79 Table 2.8: Summary of lead isotope compositions from Kemess North^ 81 Table A.1: Whole-rock and trace element compositions for selected Kemess North rocks^ 138 Table B.1: Structural Data^  146 Table C.1: Fluid Inclusion Analyses^  156 ix List of Figures Figure 2.1: Regional geology map of the Toodoggone district^  11 Figure 2.2: Geological maps of the Kemess North study area   18 Figure 2.3: Photoplate showing hand specimen and thin section examples of the major rock types at Kemess North ^ 20 Figure 2.4: Simplified stratigraphic column for Kemess North^ 22 Figure 2.5: Major- and trace-element plots for least-altered igneous rocks at Kemess North^ 24 Figure 2.6: Immobile element classification diagrams for the different lithologies of Kemess North^ 28 Figure 2.7: North-south striking (west-facing) section through the centre of the Kemess North ore body  ^ 30 Figure 2.8: Chondrite-normalized rare earth element plots for plutons and volcanic rocks at Kemess North^ 33 Figure 2.9: Visual log of a representative diamond drill hole through Kemess North^ 37 Figure 2.10: Equal area (Schmidt) lower-hemisphere stereonet for shear zones and veins at Kemess North ^ 42 Figure 2.11: Simplified outcrop maps showing the distribution of faults and joints, along with equal area (Schmidt) lower-hemisphere stereonet and rose diagrams   45 Figure 2.12: Schematic representation of different vein types at Kemess North^ 49 Figure 2.13: Photoplate showing vein types and associated alteration mineral assemblages at Kemess North   52 Figure 2.14: Rose diagrams displaying alpha angles (i.e., the acute angle between the vein and core axis) for the seven Kemess North vein types (shown in chronological order)^ 54 Figure 2.15: Distribution of surface alteration at Kemess North ^ 60 Figure 2.16: Gridded gold concentrations from 216 diamond drill holes for two elevations At Kemess North^ 65 Figure 2.17: Photoplate showing the different fluid inclusions hosted by quartz in early- and main-stage veins at Kemess North  ^ 69 Figure 2.18: Covariate plots showing final homogenization by halite dissolution temperatures versus final dissolution by disappearance of the vapour phase temperatures for Type I liquid-rich inclusions^  84 Figure 2.19: Pressure estimates for early- and main-stage Au-Cu-Mo mineralization^ 87 Figure 2.20: S versus AS diagram for equilibrium sulfide-sulfate pairs in the late-stage anhydrite ± pyrite veins^  94 Figure 2.21: Carbon and oxygen isotopic values of post-mineralized calcite-zeolite veins^ 97 Figure 2.22: Throrogenic Pb isotope diagram for mineralized veins, plutonic and volcanic rocks of Kemess North   102 Figure 2.23: Uranogenic Pb isotope diagram for mineralized veins, plutonic and volcanic rocks of Kemess North^  104 Figure 2.24: 207ri0/ ,206Pb versus 02 8p. ,20610/ Pb diagram for mineralized veins and plutonic and volcanic rocks of Kemess North^  106 Figure 2.25: Thrust fault model for the genesis of the Kemess North porphyry Au-Cu deposit^  110 Figure 2.26: Intrusion model for the genesis of the Kemess North porphyry Au-Cu deposit^  116 Figure A.1. Point counting results for selected Kemess North rocks^ 143 xi Acknowledgments I am deeply indebted to my supervisor, Dr. Steve Rowins, for his guidance and friendship. Throughout my graduate studies at UBC, he has generously and patiently provided his time, advice, and incredible passion for all things related to this project. My appreciation also goes to my "unofficial" supervisor and mapping partner, Dr. Paul Duuring, for his guidance, friendship, insight, and for constantly challenging me to expand my capabilities and thinking. I would like to thank our assistants, Andrew On for assisting in the field and Colin Smith for assisting in the laboratory. I extend my appreciation for the support of Chris Rockingham, Carl Edmunds, Brian Kay, and Ron Konst of Northgate Minerals for allowing me access to the study area, data, and their own personal insights regarding the deposit. I also extend my gratitude to Dr. Larry Diakow of the British Columbia Geological Survey for personally coming out to the study area and adding his insights about the Toodoggone region. Dr. James Scoates, Dr. Jim Mortensen, and Dr. Lee Groat are thanked for reviews of my thesis and serving on my committee. Janet Gabites is thanked for her laboratory work on the sulfide and feldspar lead isotope analyses. I thank my fellow grad students, Jenni Dickinson for her friendship throughout the project, and Katrin Breitsprecher, Sasha Wilson, Caroline- Emmanuelle Morisset and Steve Moss for their advice regarding my graduate studies. Above all, I wish to extend my appreciation to my family who continue to support me throughout all my endeavours in life. And finally, I would like to thank my wonderful friend and partner, Sarah, for her understanding, constant support, and friendship. xii Co-Authorship Statement This thesis represents the collaborative work of researchers from The University of British Columbia and Northgate Minerals Corporation. The results of this thesis are prepared for publication in a peer-reviewed earth science journal. This forward is to acknowledge the contribution of these collaborators. The thesis has been prepared as a paper for submission to Mineralium Deposita and was co-authored by Dr. Steve Rowins and Dr. Paul Duuring (The University of British Columbia). Dr. Rowins and Dr. Duuring provided guidance and supervision throughout all aspects of the paper. Chapter I General Introduction Existing studies on the Kemess North porphyry Au-Cu-Mo Deposit Prior to this study, only limited research had been undertaken on the nature and genesis of the Kemess North deposit. The first compiled outcrop map for the Kemess North area was completed in 1992 by El Condor Resources Limited. The map shows the distribution of lithological units, surface alteration, and major faults, bedding contacts, foliation, and diamond drill hole locations for the 7 km area between and including the Kemess North and Kemess South deposits. Although most of these early diamond drill holes were centred on the main Kemess North ore body, the drill holes were relatively shallow (<350 m) and intersect mostly mineralized Takla Group country rock and swarms of porphyritic monzodiorite dykes. The morphology and extent of the underlying Kemess North diorite-hosted ore body was not determined. More recently, work by Rebagliati et al. (1995) used these diamond drill holes to describe the major lithologies, mineralization, and alteration styles at Kemess North. The main conclusions are that the mineralization is hosted in potassically-altered Takla Group country rock, centered on porphyritic monzodiorite dyke swarms. Northgate Minerals Corporation have been conducting deep (<900 m) drilling programs in the Kemess North deposit since 2001 and are presently attempting to define the geographical limits of mineralization. Funding for this research study is provided by an NSERC Collaborative Research and Development grant (CRD) to Dr. Steve Rowins, as well as contributions from Northgate Minerals Corporation and Stealth Minerals Limited. 1 No existing study integrates detailed geological mapping of Kemess North with geochronology, fluid inclusion, and stable and radiogenic isotope studies. The main goals of this study include: • describing the distribution and geochemistry of the different intrusive and volcanic rocks at Kemess North, • documenting the vein paragenesis and associated hydrothermal alteration within the high-grade core of the deposit, • determining the physical and chemical properties of the ore fluid during metal deposition, • identifying the source and metals of the hydrothermal fluid, and • integrating the findings of these studies to produce a genetic model for the Kemess North deposit. Methodology Geological Mapping The Kemess North study area is approximately 4 x 3 km in area and was mapped at 1:2000 scale in terms of the distribution of lithologies, alteration styles and major structures. Outcrop mapping was complemented by logging and sampling from eight diamond drill holes; the drill holes penetrate a maximum vertical depth of 737 meters below the present surface. Geochemistry Thirty-eight, 1-2 kg, least-altered whole rock specimens that are representative of each intrusive and extrusive igneous suite were submitted to ALS Chemex (Vancouver) for major and trace element analysis. The results were used to classify the rocks using compositional and tectonic discrimination diagrams. Hand specimens of intrusive rocks were stained with sodium- 2 cobalt nitrate in preparation for point-counting using a 1 by 1 mm grid. The mineral frequency data were plotted on a Quartz-Alkali-feldspar-Plagioclase (QAP) ternary diagram. Re-Os Geochronology Precise rhenium and osmium concentrations of molybdenite were determined at the University of Alberta, Canada. Detailed methods used for molybdenite geochronology are described by Selby and Creaser (2004). The samples were processed by metal-free milling and grinding, followed by density and magnetic separation to produce a molybdenite concentrate. The 187Re and 1870S 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, 1900s, and 1880s was used. Isotopic analysis was made using a Micromass Sector 54 mass spectrometer by Faraday collector. Total procedural blanks for Re and Os are less than 3 picograms and 1 picogram (<20 fg 1870s), respectively. These procedural blanks are insignificant in comparison to the Re and Os concentrations in molybdenite. The Chinese molybdenite powder HLP-5 (Markey et al. 1998), which is used as an in-house "control sample" by AIRIE, Colorado State University, is also routinely analyzed at the University of Alberta. For this "control sample" a Re-Os date of 220.0 ± 1.0 Ma was determined at the time of the Kemess North molybdenite analysis. This "control sample" Re-Os age is identical within error to that reported by Markey et al. (1998). Fluid Inclusions Microthermometric measurements were made using a Linkam THMSG 600 fluid inclusion stage at the University of British Columbia. Fluid inclusion standards for the CO 2 and H2O systems were used to monitor the accuracy of the stage. Precision for temperature estimates are based on published data for the Linkam THMSG 600 fluid inclusion stage; the precision for 3 measured temperatures below 30 °C is +0.2°C, whereas the precision for measurements above 30°C is +2.0°C (Macdonald and Spooner 1981). Salinities for halite-saturated aqueous inclusions were calculated using the dissolution temperature for halite and the equation-of-state described by Bodnar and Vityk (1994). Salinities for halite-unsaturated aqueous inclusions were calculated using final ice melting temperatures and the equation-of-state of Bodnar et al. (1985) for the F 2O-NaC1 system. Salinities for inclusions that contained minor CO, were calculated using the melting temperature of the clathrate and the equation-of-state described by Bowers and Helgeson (1983) for the H2O-0O2-NaC1 system. Fluid inclusion salinities and isochores were calculated using the MacFlincor© program (Brown and Hageman 1995). Sulfur Isotopes Sulfur (1534S) isotope compositions were determined at the G.G. Hatch Isotope Laboratory at the University of Ottawa, Ontario. Veins containing pyrite, chalcopyrite or anhydrite were crushed and the sulfide and sulfate minerals collected. Pure (>98 %) sulfide and sulfate minerals were placed in tin capsules and were flash-combusted at 1800°C in the presence of oxygen. Ultra-pure helium was used to carry the resulting gases through a column of oxidizing/reducing chemicals to obtain N2, CO2, H2O, and SO2. The SO2 was separated for analysis by a Thermo Finnigan DeltaPlus IRMS (technique adapted from Coplen et al. 1983). Calibrated internal standards were prepared with every sample to normalize the data. The analytical precision for each analysis is +0.2 per mil. Sulfur isotope compositions are reported relative to the Canyon Diablo Troilite (CDT) standard. Carbon and Oxygen Isotopes Carbon (6 13 C) and oxygen (5 180) isotope compositions were determined at the G.G. Hatch Isotope Laboratory at the University of Ottawa, Ontario. Hand specimens of limestone or veins containing calcite were crushed and calcite separates were collected with a sample purity 4 of greater than 95%. Carbon and oxygen isotopes in calcite were measured directly by continuous flow on a Thermo Finnigan GasBench coupled to a DeltaPlus XP IRMS, using methods adapted from Coplen et al. (1983) and Al-Aasm et al. (1990). Calibrated internal calcite standards were loaded with each sample batch. The analytical precision for each analysis is ±0.1 per mil. Carbon isotope compositions are reported relative to the Vienna Pee Dee Belemnite (V-PDB), and oxygen isotope compositions are reported relative to the Vienna Standard Mean Ocean Water (V-SMOW) standard. Lead Isotopes Lead isotope compositions were determined at the Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia. About 10-50 mg of > 95% pure pyrite or chalcopyrite from veins was leached in dilute hydrochloric acid to remove surface contamination before they were dissolved in nitric acid. Similarly, about 10-50 mg of > 90% pure igneous plagioclase and potassium feldspar were collected from least-altered rock samples. The separates were leached by dilute hydrochloric acid, followed by dilute hydrofluoric/hydrobromic acids to remove surface contamination, and then dissolved by hydrofluoric acid. Separation and purification of Pb involved ion exchange column techniques. The samples were converted to bromide, and the solution was passed through ion exchange columns in hydrobromic acid, and the lead eluted in 6N hydrochloric acid. Approximately 10-25 ng of the lead in chloride form was loaded on a rhenium filament using a phosphoric acid-silica gel emitter, and isotopic compositions were determined in peak-switching mode using a modified VG54R thermal ionization mass spectrometer. The measured ratios were corrected for instrumental mass fractionation of 0.12%/amu (Faraday collector) or 0.43%/amu (Daly collector) per mass unit based on repeated measurements of the N.B.S. SRM 981 Standard Isotopic 5 Reference Material and the values recommended by Thirlwall (2000). Errors, including all mass fractionation and analytical errors, were numerically propagated using the technique of Roddick (1987) and are quoted at the 26 level. 6 Thesis Overview The results of the research conducted on the Kemess North porphyry Au-Cu deposit are presented as a single chapter (Chapter 2) in this thesis. This chapter fully characterizes the results of field and laboratory studies by describing the lithologies, geochemistry, and structural features of the study area, as well as the age and paragenesis of mineralization and associated alteration. Laboratory studies include fluid inclusion microthermometry, and the application of stable isotopes and radiogenic isotopes. Fluid inclusions results and interpretation are presented in the physiochemical properties of the ore fluid, while stable and radiogenic results and interpretation are given in the constraints on the source of the hydrothermal ore fluid section. All field and laboratory studies were intergraded to produce a genetic model for the Kemess North porphyry Au-Cu-Mo deposit. Comparisons are then given with the nearby Kemess South porphyry Au-Cu-Mo deposit, as well as exploration implications, conclusions and suggested further work. 7 References: Al-Aasm IS, Taylor BE, South B (1990) Stable isotope analysis of multiple carbonate samples using selective acid extraction. Chemical Geology: Isotope Geoscience 80: 119-125 Bodnar RJ, Vityk MO (1994) Interpretation of microthermometric data for H 2O-NaCI fluid inclusions. In Fluid Inclusions in Minerals, Methods and Applications 117-130 Bodnar RJ, Burnham CW, Sterner SM (1985) Synthetic fluid inclusions in natural quartz; III, Determination of phase equilibrium properties in the system H 2O-NaC1 to 1000 degrees C and 1500 bars. Geochimica et Cosmochimica Acta 49: 1861-1873 Bowers TS, Helgeson HC (1983) Calculation of the thermodynamic and geochemical consequences of nonideal mixing in the system H2O-0O2-NaC1 on phase relations in geologic systems; equation of state for H2O-0O2-NaC1 fluids at high pressures and temperatures. Geochimica et Cosmochimica Acta 47: 1247-1275 Brown PE, Hageman SG (1995) MacFlinCor and its application to fluids in Archean lode-gold deposits. Geochimica et Cosmochimica Acta 59: 3943-3952 Coplen TB, Kendall C, Hopple J (1983) Comparison of stable isotope reference samples. Nature 302: 236-238 Macdonald AJ, Spooner ETC (1981) Calibration of a Linkam TH 600 programmable heating- cooling stage for microthermometric examination of fluid inclusions. Economic Geology 76: 1248-1258 Markey RJ, Stein HJ, Morgan JW (1998) Highly precise Re-Os dating for molybdenite using alkaline fusion and NTIMS. Talanta 45: 935-946 8 Rebagliati CM, Bowen BK, Copeland DJ, Niosi DWA (1995) Kemess South and Kemess North porphyry gold-copper deposits, northern British Columbia. In Schroeter, T., ed., Porphyry Deposits of the Northwestern Cordillera of North America: Canadian Institute of Mining Special Volume 46: 377-397 Roddick JC (1987) Generalized numerical error analysis with applications to geochronology and thermodynamics. Geochimica et Cosmochimica Acta 51: 2129-2135 Selby D, Creaser RA (2004) Macroscale NTIMS and microscale LA-MC-ICP-MS Re-Os isotopic analysis of molybdenite: Testing spatial restrictions for reliable Re-Os age determinations, and implications for the decoupling of Re and Os within molybdenite. Geochimica et Cosmochimica Acta 68: 3897-3908 Thirlwall MF (2000) Inter-laboratory and other errors in Pb isotope analyses investigated using a 207Pb-2°4Pb double spike. Chemical Geology 163: 299-322 9 Chapter II Geological Characteristics and Genesis of the Kemess North Porphyry Au-Cu-Mo Deposit, Toodoggone District, North-Central British Columbia, Canada' Introduction The Kemess North porphyry Au-Cu-Mo deposit is located in the Toodoggone district of north-central British Columbia, Canada. The district forms part of the Stikinia terrane, situated on the western margin of the Intermontane belt of the Canadian Cordillera (Fig. 2.1). The Toodoggone district hosts numerous gold-rich porphyry copper deposits, including Canada's largest current gold producing mine at Kemess South (current reserves 68 Mt at 0.65 g/t Au and 0.21% Cu, O'Connor 2005). The district also hosts several smaller low-sulfidation (e.g., Baker, Lawyers, and Shasta) and high-sulfidation (e.g., Silver Pond, Griz-Sickle) epithermal Au-Ag systems. Porphyry-style Au-Cu ± Mo mineralization ranges in age from ca. 221 Ma at Fin (Dickinson 2006) to 194 Ma at Pine (Dickinson 2006) and is genetically associated with plutons that intrude Upper Triassic Takla Group country rock (Diakow et al. 1991; Diakow et al. 1993; Diakow 2001, 2006b). High- and low-sulfidation epithermal mineralization is younger (ca. 196 to 187 Ma, Clark and Williams-Jones 1990) than porphyry mineralization, but overlaps the later stages of plutonism in the district (Diakow et al. 1991). The epithermal mineralization is primarily hosted by Toodoggone Formation volcaniclastic rocks. A broad temporal and spatial correlation exists between plutonism, volcanism, and porphyry-epithermal styles of mineralization in the district although their specific genetic associations are unclear: understanding these associations is the focus of this study. A version of this chapter has been prepared for submission to Mineralium Deposita. McKinley, B., Rowins, S.M., Duuring, P., and Creaser, R.A. (2006)^10 MIDDLE TRIASSIC IN TAKLA GROUP kilometers IN •Toodoggone deposits fault ^ epthermal porphyry normal fault --1-1-1-1. AlI and Lawyers 500 k01 SYMBOLS Kemess North study area El thrust fault LITHOLOGIES UPPER TOODOGGONE FORMATION BELIE Pit I AR.^MEMBERSGRAVES. QUARTZ LAKE LOWER TOODOGGONE FORMATION 1 SAUNDERS MEMBER 00 METSANTAN MEMBER 0C DUNCAN MEMBER EARLY JURASSIC BLACK LAKE INTRUSIVE SUITE MID-PENNSYLVANIAN TO LOWER-PERMIAN ASITKA GROUP Figure 2.1 11 Figure 2.1. Regional geology map of the Toodoggone district located in north-central British Columbia, Canada. The map shows major structures, lithologies, the location of the Kemess North porphyry Au-Cu deposit, and other mineral occurrences. The regional map is modified after Diakow (2001, 2006). 12 Kemess North was first recognized as an exploration target in 1966 by Kennco Explorations (Western) Limited based on the extraordinarily well-defined surface gossan that overlies the covered intrusion (Rebagliati et al. 1995). Since that time, exploration efforts have included outcrop mapping, surface geochemical surveys, geophysical surveys, and diamond drilling (Rebagliati et al. 1995). The first attempt at compiling a geological outcrop map was done by El Condor Resources Limited in 1992. Diakow (2001) re-mapped the area at 1:50,000 scale, focussing on lithological relationships rather than describing the magmatic-hydrothermal features of the porphyry Au-Cu-Mo system. Rebagliati et al. (1995) examined mineralized veins in Takla Group country rock and monzodiorite dykes but did not describe the nature of mineralization in the host Kemess North diorite. Recently, Northgate Minerals Corporation has drilled deeper (>800 m) diamond drill holes that intersect the mineralized diorite. This is the first study of the Kemess North deposit that integrates geological mapping with deep diamond drill hole data through the diorite-hosted ore body in an effort to understand the major controls on the geometry and distribution of gold-copper mineralization. Included in this study is the characterization and distribution of lithologies, structures, magmatic-hydrothermal alteration, and Au-Cu-Mo mineralization at Kemess North. Complementary laboratory studies including fluid inclusion microthermometry, and sulfur, carbon, oxygen, and lead isotope analyses, are used to constrain the physicochemical conditions of ore formation and identify the likely source(s) of the hydrothermal fluids and contained metals. Re-Os geochronology on molybdenite from main-stage veins is used to provide precise constraints on the timing of main- stage mineralization with respect to magmatism. Finally, results from all these studies are integrated into a comprehensive genetic model for the origin of the Kemess North porphyry Au- Cu-Mo deposit. This detailed, factual, deposit model is the basis for comparison with other porphyry (and related epithermal) styles of mineralization in the Toodoggone district and can be 13 used to construct exploration models with much more predictive capacity than those currently in use. Regional Geology The Kemess North Au-Cu-Mo deposit is located in the Toodoggone district of north- central British Columbia, Canada. The Canadian Cordillera is divided into five morphogeological belts comprised of a succession of volcanic arcs and accretionary complexes (Monger and Nokleberg 1996) that formed during the subduction of the Panthalassa oceanic plate and the Pacific Ocean basins beneath the continental and oceanic North American plate (Monger and Nokleberg 1996). Porphyry Cu-Au±Mo deposits in British Columbia formed as a consequence of collisional tectonic processes in this convergent plate boundary setting (Titley and Beane 1981; McMillan and Panteleyev 1995). The Mesozoic Intermontane belt is one of the five morphogeological belts and hosts most known porphyry-style deposits in the Canadian Cordillera (McMillan et al. 1995). The Intermontane belt contains four discrete tectonostratigraphic terranes including Stikinia, which consists of Devonian to Jurassic island- arc volcanic, sedimentary, and plutonic rocks. The Toodoggone district occurs within the Stikinia terrane along the western margin of the Intermontane belt (Diakow et al. 1993). The Toodoggone district is situated about 900 km north-northwest of Vancouver and 270 km north of Smithers, B.C. (Fig. 2.1). The district contains Permian to Cretaceous volcanic and plutonic rocks of the Asitka, Takla, Hazelton, and Sustut Groups. The Early Permian Asitka Group (ca. 308 Ma: Diakow 2001) is comprised chiefly of marine sedimentary and volcanic rocks. This package is overlain by Middle Triassic Takla Group rocks, which include coarse- grained, porphyritic, augite phenocryst-rich basalt and aphyric basalt lava with interbeds of lapilli tuff and volcanic breccia (Diakow et al. 1993). The Takla Group are overlain by Late Triassic to Early Jurassic Hazelton Group volcanic and volcaniclastic rocks (Diakow et al. 14 1993). The Toodoggone Formation, within the Hazelton Group, is exposed throughout the Toodoggone district, with strata representing more than 80 km 2 of the exposed area in district (Diakow et al. 1993). The Toodoggone Formation is Early Jurassic in age (ca. 200-190 Ma, Diakow 2001), greater than 2200 meters thick, and is composed mostly of volcanic flow and pyroclastic rocks (Diakow et al. 1991; Diakow et al. 1993). The Toodoggone Formation is further divided into lower and upper volcanic cycles and then several members. Asitka, Takla and Hazelton Group lithologies are locally intruded by Late Triassic to Early Jurassic (ca. 203- 191 Ma, Diakow 2001; Diakow 2006a) Black Lake suite calc-alkaline plutons and NW- to NE- trending dykes (Diakow et al. 1991; Diakow et al. 1993). These plutons are broadly coeval with volcanism related to Toodoggone Formation volcanic rocks. The Toodoggone Formation volcanic and volcaniclastic rocks may be the near-surface expression of the plutonic suite at depth (Diakow et al. 1993). Early to Late Cretaceous Sustut Group rocks overlie the intruded stratigraphy and consist of two formations; the oldest is the Tango Creek Formation, which consists of conglomerate and interlayered mudstone and sandstone (Diakow et al. 1993). The Tango Creek Formation is overlain by the Brothers Peak Formation, which consists of conglomerate interlayered with ash-tuff units. The ash-tuff grades into stratigraphically younger intercalated sandstone, ash-tuff and mudstone (Diakow et al. 1993). All rock types in the Toodoggone district are cut by steeply dipping normal faults (Fig. 2.1). Strike-slip and thrust faults are not as common (Diakow et al. 1993). The major northwest- striking faults have been offset by northeast high-angle striking structures (Diakow et al. 1993). A large number of faults are extensional and display normal movement, with little evidence for strike-slip motion (Diakow et al. 1993). Diakow et al. (1993) notes that the strike-slip component of the faults is uncertain, but the elongate shape of many of the plutons suggests that the faults are deep crustal structures. All volcanic rocks in the Toodoggone region are affected to a small degree by very low grade, zeolite facies, regional metamorphism (Diakow et al. 1993). 15 Mineralization styles in the Toodoggone district include porphyry Au-Cu-Mo (e.g., Kemess South and Kemess North), low-sulfidation epithermal Ag-Au (e.g., Baker, Lawyers, and Shasta), high-sulfidation Au-Ag epithermal (e.g., Silver Pond and Griz Sickle), and minor placer Au systems. Porphyritic intrusions that host Au-Cu-Mo mineralization at Kemess South and Kemess North have U-Pb zircon ages of 199.1 + 0.6 Ma (Mortensen et al. 1995) and ca. 202 Ma (Diakow 2006b), respectively. Both porphyries intrude basaltic rocks of the Takla Group. Kemess South has proven reserves of 109.4 Mt of ore containing an average of 0.71 g/t Au and 0.23% Cu (Rebagliati et al. 1995), and Kemess North has a resource of 300 Mt of ore containing 0.30 g/t Au and 0.16% Cu (Gray and Edmunds 2005). Precious metal Au-Ag epithermal deposits in the Toodoggone district are primarily hosted by volcaniclastic rocks of the Toodoggone Formation and range in age from ca. 196 to 187 Ma (Clark and Williams-Jones 1990). The known epithermal mineral occurrences are smaller but contain higher gold grades than the porphyry deposits. Reserves before mining at the Shasta low-sulfidation epithermal deposit were 1.6 Mt of ore with an average of 2.84 g/t Au and 132.2 g/t Ag (Thiersch et al. 1997). Although a broad temporal and spatial correlation exists between plutonism, volcanism, and porphyry-epithermal mineralization in the Toodoggone district, their specific genetic associations are poorly understood and are the main focus of the current 3-year collaborative NSERC-sponsored research project between the UBC research group lead by Professor Rowins and several mining companies. 16 Kemess North Lithogeochemistry and Lithostratigraphy Takla Group Basalt The central area of the Kemess North deposit is dominated by Upper Triassic basaltic units (Fig. 2.2). These rocks are typically fine-grained and massive, although locally they are augite-phyric and, more rarely, plagioclase-phyric. These latter rocks are colloquially called "basaltic bladed feldspar porphyry" and are used in the field to identify the top of the Takla Group (Fig. 2.3). Least altered basalt is dark green-brown with a fine-grained groundmass consisting of primary igneous plagioclase. Typical alteration minerals include biotite, chlorite, and sericite. Anhydrite and calcite are minor constituents. Massive basalt is dark green and contains 0.5 to 1 mm diameter, hexagonal augite phenocrysts surrounded by finer-grained chlorite (-70 vol. %) and randomly oriented, <100 ilM plagioclase laths. Augite phenocrysts are >80% altered to chlorite and possess a poikilitic texture with inclusions of magnetite. Anhydrite and recrystallized quartz (-10 vol. %) occur locally in the groundmass. Massive basalt exposed at Kemess North is up to 200 m thick. The basaltic bladed feldspar porphyry unit intrudes the massive basalt (Fig. 2.4). The lower contact with basalt is subhorizontal, whereas the upper contact is defined by an unconformable contact with Toodoggone Formation rocks. The porphyry contains —45 vol. % plagioclase phenocrysts that are randomly orientated, 1-2 cm long and 1-5 mm wide. Plagioclase phenocrysts display Carlsbad twinning and are altered (-15%) to sericite (Fig. 2.3). The groundmass comprises <1 mm long, elongate plagioclase surrounded by finer-grained secondary sericite (15-25 vol. %), chlorite (25-35 vol. %), and minor (2-7 vol. %) anhydrite and calcite (Fig. 2.5). 17 6327500 mN .004r North-east ridge illEast ridge SYMBOLS geological contact um.onfornsty^—_.- normal fault wrench fault logged diamond drill hole locations * LITHOLOGIES DUKES felsic to intermediate dyke rualic dyke 612 EAR, V JURASSIC, HAZEL TON GROUP LOWER TOODOGG,NE FORMATION 32 I^I andesite FAR :JURASSIC BLACK r AKE INTRUSIVE Still 1111 Duncan diorite I^1 Sovereign diorite MIDDI. E TRIASS IC'. 632 TAKLA GROUP sob-alkaline basalt 6325500i0QN West ridge Central ridge 6325(100 632 50_0 m SYMBOLS geological contact unconformity normal fault (bsicK. n. ,roan -i.,.,^ wrench fault 1 , 1, 1ner■ avprn,l, logged diamond drill hole locations * LITHOLOGIES DYKES felsic to intermediate dyke 1.111 mafic dyke EARLY JURASSIC HAZEL TON GROUP LOWER TOODOGGONE FORMATION andesite EARLY JURASSIC BLACK LAKE INTRUSIVE SUITEMI Duncan diorite Sovereign diorite MIDDLE TRIASSIC TAKLA GROUP MI sub - alkaline basalt 63 5000 kilometers Figure 2.2 18 Figure 2.2. Kemess North geological maps: (A) Outcrop map of the Kemess North study area showing the distribution of major rock types and the orientation of major structures. Note the location of the northerly oriented section line "N-S" in red. The interpreted sections are shown in Figure 2.7. (B) Geological map with the distribution of major lithologies and structures. The interpretation is based on a combination of outcrop, diamond drillhole data, and aeromagnetic data. 19 1, ,,, 4 ' i 4 t, 110 ';' t : I ^' ) . t/t4 4: , . ^1 .11 1, \ J li i,  1 0  .,  'A  ) I tE l '^ 'I^ %‘ P° - 4  44 P ..^ * ^ - I^ O ' .'^ I. i ^ 1 1 ' :`  4  ' ^'  't  ' 4  ' A  , *  , ; 4 '' ^ ! It  t A 4, It t ' - ^ "1 ,-‘  -  t i' 4 ^ ' ..,* ^ iis. ^ t i  4- , ^ , ^ , , , , , , , ^ 4 - ,^ , r . ii s . , ^ -,--,^ t / „ ^ . 4 ^ , ' t  .  4 I / '^. .. 1 1 .1 L  • 1 1 co C CD N) co Figure 2.3. Photographs and photomicrographs showing hand specimen and thin section examples of the major rock-types at the Kemess North deposit. Note that all photomicrographs were taken in cross-polarized transmitted light: (A) Basaltic bladed feldspar porphyry rock (Takla Group). (B) The photomicrograph shows euhedral, multiply twinned, blades of plagioclase in a fine-grained groundmass. (C) Basaltic augite porphyry rock (Takla Group) that displays dark green augite phenocrysts in a finer grained chlorite-plagioclase groundmass. (D) The photomicrograph shows an euhedral augite phenocryst surrounded by plagioclase and chlorite groundmass. (E) Weakly porphyritic Sovereign diorite. (F) The photomicrograph shows phenocrysts of amphibole (bright colours) and plagioclase set in a fine-grained groundmass. (G) Least-altered Kemess North diorite, which is the main host to Au-Cu mineralization. (H) The photomicrograph of the Kemess North diorite shows zoned, slightly sericite-altered plagioclase phenocrysts that are surrounded by a fine-grained quartz, biotite, pyrite, chalcopyrite, and magnetite groundmass. (I) Coarse-grained, porphyritic Duncan diorite. (J) The photomicrograph displays a cumulate texture defined by plagioclase and hornblende crystals (orange). (K) The hand specimen represents a close-up of a sub-angular clast of basaltic bladed feldspar porphyry rock in the Toodoggone Formation (i.e., sourced from the older Takla Group). (L) Core sample of Toodoggone Formation displaying a "smoky" quartz grain, which is diagnostic of Toodoggone Formation units in the Kemess North deposit area. 21 unconformity --"1/4.1— pyroclastic flow •/.^ lava flow —rw- Au-Cu-Mo mineralization / felsic to intermediate dyke andesite conglomerate Lower Toodoggone Formation 199.1 ± 0.3 Ma ++— + Duncan pluton 197.3 ± 1.1/0.9 Ma +  x m D m N r- --I -, O a) Z O 5 0 C'a o0• a 0 ■0 MP 0 0 • 0 IN . 0 Cr-C-75 0^00 0 0 ° • mafic dyke basaltic bladed En feldspar porphyry limestone basalt - 500'm] 0 MN MN MOM X X X x Sovereign pluton202.7 ± 1.9/1.6 Ma X X X X X k Kemess North k pluton ca. 202 Ma k k k • 0- D c XI Ey 0C- 'a 5 Figure 2.4 22 Figure 2.4. Simplified schematic stratigraphic column for the Kemess North deposit. Middle Triassic Takla Group volcanic country rock units are intruded by the 202.7 + 1.9/1.6 Ma Sovereign pluton (Diakow 2001) and the ca. 202 Ma mineralized Kemess North pluton (Diakow 2006). Lower Toodoggone Formation (199 + 0.3 Ma; Diakow 2001) conglomerate and andesitic volcanic/volcaniclastic units overlie Takla Group rocks. Lastly, the 197.3 + 1.1/0.9 Ma Duncan pluton intrudes all other rock-types, including the basal rock units of the Toodoggone Formation. All dates are U-Pb (zircon) crystallization ages for plutonic rocks and a detrital zircon age for the Lower Toodoggone Formation. 23 Syenite 70 75 Phenocryst-rich granodiorite ♦Diorite dyke 0 Alkali-feldspar syenite dyke X Quartz-diorite dyke Mafic dyke 15 10 heline Ijolite Gahb a Diorite Quartz diorite lgranodiorite) Alkali granite O — V — I^I 40^45^50 55^60^65 Si0 2 (wt%) 0 35 z 0 0 10 15 0 35 5 40^45^50^55^60^65 Si0 2 (wt%) 70^75 Spanile 1 I=1 Duncan pluton 7 • Kemess North pluton Nepheiim, A Sovereign pluton Alkali granite Ilolite Gabbro Onarrz dioree eiranodinritel Gabbro 0Csz 5 6z 1111111111111111111111111111111111111 1 14^5' Toodoggone Formation Phonolite *Altered Takla Group 1 * Bladed feldspar porphyry12 ^ _ • Basaltic augite porphyry^Trachyte 0, 10 — Foldlte O 8 16 0^111111111^111111 35^40^45^50 8111111111 11111111111111 55^60^65^70^75 Si0 2 (wt%) 70 7550^55^60^65 SiO, (wt%) 1 1 111111 1^1 1 111111^1^1^1111 7 11111 1^1^1^111^I^1111^111 6 1Shos: pasaltilShoshonitel 1Latite^iTracytei 1^- I [Rest: Basal iBasAndl lAndesitei^Dacitel 5 DJ 1Rhyolitel IShoshonitic Seriesi High-K Calc-pkaline Series -• iplArc Tholeiite Series 0 45 Syn-collisional granites !\#1 Within-plate granites Volcanic- arc granite 1^1 1 1 1 111^1^1^1 10 /Ocean-ridge =- granites 11111^I^1^1 1 1 1 111 100 1 000 ‘*' 34 0 2 3 2 1 1000 1 0 A Sovereign pluton 1:1 Duncan pluton Kemess North pluton E I^1^1 _ Metaluminous _ 1 A I I I^I^ I^" Peraluminous^E _ ^4^' "altered'( -)^  .^— - _ Peralkalin I^1 I I 1 1 1 Cl Duncan pluton^— . Kemess North pluton A Sovereign pluton^... 1^I^1^I 1 0^1.5 20 Al/(Ca+Na+K) Y+Nb (ppm) Figure 2.5 3 2 0 0 5 24 Figure 2.5. Major- and trace-element plots for least-altered igneous rocks at Kemess North. (A) Total alkalis versus silica (TAS) diagram (after Wilson 1989) for plutonic rocks. Samples from the Sovereign, Kemess North, and Duncan plutons plot in the granodiorite to diorite fields. (B) TAS diagram (after Le Bas et al. 1986) for volcanic rocks. Takla Group volcanic rocks fall within the basalt to andesite fields, whereas the Toodoggone Formation rocks are classified as andesite. (C) TAS diagram (after Wilson 1989) for felsic, intermediate, and mafic dykes. The rhyolite, phenocryst-rich granodiorite, and alkali-feldspar syenite dykes are classified as alkali granites. The diorite dykes span the syeno-diorite, diorite, quartz-diorite fields and the mafic dykes plot in the gabbro field. (D) The geochemical diagram of Peccerillo and Taylor (1976) divides subalkalic igneous rocks into high-, medium-, and low-K series; the Kemess North rocks (symbols are explained in the previous legends) show that many of the Kemess North samples plot in the High-K calc-alkaline series field. (E) Plutonic rocks plotted on the metaluminous versus peraluminous diagram (after Maniar and Piccoli 1989) indicate that most plutons are metaluminous. The cluster of Kemess North pluton samples that occur in the peraluminous field are probably caused by the mobility of Ca, Na, or K during hydrothermal alteration of the protoliths. These altered rocks indicate that the use of the more mobile elements (e.g. Ca, Na, K, Si) may not be as reliable as the more immobile elements (e.g. Zr, Ti, Nb, Y) for discriminating protoliths at Kemess North. (F) Y+Nb versus Rb tectonic discrimination diagram (after Pearce et al. 1984) indicates that Kemess North plutonic rocks are volcanic-arc related. 25 A 20 m thick, fault-bounded carbonate-rich unit occurs within basaltic bladed feldspar porphyry in the headwall of the east cirque; it is unclear if it is a slice of Asitka Group limestone that is now structurally juxtaposed against Takla Group basalt or if it is a carbonate-rich dyke that cuts Takla Group rocks. Based on the Total Alkalis versus Silica (TAS) classification diagram (after Le Bas et al. 1986) the major element geochemistry for Takla Group volcanic rocks (Table 2.1) falls within the basalt to andesite fields (Fig. 2.5B). However, Takla Group rocks at Kemess North are all altered to some extent. Consequently, the least-mobile elements are used to geochemically classify Takla Group units. Using the immobile element ratio diagram (Nb/Y vs. Zr/Ti0 2) of Winchester and Floyd (1977), the bladed feldspar porphyry rocks are classified as subalkaline basalt, whereas the basaltic augite porphyry rocks plot as andesite/basalt to slightly subalkaline basalt (Fig. 2.6). The geochemical diagram of Peccerillo and Taylor (1976) divides subalkalic igneous rocks into high-, medium-, and low-K series; the Takla Group rocks, as well as all other rocks in the Kemess North study area, plot in the high-K calc-alkaline series field (Fig. 2.5D). Kemess North Pluton The mineralized Kemess North pluton intrudes Takla Group basalt units. The pluton is not exposed at surface and is only observed in drill core more than 150 m below surface in the western and central areas of Kemess North. Cross-sections constructed from diamond drilling show that the pluton is 700 m long by 500 m wide and plunges moderately to the SE (Fig. 2.7). Least-altered hand specimens are dark-green to grey, fine- to medium-grained, and contain subhedral to euhedral, 1-5 mm long plagioclase phenocrysts in a groundmass of recrystallized quartz (>60 vol. %), with minor magnetite, biotite, sericite, and rounded quartz grains. Plagioclase phenocrysts are commonly zoned, multiply twinned, and moderately altered to sericite. 26 Table 2.1: Representative Major- and Trace-element compositions for plutonic and volcanic rocks, Kemess North Lab No^N I 39375 Unitr^Soy NI39376 Sov NI39377 Sov N139601 KN N139662 KN N139603 KN N139394 Dun NI30305 Dun NI30396 Dun N 13937 1 / BFP N139380 BFP N139612 BAP N1393114 Tdog N13938 , Tdog N139607 Tdog 63.63 62.83 63.26 60.39 61.89 61.47 61.31 62.15 61.02 48.92 52.53 48.09 59.58 60.57 56.65 TiO 2 0.44 0.45 0.44 0.44 0.47 0.43 0.54 0.53 0.58 I.12 0.99 0.72 0.56 0.6 0.66 Al 203 16.29 16.5 16.6 14.84 15.51 15.56 15.89 15.72 16.16 17.47 15.4 11.01 17.45 17.45 15.04 Fe203 T 1 4.11 5.35 3.99 8.65 6.75 6.74 5.78 5.49 5.8 8.71 8.47 12.29 5.16 6.85 10.13 Fe0 1 1.81 2.46 1.75 3.52 3.67 3.54 2.94 2.75 2.9 5.02 4.7 7.82 1.72 3.14 3.06 Fe20 3 2 2.10 2.62 2.05 4.74 2.67 2.81 2.51 2.43 2.58 3.13 3.25 3.60 3.25 3.36 6.73 MnO 0.07 0.06 0.06 0.09 0.09 0.07 0.12 0.1 0.12 0.44 0.2 0.41 0.15 0.15 0.17 MgO 1_45 1.51 1.33 2.45 226 1.68 2.18 2.09 2.17 5.62 5.4 14.49 1.69 1.79 1.93 CaO 4.13 4.1 4.72 1.29 1.56 3.94 4.86 4.76 4.71 8.75 7.59 3.57 6.58 5.15 2.17 Na 2O 4.13 3.78 4.19 2.46 2.68 2.5 3,31 3.29 3.45 3.02 3.95 0.2 2.56 3.58 0.97 K2 O 3.31 2.71 2.39 2.79 2.73 3.34 2.99 3.13 3 1.74 1.82 0.32 2.91 0.96 2.91 P2 O5 0.19 0.2 0.21 0.2 0.23 0.2 0.22 0.21 0.21 0.31 0.29 0.21 0.25 0.22 0.26 Cr2O 3 0.01 <0.01 0.01 0.01 <0.01 <0.0I <0.01 <0.01 0.01 0.02 0.01 0.11 <0.01 <0.01 0.01 SrO 0.06 0.07 0.06 0.04 0.04 0.06 0.06 0.06 0.06 0.06 0.06 <0.01 0.06 0.07 0.31 BaO 0.19 0.18 0.19 0.09 0.09 0.12 0.16 0.16 0.16 0.09 0.05 0.01 028 0.12 0.17 L01$ 0.94 0.94 0.72 5.05 3.96 2.37 0.96 0.66 0.81 2.85 1.89 7.3 1.78 1.22 6.8 Total 98.96 98.66 98.17 98.78 98.25 98.48 98.4 98.35 98.24 99.1 98.64 98.71 99 98.73 98.17 V 89 86 83 90 93 90 142 140 140 434 274 280 125 166 218 Cr 40 10 40 10 30 10 30 10 40 90 110 970 30 20 90 Co 4 8 3 16 14 6 10 10 10 27 26 36 14 14 36 Ni 8 <5 5 7 7 5 6 5 5 38 26 173 7 7 29 Cu 9 7 11 1265 1185 93 15 17 10 294 12 816 10 14 913 Zn 50 42 48 118 126 85 69 46 61 206 126 331 97 95 68 Ga 18 18 18 14 16 17 17 17 17 21 17 17 20 19 18 Rb 56 79 35 72 69 65 72 85 71 39 43 15 62 26 105 Sr 614 635 575 426 383 550 586 562 563 559 530 19 522 691 2800 Y 18 17 17 15 18 17 19 17 19 20 22 15 18 20 18 Zr 98 91 106 79 79 77 84 89 104 65 102 40 106 104 99 Nb 6 6 6 5 6 5 6 6 6 4 6 3 5 4 6 Mo <2 <2 <2 12 13 5 <2 <2 <2 <2 <2 8 <2 <2 93 Ag <I <1 <I <I I <I <I <1 <1 <I <I 1 <1 <1 I Sn I I 1 3 3 2 I I I 1 I 5 1 1 4 Cs 1 2 I 2 3 2 2 2 2 3 4 1 6 2 4 Ba 1825 1585 1685 856 828 1170 1540 1500 1490 788 481 119 2650 1140 1580 La 20 18 18 17 20 12 19 21 20 12 13 8 22 17 18 Ce 38 35 37 32 39 26 37 39 38 25 27 16 37 34 35 Pr 4 4 4 4 5 3 4 4 4 3 3 2 4 4 4 Nd 16 16 17 14 17 13 16 16 17 15 15 10 16 16 18 Sm 3 3 4 3 4 3 3 3 3 4 4 3 3 4 4 Eu 1 1 I I 1 I 1 1 1 I 1 1 1 I 1 Gd 3 3 3 2 3 3 3 3 3 4 4 3 3 3 4 Tb 0.5 0.5 0.5 0.4 0.5 0.4 0.5 0.5 0.5 1 I 0.5 0.5 1 0.3 Dy 3 3 3 2 3 3 3 3 3 3 4 3 3 3 3 Ho 1 1 1 0.5 1 1 1 1 1 1 1 1 1 1 0.3 Er 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Tm 0.3 0.3 0.2 0.2 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.2 0.3 0.3 <0.1 Yb 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Lu 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3. 0.3 0.2 0.3 0.3 0.3 0.3 <0.1 Hf 3 3 3 3 3 3 3 3 3 2 3 I 3 3 3 Ta I 0.4 1 0.4 0.4 0.3 I I 0.4 0.3 0.4 0.3 0.4 0.3 <0.1 W 3 3 I 3 2 1 3 1 1 8 5 3 10 5 11 Au 0.002 0.002 0.001 0.527 0.319 0.020 0.001 <0.001 <0.001 0.022 0.001 0.164 0.001 0.001 0.067 TI <0.5 <0.5 <0.5 0.5 0.6 0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 1 Pb 10 11 9 20 32 17 8 6 7 12 10 <5 19 10 17 Th 5 5 4 4 5 4 7 6 6 1 2 1 4 4 3 U 3 3 3 2 2 2 3 4 3 1 I 1 2 2 2 Note: Analysis by Chemex Labs Ltd. In Vancouver, British Columbia. 1n-house standards submitted with analyzed samples indicate error for major element abundances is± <0.3 % and for trace element abundances^<0.5 ppm with the exception of La, Ce, and 1\1) which are <2 ppm. t Rock unit: Soy = Sovereign pluton; KN = Kemess North pluton; Dun = Duncan pluton BFP = Bladed feldspar porphyry (Takla Group); BAP = Basaltic augite porphyry (Takla Group); Tdog = Toodoggone Formatic Whole rock data are given in wt%, trace elements are in ppr LOI = wt. % loss on ignition at 1000°C 27 .01 0.1 10 Toodoggone Formation * Altered Takla Group * Bladed feldspar porphyry Basaltic augite porphyry Mafic dyke Comendite/ Pantellerite Phonolite Rhyolite Rhyodacite/Dacite Andesite Andesite/Basalt Subalkaline basalt 0.1 N b/Y Trachyandesite Alkaline basalt Basanite/ = Nepheline Trachyte .001 .01 1^1^111,1_I_ 10 0.01 N b/Y N b/Y 28 0 Rhyolite dyke Phenocryst-rich granodiorite dyke • Diorite dyke 0 Alkali-feldspar syenite dyke X Quartz-diorite dyke Nepheline syenite Alkali gabbro 1^1^111111 0.1 Granodiorite tonalite Theralite _ Gabbro-diorite 1^1^ 1111 10 0.01 .001 .01 N Figure 2.6 N 0.01 .001 V 11111 ^ Duncan pluton • Kemess North pluton A Sovereign pluton Nephelinesyenite Granite Syenite Granodiorite tonalite morn odiorite Monzonite Theralite Alkali gabbro^— Diorite Gabbro-diorite I^1^1^11111 Figure 2.6. Immobile element Nb/Y versus Zr/Ti02 classification diagrams (after Winchester and Floyd 1977): (A) Mafic dykes, basaltic augite porphyry, bladed feldspar porphyry, and altered Takla Group rocks are classified as subalkaline basalts, whereas Toodoggone Formation rocks are classified as andesite. (B) Sovereign plutonic rocks are classified as diorite to granodiorites, whereas Kemess North and Duncan plutonic rocks are classified as diorites. (C) The diorite and quartz-diorite dykes plot in the diorite field, whereas the phenocryst-rich granodiorite and alkali-feldspar syenite dykes plot in the granodiorite-tonalite and monzodiorite fields. The rhyolite dyke plots in the alkali gabbro field. 29 1800 m 1800 m ? Legend Kerness North Diorite Basalt (Takla Group) Fault F- Pfsh: dyke DsP hole (red-A0 Gypsorn-anhydritp alteration transition Legend Au Cu 1 5 - 3 g/1Au 1 - sh, Cu 1- 1. 5 glt Au 0.5 -^Co 7 7. Ly tI 7 - q/I 1 1 -n 1>% Cu 00 2 clit An 0 - 0 170 0, Fault Drill hole (red3AL3 gree0303.) 1600 1 460 1200 1000 m 1600 m 1 400 rn Duncan pluton Figure 2.7 30 Figure 2.7. North-south striking (west-facing) section through the centre of the Kemess North ore body based on surface mapping and diamond drill hole logging. (A) The photograph of the Kemess North northeast ridge, (looking NNW) shows the sharp contact between the supergene- altered, gossanous, Takla Group basalt (red-brown) and the grey, propylitic-altered, Toodoggone Formation andesite. The location of the NS section line is also indicated. (B) North-south section showing the structural dismemberment of the moderately SE-plunging Kemess North diorite. The northern extremity of the diorite is structurally defined by the E-W trending fault contact with Toodoggone Formation rocks that occur to the north (shown in outcrop in Figure 2.7A). Diamond drill holes show the relative distribution of Au and Cu grades from drill core analyses. (C) North-south section showing the distribution of Au and Cu, modelled from diamond drill hole assay results. Note that there is no mineralized carapace at the top of the Kemess North diorite. Consequently, the present geometry of the Kemess North diorite is not likely to represent the original shape of the intrusion. For example, the zone of highest Au and Cu (>3g/t Au and >3 % Cu) is situated at the northern-most tip in the middle of the Kemess North diorite. In contrast, the highest position of the Kemess North diorite is relatively weakly mineralized (1.0-1.5g/t Au and 0.5-1.0 % Cu). 31 Plutonic rocks plotted on the TAS diagram (after Wilson 1989) show that the least- altered Kemess North pluton samples plot in the quartz diorite (granodiorite) classification field (Fig. 2.5A). Using the classification system of Winchester and Floyd (1977), samples of least- altered Kemess North pluton are classified as diorite (Fig. 2.6B). Point-counting results for feldspar-stained, least-altered rocks indicate that the Kemess North pluton is more felsic in composition and is consequently classified as a monzonite (Appendix A.1). It is possible that the point-counting data includes some hydrothermal, rather than primary, minerals. Hence, the Winchester and Floyd (1977) immobile element plot is preferred and the Kemess North pluton is therefore referred to as a diorite. The pluton has an U-Pb zircon crystallization age of ca. 202 Ma (Diakow 2006b). Sovereign Pluton The Sovereign pluton crops out in the southern portions of the map area (Fig. 2.2). Based on outcrop, drilling, and geophysical data, the Sovereign pluton is about 4.5 km long and 875 m wide. No lithological contact was observed between the Sovereign and the Kemess North pluton located to the north. The Sovereign pluton has an U-Pb zircon crystallization age of 202.7 ± 1.9 Ma; (Diakow 2001), which is coeval with the mineralized ca. 202 Ma (Diakow 2006b) Kemess North pluton. Despite these temporal similarities (Fig. 2.8), the Sovereign pluton does not host significant Au-Cu-Mo mineralization. In hand specimen, the Sovereign pluton is dark grey to brown and porphyritic. Phenocrysts comprise up to 34 to 48 vol. % of the rock and include K- feldspar (33-46 vol. %), plagioclase (25-36 vol. %), hornblende (15-24 vol. %), biotite (1-5 vol. %), and quartz (3-7 vol. %). The groundmass includes euhedral plagioclase, hornblende, biotite, and quartz, with minor (<1 vol. %) magnetite, chlorite, sericite, and pyrite. Hornblende and plagioclase phenocrysts are about 20 % altered to chlorite and sericite, respectively. 32 1 11 Y Lu .1 I Cs Rb Ba Th U Nb Ta La Ce Pb Pr Sr Nd Zr HfSmEuGd Tb Dy Ho Er Yb — 11111111111111 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Sun+McDon. 1995-REEs ^ Duncan pluton ♦ Kemess North pluton ! Sovereign pluton La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 1 Rock/Chondrites 100 10 Sun+McDon. 1995-REEs 10 100 Rock/Chondrites —=71 .= 10 Sun+McDon. 1995Rock/Chondrite 1000 =^ 100 =- ^ Duncan pluton r7-'0 Toodoggone Formation Sun+McDon. 1995 ^ Duncan pluton Kemess North pluton t‘ Sovereign pluton I^llllllllllllllllll Cs RbBa Th U Nb Ta La Ce Pb Pr Sr Nd Zr HfSmEuGd Tb Dy Ho Er Yb Y Lu Rock/Chondrite 1000 100 10 1 1 Figure 2.8 33 Figure 2.8. Chondrite-normalized rare earth element and primitive mantle normalized trace element plots (after McDonough and Sun 1995) showing the compositional trends for plutons and volcanic rocks at Kemess North. (A) Samples from the three plutons are compared on a chondrite-normalized rare earth element plot showing an almost identical trend. (B) The three plutons are compared on a primitive mantle normalized trace element plot again showing an almost identical trend. (C) The Duncan pluton and Toodoggone Formation are compared on a chondrite-normalized rare earth element plot showing an almost identical trend. (D) The Duncan pluton and Toodoggone Formation are compared on a primitive mantle normalized trace element plot again showing an almost identical trend. 34 The TAS diagram (after Wilson 1989) for plutonic rocks shows that the least-altered samples of Sovereign pluton plot in the quartz diorite (granodiorite) classification field (Fig. 2.5A). Using the Winchester and Floyd (1977) diagram, least-altered samples of the Sovereign pluton are classified as diorite (Fig. 2.6B). Hence, both the Kemess North and Sovereign plutons are classified as diorite. Furthermore, these rocks show very similar trace-element trends on a rare earth element plot and multi-element (i.e., spidergram) plot after McDonough and Sun (1995) (Fig. 2.8). The coeval timing of emplacement for these plutons, combined with shared chemistries, suggest that they are possibly genetically related. Toodoggone Formation Volcaniclastic Rocks Toodoggone Formation rocks crop out as prominent N-trending ridges at Kemess North. Isolated Toodoggone Formation units also occur amongst Takla Group basalt in the main E- striking headwall (Fig. 2.2). Least-altered Toodoggone Formation rocks are grey and poorly sorted. Clasts are 2-40 cm long, angular to sub-rounded, and include fragments of Sovereign pluton and the various types of Takla Group basalt (Fig. 2.3). Locally, Toodoggone Formation rocks are finer-grained and equigranular. These rocks appear very similar to massive basalt in hand specimen, however, the presence of <1 mm diameter, rounded, grey "smoky" quartz grains amongst a finer-grained matrix are diagnostic of Toodoggone Formation rocks (Diakow pers. comm., 2004). Three least-altered samples of medium-grained, equigranular Toodoggone Formation units plot in the andesitic field of the TAS diagram (after Le Bas et al. 1986) and Winchester and Floyd (1977) immobile element plot (Fig. 2.6A). Hence, Toodoggone Formation units are hereafter referred to as andesitic volcaniclastic rocks. A sample of Toodoggone Formation rocks from the ridge in the central map area has a U- Pb detrital zircon age of 199.1 ± 0.3 Ma (Diakow 2001). This maximum depositional age for the 35 Toodoggone Formation post-dates the emplacement of the mineralized Kemess North (ca. 202 Ma, Diakow 2006b) and Sovereign (202.7 + 1.9 Ma, Diakow 2001) plutons. The Toodoggone Formation units are mostly barren with respect to gold, chalcopyrite, and pyrite. These metals only occur in 1-2 m wide, 30 m long, NW-striking faults in the central ridge and within 40 m of the Takla Group-Toodoggone Formation fault contact in the northeast ridge (Fig. 2.2A). The presence of minor, structurally-controlled, Au-Cu mineralization in Toodoggone Formation units suggests that these metals were remobilized from existing hypogene ore bodies associated with the Kemess North pluton. Toodoggone Formation units are intersected by diamond drilling below the northern most margin of the moderately SE-plunging Kemess North pluton (Fig. 2.7 & 2.9). These units are a matrix-supported breccia that contains angular fragments of pyrite-bearing Kemess North pluton; the matrix comprises the grey, "smoky" quartz grains that are characteristic of Toodoggone Formation volcaniclastic rocks. The possible explanations for the occurrence of Toodoggone Formation volcaniclastic rock beneath the older Kemess North pluton will be interpreted in the Discussion section. Duncan Pluton The Duncan pluton crops out to the north of the west and central ridges (Fig. 2.2A). No lithological contacts with country rock were observed, although hornfels was observed in Takla Group basalt within 30 m of Duncan pluton outcrop to the north of the west ridge. Least-altered Duncan plutonic rock is grey, coarse-grained, equigranular, and comprises <2 mm long, euhedral plagioclase (36-48 vol. %), potassium-feldspar (20-30 vol. %), quartz (10-20 vol. %), hornblende (8-15 vol. %), and biotite (4-12 vol. %) phenocrysts. The groundmass consists of <2mm long plagioclase crystals that define a cumulate texture (Fig. 2.3). Biotite and hornblende are weakly altered (-15 %) to chlorite. 36 6*Z ambid 0100 Ip1f),I0 f1 J le 1,4101101 SplOctiOaf] floe fSo4,502PO1) -fed01.1103 01107 ..reays 4.11,4A L£ CltiY F.L:C c• • "0 0 0 • c? • • ° WOO ^ 0/01/ pug 11101 ,q1^riezwar,,,,,tii-/sod^, r sole/u<10 /11/0 010060/// •1/i/i,•4 70/ 0/ Je-In6tiO 0,0 E.,-;PUJOLI/O.O5 9fo,a16/5eJJ >(901 U.., WWI •lUitiOlO ue 1..6? A.,1-40.10d O.Eqg 10 ..;•:.•iolo,; sAcids,p 9001 01/3 92.0 of Cl 1:PC :pun ,psefaftle3fa4 dno,9 uoffazeH S-1110/1 ow-do-Ad •.,OO.oN 1^,...,,...1,1.• -.1:^r111,11,0lle d • ..".d^..10 •.r 1•/,^o, , vl,r Ory^::•;•Lu-7; ..•.1111 ..; OW 1, <-1,1,07 .,110911/ON ••-.^019^I. 906 'afpofp Iffdolv ssoufam suran ,fher,-1110111 Aq^00e 510 ^ 01 Oe..1, ONIOA 0611/5 AtIO3 110MU.10.l^all.,(10011,140 ,fOop1100J5^ul sae 011 ,-41,t1115 su 503 0/ i.91. s-sewpaticub •••11 1,j,p790111., pUe 1110i1/^l//IM Aa15 •• ::••• 111,1; •.11.Li., OL1SS,/ /WM 0: •.^1,1^010', /1.1ofod1110-. 013 wb 961 0/ 67/ ,11.1(05V4 0100 7410 fib bUIO11110,115 01401,10111e36- e 1n:,IOJOLULefo., 1/4.117SdÃO 0,1 pa,me. Apr.,-)o/1 que put, 010)301/ plzlfrxo or OOJA,1 pcie ONOI, Of 4,, ,o,O^SiL0416.•1/ 4,00n^tot, 1/310 pesodwo., A11,1110 du^• ■ Hop p,Jottle,p of 500, Ol2,1,',4C1Ltioj .;^.J4O,1,1117,>7145^5.010oo lle,;eq •do/ ,qt 11 / 651.'0 7 1100,10f11e3fon dnai9 epfei .. -, . ,f, n. ,., ,,,„ a. -‘,. S. T. swagr, 1Igimmomirail4113^18551541057/03^1314nwak .i7100(11(1105 0110 (10OlitiO,O7  O)PEO^X5T)f61,Ffil Figure 2.9. A visual log of diamond drill hole KN-02-05 through Kemess North drilled at an inclination of -85° from a collar located at 10356.2mE, 16236.3mN, azimuth 360°, and an elevation of 1737 m. Photos illustrate lithologies and alteration observed. (A) Altered Takla Group bladed feldspar porphyry rock, anhydrite within the rock has hydrated to gypsum producing a highly friable rock. (B) An early-stage veins observed in altered Kemess North diorite. (C) A representative sample of Hazelton Formation rock seen under the mineralized diorite. (D) A thin-section seen in polarized light of the Hazelton Formation rock. 38 The TAS diagram (after Wilson 1989) for plutonic rocks demonstrates that least-altered samples of the Duncan pluton plot in the diorite to quartz diorite (granodiorite) field (Fig. 2.5A). Using the classification system of Winchester and Floyd (1977), the Duncan pluton is classified as diorite (Fig. 2.6B). Despite the Duncan pluton being approximately 5 million years younger than the Sovereign and Kemess North plutons, all three plutons share similar trace-element (REE and multi-element) trends to the older plutons (Fig. 2.8). The negative Nb and Ta anomalies in Figure 2.8B are typical of magmatic arc rocks, while the Sr abundance is controlled by plagioclase (Rollinson 1993). All plutonic rocks are considered to be metaluminous, using the metaluminous versus peraluminous discrimination diagram (Fig. 2.5E) of Maniar and Piccoli (1989). The few Kemess North pluton samples that occur in the peraluminous field are probably caused by the mobility of Ca, Na, or K during hydrothermal alteration of the pluton. The Y+Nb versus Rb tectonic discrimination diagram (Fig. 2.5F) (after Pearce et al. 1984) indicates that all plutonic rocks are volcanic-arc related. Late Dykes At least six generations of late dykes cut the Takla Group and Toodoggone Formation units. The dykes are up to 10 m wide and 20 m in strike length and are commonly NW-striking with subvertical dips. They are divided into mafic and felsic to intermediate groups and briefly described below. Mafic Dykes Mafic dykes cut Takla Group basalt throughout the map area but they are particularly common in the west ridge, near the erosional contact between Takla Group basalt and overlying Toodoggone Formation volcaniclastic rocks. At this location, the dykes cut the basalt about 10 m to the south of the contact with the volcaniclastic rocks; mafic dykes were not observed in these Toodoggone Formation rocks, however, it is uncertain if this relationship holds throughout 39 Kemess North. In general, the mafic dykes are 1 to 15 m wide, 20 to 70 m long, and have a subvertical dip and strike towards 300 0 . The dykes are dark green, massive, fine-grained, and comprise plagioclase (55-65 vol. %), orthopyroxene (20-30 vol. %) and chlorite (10-20 vol. %). Dykes commonly have very fine-grained chill margins within 30 cm of dyke margins. Grain size and the prevalence of <1 cm diameter carbonate-filled vesicles increase towards the centre of the dykes. Felsic to Intermediate Dykes Five generations of felsic to intermediate compositional dykes cut Takla Group basalt and Toodoggone Formation volcaniclastic rocks at Kemess North. They include: (i) diorite, (ii) quartz-diorite, (iii) alkali-feldspar syenite, (iv) quartz phenocryst-rich granodiorite and (v) rhyolite. Diorite dykes are most common and occur throughout Kemess North. The dykes are 15- 20 m wide and 30 m long and display subvertical dips and northwest trends. The diorite dykes are orange, coarse-grained, porphyritic and comprise about 28 to 35 vol. % of 1 mm long phenocrysts of K-feldspar (66-74 vol. %), plagioclase (17-25 vol. %), and hornblende (2-7 vol. %) and a groundmass of magnetite (1-2 vol. %), quartz (<1 vol. %), and biotite (<1 vol. %). Locally, the diorite dykes display 50 to 100 cm wide chill margins. Quartz-diorite dykes are commonly 15 m wide by 70 m long and strike NW with subvertical dips. The dykes cut Toodoggone Formation rocks in the east ridge. The quartz- diorite dykes are brown, coarse-grained, porphyritic, and contain 0.5 to 10 mm diameter phenocrysts of plagioclase (34-40 vol. %), potassium feldspar (27-38 vol. %), hornblende (10-19 vol. %), and quartz (9-15 vol. %) surrounded by a chlorite-rich groundmass. Alkali-feldspar syenite dykes cut Takla Group basalt in the east ridge and east cirque areas. The dykes are 2 m wide and 4 m long; they have subvertical dips and strike northwest. 40 The rock is brown, coarse-grained, porphyritic, and comprised of alkali-feldspar (85-93 vol. %), plagioclase (7-15 vol. %), and quartz (1-3 vol. %) phenocrysts surrounded by a potassium- feldspar, plagioclase, quartz, biotite groundmass. A quartz phenocryst-rich granodiorite dyke cuts Takla Group basalt in the headwall of the central cirque. The dyke is 60 m wide by 70 m long, has a subvertical dip and strikes northwest. The dyke is grey, coarse-grained, porphyritic, and comprises plagioclase (54-60 vol. %), quartz (27-33 vol. %), and potassium-feldspar (9-15 vol. %) phenocrysts that are surrounded by a groundmass of plagioclase, quartz, potassium-feldspar, and biotite. A rhyolite dyke crops out in the central ridge. Although no lithological contacts are exposed, the rhyolite dyke is bordered in all directions by Toodoggone Formation rocks. The rhyolite dyke is 2 m wide by 9 m long and strikes towards 300 ° ; the dip of the dyke is uncertain. The rhyolite dyke is white, fine-grained, equigranular and comprised dominantly of quartz (>80 vol. %), with minor potassium-feldspar, plagioclase, and disseminated pyrite. Structure Structures were mapped with the purpose of determining structural controls on the present distribution of rock types, hypogene alteration, and Au-Cu-Mo mineralization. Structures are described below in order from ductile to brittle styles of deformation. Shear Zones Ductile shear zones rarely crop out at Kemess North. Where observed, the shear zones cut Takla Group and Toodoggone Formation rocks as 1 to 2 m wide, 40 m long zones defined by chlorite, hematite, and locally by pyrite. All shear zones strike NW and dip moderate to steeply (69 to 90°) to the NE and SW (Fig. 2.10). No movement sense or magnitude of displacement was observed. 41 Equal Area (Schmidt) Shear Zones +6S +4S +2S E n = 5 A', Axial n = 27 Equal Area (Schmidt) Veins 6S 4S 2S B Figure 2.10 Figure 2.10. A. An equal area (Schmidt) lower-hemisphere stereonet showing poles-to-planes for shear zones at Kemess North. The shear zones are predominantly northwest striking and steeply dipping. B. An equal area (Schmidt) lower-hemisphere stereonet showing poles to planes for all veins at the Kemess North deposit. The veins are predominantly northeast-striking and steeply dipping. 43 Veins Seven main vein types are observed at Kemess North; their description and paragenesis are described in detail in a later section below. Carbonate-zeolite veins were the most common vein-type observed and measured in outcrop. All other veins were observed mainly in unoriented drill core, hence, their orientation is unclear. The carbonate-zeolite veins are 3 to 5 cm wide and cut Takla Group and Toodoggone Formation rocks. These veins mainly strike NW and have moderate to steep dips (55 to 84°) towards the NE and SW in the eastern area of the deposit, whereas they mostly strike NE and dip moderate to steeply (45 to 89 °) towards the NW and SE in western areas (Fig. 2.10). Faults Faults are divided into sets based on their relative crosscutting relationships. The earliest recognized faults are E-W striking, moderate to steeply dipping (50 to 90°) faults (Fig. 2.11). The E-W striking faults cut Takla Group and Toodoggone Formation rocks in the area of the deposit between the central ridge and the east cirque (Fig. 2.2B). The most obvious example of this fault set occurs at the contact between Takla Group and Toodoggone Formation rocks. The E-W striking fault zone dips steeply (70 to 90°) to the north and extends in strike length for at least 1.4 km and to depths of 500 m below the present surface. In outcrop, this fault zone is 2 m wide and contains 3 cm wide quartz veins surrounded by intensely limonite-kaolinite-altered wallrock. Although no movement or displacement indicators were observed in the fault zone, drilling and aeromagnetic results indicate that a sequence of at least 1.2 km thick Toodoggone Formation rocks are structurally juxtaposed against older Takla Group rocks (Fig. 2.7). Thus, the north-side-down displacement of Toodoggone Formation rocks suggests that the dominant displacement on this fault zone is normal dip-slip. 44 6327560 r513 Equal Area (Schmidt) Planes (Strike/ _ 63270 = 90^Axial^ n = 90 SYMBOLS 632 fr/r14 fault orientation and dip LITHOLOGIES 11111  felsic to intermediate dyke DYKES mafic dyke 632 FARE Y IIIRASSIC HA7ELTON GROUP L OWFR rOCIDQGGDNF FORMAI ION I^J 632 andesite EARLY JURASSIC BLACK LAKE INTRUSIVE SUITE MI Duncan diorite I^I Sovereign diorite MIDDI . F TRIASSIC TAKE A GROUP IN sub-alkaline basalt 6327500 mN E S 632700 n = 380^Axial^ n = 380 63265E / 87 SYMBOLS oint orientation and dip LITHOLOGIES DYKES 1111 felsic to intermediate dyke 11.1 malic dyke .612. EARLY JURASSIC HAZEI TON GROUP LOWER TOODOGLNONE FORMATION I^I andesite EARLY JURASSIC BLACK I AKF INTRUSIVE SUITE 1111 Duncan diorite 632 Sovereign dioriteI^1 MIDDLE TRIASSIC TAKLA 090110 El sub-alkaline basalt I rs Figure 2.11 45 Figure 2.11. Simplified outcrop maps showing the distribution of faults and joints at Kemess North. The structural data shown in both maps are spatially averaged data that are representative of much larger data sets. The spatially averaged data in each plot were calculated using the Spheristat 2.2 program, which uses a moving circle method to calculate the average structural orientation for a group of data falling within a user-defined space (i.e. fifteen adjacent stations that strike East-West with a spacing of 202 m; ten adjacent stations that strike North-South with a spacing of 207 m). The inserts represent equal area, Schmidt, lower-hemisphere stereonets that show contoured poles-to-planes (left) and Rose diagrams (right): (A) Faults are predominantly NW-striking (i.e. 270 to 330°) and steeply dipping (dip 70 to 90 ° to the NE and SW) with the rare NE-striking, steeply dipping (65 to 90 °) fault appearing in the eastern region of the study area. (B) Joints are NW-striking, steeply dipping (65 to 90 °), these joints represent the most common joint set at Kemess North. 46 The E-W striking normal faults are cut by NW to NNE striking faults. The NW to NNE striking faults are 15 m wide, up to 80 m long, and dip between 70 to 90° to the NE and SW (Fig. 2.11A). The faults offset all rock types and carbonate-zeolite veins at Kemess North and locally show normal-dextral displacements of 2 cm to 20 m in outcrop. Slivers of Toodoggone Formation rocks are bound on either side by NW to NNE striking normal-dextral faults and Takla Group basalt in the main E-W trending headwall (Fig. 2.2B). These structural relationships suggest that the slivers of Toodoggone Formation rocks have been vertically displaced downwards relative to adjacent Takla Group basalt and suggest evidence for a horst- and-graben style block shuffling of the Kemess North stratigraphy by the NW to NNE striking faults. Joints Joints are very common and were measured in all rock types throughout Kemess North. Joints are up to 3 m wide and 10 m long and are divided into four joint sets based on their relative timing. The earliest joints strike E-W and are steeply dipping (75 to 90°). This joint set is cut by NW striking, steeply dipping (65 to 90°) joints, which represent the most common joint set at Kemess North. Later N-S striking, steeply dipping (86 to 88°) joints are cut by late, NE striking, steeply dipping (82 to 86°) joints, which occur mainly in the west ridge of the study area (Fig. 2.11B). Vein Paragenesis and Associated Hypogene Alteration Seven vein types are identified at Kemess North and are separated into four stages of formation with respect to Au-Cu-Mo mineralization (i.e., early-, main-, late-, and post- mineralization-stage). The vein types are differentiated based on their vein mineralogy, texture, and relative cross-cutting relationships. The section below describes the characteristics and 47 distribution of vein types listed in chronological order. Most vein measurements were obtained from drill core due to the scarcity of exposed veins in the map area. Recall that the main Kemess North deposit is hosted mainly in diorite approximately 450 m below the present-day surface. Alpha angles (i.e., the acute angle between the vein and core axis) were recorded from unoriented core and the data were restored to the horizontal so that dip angles could be estimated for each vein type. Early-stage veins Magnetite stringer veins Magnetite stringer veins are the earliest recognized vein type (Fig. 2.12). These veins are rare, representing <3 % of measured veins in drill core, and are restricted to the Kemess North diorite. The magnetite stringer veins are 0.5 to 2 mm wide and have restored dip angles of 38 to 40° to the horizontal. Subhedral magnetite in the veins is locally rimmed by hematite, and veins commonly possess a 5 to 10 mm wide, weakly-developed, biotite alteration selvage (Fig. 2.13). 48 Vein^ Early Main Late Post-min. 1. Magnetite Stringers biotite alteration (potassic) 2. Qtz-mt-py ± cp ± mo ± Au biotite alteration (potassic) 3. Qtz-py-cp ± mo ± Au sericite-chlorite (phyllic) 4. Py-cp veins sericite-chlorite (phyllic) 5. Anhydrite ± py ± cp sericite alteration (phyllic) 6. Anhydrite veins (phyllic) 7. Carbonate-zeolite veins carbonate alteration Figure 2.12 49 Figure 2.12. Schematic representation of different vein types at the Kemess North deposit showing their relative timing and abundance (line thicknesses demonstrate their relative abundance). Related hydrothermal alteration events are shown in italics. Abbreviations: qtz: quartz, mt: magnetite, py: pyrite, cp: chalcopyrite, mo: molybdenite, Au: gold. 50 Quartz-magnetite-pyrite ± chalcopyrite ± molybdenite veins Quartz-magnetite-pyrite ± chalcopyrite molybdenite veins cut magnetite stringer veins (Fig. 2.13) and occur in diorite and overlying Takla Group basalt within 150 m of the contact. The former veins are 1 to 20 cm wide and contain mostly magnetite (27-33 vol. %), pyrite (14- 20 vol. %), chalcopyrite (5-9 vol. %), and minor molybdenite (2-4 vol. %), with trace hematite rimming the magnetite. Magnetite occurs as 1 to 10 mm wide, multiple bands (parallel to vein margins) or as finer-grained disseminations in the vein. Magnetite commonly occurs with pyrite and chalcopyrite along vein margins. Quartz is recrystallized and often displays triple junctions along grain boundaries and undulose extinction. The central seam of the vein commonly lacks magnetite and consists primarily of quartz, pyrite, chalcopyrite, molybdenite, and minor anhydrite and calcite. Geochemical analysis of these veins indicates that they are associated with gold and copper grades of up to 3.5 ppm and 1.8 %, respectively (Fig. 2.14). The veins dip about 30 to 45 ° to the horizontal. Alteration selvages associated with this vein type are only preserved locally due to pervasive replacement by later vein and alteration events. Where they are preserved, they are defined by a moderate to weakly developed, 2 to 3 cm wide zone of biotite alteration. Hence, early-stage veins at Kemess North are associated with early potassic- style alteration. 51 Figure 2.13 Figure 2.13. Photographic plate of vein types and associated alteration mineral assemblages at the Kemess North deposit. All photomicrographs were taken in cross-polarized transmitted light, unless otherwise stated: (1) Altered diorite showing early-stage magnetite stringer veins. (1A) The photomicrograph of an early-stage magnetite stringer vein shows a weak biotite alteration halo. (1B) The matching photomicrograph in reflected light shows minor hematite that rims magnetite. (2) Altered diorite showing an early-stage quartz-magnetite-pyrite- chalcopyrite ± molybdenite vein. (2A) The photomicrograph in plain light shows a chlorite alteration halo in diorite. (2B) A photomicrograph of an early-stage quartz-magnetite-pyrite ± chalcopyrite ± molybdenite vein showing polygonal quartz and indicating minor recrystallization. (3) A main-stage quartz-pyrite + chalcopyrite + molybdenite vein in altered diorite. (3A) The photomicrograph of the main-stage vein shows a sericite alteration halo. (3B) Locally, main-stage veins show polygonal quartz, indicating minor recrystallization. (4) A late- stage pyrite ± chalcopyrite vein displaying an intense sericite-chlorite-hematite alteration halo in diorite. (4A) The photomicrograph shows a late-stage vein with surrounding sericite alteration. (4B) The photomicrograph shows a late-stage pyrite-chalcopyrite vein in Takla Group basalt with a sericite alteration halo. (5) A late-stage purple anhydrite ± pyrite chalcopyrite vein that displays a sericite alteration halo within altered Takla Group basalt. (5A) The photomicrograph shows a late-stage anhydrite ± pyrite + chalcopyrite vein in Takla Group basalt exhibiting a very weak sericite alteration halo. (5B) The photomicrograph of a post-mineralization anhydrite vein in Takla Group basalt showing no obvious associated alteration. (6) A post-mineralization calcite-zeolite vein within Toodoggone Formation andesite. (6A) Outcrop that shows calcite- zeolite stockwork veins in Toodoggone Formation andesite. (6B) The photomicrograph of a post-mineralization calcite vein cutting a main-stage quartz-pyrite ± chalcopyrite ± molybdenite vein within Takla Group basalt. 53 45 n=22 II^ 90' 0^2 4^6 8 45 ^ n=1871^ n=277r^90" F f^9 10^20^30 0 10 20 30 40 n=210 90' 30 40 Try 0 10 20 4. Pyrite-chalcopyrite veins 5. Anhydrite ± pyrite ± chalcopyrite veins o" 6. Carbonate-zeolite veins 45" o" 1. Magnetite stringer veins 0 2.Quartz-magnetite-pyrite± chalcopyrite±molybdenite veins 3.Quartz-pyrite±chalcopyrite± molybdenite veins o" 111111 Au (ppm) Depth 100 m 1.8 2.0^0 0 11,^1111111111^J1111111111 Cu%^Au (ppm) Outline of Diamond drill holes: 1.0 111111111j Cu% 4.0^0 0 KN-02-05^KN-02-09 200 m 300 m Takla Group Basalt 400 m Takla Group Basalt ft Kemess North Diorite I 500 m ft Kemess North Diorite ft A fl Toodoggone Formation 600 m ToodoggoneFormationEnd of hole End of hole Figure 2.14 54 Figure 2.14. Rose diagrams displaying alpha angles (i.e., the acute angle between the vein and core axis) for the seven Kemess North vein types (shown in chronological order). Note that all alpha angles are restored to the horizontal so that they now represent dip angles to the veins. The lower half of the figure displays two diamond drill holes (KN-02-05 and KN-02-09) drilled from the surface in the centre of the deposit that show the relative distribution and metal values for the seven vein types. The coloured vein symbols correspond to the respective colours used in the Rose diagram. The drill hole diagrams demonstrate that early-stage veins (black and red) correspond to the highest Au and Cu concentrations in the diorite. 55 Main-stage veins Quartz-pyrite ± chalcopyrite ± molybdenite veins Quartz-pyrite ± chalcopyrite ± molybdenite veins are the most abundant vein type at Kemess North, occurring in diorite and Takla Group basalt within 250 m of the contact (Fig. 2.14). The veins are 1 to 15 cm wide and contain mainly quartz (60-80 vol. %) with bands of pyrite (15-25 vol. %) ± chalcopyrite (10-20 vol. %) f molybdenite (4-7 vol. %) aligned parallel to vein margins. Vein quartz grains commonly show signs of recrystallization, such as undulose extinction and triple point junctions defined by grain boundaries. Geochemical analysis of these veins indicates that they are associated with gold and copper grades of 0.8 ppm and 0.3 %, respectively (Fig. 2.14). Molybdenite from a main-stage quartz-pyrite ± chalcopyrite ± molybdenite vein has a Re-Os Model age of 201.8 + 1.2 Ma (Table 2.2). Veins dip about 35 to 42° to the horizontal. Alteration selvages associated with these veins are 2 to 7 cm wide and defined by sericite and quartz. Late-stage veins Pyrite-chalcopyrite veins Pyrite-chalcopyrite veins cut all previous mentioned vein types (Fig. 2.13). The veins are 1 to 2 cm wide and consist mainly of pyrite (90-95 vol. %) with minor chalcopyrite (5-8 vol. %). These late-stage veins occur in diorite and in overlying basaltic rocks to the surface. The veins dip about 40 to 47° to the horizontal (Fig. 2.14). Alteration selvages are characterized by 1 to 7 cm wide zones of sericite-chlorite-pyrite in diorite and basalt. 56 Table 2.2. Summary of Re-Os dating results from molybdenite in a Kemess North Main-stage vein I Sample^I^Source^I Re ppm' +/- 2a absolute1 1870s ppb1 +/- 2a absolute' Total common Os pgI Model age Ma I +1- 2a absolute A uncertainty included" KN-01-03 514.7m Main-stage vein^78 ^ 0.4 ^ 165.1 ^ 0.4 ^ 0.9 ^ 201.8 ^ 1.2 The 187Re and 1870s concentrations in molybdenite were determined by isotope dilution mass spectrometry using Carius-tube, solvent extraction, anion chromatography and negative thermal ionization mass spectrometry techniques. Anhydrite ± pyrite ± chalcopyrite veins Anhydrite ± pyrite ± chalcopyrite veins cut all vein types described above and comprise purple anhydrite (83-87 vol. %), with minor pyrite (7-13 vol. %) and chalcopyrite (2-7 vol. %). The veins are 0.5 to 3 cm wide and commonly cut existing veins parallel to their vein margins. The anhydrite ± pyrite ± chalcopyrite veins occur throughout the diorite and Takla Group basaltic rocks and dip about 34 to 40° to the horizontal (Fig. 2.14). Weakly-developed sericite alteration occurs up to 2 cm from vein margins in Takla Group basaltic rocks. No alteration is observed in diorite wallrock. Post-mineralization veins Anhydrite veins The second style of anhydrite vein does not contain any chalcopyrite or pyrite and is therefore classified as a post-mineralization vein. These veins are 1 to 5 cm wide and comprised solely of white anhydrite. The veins occur throughout diorite and Takla Group basaltic rocks and dip about 34 to 40° to the horizontal. Carbonate -zeolite veins Carbonate-zeolite crosscut all other vein types and are a common constituent of faults that cut diorite, Takla Group basalt, and Toodoggone Formation rocks (Fig. 2.13). The veins are the most common vein type mapped in outcrop. Carbonate-zeolite veins are 1 to 8 cm wide, have an irregular morphology, and primarily composed of calcite (87-93 vol. %), with pink zeolite (7- 12 vol. %) commonly distributed along vein margins. The veins strike to the NW and dip about 40 to 50° to the horizontal (Fig. 2.14). 58 Distribution of Deposit-Scale Alteration The previous section documents vein-types and their associated alteration styles at the micro- to meso-scale (i.e., 0.1 to 50 cm). This section describes macro-scale (i.e., 10 to 100 m) alteration at Kemess North. Five styles of deposit-scale alteration are recognized based on their alteration mineral assemblages and relative timing (Fig. 2.15). The alteration styles include: (i) biotite ± potassium-feldspar (i.e., potassic), (ii) sericite-quartz (phyllic), (iii) chlorite-epidote (propylitic), (iv) quartz (siliceous), and (v) gypsum-limonite-kaolinite (supergene) alteration. Biotite ± Potassium-Feldspar (Potassic) Alteration Biotite ± potassium-feldspar alteration is temporally and spatially related to early-stage veins and is the earliest alteration style recognized at Kemess North. Biotite + potassium- feldspar alteration is only locally preserved in the Kemess North diorite because it is commonly replaced by intensely developed chlorite-sericite alteration related to the later phyllic event. Light-brown hydrothermal biotite occurs in the early-stage veins and commonly displays rims replaced by chlorite. Kemess North diorite that occurs 700 m below the present surface in the southern portion of the map area locally displays potassium-feldspar associated with 1 to 3 cm wide, early-stage quartz-magnetite-pyrite ± chalcopyrite ± molybdenite veins. The restriction of potassium-feldspar alteration in diorite at depths in the deposit suggests that biotite + potassium- feldspar alteration may be more prevalent in deeper portions of the diorite, beyond the current maximum depths of drilling. The biotite ± potassium-feldspar alteration is consistent with the early potassic style of alteration recognized in many porphyry Cu-Au-Mo deposits (e.g., Titley 1982). 59 ft ..t. ^ --,----ci^1^'-.-.-r -,--^----,,. _,„.‘^'t^7 ------^---^----\._.- --\•s--^--- --- ---„----^_--- _.---^,.. --- „----T.^,_ -- A i  ---- _^c-t■^—^/^t . ,440thp ufil,lanos a o t r Ina Ell 47 • V1U ^n Ada L.] / •^.^•)1^,E9 SI9C)10H11 oll,a1,-1-0;11euloE{ NOLLVH3L1VrIt4 4••■,'` sot— .0116- ;we{ leu./...0 SlOCAViAS Nrw 06,,tLE9 \^i^I -- r^\*t.■ \1 1^i r ^\ \4^L. r I^in' ■ i^t. ^,I 11^I .\ .-1^ 1\^.1 ^7^r i.^. \ C^ I\ I^1 \ ,tI^1 I\ \(11.^A ,..." r- -X\ 4\ I ,‹^— — -4—^,., i^I \ ..,^.1 1 ---1, \*4 1401:v1...4801 -3t.• 09 g am6u Figure 2.15. The distribution of surface alteration at Kemess North. The symbols, A, B, C, and D, indicate the locations shown in the photographs. A. Looking southeast, supergene-altered Takla Group basalt displays hematite-limonite-kaolinite alteration. This alteration replaces quartz-sericite-pyrite (phyllic) alteration in the basalt. In more distal areas, the basalt and Toodoggone Formation rocks are epidote-chlorite (propylitic) altered. Toodoggone Formation rocks to the north of the main E-W fault are quartz-altered. B. Looking northwest at the "northeast ridge", Takla Group basalt to the south of the main W-striking normal fault is altered to hematite-limonite-kaolinite. The more competent Toodoggone Formation rocks north of the fault are altered to quartz. C. Looking west towards the "central ridge", Takla Group basalt in the foreground is altered to hematite-limonite-kaolinite D. Looking south-west at the beginning of the "west ridge" Takla Group basalt is altered to hematite-limonite-kaolinite (on the right) and are in contact with epidote-chlorite altered Toodoggone Formation rocks (on the left). 61 Quartz-Sericite-Chlorite-Pyrite (Phyllic) Alteration Quartz-sericite-chlorite-pyrite alteration occurs pervasively throughout the Kemess North diorite and overlying Takla Group basalt. This alteration style is related to the main- and late- stage veins and replaces most of the earlier biotite alteration and primary igneous textures in the Kemess North diorite and Takla Group basalt. The quartz-sericite-chlorite-pyrite alteration at Kemess North is the same as the phyllic alteration developed in porphyry deposits by Lowell and Guilbert (1970) and Titley (1982). Chlorite-Epidote (Propylitic) Alteration Chlorite-epidote alteration occurs in Toodoggone Formation and Takla Group rocks between 350 and 800 meters away from the Kemess North diorite, thus defining an outer halo around phyllic-altered rocks (Fig. 2.15). Within Takla Group basalt, chlorite and epidote partially (20 to 30%) replace plagioclase phenocrysts. Toodoggone Formation rocks that contain felsic and mafic clasts are moderately (30 to 40%) replaced by epidote and chlorite. Epidote- chlorite alteration at Kemess North is compatible with propylitic alteration as defined by Lowell and Guilbert (1970). Quartz (Siliceous) Alteration Quartz alteration occurs mostly in Toodoggone Formation units within 10 m of the main E-W striking fault contact with Takla Group basalt in the northeast ridge (Fig. 2.15). The intense quartz alteration is probably caused by fluid flow along the E-W striking contact during late normal faulting. Toodoggone Formation rocks more than 10 m to the north of the fault contact become progressively epidote-chlorite altered. In these distal areas, discrete 1 to 10 cm wide quartz-rich veins cut the pervasive epidote-chlorite alteration. Hence, the siliceous alteration post-dates propylitic alteration. 62 Gypsum-Limonite-Kaolinite ± Hematite Alteration Gypsum-limonite-kaolinite + hematite alteration occurs within 175 meters of the present surface throughout the map area in Takla Group and Toodoggone Formation. The alteration is best developed in Takla Group basalt that overlies the Kemess North pluton in the central portions of the Kemess North map area (Fig. 2.15). The limonite and kaolinite replaces existing disseminated pyrite, chalcopyrite, and sericite associated with the earlier phyllic alteration event. Locally, anhydrite associated with the late- and post-mineralization veins is hydrated to form gypsum. The volume increase associated with this alteration results in a highly broken and permeable zone within 100 m of the present surface. The circulation of oxidized meteoric fluids is interpreted to have caused the destruction of sulfide minerals, sericite, and anhydrite, resulting in the formation of clays and gypsum (i.e., supergene alteration). Major Controls on the Distribution and Geometry of the Kemess North Ore Body Grade distribution results from diamond drill holes indicate that the highest concentrations of Au and Cu are located in the Kemess North diorite, particularly in the upper 100 m of the diorite (Fig. 2.7). The ore body plunges with the diorite to the SE. Grade concentrations of >3 g/t Au and >3% Cu occur in diorite proximal to the E-W striking fault contact with the Toodoggone Formation units. Metal grades in overlying Takla Group basalt decrease away from the diorite, with Takla Group rocks at surface containing 0.2 to 1 g/t Au and 0.1 to 0.5% Cu. At surface, two gossanous (limonite-kaolinite-rich) areas in Takla Group basalt are separated by a 510 m wide, less-altered and barren, block of Toodoggone Formation units (presently exposed in the central ridge; Fig. 2.2B). The block is bounded on both sides by NW striking, steeply dipping normal faults. The vertical dropping of this central Toodoggone Formation block relative to surrounding mineralized Takla Group basalt units corresponds with a 63 barren zone from surface to about 250 m below surface (Fig. 2.16). At depths greater than 250 m below surface, mineralized Takla Group basalt that underlies the barren Toodoggone Formation units is now adjacent with surrounding mineralized Takla Group basalt. Hence, the Au and Cu ore body is continuous from east to west at depths greater than 250 m. The major control on the distribution and morphology of the Kemess North ore body is the Kemess North pluton (i.e., a magmatic control). However, subsequent horst-and-graben block faulting associated with NW-striking normal faults are also important in dismembering the ore body and explain the origin of two separate gossanous expressions at surface at Kemess North. 64 6127570 n'eg I SYMBOLS geolbdihal r:ob!ach doconfidrrudy normal fault B 1640 m Elevationwfer,-b (abr.^ - 632 Au (ppm, , :IES A • 6^AKE ',TA,^F Offocao diorde SnvbreTdr diontP M■DOLF C,PFAJP 1^sub alkaline^alt 6325^1,2 0 b kilon.roters, 632750 rnN SYMBOLS^N^. geological LAW.",  ^/! bk. i A PM or fon -pity^— — normal fault ad , d ,Fro, ,,,F, 1 ,,, .FF 1,,,,,, -,,,,,,,-, F , ,,, ,A,A wrench fault^'VP' -WO' -AO' 6327 Au (ppm) 1111.11111111Pr^...MM. 1 0^ 0.9 LITHOL0011 MAZE* '•J 1 6 A LOWER /^• • •• I ••'F.F FF,PMATION, 7 andesbe 7 Al̂ ALF F,11- R11:401 F SL, OF Duncan diorite verelgn diorite FPIASSIP r^A , UP a 2̂ sub-alkaline basalt 63250AFF, fl` 01,•••■,_ kilornetem 1490m Elevation Figure 2.16 65 Figure 2.16. Gridded gold concentrations from 216 diamond drill holes for two elevations at Kemess North. A. Gold values for the near-surface 1640 m elevation (relative to sea level) define two discrete ore bodies in Takla Group basalt that are separated by unmineralized Toodoggone Formation rocks. B. About 150 m beneath the 1640 m elevation level, gold values are more continuous and correspond to mineralized Takla Group basalt that occurs throughout the deposit at this elevation. C. The block model demonstrates the disruption of a laterally continuous ore body by horst-and-graben type normal faulting. This is the preferred model for Kemess North, specifically unmineralized Toodoggone Formation rocks (shown in yellow) have dropped down in the graben thereby lying adjacent to mineralized Takla Group units (green). Beneath this location, the ore body is laterally continuous. 66 Fluid Inclusion Microthermometry Microthermometric analyses were performed on fluid inclusions in hydrothermal quartz from early- and main-stage veins to estimate pressure-temperature-compositional conditions for the metalliferous fluids. Early- and main-stage veins are associated with potassic and phyllic alteration mineral assemblages, respectively, and are both responsible for Au-Cu mineralization in the Kemess North porphyry system. Later pyrite-chalcopyrite, anhydrite-bearing, and carbonate-zeolite veins have negligible Au-Cu mineralization and are not discussed further. Distribution and Petrography of Fluid Inclusions Veins were sampled from seven drill holes that intersect high Au-Cu zones in diorite. Sample depths ranged from 400 to 600 meters below the present surface. Fifteen doubly- polished thin sections of early- and main-stage veins were prepared for fluid inclusion studies. From detailed examination of these sections, only seven contained workable inclusions (i.e., greater than 5 gm in length). Fluid inclusions were analyzed within unstrained hydrothermal quartz grains that are in textural equilibrium with ore minerals (chalcopyrite, pyrite, and magnetite). Locally, these quartz grains host 5 to 10 gm diameter inclusions of chalcopyrite, suggesting that these quartz grains formed contemporaneously with chalcopyrite. Fluid inclusions within the quartz grains are distinguished based on their relative time of formation as primary, pseudosecondary, or secondary inclusions, using the criteria proposed by Roedder (1984) and Goldstein (2003). All measured fluid inclusions are further grouped into fluid inclusion assemblages (FIAs). That is, groups or trails of inclusions that are similar in size, display visually identical phase ratios, and formed together as either primary, pseudosecondary, or secondary inclusions (Goldstein and Reynolds 1994). As a result, these FIAs are considered to represent a single fluid event. 67 Secondary inclusions that occur along fractures that transgress quartz grain boundaries are the most abundant fluid inclusion type in early- and main-stage veins. Primary fluid inclusions were difficult to conclusively identify because of the absence of crystal growth textures in hydrothermal quartz. Pseudosecondary fluid inclusions occur in healed fractures inside quartz grains. These fluid inclusions were easily identified and were the focus of the study because they are interpreted to have trapped fluids responsible for ore mineral deposition. Three types of coeval pseudosecondary fluid inclusions were identified in early- and main-stage veins based on their shape, size, and proportion of phases present at room temperature (Fig. 2.17). Type I pseudosecondary fluid inclusions are liquid-rich (>60 vol. % liquid) aqueous inclusions that contain <30 vol. % halite, <10 vol. % vapour, and minor (<2 vol. %) opaque daughter minerals. The opaque minerals commonly have a triangular habit, are yellow in unpolarized reflected light, and are thus interpreted to be chalcopyrite. Type I inclusions have an equant negative crystal shape and their lengths range from 5 to 34 gm, with >80% of analyzed inclusions 10 to 12 gm long. Type I inclusions define healed fracture planes inside quartz grains. Unlike early-stage veins, Type I liquid-rich inclusions in main-stage veins rarely contain opaque daughter minerals but more commonly host translucent daughter minerals, such as halite and carbonate. 68  Type I (brine-rich) carbonatechalcopyrite quartz liquid • Paque^,vapour halite mr•^chalcopyrite B • opaque halite vapour - liquid- • Type I 4b-rich) • vapour liquid '^ —opaque * carbonate halite^quartz 20 urn NMI^IIIIIIII_ vapour 441 Type II, quartz secondary^40 inclusions 1.6 mini .141 1. ur(4,N vapour liquid C I • Type II (a) D Type II (b) (vapour-rich)^ '(vapour-rich) liquid ok..4 vapour quartz 25 urn Mr MINE ^Type I^opaque.; 49^`,\ • V r vapour quartz 0^• • /^›: - 'secondary ^ Type II }^(;) 1.6 aim 411:,-^•9tuct- wrpour MI MINI^ 44, Figure 2.17 69 Figure 2.17. The photoplate shows the different fluid inclusions hosted by quartz in early- and main-stage veins at Kemess North. All photomicrographs were taken in unpolarized, transmitted light unless otherwise stated: A. The photomicrograph taken in unpolarized reflected light shows a Type I liquid-rich inclusion in an early-stage vein. The insert shows a photomicrograph of the same inclusion with a halite cube, triangular chalcopyrite crystal, vapour bubble, unknown opaque mineral, and a liquid. B. The photomicrograph shows two Type I liquid-rich inclusions from a main-stage vein containing a halite cube, opaque daughter crystal, vapour bubble, and liquid. C. The photomicrograph shows a Type Ha vapour-rich inclusion from an early-stage vein. D. A photomicrograph of a Type IIb vapour-rich inclusion from a main-stage vein. E. A photomicrograph of an early-stage vein containing Type I liquid-rich inclusions, Type II vapour- rich inclusions, and secondary inclusion trails. F. A photomicrograph of a main-stage vein containing Type II vapour-rich inclusions and secondary inclusion trails. 70 Type II pseudosecondary fluid inclusions are two-phase (vapour + liquid), vapour-rich inclusions (>80 vol. % vapour). The inclusions are commonly elongate to sub-rounded, display a negative crystal shape, and range in length from 6 to 28 vim, with >80% of analyzed inclusions from 8 to 11 vim. Although these vapour-rich inclusions are present in early- and main-stage veins, they are more abundant in the latter. Type II inclusions are further subdivided into Type IIa and IIb; Type Ha inclusions homogenized to a vapour, whereas Type IIb inclusions homogenize to a liquid. Clathrates were only rarely observed during freezing of Type IIa and IIb inclusions, indicating the local presence of very minor CO2. In most cases a discrete CO-) phase was not visible at 25°C, which suggests that the CO2 content of Type Ha and IIb inclusions is less than 3 mol percent (i.e., the lower limit for visible CO2 liquid at 25°C, Nash 1976). Type III "mixed" inclusions are aqueous inclusion that contain between 10 and 80 vol. % vapour (i.e., vapour proportions that are between the Type I and II flints). Although these Type III inclusions are present throughout the early- and main-stage veins, they were not the focus of the fluid inclusion study because their total homogenization temperatures are considered not to represent true trapping temperatures (cf. Bodnar 2003). Results Freezing results Fluid inclusion microthermometry results for early- and main-stage veins are summarized in Tables 2.3, 2.4, and 2.5. Eutectic temperatures (TO were difficult to determine due to the small size of most inclusions. Where observed, eutectic temperatures for Type II pseudosecondary inclusions in early-stage veins (-43.4°C, n=1) and main-stage veins (-23.8 to - 28.3°C, n=3) are below the eutectic temperature for the H2O-NaCI system (-20.8°C), indicating the presence of dissolved salts other than NaCI (Shepherd et al. 1985). 71 FIA* Sample Chip ID Petrographic description (at 25 °C) Contains halite and opaque daughter crystals. Inclusions are elongate to irregular in shape and are 5 to 25 pm long. They are randomly distributed as a pseudosecondary cluster within quartz bordered by magnetite and chalcopyrite. Tightly packed inclusions contain halite and opaque daughter minerals with equant inclusions distinguished by a negative crystal shape and are 8 to 10 pm long. Inclusions are randomly distributed as a pseudosecondary cluster within quartz bordered by magnetite and chalcopyrite. Vapour-rich inclusions. Inclusions are elongate and rounded and are 6 to 10 pm long. Inclusions are located near aqueous brine inclusions. Contain a single halite daughter crystal with a trapped opaque mineral. Elongate inclusions are 7 to 9 pm long. Inclusions occur in a tightly clustered pseudosecondary trail within quartz in contact with magnetite. 1-3 daughter crystals including an opaque, halite, and possibly carbonate. Inclusions have an elongate to equant negative crystal shape and are 8 to 17 pm long. Inclusions exist as a tight pseudosecondary cluster within quartz surrounded by chalcopyrite. A single halite daughter crystal with elongate inclusions that are 8 to 25 pm long. Inclusions occur in a random pseudosecondary cluster. Contain halite and opaque daughter minerals with elongate to irregular morphologies and are 6 to 12 pm long. These inclusions occur along a linear pseudosecondary trail. Tightly packed inclusions containing a single halite crystal and a triangular opaque daughter mineral. Inclusions are irregular to elongate and are 15 to 32 pm long. Inclusions are randomly distributed as a pseudosecondary cluster within quartz bordered by maunetite. Vapour-rich inclusions that have a rounded shape and are 12 to 15 pm long. Inclusions are located near aqueous brine inclusions. Tightly packed inclusions that contain a single halite crystal and an opaque daughter mineral. Inclusions have irregular morphologies and are 10 to 12 pm long. Inclusions are randomly distributed as a pseudosecondary cluster. 1-2 daughter crystals, including halite and possibly carbonate. Inclusions are irregularly shaped and are 10 to 12 pm long. Inclusions exist as a pseudosecondary cluster located in quartz bordered by chalcopyrite. 1^KNO106- (n=4) 600.31-Al 3a^KNO106- (n=3) 600.31-A2 3b^KNO106- (n=2) 600.31-A2 5^KNO106- (n=5) 600.31-A3 9^KNO106- (n=4) 462-A2 ^10^KNO106- (n=4) 462-A2 ^12^KNO106- ^(n=6)^519-Al ^ 14^KNO106- (n=6) 519-A3 17^KNO106- (n=2) 519-A3 19^KNO205- (n=3) 430b-A2 21^KNO205- (n=2) 430b-A3 Table 2.3. Summary of microthermometric results from fluid inclusion assemblages in Early- and Main-stage veins Early-stage quartz-magnetite-pyrite-chalcopyrite veins Type of inclusion Vol % of^ Th (°C) (,) vapour Tm halite (°C) or Tm ice (°C) Salinity wt. % NaCI equiv. Type I 5 to 15^207 to 334 325.9 to 40.3 to 54.3 (L) 458.6 Type I 10^209 to 264 412.6 to 48.8 to 52.1 (L) 440.6 Type Ilb 30 to 50 357 to 376 -11.8 15.8 (L) Type I 5 to 10^221 to 260 350.1 to 42.4 to 45.9 (L) 386.2 Type I 5 to 10^131 to 209 450.6 to 53.3 to 53.5 (L) 452 Type I 5 to 15^141 to 184 441.5 to 52.2 to 65.9 (L) 544.1 Type I 5 to 10^101 to 137 314.9 to 44.2 to 49.8 (L) 420.6 Type I 5 to 10^274 to 308 284.6 to 37.0 to 43.5 (L) 310.4 Type Ilb 30 to 40 356 to 361 (L) Type I 5 to 10^161 to 242 418.7 to 49.5 to 52.5 (L) 443.9 Type I 5^160 to 168 288.8 to 37.3 to 57.1 (L) 480 * Fluid inclusion assemblage 72 Table 2.4. Summary of microthermometric results from fluid inclusion assemblages in Early- and Main-stage veins Main-stage quartz-pyrite-chalcopyrite ± molybdenite veins FIA* Sample Chip ID Petrographic description (at 25 °C) Type of inclusion Tm halite Salinity wt % NaCIVol % of Th (°C)^ (°C) or Tm vapour^ equiv. ice (°C) 22a^KNO209- This assemblage contains a single halite crystal and^Type I^5 to 10 241 to 286 356.3 to^43.0 to 54.4 (n=9)^399-Al ^ occasionally an opaque daughter mineral. Inclusion (L)^458.8 shapes range from elongate to irregular and are 5 to 11 pm long. Random distribution is noted in a pseudosecondary cluster within quartz bordered by pyrite and chalcopyrite. 26a^KNO209- This assemblage contains a single halite daughter^Type I^10^202 to 261 292.2 to^37.6 to 45.9 (n=3)^399-A2 ^ crystal with irregularly shaped inclusions that are 5 to (L)^385 10 pm long. These inclusions occur in a pseudosecondary cluster within quartz in contact with pyrite and chalcopyrite. 28^KNO209- Inclusions contain a single halite daughter crystal.^Type I^5 to 10 212 to 233 315.6 to^39.4 to 42.7 (n=3)^399-A3 with morphologies that are equant, having a negative (L)^352.7 crystal shape and are 9 to 10 pm long. Inclusions are randomly distributed as a pseudosecondary cluster within quartz imbedded with chalcopyrite. 29^KNO209- Vapour-rich inclusions displaying rounded to elongate Type Ilb^50 to 60 394 to 412 (n=4)^399-A3 shapes and are 6 to 11 pm long. Inclusions are^ (L) located near aqueous brine inclusions. 31^KNO103- Vapour-rich inclusions. Inclusions display a semi-^Type Ilb^20 to 60 254 to 389 -3.1 to -4.7^5.0 to 7.4 (n=5) 503.7-A1 rounded to equant shape and are 9 to 23 pm long. (L) Inclusions are located within quartz surround by molybdenite and chalcopyrite. 33^KNO103- Vapour-rich inclusions. Inclusions display a rounded^Type Ila^60^423 to 439 (n=3) 503.7-A2 to irregular shape, and are 6 to 18 pm long.^ (V) Inclusions are located within quartz surround by molybdenite. 34^KNO103- Vapour-rich inclusions displaying a rounded shape^Type Ila^35 to 60 404 to 486 -8.3 to -9.3^12.1 to 13.2 (n=4) 503.7-A3 are 9 to 18 pm long. Inclusions are located within (V) quartz surround by molybdenite. 35^KNO209- Contains a single halite daughter crystal. There^Type I^5 to 15 264 to 284 351.3 to^42.5 to 49.1 (n=5) 418.28-Al morphologies are irregular, and are 9 to 11 pm long. (L)^415.1 Inclusions are randomly distributed as a pseudosecondary cluster within quartz surrounded by pyrite and chalcopyrite. 37^KNO209- Brine-rich inclusions containing 1-2 daughter crystals^Type I^5 to 10 244 to 297 382.9 to^45.6 to 52.1 (n=4) 418.28-A3 (halite and carbonate?) with morphologies that are (L)^440.2 equant with a negative crystal shape, and are 10 to 25 pm long. Inclusions are randomly distributed as a pseudosecondary cluster within quartz in contact with chalcopyrite. 40^KNO209- Brine-rich inclusions that contain 1-2 daughter^Type I^5 to 20 164 to 269 346.6 to^42.1 to 53.4 (n=8) 418.28-A6 crystals (halite and carbonate?) with irregularly (L)^450.9 shaped inclusions that are 12 to 30 pm long. Inclusions occur in a tight pseudosecondary cluster within quartz surrounded by pyrite and chalcopyrite. * Fluid inclusion asemblage 73 PIA* Sample Chip ID Petrographic description (at 25°C) 8^KN0106- Carbonic-rich inclusions with visible CO 2 vapour ^(n=4)^462-Al^noted within CO 2 liquid. Inclusions are elongate and are 3 to 6 pm long. Inclusions occur in a tightly packed pseudosecondary cluster in quartz surrounded by magnetite. 18^KN0106- Carbonic-rich inclusions with visible CO 2 vapour (n=2) 600.31-A2 within CO2 liquid. Inclusions are rounded to elongate and are 10 to 14 pm long. Inclusions occur in a tightly packed pseudosecondary cluster within quartz surrounded by magnetite and chalcopyrite. ^22b^KNO106- Carbonic-rich inclusions. Inclusions are ^(n=9)^399-Al^rounded to elongate and are 7 to 16 pm long. Inclusions are randomly distributed in a pseudosecondary cluster along with brine-rich (Type I) inclusions. Inclusions are within quartz near pyrite and chalcopyrite. ^26b^KN0106- Carbonic-rich inclusions are rounded to (n=3) 399-A2 elongate in shape and are 5 to 9 pm long. Inclusions are randomly distributed in a pseudosecondary cluster that includes brine- rich (Type I) inclusions. Inclusions are within quartz near pyrite and chalcopyrite. ^26c^KNO106- Carbonic-rich inclusions. Inclusions are semi- (n=4) 399-A2 rounded to elongated and are 9 to 22 pm long. Inclusions are randomly distributed in a pseudosecondary cluster along with brine-rich (Type I) inclusions. Inclusions are within quartz near pyrite and chalcopyrite. Table 2.5. Summary of microthermometric results for CO 2 fluid inclusion assemblages in Early- and Main-stage veins Early- and Main-stage veins Type of Vol % of TM(c02) Th now) Tm (clathrete) Salinity wt. % NaCI inclusion vapour (°C) y) (°C) (°C) equiv. Type Ilb 5 27.6 to 295 to 7.7 to 7.8 4.2 to 4.7 (Early-stage vein) 27.9 360 (L) Type Ilb 5 29.9 to 315 to 5.9 to 7.2 5.3 to 7.5 (Early-stage vein) 30.9 412 (L) Type Ilb 5 30.9 to 357 to -6 to 7.5 5.0 to 20 (Main-stage vein) 31 447 (L) Type Ila 5 30.9 398 to 3.6 18 (Main-stage vein) 434 (V) Type Ilb 5 30.9 381 to -2.4 to -3 17.8 to 18.3 (Main-stage vein) 398 (L) * Fluid inclusion asemblage 74 Final ice melting temperatures (Tm ) for two Type II inclusions in early-stage veins are identical at -11.8°C (n=2), corresponding to a salinity of 15.8 wt.% NaC1 equiv. The six Type II inclusions that contain 3 to 5 mol. % CO2 have final melting of clathrate temperatures that range from 5.9 to 7.8°C (mean = 7.4 ± 0.8°C), indicating a range in salinity from 4.3 to 7.5 wt.% NaC1 equiv. (mean = 5.0 + 1.3 wt.% NaC1 equiv.). Final ice melting temperatures for the main-stage veins include ten Type II inclusions that demonstrate a Tm range of -9.3 to -3.1°C (mean = -5.8 ± 2.3°C), corresponding to a salinity range of 5.0 to 13.2 wt.% NaC1 equiv. (mean = 8.9 ± 3.0 wt.% NaC1 equiv; n=10). Eleven Type II inclusions that contain CO2 give a final clathrate melt range from -5.9 to 7.5°C (mean = 0.8 ± 5.0 °C), and a corresponding salinity range of 4.8 to 20.2 wt.% NaC1 equiv. (mean = 13.5 ± 6.0 wt.% NaCl equiv.; n = 11 ). All salinities for Type I inclusions were calculated based on their halite dissolution temperatures during heating runs and are discussed below. Heating Results Early-stage veins Microthermometry results for early-stage veins are summarized in Table 2.3 and shown in Figure 2.18. Type I liquid-rich inclusions in early-stage veins have vapour homogenization temperatures (to the liquid) that range from 102 to 335°C (Fig. 2.18A). Total homogenization temperatures (ThTOTAL) are indicated by the dissolution of the halite crystal to liquid (halite homogenization) and range from 192 to 480 °C (Fig. 2.18C; mean = 375 ± 71°C; n=34). Salinities, calculated using the dissolution temperatures of halite, demonstrate a range from 31.5 to 57.1 wt.% NaC1 equiv. (mean = 45.6 ± 6.7 wt.% NaC1 equiv.; n=34). Type IIb vapour-rich inclusions have vapour homogenization (to liquid) temperatures that range from 315 to 412°C (mean = 329 ± 48°C; n=6). 75 Main-stage veins Microthermometric results for main-stage veins are summarized in Table 2.4 and shown in Figure 2.18. Type I liquid-rich inclusions in main-stage veins have vapour homogenization temperatures (to liquid) that range from 165 to 333°C (Fig. 2.18B; mean = 248 + 38°C; n=30). Total homogenization (ThTOTAL) occurs by the dissolution of the halite between 267 and 459°C (Fig. 2.1813; mean = 385 ± 47°C; n=28). Salinities, calculated from the dissolution temperature of halite, range from 35.8 to 54.4 wt.% NaC1 equiv. (Fig. 2.18D; mean = 46.2 ± 4.7 wt.% NaCI equiv.; n=28). Main-stage veins host Type IIa and IIb vapour-rich inclusions, with the latter fluid inclusion type more abundant. Type Ha inclusions homogenize to vapour (equal to ThroTAL) at temperatures ranging from 398 to 486°C (Fig. 2.18D; mean = 438 + 29°C; n=10). Type IIb inclusions homogenize to liquid (equal to ThTOTAL) at temperatures ranging from 360 to 431°C (mean = 394 ± 22°C; n=9). Sulfur Isotope Compositions Sulfur isotope compositions were measured for pyrite, chalcopyrite, and anhydrite from four of the seven vein types occurring at Kemess North. The sulfur isotope values from these minerals provides information on the: (i) source of sulfur (i.e., igneous, sedimentary, or metamorphic), (ii) initial unfractionated sulfur source, and (iii) temperature constraints for the formation of late-stage anhydrite-pyrite veins. Sulfur isotope compositions were collected from pyrite and chalcopyrite in early-stage quartz-magnetite-pyrite ± chalcopyrite ± molybdenite veins, main-stage quartz-pyrite ± chalcopyrite ± molybdenite, and late-stage pyrite-chalcopyrite veins and anhydrite ± pyrite ± chalcopyrite veins. Anhydrite was analysed only from late-stage anhydrite ± pyrite ± chalcopyrite veins. The veins were sampled from five diamond drill holes that intersect the 76 highest Au and Cu zones in the centre of the Kemess North diorite ore body. The samples were collected from depths that range from 43 to 527 meters below the present surface. Sulfide 13 34 S values for early-stage quartz-magnetite-pyrite + chalcopyrite ± molybdenite veins define a range from 0.5 to 1.4%0 (mean= 1.0 ± 0.5%0, n=4), whereas main-stage veins define a range from -3.2 to 1.2%0 (mean= -0.1 ± 1.7%0, n=6). Late-stage pyrite-chalcopyrite veins define a $3 34 S range from 0.2 to 0.9%0 (mean= 0.6 + 0.5%0, n=2), whereas pyrite from anhydrite + pyrite veins define a range from -0.1 to 0.5%0 (mean= 0.3 ± 0.3%0, n=4). The 8 34S values for anhydrite define a range from 11.1 to 12.4%0 (mean= 11.7 ± 0.5%0, n=8). Sulfur isotope compositions are shown in Table 2.6. Carbon and Oxygen Isotope Compositions Carbon and oxygen isotope values were measured for calcite from post-mineralization carbonate-zeolite veins with the purpose of identifying the source of the fluid responsible for these late veins. Carbon and oxygen isotopes were also measured for least-altered carbonate-rich samples. Carbon and oxygen isotope compositions are shown in Table 2.7. Post-mineralization carbonate-zeolite veins were sampled from four diamond drill holes that intersect the centre of the Kemess North diorite ore body at depths that range from 150 to 600 meters below the present surface. Calcite 8 13C values for post-mineralization veins range from -10.28 to -2.19%0 (mean= -6.66 3.20%0, n=8) while calcite 8 180 values range from 6.89 to 14.66%0 (mean= 9.65 ± 2.55%0, n=8). Three carbonate-rich rocks from the main headwall in the East cirque area have a S I3C range from 0.87 to 2.39%0 (mean= 1.77 ± 0.80%0, n=3) and a 6 180 range from 3.57 to 8.54%0 (mean= 5.89 + 2.50%0 n=3). 77 Table 2.6. Summary of sulfur isotope compositions from Kemess North veins Sample Vein-type I Mineral I Weight (ug)I 6 34S (cdt) I^%S^I KN-02-01-493.4 Early-stage cp^289^0.6^38.8 KN-02-01-493.4 Early-stage py 219 1.4 17.0 KN-01-06-237.3 Early-stage py 209 0.5 36.3 KN-01-06-526.6 Early-stage py 236 1.3 40.0 KN-01-06-43.1 Main-stage py 180 0.6 47.8 KN-02-09-399.0 Main-stage cp 306 -0.8 40.3 KN-02-09-418.3 Main-stage py 183 1.2 43.2 KN-01-06-334.1 Main-stage py 224 0.7 50.5 KN-01-03-345.5 Main-stage py 212 0.8 53.3 KN-02-01-185.2 Late-stage (py-cp) py 230 0.2 49.5 KN-01-06-424.4 Late-stage (py-cp) PY 251 1.0 43.5 KN-01-06-113.4A Late-stage (anh-py±cp) py 234 0.5 50.3 KN-01-06-113.4AB Late-stage (anh-py±cp) py 223 0.2 45.6 KN-01-06-108.4 Late-stage (anh-py±cp) py 253 0.5 51.2 KN-01-06-124.8 Late-stage (anh-py±cp) py 254 -0.1 52.8 KN-02-05-307.2 Late-stage (anh-py±cp) pk-anh 450 12.1 17.7 KN-01-06-113.4A Late-stage (anh-py±cp) pk-anh 437 11.5 18.9 KN-01-06-330.5 Late-stage (anh-py±cp) pk-anh 433 12.1 20.4 KN-01-06-108.4 Late-stage (anh-py±cp) pk-anh 459 11.1 21.6 KN-02-09-348.6 Post-mineralized wh-anh 470 11.5 18.7 KN-02-05-391.6 Post-mineralized wh-anh 409 11.1 19.1 KN-01-06-113.4B Post-mineralized wh-anh 398 11.6 19.1 KN-01-06124.8 Post-mineralized wh-anh 438 12.4 11.0 Mineral abbreviations; cp:chalcopyrite, py:pyrite, anh:anhydrite Colour; pk:pink, wh:white cdt; Canyon Diablo Troilite standard 78 Table 2.7. Summary of carbon and oxygen isotope compositions from Kemess North veins I ̂ Sample^I^Vein-type^I^Host rock^I Mineral I Delta 13C (vpdb)I Delta 180 (V-SMOW) I KN-01-06 153.9^Post-mineralized Basalt (Takla Group) ca -10.3 11.2 KN-01-03 231.02^Post-mineralized Basalt (Takla Group) ca -8.7 10.6 KN-01-06 300.61^Post-mineralized Basalt (Takla Group) ca -9.8 14.7 KN-02-05 348.39^Post-mineralized Basalt (Takla Group) ca -2.2 9.1 KN-01-06 414.76^Post-mineralized Basalt (Takla Group) ca -7.7 6.9 KN-01-03 415.09^Post-mineralized Basalt (Takla Group) ca -7.9 7.1 KN-02-09 441.48^Post-mineralized KN* Diorite ca -3.6 8.0 KN-01-03 599.4^Post-mineralized KN* Diorite ca -3.1 9.7 #1 Limestone Basalt (Takla Group) ca 2.0 3.6 #2 Limestone Basalt (Takla Group) ca 2.4 8.5 #3 Limestone Basalt (Takla Group) ca 0.9 5.6 Mineral abbreviations; ca:calcite *KN=Kemess North vpdb; Vienna Pee Dee Belemnite standard V-SMOW; Vienna Standard Mean Ocean Water 79 Lead Isotope Compositions Lead isotope compositions were determined from sulfides in mineralized veins and from feldspars in intrusions and country rock. The objective of this part of the study was to help constrain the source of Pb and, possibly, other metals in the ore fluid. Lead isotope compositions for pyrite and chalcopyrite were obtained from early-stage quartz-magnetite-pyrite ± chalcopyrite ± molybdenite veins, main-stage quartz-pyrite ± chalcopyrite ± molybdenite, and late-stage pyrite-chalcopyrite veins and anhydrite ± pyrite + chalcopyrite veins. Lead isotope compositions are shown for each vein type in Table 2.8. In general terms, the lead isotopic compositions for all Kemess North veins display minor variation in 2o6pw2o4pb, 207pb/2o4pb, zospbizo4pb, 207pb/2o6pb and 208pb/2o6 Pb ratios, with ranges of 18.825 to 19.130, 15.589 to 15.709, 38.253 to 38.630, 0.821 to 0.830, and 2.019 to 2.043, respectively. Lead isotope compositions for igneous plagioclase and potassium-feldspar phenocrysts from felsic to intermediate intrusions and Takla Group country rock are shown in Table 2.8. The Pb isotope compositions are similar for each rock type, with the exception of the two late diorite dykes, which have significantly higher radiogenic values. Apart from the two diorite dykes, Kemess North rock 206pb/204pb, 207pb/204pb , 208pb/204pb , 207pb/206pb and 208—, /206Pb ratios range from 18.793 to 19.025, 15.452 to 15.649, 37.957 to 38.474, 0.820 to 0.829 and 2.016 to 2.035, respectively. 80 °° Table 2.8. Summary of lead isotope composition from Kemess North Sample Host rock Source^I Mineral mP13/2"n' lrig! 2a,% Impbem,,,A 2a,% I 2HP 13/2"Pb1 2a,% 12o7 mmpb 1 I20Bpospb1 ary. 1 KN-01-06-17 Basalt (Takla Group) Early-stage vein py 18.93 0.02 15.61 0.02 38.31 0.08 0.82 0.00 2.02 0.00 KN-01-06-52 KN* diorite Early-stage vein py 18.86 0.02 15.60 0.02 38.34 0.08 0.83 0.00 2.03 0.00 KN-02 01-11 KN* diorite Early-stage vein py 18.93 0.02 15.65 0.02 38.38 0.08 0.83 0.00 2.03 0.00 KN-01-03-53 KN* diorite Main-stage vein py 19.04 0.02 15.66 0.02 38.54 0.08 0.82 0.00 2.02 0.00 KN-01-06-13 Basalt (Takla Group) Main-stage vein py 18.89 0.02 15.67 0.02 38.61 0.08 0.83 0.00 2.04 0.00 KN-01-06-19 Basalt (Takla Group) Main-stage vein py 18.86 0.02 15.62 0.03 38.37 0.08 0.83 0.00 2.03 0.00 KNO 1-06-47 KN* diorite Main-stage vein py 18.89 0.02 15.64 0.02 38.51 0.08 0.83 0.00 2.04 0.00 KN-01-06-49 Basalt (Takla Group) Main-stage vein py 18.83 0.02 15.63 0.03 38.44 0.08 0.83 0.00 2.04 0.00 KN-02-09-14 Basalt (Takla Group) Main-stage vein cp 18.89 0.03 15.63 0.03 38.47 0.09 0.83 0.00 2.04 0.00 KN-02-09-15 KN* diorite Main-stage vein cp 18.89 0.02 15.63 0.02 38.53 0.09 0.83 0.00 2.04 0.00 KN-01-06-31 KN* diorite Late-stage vein py 18.92 0.04 15.59 0.04 38.34 0.10 0.82 0.00 2.03 0.00 KN-01-06-31 KN* diorite Late-stage vein py 18.98 0.03 15.61 0.03 38.46 0.10 0.82 0.00 2.03 0.00 KNO1 06-45A Basalt (Takla Group) Late-stage vein py 19.13 0.02 15.71 0.03 38.63 0.08 0.82 0.00 2.02 0.00 KNO2-01-12 Basalt (Takla Group) Late-stage vein py 18.96 0.07 15.66 0.04 38.36 0.22 0.83 0.00 2.02 0.01 KNO1-06-45B Basalt (Takla Group) Late-stage vein py 19.03 0.02 15.70 0.03 38.61 0.08 0.83 0.00 2.03 0.00 KNO 1-06-50 Basalt (Takla Group) Late-stage vein py 18.82 0.02 15.60 0.03 38.25 0.09 0.83 0.00 2.03 0.00 BFP-1 Basalt (Takla Group) pl 18.79 0.01 15.58 0.01 38.25 0.04 0.83 0.00 2.04 0.00 BFP-2 Basalt (Takla Group) pl 18.74 0.02 15.58 0.02 38.24 0.07 0.83 0.00 2.04 0.00 CG dyke Quartz-diorite dyke pl 19.02 0.02 15.60 0.02 38.47 0.07 0.82 0.00 2.02 0.00 Duncan 1 Duncan Pluton pl 18.96 0.02 15.60 0.02 38.41 0.07 0.82 0.00 2.03 0.00 Duncan 2 Duncan Pluton Pi 18.92 0.02 15.59 0.02 38.34 0.07 0.82 0.00 2.03 0.00 Duncan 3 Duncan Pluton pl 18.88 0.02 15.59 0.02 38.34 0.07 0.83 0.00 2.03 0.00 KN-02-07-693.8 KN* diorite p1 18.92 0.01 15.65 0.01 38.47 0.04 0.83 0.00 2.03 0.00 SOV 1 Sovereign Pluton pl 18.83 0.03 15.45 0.03 37.96 0.07 0.82 0.00 2.02 0.00 SOV 3 Sovereign Pluton pl 18.89 0.02 15.60 0.02 38.34 0.07 0.83 0.00 2.03 0.00 SOV 4 Sovereign Pluton P 1 18.91 0.02 15.57 0.02 38.27 0.07 0.82 0.00 2.02 0.00 Felsic Dyke 1 Diorite dyke p1 19.56 0.05 15.63 0.04 38.87 0.10 0.80 0.00 1.99 0.00 Felsic Dyke 2 Diorite dyke ks 19.78 0.01 15.63 0.01 38.94 0.04 0.79 0.00 1.97 0.00 Mineral abbreviations; py:pyrite, cp:chalcopyrite, pl: plagioclase, ks: potassium-feldspar *Kemess North Physicochemical Conditions of Ore Formation Ore Fluid Composition and Temperature This section describes the physical and chemical conditions of the hydrothermal fluid responsible for Au-Cu-Mo mineralization at Kemess North. The interpretations are based on fluid inclusion microthermometry data for early- and main-stage veins, S isotope compositions for late-stage veins, as well as vein and alteration equilibrium mineral assemblages. Fluid Salinity Early-stage veins have a salinity range of 31.5 to 57.1 wt.% NaCl equiv. for Type I liquid-rich inclusions and a salinity of 15.8 wt.% NaCl equiv (n = 2) for Type II vapour-rich inclusions. Main-stage veins display a very similar salinity range of 35.8 to 54.4 wt.% NaCI equiv. for Type I liquid-rich inclusions and a range of 5.0 to 13.2 wt.% NaCl equiv. for type II vapour rich inclusions. The presence of coeval (but not necessarily co-equilibrium) Type I liquid-rich and Type II vapour-rich fluid inclusions in each of the early-stage and main-stage veins could be the result of at several processes. Boiling, or immiscible phase separation, of an initially homogeneous, moderate salinity (-10 wt.% NaCI equiv.) fluid would cause the separation of the fluid into immiscible liquid- and vapour-rich components. Subsequent trapping of these two immiscible endmembers in hydrothermal quartz will produce a suite of coeval fluid inclusions with a classic "boiling assemblage" of vapour and brine (c.f., Gammons and Williams-Jones 1997). Alternatively, the immiscible mixing of at least two fluids of different composition and origin (i.e., a cool basinal brine mixing with a magmatic water) could result in the heterogeneous (non-equilibrium) trapping of liquid- and vapour-rich fluid inclusions. This may give the appearance at first of resembling an equilibrium boiling assemblage but upon inspection the phase proportions in the respective inclusions will not be representative of fluid 82 equilibria. It should also be recognized that previously boiled fluids may "remix" higher up in the hydrothermal system and be trapped together at significantly different PTX conditions than existed at the initial site of boiling. This appears to be the case with the pseudosecondary fluid inclusions in the early- and main-stage veins at Kemess North. Figure 2.18 shows that pseudosecondary Type II fluid inclusions in the early- and main-stage veins homogenized by halite dissolution rather than by vapour bubble disappearance and homogenization to liquid. Consequently, although they were trapped together (i.e., coevally), these halite-bearing liquid- rich inclusions cannot be in equilibrium with the low salinity vapour-rich inclusions because phase equilibria in the NaCl-H20 system precludes equilibrium between liquid-rich inclusions that homogenize by halite dissolution being in equilibrium with a vapour phase (Bodnar 1994). The Type I and Type II salinity ranges recorded in the early- and main-stage veins at Kemess North are similar to the ranges shown by coeval liquid-rich and vapour-rich fluid inclusions reported for porphyry Cu-Au systems world wide (Nash 1976). These ranges are repeatedly observed in porphyry Cu-Au-Mo ore systems because they are based on fluid boiling and phase equilibria in the NaCI-H20 system (e.g., Sourirajan and Kennedy 1962), although in the case of Kemess North, the fluid boiling event(s) took place at depth with non-equilibrium trapping at a later time in different PTX space. 83 12^19 21 35 CAMP; r4r, 41 400 500^6000 ^ 100^200^300 Th liquid ('C) 40 22 Th halite 37 - 35 Th liquid 400 500^600100^200^300 Th liquid ('C) 0 0 100^200^300^400^500^600 ^ Total homogenization either by Th,,, , or Th^(°C) 100^200^300^400^500^600^0 Total homogenization either by Th or^(CC) 0 600 550 500 450 40 7; 350 -c 300 25 20 15 10 600 550 50 450 40 25 20 15 10 22b 34 • • 70 D 6°' • Main-stage Type I • Type II(a) 50- I Type II(b) * Type II(a)CO2 (1) 4a^Type II(b)CO2 az 30- >, To 20-c() 10- 70^ 60- • Early-stage Type I Type II(b)CO2 10- 14 8 )8 Th halite 14 • Early-stage vein n=27 0 Th liquid 28' 26 Main-stage vein n=26 Figure 2.18. The upper covariate plots show final homogenization by halite dissolution temperatures (Th halite) versus final dissolution by disappearance of the vapour phase temperatures (Th liquid) for Type I brine-rich inclusions (A) Early- and (B) Main-stage veins. For both early- and main-stage veins, all fluid inclusion data plot in the field above the line indicating coeval halite and vapour homogenization. The data indicate that most fluid inclusions homogenized by halite dissolution. Hence, Type I liquid-rich inclusions that homogenized by halite dissolution cannot have formed by immiscible phase separation of a supercritical aqueous fluid (cf. Bodnar 1994). The lower covariate plots show salinity (wt% NaC1 equiv.) versus total homogenization temperatures (either by vapour, liquid, or halite disappearance) for FIAs measured in the (C) Early- and (D) Main-stage veins. 85 Temperature Early-stage veins consist of quartz-magnetite-pyrite ± chalcopyrite ± molybdenite with alteration selvages defined by a moderate to weakly developed zone of biotite (i.e., potassic) alteration. Several authors have suggested temperature ranges for biotite alteration in porphyry systems; from as low as 350°-550°C (Beane 1974) up to 550°-700°C (Roberts 1973). Main-stage quartz-pyrite + chalcopyrite ± molybdenite veins have quartz-sericite-chlorite-pyrite (i.e., phyllic) alteration selvages within Kemess North diorite. The presence of hydrothermal sericite in porphyry systems indicates a fluid temperature range of 360 to 550°C (Seedorff et al. 2005). Total homogenization temperatures for pseudosecondary fluid inclusions in early-stage veins are between 319 and 408 °C. However, these temperatures represent only minimum trapping temperatures for ore deposition because the data (Fig. 2.18) show that a boiling ore fluid was not trapped by these veins. Rather, the true trapping temperatures lie somewhere along the projected isochores calculated using the method of Bodnar and Vityk (1994) (Fig. 2.19). Using a pressure range of 2-3 kbar for the mineral stability of biotite (cf. Cassidy et al. 1998), which is a pressure estimate that is independent of the fluid inclusion data, it is possible to constrain the true trapping temperature for the early-stage veins. By this method, the range for the estimated trapping temperature is 350 to 408 °C (Fig. 2.19). Total homogenization temperatures for pseudosecondary fluid inclusions in main-stage veins are between 339 and 409°C. Using the same reasoning as given for the early-stage veins, these total homogenization temperatures are minimum estimates. Hence, the intersection between the independent pressure estimate, given by the mineral stability of sericite (cf. Cassidy et al. 1998), and the projected isochores gives a range for the estimated trapping temperature for main-stage veins of 339 to 400 °C (Fig. 2.19). 86 (0 3.0 –^ 3.0 — L+H+Vi.„, 363.4 ± 44.4'0 30^^0 70 80 90 100 wt% NaCI    30 ^ 40'^0 60 70 80 90 100 wt% NaCI 2.5^ I^ 2.5 Biotite alteration stability field (375 to 550 °G and 2-3 Kb) z; 2.0 - Y_ a) cr) U, 00^2 1.5CL^• 1.0 –^ 1.0 – 0.5 –^ 0.5– 1.8 ± 0.6 kb 2.0 – 1.5 '– -T1^0.0 200^400^600 Temperature (°C) CD n=7 800^1000 0.0 mean mean Early-stage Qtz-mag-py-cpy-mo veins with biotite alteration 2.1 ± 0.5 kb White mica stability field (250 to 400°C and <1-2  Kb) ^ 373.9±35 0 n=16 200^400^600^800^1000 Temperature (°C) Main-stage Qtz-py-cpy-mo veins with sericite alteration A Figure 2.19. Pressure estimates for early- and main-stage Au-Cu-Mo mineralization. Isochores for the Type I liquid-rich pseudosecondary fluid inclusions were calculated using the MacFlinCor program (Brown and Hageman 1995) and the Bodnar and Vityk (1994) equation of state for the H2O-NaCI system. (A) Early-stage veins: the intersection between individual fluid inclusion salinities and their respective isochores defines a fluid pressure range of 0.9 to 2.7 kbar (mean = 1.8 ± 0.6 kbar; n=7) and corresponding minimum formational depths of 3.0 to 8.9 km (mean = 5.9 + 1.8 km; n=7). (B) Main-stage veins: fluid inclusions have a fluid pressure range of 1.2 to 3.0 kbar (mean = 2.1 ± 0.5; n=16) and corresponding minimum formational depths of 4.0 to 9.9 km (mean = 6.9 ± 1.8 km; n=16). 88 Equilibrium sulfur isotope fractionation ratios between coeval pyrite and anhydrite are used to estimate the fluid temperature responsible for the formation of the late-stage anhydrite + pyrite ± chalcopyrite veins. In these veins, anhydrite and pyrite grains are in textural equilibrium, suggesting that they are contemporaneous and that they precipitated from a common homogenous sulfur composition in the hydrothermal fluid. The 834S values for cogenetic pyrite and anhydrite are a function of the temperature at which they precipitate. The 6 34 S values for anhydrite-pyrite pairs (n=4) and the sulfur isotope thermometer equation of Ohmoto and Lasaga (1982), which takes into account fractionation factors for anhydrite (Ohmoto and Lasaga 1982) and pyrite (Ohmoto and Rye 1979), give a temperature range of 438.3° to 502.8 °C, with an average temperature of 468.0 ± 26 °C. In summary, the fluid inclusion and hydrothermal mineral stability data show that the ore-bearing hydrothermal fluids responsible for the early- and main-stage veins had similar salinities and temperatures of ore deposition. The overlapping fluid inclusion temperature ranges for early- (375 to 408°C) and main-stage (339 to 400°C) veins suggest that there was not a major temperature change marking the transition between the two mineralizing fluid events. However, the transition from potassic to phyllic alteration mineral assemblages associated with each vein stage suggests that the later main-stage veins formed from a cooler fluid. Hence, all data considered, the best temperature estimate for early-stage veins is 400°C, which is based on the overlapping temperature ranges between the minimum trapping temperatures estimated from microthermometry measurements and the mineral stability for biotite. Whereas, the best temperature estimate for main-stage veins is 375°C, based on the overlapping temperature ranges between the minimum trapping temperatures estimated from microthermometry measurements and from mineral stability for sericite. The reduction in hydrothermal fluid temperature between the early- to main-stage fluid events coincides with the deposition of the bulk of the Au, Cu, and Mo mineralization at Kemess North. These retrograde temperature-time relationships for evolving ore 89 fluids are commonly expressed in other porphyry Cu-Au systems in the Toodoggone district (e.g., Kemess South: (Duuring et al. 2006a); Pine: (Dickinson et al. 2006) and elsewhere in the world (Seedorff et al. 2005). In other documented porphyry systems, the decrease in temperature destabilizes metal complexes, resulting a decrease in metal solubilities, and their deposition from the ore fluid (Gammons and Williams-Jones 1997). The relatively high sulfide-sulfate equilibrium sulfur isotope fractionation temperature estimate of 468.0 ± 26° C for late-stage anhydrite ± pyrite ± chalcopyrite suggests that hydrothermal fluids in the evolving Kemess North porphyry system remained relatively high even up until the later stages of Cu ± Au ± Mo mineralization. Alternatively, they may indicate the influx of a later, high-temperature, less mineralized, hydrothermal fluid after metal deposition associated with the early- and main-stage fluids. Finally, late post-mineralization carbonate-zeolite veins at Kemess North suggest formation from a low-temperature hydrothermal fluid. Pressure and depth estimates To estimate pressure conditions during early- and main-stage Au-Cu-Mo mineralization, isochores for the respective Type I brine-rich pseudosecondary fluid inclusions were calculated using the MacFlinCor program (Brown and Hageman 1995) and Bodnar and Vityk (1994) equation of state for the H 2O-NaC1 system. For early-stage veins, the intersection between individual fluid inclusion salinities and their respective isochores defines a fluid pressure range of 0.9 to 2.7 kbar (mean = 1.8 ± 0.6 kbar; n=7) (Fig. 2.19A). In comparison, main-stage veins have a fluid pressure range of 1.2 to 3.0 kbar (mean = 2.1 + 0.5; n=16) (Fig. 2.19B). In the absence of evidence for the trapping of a boiling fluid (see above), these fluid pressure ranges are minimum pressures only. Assuming lithostatic fluid pressure conditions and a pressure gradient of 3.3 km/1 kbar (Hagemann and Brown 1996), these minimum pressure estimates correspond to minimum formational depths of 90 3.0 to 8.9 km (mean = 5.9 ± 1.8 km; n=7) for early-stage veins and 4.0 to 9.9 km (mean = 6.9 ± 1.8 km; n=16) for main-stage veins. The fluid pressure and formational depth estimates interpreted from fluid inclusion studies are compatible with pressures interpreted from hydrothermal mineral assemblages associated with the two vein types. For example, the stability of hydrothermal biotite in potassic alteration assemblage associated with early-stage veins suggests a pressure range of 2 to 3 kbar (cf. Cassidy et al. 1998) and corresponding depths of 6.6 to 9.9 km. Whereas, the presence of sericite in phyllic alteration assemblages associated with main-stage veins suggests a pressure range of 1 to 2 kbar (cf. Cassidy et al. 1998) and corresponding depths of 3.3 to 6.6 km. The overlapping fluid pressure and formational depth estimates for the early- and main- stage veins, combined with their similar fluid compositions and temperatures, suggests that they formed at similar crustal depths, although the main-stage fluid may have been slightly cooler. Both vein types formed at relatively deep (-3 to 10 km) crustal depths. Tosdal and Richards (2001) note that concentric, quasi-concentric and radial fracture patterns are more common within shallower (1-3 km) crustal levels of porphyry systems, whereas veins and fractures in deeper crustal levels (3-6 km) display a singular dominant trend. The consistent vein orientation at Kemess North (i.e., all seven vein types display a 30 to 40° dip to the horizontal) is compatible with the mineralization at Kemess North forming at relatively deep crustal depths. These depth estimates are feasible considering that mineralization at the Butte Cu-Mo porphyry deposit in Montana, USA is demonstrated to have formed at depths up to 9 km (Rusk et al. 2004). 91 Constraints on the source of the hydrothermal ore fluid Sulfur, Carbon, and Oxygen Stable Isotopes Sulfur (6 34S) isotope values were determined on pyrite, chalcopyrite, and anhydrite in mineralized veins to provide insight on possible sources of sulfur in the ore fluids. Sulfur has three main isotopic reservoirs in the Earth: (1) mantle (0 ± 3%o), (2) seawater (10 to 30%o), and (3) strongly reduced sediments (-70 to +70%o) (Ohmoto and Rye 1979). Using an estimated hydrothermal fluid temperature of 400°C, as constrained by fluid inclusion microthermometry of early-stage veins, in conjunction with sulfide mineral-H 2S sulfur isotope fractionation factors for pyrite and chalcopyrite (Ohmoto and Lasaga 1982), calculated 6 34 S H2s values range from -0.1 to 0.9 per mil (n=4). For main-stage veins, use of a formation temperature of 375°C together with sulfide mineral-H 2 S isotope fractionation factors for pyrite and chalcopyrite, yield a range of 634SH2s values from -4.3 to 0.3%0 (n=6). Late-stage pyrite-chalcopyrite veins display a range of 634SH2s values from -0.7 to 0.1%0 (n=2) based on a fluid temperature estimate of 350°C and the sulfide mineral-H2S isotope fractionation factors for pyrite. Finally, late-stage anhydrite-pyrite ± chalcopyrite veins have a range of calculated 6 34SH2s values from -0.8 to -0.2°/00 (n=4), using a hydrothermal fluid temperature estimate of 468°C and pyrite-H 2 S fractionation factors. To determine the original isotopic composition of the sulfur in the ore fluid prior to fractionation between sulfate and sulfide species (and thus obtain the 6 34S value of the sulfur source) the temperature and ratio of oxidized to reduced species needs to be determined as this ratio is a function of the oxidation state (f0 2) and acidity (pH) of the fluid (Ohmoto and Rye 1979). The proportion of oxidized species in the ore fluids can be assumed to be negligible in the early and main-stage stages of vein formation because sulfate minerals are absent and there is little variation in the 6 34 S H2s values throughout vein paragenesis from early- to late-stage; thus it can be assumed that the oxidation state was below the S02/H2S boundary (Ohmoto and Rye 92 1979). Since, the magmatic fluid was initially H 2S dominant there is no change in 6 34S, rs (Ohmoto and Rye 1979). Therefore, 6 34S values from sulfide minerals in the Kemess North veins have a similar value to that of the ore forming fluid assuming equilibrium was achieved. The narrow range of 6345 values (clustering around 0%0) of the sulfides from the mineralized veins in the Kemess North deposit suggests that the sulfur source was derived from a homogenous igneous source. Sulfur isotope compositions for coexisting anhydrite and pyrite in late-stage anhydrite- pyrite ± chalcopyrite veins are used to calculate the initial unfractionated sulfur isotope signature of the ore fluid (6 34SEs) and the mole fraction of oxidized and reduced sulfur components (Ohmoto and Rye 1979; Field et al. 2005). Figure 2.20 shows 6 34S values for sulfate-sulfide mineral pairs versus the A34 Ssulfate-sulfide for late-stage anhydrite-pyrite ± chalcopyrite veins from Kemess North. Lines of best-fit calculated for the anhydrite and pyrite data, respectively, converge at 3.6%0 on the y-axis (i.e., where A=0), which corresponds to the 6 34SEs of the unfractionated ore fluid (Field and Gustafson 1976; Field et al. 2005). This initial sulfur value is typical for porphyry Cu deposits (Ohmoto and Rye 1979) and suggestive of an igneous source. The value is slightly higher than the —0%0 calculated for the early- and main-stage veins, which could be interpreted to represent fluids exsolved from a different batch of porphyry magma than the one which produced the early- and main-stage veins. This interpretation is consistent with the slightly higher temperatures calculated for the late-stage anhydrite-pyrite + chalcopyrite veins from the Kemess North deposit, which is suggestive of magma recharge (i.e., introduction of a new magma batch) and subsequent exsolution of hotter fluids. Similar prograde hydrothermal fluid events have been documented at the North Fork porphyry Cu-Au deposit in Washington state (Smithson 2004) and at the Henderson porphyry Mo deposit in Utah (Seedorff and Einaudi 2004). From the slopes of the lines of best-fit on Figure 2.20, a mole fraction of 1:2 for SO4 :H2 S was calculated for the fluid (c.f., Field and Gustafson 1976; Field et al. 2005). 93 y= 0.70x + 3.6 ctionated so y= -0.30x + 3.6 6^8^10 A Anhydrite - Pyrite 4 12^14 Anhydrite • Pyrite 15— 5 3.6 %o Initial unfr Figure 2.20 94 Figure 2.20. Equilibrium sulfide-sulfate pairs (n=4) in the late-stage anhydrite + pyrite veins. By projecting lines of "best-fit" for these data back to their intersection on the y-axis, an estimate of the isotopic composition of the unfractionated sulfur source (3.6 %o) can be determined. 95 Carbon (6 13C) and oxygen (6 180) isotope compositions were determined for calcite from post-mineralization zeolite-calcite veins with the purpose of identifying possible sources of carbon and oxygen in these fluids. Isotopic values for hydrothermal calcite are controlled by a variety of factors, including initial fluid and wall-rock isotopic compositions, temperature, and proportions and types of dissolved carbon species (Zheng and Hoefs 1993). Temperatures of carbonate deposition in these zeolite-calcite veins are unknown and can only be estimated from low grade zeolite-facies metamorphism. According to Turner (1981), maximum temperatures for zeolite facies metamorphism are -200°C. At this temperature, the 6 13C fractionation between calcite and CO2 in the hydrothermal fluid is negligible with the Aco2-calcite 0.2%0 (Bottinga 1969). At a temperature of 200°C and assuming that CH4 is absent from the fluids, which is reasonable given that none was identified in fluid inclusions from the veins studies nor expected given the dominantly volcano-plutonic host-rocks, then the dominant carbon species in the fluid is assumed to be CO2 (e.g., Ohmoto 1986). Consequently, the SI3Ccalcite values for these veins can be considered good approximations of the 6 13 C values of CO2 in the hydrothermal fluids. Examination of Figure 2.21 and the results in Table 2.6 reveals that the 613Ccalcite values range from -2.2 to -10.3%0. Within this range are several carbon isotope reservoirs including igneous and metamorphic sources. Importantly, however, the negative 6 13C values do rule out marine carbonate from limestones and marbles as a source of carbon in the calcite-zeolite veins. Consideration of the geological setting of the Kemess North deposit, the widespread distribution of zeolite-calcite veins in rocks throughout the Toodoggone district, and the zeolite facies regional metamorphism that affected the area leads to the conclusion that the calcite-zeolite veins likely utilized a dominantly metamorphic source of carbon. A contribution of carbon from an igneous source is also possible, but the widespread distribution of the zeolite-calcite veins throughout the Toodoggone is suggestive of a regional metamorphic event. 96 10 5 unaltered marine limestone 0 0 a) 5" (mo o -5 0 0 0  -10 Go •^•• arbonatite mantl ■■ primitive igneous rock • metamorphic fluids marble -15 -20 0 A Kemess South Asitka limestone • Carbonate-rich unit ■ Post-mineralized calcite- zeolite veins 10^15^20^25^30^35^40 6 180v_sm0w of calcite (°/00) Figure 2.21 97 Figure 2.21. The carbon and oxygen isotopic compositions of post-mineralization zeolite- calcite veins and deformed/altered blocks of Asitka limestone from the Kemess North porphyry Au-Cu deposit. See text for discussion. 98 The use of oxygen isotopes to trace the source(s) of oxygen in the hydrothermal fluids that deposited the calcites is difficult due to the strong temperature dependency of the oxygen isotope fractionations between the 0-bearing minerals and equilibrium waters (e.g., Taylor 1979). If it is assumed that the post-mineralization zeolite-calcite veins formed at 200°C, then the fluids that deposited the calcites will have 00 values approximately 9.5%0 lower than those measured on the calcites. Examination of Figure 2.21 and Table 2.6 reveals that calcites from the zeolite-calcite veins have 6 180 values from 6.9 to 14.7%0. Application of the fractionation factors cited above to the 13 18 0calcite data reveals that the 6 180 of the equilibrium waters could have ranged between -2.6 and 5.2%0. Comparison of these values with the meteoric water line for the Canadian Cordillera, which is believed to be relatively unchanged since Early Cretaceous time (Taylor 1979), indicate that they are very typical of moderately 180-enriched meteoric waters (Nesbitt et al. 1986). Similar meteoric waters have been found in shallow epithermal deposits such as the Dusty Mac gold mine in southeastern British Columbia (Nesbitt et al. 1986). In summary, the lack of precise temperature constraints for zeolite-calcite vein formation precludes any definitive identification of the sources of carbon and oxygen in the fluids from which they formed. It is tentatively concluded, however, that the veins formed from heated meteoric waters that either incorporated carbon from metamorphic-magmatic host rocks, or interacted with metamorphic and/or magmatic fluids accompanying low grade regional metamorphism. Carbon and oxygen isotope data were also collected from a thin carbonate-rich unit (several meters wide) that occurs within Takla Group basalt on the E-W trending headwall of the east cirque (Table 2.6). The original lithology of the unit is uncertain and carbon and oxygen isotope compositions may help determine whether it represents: (1) a small block of altered Asitka limestone that is tectonically emplaced within Takla Group basalt; (2) a deformed lens of clastic carbonate within the Takla Group; (3) a magmatic dyke (carbonatite?); or (4) a vein of 99 hydrothermal carbonate. The 6 130 values (0.9 to 2.4%o) for this carbonate-rich unit overlap with 13 13 C values for Permian limestone (approx. 0 to 6%o, Veizer and Hoefs 1976), but the 6 180 values of 3.6 to 8.5%0 are much lower than that of unaltered Permian marine limestone (22 to 32%0, Veizer and Hoefs 1976) or typical marble (Fig. 2.21). However, 6 180 depletions of 15 to 20%o have been documented in Permian carbonate rocks from Arizona (Guerrera et al. 1997) metamorphosed at low metamorphic grades and similar processes may explain the low 6 180 values measured in the carbonate-rich unit in this study. Moreover, the close proximity of the carbonate-rich unit to the large Kemess North porphyry system has exposed it to contact metamorphism and metasomatism. Contact metamorphosed rocks commonly exhibit large depletions in 180 (10 to 15%o, Valley 1986) that reflect interaction with large volumes of meteoric and/or magmatic fluids. Consequently, this unit is probably a small block of Asitka limestone that was altered and metasomatized during both tectonic relocation to its current position in the Takla basalt and, subsequently, by various fluids associated with the emplacement of the Kemess North porphyry complex and development of the Au-Cu orebody. Note that although the 6 180 values are fluid-buffered, the 6 13 C values are rock-buffered and have retained their original marine limestone signature. This situation occurs in hydrothermal systems developed in sedimentary carbonates due to the fact that hydrothermal fluids have a very low carbon content relative to the marine sedimentary rock in which they invade (c.f., Rowins et al. 1997) Lead Isotopes Lead isotopes are used to help constrain the potential sources and pathways of hydrothermal fluids responsible for Au-Cu-Mo mineralization at the Kemess North deposit. In some, but not all cases, Pb may be used to trace the source of Au, Cu, and Mo assuming that all the metals originated from the same source area and that these metals have similar behaviours in 100 terms of their transport and depositional processes (Tosdal et al. 1999). This assumption, however, is not necessarily true and interpretation of Pb isotope compositions must be done with caution. Lead isotope values were determined for pyrite and chalcopyrite for the early-, main-, and late-stage mineralized veins. Igneous alkali feldspar and plagioclase phenocrysts were separated and analysed from intrusive phases and the bladed feldspar porphyry variant of Takla basalt in the Kemess North area. Lead isotope results are presented on thorogenic (208Pb/204Pb versus 206pw204pb; Fig. 2.22) and uranogenic (207p, D//204Pb versus 2o6pw2o4p , ;D Fig. 2.23) diagrams. Both Pb diagrams include the model crustal reservoir curves from Zartman and Doe (1981). Lead isotope values for the Kemess North, Sovereign, and Duncan plutons cluster with overlapping error envelopes. The Pb isotope values for these plutonic rocks are more radiogenic than the average Pb isotope signature of the mantle, suggesting that the plutons assimilated Pb from the upper crust so that they now display Pb isotope values that are similar to the upper crust. The 207p, D/ /206Pb versus 208p, /206Pb diagram (Fig. 2.24) is useful because the errors associated with the Pb isotope measurement of 204Pb are eliminated. Note that the Kemess North plutons have Pb isotope values that overlap on this diagram. The early-, main-, and late-stage veins all have similar Pb isotope values that overlap the fields defined by the plutons occurring in the Kemess North area. In particular, the Pb isotope compositions for early-stage quartz-magnetite-pyrite-chalcopyrite-molybdenite veins closely overlap those for the plutons (Fig. 2.24), suggesting that fluids responsible for these veins have a magmatic Pb component (and probably magmatic Au, Cu and Mo). The main- stage veins have a slightly greater range of Pb isotope values, some of which plot close to the Pb isotope values for Takla Group country rock (Fig. 2.24). This suggests that the main-stage veins, which are associated with widespread phyllic alteration, incorporated significant Pb from the Takla Group country rocks as hot magmatic-hydrothermal fluids circulated and mixed with meteoric waters. 101 Lithologies 40- diorite dyke X K-feldspar syenae dyke ^ Duncan pluton ♦ Kemess North pluton A Sovereign pluton * Takla Group basalt Mineralization • late-stage anh-py veins A late-stage py-cp veins g main-stage glz-py-cp-mo veins ,early-stage qtz-mt-py-cp-mo veins Average error 40.0 A U 15.0 34.0 - 13.0 -° 38.0 H (N° 0 co O 36.0 - 17.0 206 p b/204 p b 19.0^21.0 _o 39.5 39.3 - 39.1 - 38.9 - Nsto B 38.7 A 38.5 Xa_ 38.3 'A'641?..**099 O 38.1 - 37.9 - A 37.7 - 37.5 - 18.50 18.75^19.00 19.25 19.50 19.75 20.00 206p 13 /204 p b Figure 2.22 102 Figure 2.22. 208Pb/204Pb versus 206Pb/204Pb ,I'D along with ideal crustal reservoirs curves of Th-Pb evolution from Zartman and Doe (1981). The lithologies all appear to have a similar Pb ratio which is consistent with an interaction with the upper crustal reservoir. Mineralization from the deposit shows a consistent trend with the lithologies. 103 AUpper crust^• 400 Ma 11° Orogene •* * 11.■ Lithologies • diorite dyke X K-feldspar syenite dyke ^ Duncan pluton Kemess North pluton A Sovereign pluton * Takla Group basalt Mineralization • late-stage anh-py veins A late-stage py-cp veins main-stage qtz-py-cp-mo veins Learly-stage qtz-mt-py-cp-mo veins Average error I --a 0 Ma —r 16.01 A 15.2 - 15.0 - 13.0 15.0 17.0 206 p b/204 pb 19.0^21.0 15.80 ^ B 15.75 15.70 - ID 11. 15.65 -o 15.60 RI 15.55 - 15.50 - 15.45  - 15.40 - 18.50 A 18.75 19.00^19.25 19.50^19.75 20.00 206p b/204p b Figure 2.23 104 Figure 2.23. 207Pb/204Pb versus o2 6pb/204—, ,I'D along with ideal crustal reservoirs curves of U-Pb from Zartman and Doe (1981). Lithologies and mineralization show similar ratios and is consistent with upper crustal interaction. 105 • Lithologies 41 , diorite dyke X K-feldspar syenite dyke ^ Duncan pluton Kemess North pluton A Sovereign pluton * Takla Group basalt Mineralization • late-stage anh-py veins A late-stage py-cp veins • main-stage qtz-py-cp-mo veins ▪ early-stage qtz-mt-py-cp-mo veins Average error ^ X X 3E 1 2°7Pb/ 206 Pb 0.85^0.84^0.83^0.82^0.81^0.80 ^ 0.79 ^ 0.78 ^ 0.77 1.97 1.98 1.99 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 O CO -0 0 rn -00 Figure 2.24 106 Figure 2.24. 207Pb/206Pb versus o2 spw2o6pb diagramram indicates that the early- and main-stage veins have similar Pb ratios to the Kemess North pluton and Takla host rocks. A few late-stage mineralized veins have slightly higher radiogenic Pb values, which might reflect wider circulation of fluids through the country rock during the phyllic event. 107 Formation of the Kemess North Porphyry Au-Cu-Mo Deposit Asitka and Takla Group country rock Country rock in the vicinity of the Kemess North deposit includes Permian Asitka Group limestone and Upper Triassic Takla Group basalt. Takla Group basalt is intruded by the Sovereign, Kemess North, and possibly the Duncan plutons, whereas Asitka Group limestone is only exposed in the N-trending Duncan ridge, approximately one kilometre to the west of Kemess North. This study has also tentatively identified it as a narrow block tectonically emplaced into the headwall of the east cirque. The Takla Group volcanic rocks consist of a lower massive basalt unit that is overlain by a basaltic bladed feldspar porphyry unit. Although extrusive flow indicators were not recognized in the basalt at Kemess North, obvious pillow structures, lava flows, and volcanic breccias are recognized elsewhere in the district and indicate that the Takla Group rocks are extrusive units (Diakow et al. 1993). The basaltic bladed feldspar porphyry unit is an exception to this extrusive history and likely intruded massive basalt at relatively shallow crustal depths, possibly as shallow-dipping sills. Fine-grained mafic dykes that cut only the Takla Group rocks probably represent the last phases of mafic magmatism prior to the emplacement of the felsic plutons. 108 Early-Jurassic plutonism and porphyry-style Au-Cu-Mo mineralization Takla Group country rock is intruded by the Sovereign diorite (202.7 ± 1.9 Ma, Diakow 2001) and the Kemess North diorite (ca. 202 Ma, Diakow 2006b) (Fig. 2.25). The dimensions and morphology of the Sovereign pluton are poorly constrained by the limited surface exposure and exploration drilling. Similarly, only the upper 200 m of the Kemess North diorite has been tested by drilling. Consequently, the exact genetic relationship between the Sovereign and Kemess North plutons from field relations is uncertain. This study, however, has shown that in addition to similar ages of emplacement, both plutons display very similar trace element characteristics (e.g., REE ratios and chondrite-normalized profiles; Fig. 2.8) and radiogenic Pb isotope values. Consequently, it is likely that the Sovereign and Kemess North plutons represent two distinct magmatic batches from the same parent pluton at depth. The Duncan pluton also possesses radiogenic Pb isotope values and trace element abundances similar to those in the Sovereign and Kemess North plutons, but it is approximately 5 million years younger than both of the aforementioned plutons. Consequently, its exact genetic relationship to the Sovereign and Kemess North plutons is less certain. 109 A. Sovereign diorite intrudes the Takla Group basalt at 202.7 ± 1.9 Ma (Diakow 2001) Kemess North diorite intrudes at ca. 202 Ma (Diakow 2006b). Au-Cu-Mo mineralization associated with the Kemess North diorite occurs at 201.8 ± 1.2 Ma (Re-Os on molybdenite) Fluid inclusion data from early- and main- stage veins constrain the minimum depth of mineralization to about 6.5 km B. Erosion and uplift occurs at an estimate rate of 1.7 km/Ma This results in the exposure of the Sovereign diorite C. Toodoggone Formation rocks (Duncan Member) are deposited at 199.1± 0.3 Ma (Diakow 2001) Toodoggone Formation rocks contain clasts of Takla Group basalt and the Sovereign diorite The Duncan diorite pluton intrudes the Toodoggone Formation volcaniclastic rocks and Takla Group basalt at 197.3 ± 1.1/0.9 Ma (Diakow 2001) D. North-south directed extension results in a steeply dipping, E-W striking normal fault that truncates the diorite and Takla Group basalt, and Toodoggone Formation rocks. II E. North-south directed shortening results in the formation of shallow, S-dipping reverse faults that truncate the Kemess North diorite. Younger Toodoggone Formation rocks are displaced beneath the Kemess North diorite 411! F. NW directed extension results in horst-and-graben style block shuffling of the stratigraphy G. Finally, uplift and erosion results in the present-day exposure at Kemess North. Figure 2.25 0 km-f -L  110 Figure 2.25. Schematic diagrams showing the formation of the Kemess North porphyry Au-Cu deposit. The block model shows each step in the creation of the deposit. This model illustrates Toodoggone volcaniclastic rocks being deposited on top of Takla Group rocks. 111 The Au-Cu-Mo mineralization spatially associated with the Kemess North diorite occurred at about 201.8 + 1.2 Ma (Re-Os on molybdenite from main-stage veins; Table 2.2). Fluid inclusion constraints from early-stage veins suggest that the bulk of the Au-Cu-Mo mineralization was deposited within the diorite and adjacent Takla Group country rock at a minimum depth of about 6.5 km and temperature of about 400°C. The early-stage fluids caused potassic alteration in the diorite and surrounding Takla Group basalt. Early-stage ore fluids are trapped as liquid-rich and vapour-rich pseudosecondary fluid inclusions. The fluid inclusion results do not support the local trapping of a boiling fluid in the veins studied. Rather, they support either heterogeneous mixing of two or more fluids, or more likely, the boiling of the ore fluid in deeper parts of the porphyry system and remixing and non-equilibrium trapping higher up in the system. Sulfur isotope compositions from sulfide minerals from the early-stage veins indicate that the sulfur (and metals) were derived from a magmatic source. Similarly, the overlapping radiogenic Pb isotope values for sulfide minerals from the early-stage veins and the Kemess North diorite suggest that the early-stage fluids were dominantly derived from the Kemess North diorite. Main-stage veins and associated quartz-sericite of phyllic alteration replace the diorite and Takla Group basalt. Fluid inclusion results indicate that Au, Cu, and Mo deposited as sulfide minerals from the ore fluid at about 375°C. This suggests that the metalliferous magmatic-hydrothermal fluid had cooled from the early-stage mineralization event, which lead to a decrease in the solubility of copper chloride and molybdenate complexes and deposition of pyrite, chalcopyrite, and molybdenite (e.g., Hezarkhani et al. 1999). Sulfur isotope values for main-stage veins imply that the sulfur and metals were derived from a magmatic source. Lead isotope values for main-stage veins show a greater spread than the values for early-stage veins and plot closer to the Pb isotope values for Takla Group country rock. These results suggest that the magmatic fluid interacted with Takla Group country rock and/or other meteoric fluids incorporating Pb from these sources. 112 The earliest-forming late-stage veins and phyllic alteration occurred at relatively high temperatures of about 468 ± 25°C (based on sulfide-sulfate S isotope geothermometry). Sulfur and Pb isotope compositions indicate that magmatic fluids interacted with Takla Group country rock and/or externally-derived fluids. As discussed above, the high temperatures of late-stage vein formation may be indicative of magmatic recharge of the Kemess North parent pluton and subsequent exsolution of a magmatic-hydrothermal fluid at higher temperatures than the early- and main-stage veins (i.e., a prograding hydrothermal system). Early-Jurassic volcanism and deposition of the Toodoggone Formation rocks Porphyry-style mineralization in the Kemess North diorite occurred at a depth of 6.5 km at about 201.8 1 1.2 Ma. Takla Group rocks above the Kemess North diorite and Sovereign plutons were eroded and the Sovereign pluton was exposed at surface prior to the onset of volcanism and deposition of the Toodoggone Formation rocks at 199.1 ± 0.3 Ma (Diakow 2001). Hence, approximately 5 km of rock was eroded in about 3 million years, giving an uplift rate of about 1.7 km per million years. The Toodoggone Formation at Kemess North is at least 1.2 km deep (based on drill interceptions). The Toodoggone Formation exposed at Kemess North is interpreted to be the Duncan Member (Diakow 2001). Diakow (1993) considers the presence of ash flows within the lower volcanic cycle and the lack of depositional features in the Saunders Member as evidence against a caldera source for the Toodoggone Formation rocks. A caldera source typically produces a base of precursor fallout, ground surge, a thick layer of ash flows, thinner layers of pumice swarms, and ash cloud debris, overlain by fallout tephra (Fisher and Schmincke 1984). In contrast, the Toodoggone Formation rocks appear to be spatially related to the regional Saunders-Wrich fault, therefore suggesting that volcanism was associated with fissure-style eruptions (Diakow et al. 1993). The absence of recognized vents for the Saunders member 113 suggests that the fissure vents are buried. An analogy to the Toodoggone district may include the Sierra Madre Occidental in the southwest United States and northern Mexico. In this area, ignimbrite flows are about 1000 m thick and occupy an area of about 393,000 km 3 (Aguirre-Diaz and Labarthe-Hernandez 2003). At least 350 calderas, similar in size to the ones documented in the San Juan volcanic field in Colorado, would be needed to produce this volume of ignimbrites (Aguirre-Diaz and Labarthe-Hernandez 2003). However, only 15 calderas have been identified in the area, suggesting that fissure-fed ignimbrites must also be present. Aguirre-Diaz and Labarthe-Hernandez (2003) suggest that these large fissures are associated with a large elongate magma chamber or a series of batholith-sized magma chambers. Regional extension allowed the magma chambers to be emplaced at relatively shallow levels in the upper crust. The Duncan pluton intruded Takla Group or Toodoggone Formation rocks shortly after the deposition of the Toodoggone Formation rocks (i.e. at 197.3 ± 1.1/0.9 Ma, Diakow 2001). Fine-grained hornfels, the result of contact metamorphism of the Takla Group basalt are developed proximal to the margin of the Duncan pluton indicating that the pluton intruded Takla Group rocks. In contrast, relationships with the Toodoggone Formation rocks are unclear because lithological contacts were not observed between the pluton and rocks of the Toodoggone Formation. The present day location of the Duncan pluton adjacent to Toodoggone Formation rocks could be explained by the intrusion of the Duncan pluton into Toodoggone Formation rocks or a structural juxtapositioning of these rocks due to a fault contact. Regardless, the younger age of the Duncan pluton (ca. 197 Ma) indicates that felsic plutonism and volcanism were talking place at approximately the same time in the Toodoggone district. Northwest- trending, subvertical, felsic dykes cut the Toodoggone Formation rocks and suggest NW-SE directed shortening. 114 Structural dismemberment of the Kemess North deposit North-south directed extension resulted in the formation of a deposit-scale, steeply dipping, E-W striking, normal fault that truncates the Kemess North diorite and structurally juxtaposes Toodoggone Formation rocks against deeper Takla basaltic rocks to the south (Fig. 2.25). Displacement on the fault is at least 1.2 km vertical movement (based on the minimum thickness of the Toodoggone Formation rocks). The occurrence of Toodoggone Formation rocks below the older Kemess North pluton might be explained by at least two possibilities (Figs. 2.25 & 2.26). A shallow S-dipping reverse fault along the lower margin of the Kemess North pluton could displace Toodoggone Formation rocks beneath the Kemess North pluton. Although rocks are deformed along this contact in drill core, no shear sense indicators are apparent. Alternatively, a near-vent eruption of Toodoggone Formation volcaniclastic rocks may have resulted in the truncation of the Kemess North pluton and be the cause of the > 1.2 km thick package of Toodoggone Formation rocks immediately to the north of the pluton (Fig. 2.26). Subsequent N-S directed shortening resulted in N-striking normal faults and horst-and-graben style block shuffling of the stratigraphy. The Toodoggone Formation rocks in the central ridge define a graben in the centre of the Kemess North deposit. 115 Toodoggone volcar clastIc rock 0 km- Duncan Conte A. Sovereign diorite intrudes the Takla Group basalt at 202.7 ± 1.9 Ma (Diakow 2001) Kemess North diorite intrudes at ca. 202 Ma (Diakow 2006b). Au-Cu-Mo mineralization associated with the Kemess North diorite occurs at 201.8 ± 1.2 Ma (Re-Os on molybdenite) Fluid inclusion data from early- and main- stage veins constrain the minimum depth of mineralization to about 6.5 km B. Erosion and uplift occurs at an estimate rate of 1.7 km/Ma This results in the exposure of the Sovereign diorite C. Toodoggone Formation (Duncan Member) rocks are deposited at 199.1± 0.3 Ma (Diakow 2001) via a fissure-style eruption, with the volcanic vent truncating the Kemess North pluton Toodoggone Formation rocks contain clasts of Takla Group basalt and Sovereign diorite D. Duncan diorite intrudes the Toodoggone Formation volcaniclastic rocks and Takla Group basalt at 197.3 ± 1.1/0.9 Ma (Diakow 2001) E. Period of extension producing a large deep seated normal fault North side of the EW-trending normal fault is down 0 km 3 F. NW directed extension results in horst-and-graben style block shuffling of the stratigraphy  G. Finally, uplift and erosion results in the present-day exposure at Kemess North. 0 km Figure 2.26 116 Figure 2.26. Schematic diagrams showing the formation of the Kemess North porphyry Au-Cu deposit. The block model shows each step in the creation of the deposit. This model illustrates Toodoggone volcaniclastic rocks being deposited via a fissure-style eruption. Note that this is the alternative interpretation for the formation of the Kemess North porphyry Au-Cu deposit. 117 Comparisons with the nearby Kemess South Au-Cu-Mo porphyry deposit The Kemess South and the Kemess North deposits lie 7 km apart and are the largest known porphyry Au-Cu ± Mo systems in the Toodoggone. Many similarities exist between the two systems. Mineralization within both deposits is temporally and spatially associated with two high-K, calc-alkaline, diorite porphyry intrusions that were emplaced at ca. 200 Ma (Diakow 2001) and ca. 202 Ma (Diakow 2006b), respectively. Vein-types in each deposit have comparable mineralization events. Mineralized veins contain quartz, magnetite, pyrite, chalcopyrite, with minor molybdenite. Both deposits have late-stage pyrite stringer veins cut by successive post-mineralization, anhydrite-rich carbonate- rich veins. Hydrothermal alteration mineral assemblages are similar in that both porphyry systems display an early potassic alteration that is replaced by a phyllic (quartz-sericite ± pyrite) event. At Kemess South, the early potassic phase is dominated by K-feldspar, whereas at Kemess North it is expressed by biotite. Phyllic alteration destroys most of the early potassic alteration at Kemess North. Post-mineralization faults are important at both deposits and result in the dismemberment of the respective ore bodies. An E-W striking normal fault that dips steeply to the north truncates the Kemess North orebody, whereas at Kemess South an E-W striking normal fault that dips to the south truncates the ore body (cf. Duuring et al. 2006b). Both porphyry systems are displaced by late NW- to NE-striking normal faults that result in horst-and-graben block shuffling of each ore body. Exploration Implications The similarity in age, mineralogy, and geochemistry between the Sovereign and Kemess North plutons is suggestive of a genetic relationship. If these two plutons are genetically related, 118 then the Sovereign pluton represents an exploration target. Hence, the area between the Kemess North and Sovereign plutons deserves further drilling. The effects of horst-and-graben structures throughout the Kemess North deposit require accurate structural interpretations of the ore body in three dimensions. Abrupt horizontal changes in rock types and ore bodies may represent the transition across a fault zone from a horst to graben structure. In such a situation, the ore body may have been vertically displaced and may require deeper drilling. The eastern regions of the Kemess North deposit area remains open to exploration and interpretation, possibly because of vertical displacement of the ore body as suggested by the presence of slivers of Toodoggone Formation rocks exposed in the East ridge (Fig. 2.2). The Toodoggone Formation rocks cropping out in the central ridge represent an important exploration site. The ridge has been drilled by about four drill holes that only penetrate to shallow depths. Most of the drill intersections returned low concentrations of Au and Cu. Only through recent mapping has it been shown that this central ridge is Toodoggone Formation rocks, rather than the previously interpreted Takla Group rocks. Hence, the potential exists below the Toodoggone Formation rocks in underlying Takla Group rocks. The limited shallow drilling that penetrates Takla Group rocks confirms the interpretation that mineralization might be continuous beneath the central ridge, linking the Nugget zone with the main Kemess North deposit. Lastly, only minor remobilized mineralization occurs within structures in Toodoggone Formation rocks. As such, these rocks represent a low potential of hosting significant ore bodies at Kemess North. Rather, mineralized structures are more significant in Takla Group rocks that surround the Kemess North diorite. Toodoggone Formation rocks are younger than the porphyry-related mineralization and therefore it is unlikely that they will host high-sulfidation epithermal mineralization related to the Kemess North ore system. Peripheral low-sulfidation 119 epithermal mineralization is possible providing there is circulation of metal-bearing hydrothermal fluids through the rocks. Conclusions The Kemess North Au-Cu-Mo deposit is located in the Toodoggone district of north- central British Columbia, Canada. The district contains Permian to Cretaceous volcanic and plutonic rocks of the Asitka, Takla, Hazelton, and Sustut groups; these rocks are locally intruded by the Black Lake granitoid suite. The Kemess North deposit is dominated by Upper Triassic Takla Group basaltic units (Fig. 2.2), which includes massive basalt that is overlain by basaltic bladed feldspar porphyry rocks. Asitka Group units are not recognized in the deposit area excluding a possible limestone block tectonically emplaced within the headwall of the east cirque. Excluding this headwall location, the only other exposed Asitka limestone occurs in the Duncan ridge, about 3.5 km to the west of the deposit. The mineralized, ca. 202 Ma, Kemess North diorite pluton intrudes Takla Group basalts. The pluton is not exposed at surface and is only observed in drill core more than 150 m below the present surface in the western and central areas of the deposit. The 202.7 ± 1.9 Ma Sovereign diorite is unmineralized and intrudes Takla Group basalt in the south of the deposit. No lithological contacts between the Sovereign and Kemess North plutons have been observed but they do appear to be genetically related based on similar emplacement ages, identical trace element geochemistry, and similar radiogenic Pb isotope values. The Toodoggone Formation volcaniclastic rocks (199.1 ± 0.3 Ma) crop out as prominent N-trending ridges or as isolated, fault-bounded, blocks amongst Takla Group basalt. Units of the Toodoggone Formation also occur beneath the Kemess North diorite. The Duncan pluton crops out in the northern areas of the deposit and is surrounded by hornfels produced by contact metamorphism in Takla Group basalt. No contact was observed between the Duncan 120 pluton and Toodoggone Formation rocks. Lastly, at least six generations of late mafic to felsic dykes cut the Takla Group and Toodoggone Formation rocks. All the rocks, including the Kemess North diorite ore body, are cut by a deposit-scale, E- W striking normal fault that dips steeply (70 to 90°) to the north and extends in strike length for at least 1.4 km and to depths of 500 m below the present surface. The fault marks the contact between Takla Group and Toodoggone Formation rocks. The E-W striking normal faults are commonly cut by NW to NNE striking faults that show normal-dextral displacements. These faults cause slivers of Toodoggone Formation rocks to be vertically displaced downwards relative to adjacent Takla Group basalt and result in horst-and-graben style block faulting throughout the mineralized Kemess North stratigraphy. Seven vein types are identified at Kemess North and are separated into four stages of formation with respect to Au-Cu-Mo mineralization (i.e., early-, main-, late-, and post- mineralization-stage). Early-stage veins include magnetite stringer veins and later quartz- magnetite-pyrite ± chalcopyrite ± molybdenite veins. These veins are restricted to the diorite, are associated with locally preserved potassic (biotite + alkali-feldspar) alteration, and are considered to be the cause of most Au-Cu-Mo mineralization at Kemess North. Main-stage quartz-pyrite ± chalcopyrite ± molybdenite veins are the most abundant vein type and are present in the diorite and Takla Group basalt within 250 m of the pluton. The veins are associated with phyllic (sericite-quartz) alteration and have a Re-Os molybdenite model age of 201.8 ± 1.2 Ma, which is comparable to the ca. 202 Ma (U-Pb zircon) age for the emplacement of the diorite. Late-stage pyrite-chalcopyrite and anhydrite + pyrite ± chalcopyrite veins and their associate phyllic (sericite-chlorite-pyrite) alteration also occur in diorite and Takla Group country rocks. Lastly, the post-mineralization anhydrite veins and carbonate-zeolite veins cut all rocks. 121 Early-stage biotite alteration is only locally preserved in the diorite due to pervasive replacement by main- and late-stage sericite-quartz ± chlorite ± pyrite alteration. Chlorite- epidote (propylitic) alteration occurs in Toodoggone Formation and Takla Group rocks at distances of 350 to 800 metres away from the Kemess North diorite. Thus, propylitic alteration defines an outer alteration halo around phyllically altered rocks. Fluid inclusion and hydrothermal mineral stability constraints for early- and main-stage veins show that the ore-bearing hydrothermal fluids deposited Au-Cu-Mo at similar temperatures (400°C for early-stage veins; 375°C for main-stage veins) and comparable pressures (0.9 to 2.7 kbar for early-stage veins; 1.2 to 3.0 kbar for main-stage veins). These pressure estimates equate to a broad range of possible crustal depths of 3 to 10 km. Calculated •3 34SH2s values for early-stage vein range from - 0.1 to 0.9%o, whereas 634 S H2s values for main-stage vein range from -4.3 to 0.3%0. Late-stage anhydrite-pyrite ± chalcopyrite veins have a range of calculated 634SH2s values from -0.8 to - 0.2%0; these 634SH2s values are compatible with values for an igneous source of sulfur (0 ± 3%o). Radiogenic Pb isotope values for sulfide minerals from the early-stage veins and the Kemess North diorite overlap and suggest that the early-stage fluids were dominantly derived from the Kemess North diorite. The Pb isotope values for main-stage veins show a greater range and plot away from the diorite and closer to the Pb isotope values for Takla Group country rock. This suggests that the fluid was derived from a magmatic source but interacted with Takla Group country rock and incorporated Pb from the basalts. 122 References: Aguirre-Diaz GJ, Labarthe-Hernandez G (2003) Fissure ignimbrites: Fissure-source origin for voluminous ignimbrites of the Sierra Madre Occidental and its relationship with Basin and Range faulting. Geology 31: 773-776 Al-Aasm IS, Taylor BE, South B (1990) Stable isotope analysis of multiple carbonate samples using selective acid extraction. Chemical Geology: Isotope Geoscience section 80: 119- 125 Beane RE (1974) Biotite Stability in the porphyry copper environment. Economic Geology and the Bulletin of the Society of Economic Geologists 69: 241-256 Bodnar RJ (1994) Synthetic fluid inclusions; XII, The system H 2O-NaCl; experimental determination of the halite liquidus and isochores for a 40 wt% NaC1 solution. Geochimica et Cosmochimica Acta 58: 1053-1063 Bodnar RJ (2003) Chapter 4. Introduction to aqueous-electrolyte fluid inclusions. In: I Samson, Anderson A, Marshall D eds Fluid Inclusions- Analysis and Interpretation. 32. Mineralogical Association of Canada Vancouver, pp 81-100 Bodnar RJ, Vityk MO (1994) Interpretation of microthermometric data for H2O-NaC1 fluid inclusions. In Fluid Inclusions in Minerals, Methods and Applications 117-130 Bodnar RJ, Burnham CW, Sterner SM (1985) Synthetic fluid inclusions in natural quartz; III, Determination of phase equilibrium properties in the system H2O-NaC1 to 1000 degrees C and 1500 bars. Geochimica et Cosmochimica Acta 49: 1861-1873 Bottinga Y (1969) Calculated fractionation factors for carbon and hydrogen isotope exchange in the system calcite-carbon dioxide-graphite-methane-hydrogen-water vapor. Geochimica et Cosmochimica Acta 33: 49-64 123 Bowers TS, Helgeson HC (1983) Calculation of the thermodynamic and geochemical consequences of nonideal mixing in the system H2O-0O2-NaC1 on phase relations in geologic systems; equation of state for H2O-0O2-NaC1 fluids at high pressures and temperatures. Geochimica et Cosmochimica Acta 47: 1247-1275 Brown PE, Hageman SG (1995) MacFlinCor and its application to fluids in Archean lode-gold deposits. Geochimica et Cosmochimica Acta 59: 3943-3952 Cassidy KF, Groves DI, MCNaughton NJ (1998) Late-Archean granitoid-hosted lode-gold deposits, Yilgarn Craton, Western Australia: Deposit characteristics, crustal architecture and implications for ore genesis. Ore Geology Reviews 13: 65-102 Clark JR, Williams-Jones AE (1990) 40Ar/39Ar Ages of Epithermal Alteration and Volcanic Rocks in the Toodoggone Au-Ag District, North-Central British Columbia (94E). Geological Fieldwork, Paper 1991-1 207-216 Coplen TB, Kendall C, Hopple J (1983) Comparison of stable isotope reference samples. Nature 302: 236-238 Diakow LJ (2001) Geology of the Southern Toodoggone River and Northern McConnell Creek Map Areas, North-Central British Columbia. In: BGM 2001-1 (ed. 1:50 000) Diakow LJ (2006a) Geology between the Finlay River and Chukachida Lake, Central Toodoggone River Map Area, North-central British Columbia (Parts of NTS 94E/2, 6, 7, 10 and 11). In: MaPROFM- B.C. Ministry of Energy (ed. 1:50000) Diakow LJ (2006b), Toodoggone's Au-Cu Setting Unravelled: Mineral Exploration Roundup, Westin Bayshore, Vancouver, January 23-26, 2006b, pp 108 Diakow LJ, Panteleyev A, Schroeter TG (1991) Jurassic epithermal deposits in the Toodoggone River area, northern British Columbia; examples of well-preserved, volcanic-hosted, precious metal mineralization. Economic Geology and the Bulletin of the Society of Economic Geologists 86: 529-554 124 Diakow LJ, Panteleyev A, Schroeter TG (1993) Geology of the Early Jurassic Toodoggone Formation and gold-silver deposits in the Toodoggone River map area, northern British Columbia: Victoria, BC, Canada, British Columbia Ministry of Energy, Mines and Petroleum Resources, p. 72 Dickinson J (2006) Jura-Triassic Magmatism and Porphyry Au-Cu Mineralization at the Pine Prospect, Toodoggone District, North-Central British Columbia: Unpub. M.Sc. thesis, University of British Columbia. Dickinson J, Rowins SM, Duuring P, Friedman RM, On AJ (2006), Geochronology and Geology of the Pine porphyry Au-Cu (Mo) deposit, Toodoggone district, British Columbia: North to Alaska: GSA Cordilleran Meetings, Technology, and Natural Resources, Hilton Hotel, Anchorage Alaska, USA, 2006, pp 30 Duuring P, Rowins SM, McKinley BSM, On AJ (2006a), Magmatic-structural controls on the Kemess South Cu-Au orebody, Toodoggone, British Columbia: GAC-MAC, Montreal, Canada, 2006a Duuring P, Rowins SM, McKinley BSM, On AJ (2006b), Porphyry cousins? Geological comparison of the Kemess South and Kemess North porphyry Au-Cu (Mo) deposits, Toodoggone district, British Columbia: GSA Cordilleran Meetings: Geoscience, Technology, and Natural Resources, Hilton Hotel, Anchorage Alaska, USA, 2006b Field CW, Gustafson LB (1976) Sulfur isotopes in the porphyry copper deposit at El Salvador, Chile. Economic Geology and the Bulletin of the Society of Economic Geologists 71: 1533-1548 Field CW, Zhang L, Dilles JH, Rye RO, Reed MH (2005) Sulfur and oxygen isotopic record in sulfate and sulfide minerals of early, deep, pre-main stage porphyry Cu-Mo and late main stage base-metal mineral deposits, Butte district, Montana. Chemical Geology 215: 61-93 125 Fisher RV, Schmincke H-U (1984) Pyroclastic Rocks: Berlin, Springer-Verlag Berlin Heidelberg, 347-361 p. Gammons CH, Williams-Jones AE (1997) Chemical mobility of gold in the porphyry-epithermal environment. Economic Geology and the Bulletin of the Society of Economic Geologists 92: 45-59 Goldstein RH (2003) Petrographic Analysis of Fluid Inclusions. In: I Samson, Anderson A, Marshall D eds) Fluid Inclusions- Analysis and Interpretation. 32. Mineralogical Association of Canada Vancouver, pp 374 Goldstein RH, Reynolds TJ (1994) Systematics of fluid inclusions in diagenetic minerals. SEPM Short Course 31, Society of Economic Paleontologists and Mineralogists, Tulsa: 199 Gray J, Edmunds C (2005) Annual Report: Northgate Minerals Corporation. 52 Guerrera A, Peacock SM, Knauth LP (1997) Large 180 and 13 C depletions in greenschist facies carbonate rocks, western Arizona. Geology 25: 943-946 Hagemann SG, Brown PE (1996) Geobarometry in Archean lode-gold deposits. Fluid inclusions 8: 937-960 Hezarkhani A, Williams-Jones AE, Gammons CH (1999) Factors controlling copper solubility and chalcopyrite deposition in the Sungun porphyry copper deposit, Iran. Mineralium Deposita 34: 770-783 Le Bas MJ, Le Maitre RW, Streckeisen A, Zanettin BA (1986) Chemical classification of volcanic rocks based on the total alkali-silica diagram. Journal of Petrology 27: 745-750 Lowell JD, Guilbert JM (1970) Lateral and vertical alteration-mineralization zoning in porphyry ore deposits. Economic Geology and the Bulletin of the Society of Economic Geologists 65: 373-408 126 Macdonald AJ, Spooner ETC (1981) Calibration of a Linkam TH 600 programmable heating- cooling stage for microthermometric examination of fluid inclusions. Economic Geology and the Bulletin of the Society of Economic Geologists 76: 1248-1258 Maniar PD, Piccoli PM (1989) Tectonic discrimination of granitoids. Geological Society of America Bulletin 101: 635-643 Markey RJ, Stein HJ, Morgan JW (1998) Highly precise Re-Os dating for molybdenite using alkaline fusion and NTIMS. Talanta 45: 935-946 McDonough WF, Sun S-s (1995) The composition of the Earth. Chemical Geology 120: 223-253 McMillan WJ, Panteleyev A (1995) Porphyry copper deposits of the Canadian Cordillera. Arizona Geological Society Digest 20: 203-218 McMillan WJ, Thompson JFG, Hart CJR, Johnston ST (1995) Regional geological and tectonic setting of porphyry deposits in British Columbia and Yukon Territory. In Schroeter, T., ed., Porphyry Deposits of the northwestern Cordillera of North America: Canadian Institute of Mining Special Volume 46: 40-57 Monger JWH, Nokleberg WJ (1996) Evolution of the northern North American Cordillera: Generation, fragmentation, displacement, and accretion of successive North American plate margin arcs. Geology and Ore Deposits of the American Cordillera Geological Society of Nevada Symposium Proceedings, Reno/Sparks: 1133-1152 Mortensen JK, Ghosh DK, Ferri F (1995) U-Pb geochronology of intrusive rocks associated with copper-gold porphyry deposits in the Canadian Cordillera. In: TG Schroeter (ed Porphyry Deposits of the Northwestern Cordillera of North America. Special Volume 46. Canadian Institute of Mining and Metallurgy Nash JT (1976) Fluid-Inclusions Petrology-Data from Porphyry Copper Deposits and Applications to Exploration. Geological Survey Professional Paper 907-D 16 127 Nesbitt BE, Murowchick JB, Muehlenbachs K (1986) Dual origins of lode gold deposits in the Canadian Cordillera. Geology 14: 506-509 O'Connor B (2005) Annual Report: Northgate Minerals Corporation, p. 52 Ohmoto H (1986) Stable isotope geochemistry of ore deposits. Reviews in Mineralogy and Geochemistry 16: 491-559 Ohmoto H, Rye RO (1979) Isotopes of sulfur and carbon. In: HL Barnes (ed) Geochemistry of Hydrothermal Ore Deposits. J Wiley and Sons New York, pp 509-567 Ohmoto H, Lasaga AC (1982) Kinetics of reactions between aqueous sulfates and sulfides in hydrothermal systems. Geochimica et Cosmochimica Acta 46: 1727-1745 Pearce JA, Harris NBW, Tindle AG (1984) Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology 25: 956-983 Peccerillo A, Taylor SR (1976) Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey. Contributions to Mineralogy and Petrology 58: 63-81 Rebagliati CM, Bowen BK, Copeland DJ, Niosi DWA (1995) Kemess South and Kemess North porphyry gold-copper deposits, northern British Columbia. In Schroeter, T., ed., Porphyry Deposits of the Northwestern Cordillera of North America: Canadian Institute of Mining Special Volume 46: 377-397 Roberts SA (1973) Pervasive early alteration in the Butte District, Montana, Anaconda Co., Butte, Montana, HH1-HH8 p. Roddick JC (1987) Generalized numerical error analysis with applications to geochronology and thermodynamics. Geochimica et Cosmochimica Acta 51: 2129-2135 Roedder E (1984) Fluid inclusions. Reviews in Mineralogy 12: 644 Rollinson HR (1993) Using Geochemical Data: Evaluation, Presentation, Interpretation.: England, Pearson Education Limited, 352 p. 128 Rowins SM, Groves DI, McNaughton NJ, Palmer MR, Eldridge CS (1997) A reinterpretation of the role of granitoids in the genesis of Neoproterozoic gold mineralization in the Telfer Dome, Western Australia. Economic Geology 92: 133-160 Rusk BG, Reed MH, Dilles JH, Klemm LM, Heinrich CA (2004) Compositions of magmatic hydrothermal fluids determined by LA-ICP-MS of fluid inclusions from the porphyry copper-molybdenum deposit at Butte, MT. Chemical Geology 210: 173-199 Seedorff E, Einaudi MT (2004) Henderson porphyry molybdenum system, Colorado; I, Sequence and abundance of hydrothermal mineral assemblages, flow paths of evolving fluids, and evolutionary style. Economic Geology and the Bulletin of the Society of Economic Geologists 99: 3-37 Seedorff E, Dilles JH, Proffett JM, Einaudi MT, Zurcher L, William SJA, Johnson DA, Barton MD (2005) Porphyry deposits: Characteristics and Origin of Hypogene Features. Economic Geology One Hundredth Anniversary Volume 251-298 Selby D, Creaser RA (2004) Macroscale NTIMS and microscale LA-MC-ICP-MS Re-Os isotopic analysis of molybdenite: Testing spatial restrictions for reliable Re-Os age determinations, and implications for the decoupling of Re and Os within molybdenite. Geochimica et Cosmochimica Acta 68: 3897-3908 Shepherd TJ, Rankin AH, Alderton DHM (1985) A Practical Guide to Fluid Inclusion Studies: Bishopbriggs, Blackie and Son Ltd, 239 p. Smithson DM (2004) Late Eocene Tectono-Magmatic Evolution and Genesis of Reduced Porphyry Copper-Gold Mineralization at the North Fork Deposit, West Central Cascade Range, Washington, U.S.A.: Unpub. M.Sc thesis, University of British Columbia, 174 p. Sourirajan S, Kennedy GC (1962) The system H2O-NaC1 at elevated temperatures and pressures. American Journal of Science 260: 115-141 129 Taylor HP, Jr. (1979) Oxygen and hydrogen isotope relationships in hydrothermal mineral deposits. In: HL Barnes (ed) Geochemistry of Hydrothermal Ore Deposits. J Wiley and Sons New York, pp 236-277 Thiersch PC, Williams-Jones AE, Clark JR (1997) Epithermal mineralization and ore controls of the Shasta Au-Ag deposit, Toodoggone District, British Columbia, Canada. Mineralium Deposita 32: 44-57 Thirlwall MF (2000) Inter-laboratory and other errors in Pb isotope analyses investigated using a 2 07p1 D  _204Pb double spike. Chemical Geology 163: 299-322 Titley SR (1982) The style and progress of mineralization and alteration in porphyry copper systems; American Southwest. Titley SR, Beane RE (1981) Porphyry copper deposits; Part I, Geologic settings, petrology, and tectogenesis. Economic Geology 75th Anniversary: 214-266 Tosdal RM, Richards JP (2001) Magmatic and Structural Controls on the Development of Porphyry Cu + Mo + Au Deposits. Society of Economic Geologists 14: 157-181 Tosdal RM, Wooden JL, Bouse RM (1999) Pb isotopes, ore deposits, and metallogenic terranes. Reviews in Economic Geology 12: 1-28 Turner FJ (1981) Metamorphic Petrology: Mineralogical, Field, and Tectonic Aspects: New York, McGraw-Hill, 524 p. Valley JW (1986) Stable isotope geochemistry of metamorphic rocks. Reviews in Mineralogy and Geochemistry 16: 445-489 /Veizer J, Hoefs J (1976) The nature of 1 8 0/ 1 6 0 and 13C/12C secular trends in sedimentary carbonate rocks. Geochimica et Cosmochimica Acta 40: 1387-1395 Wilson M (1989) Igneous petrogenesis: London. Winchester JA, Floyd PA (1977) Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology 20: 325-343 130 Zartman RE, Doe BR (1981) Plumbotectonics; the model. Tectonophysics 75: 135-162 Zheng YF, Hoefs J (1993) Carbon and oxygen isotopic covariations in hydrothermal calcites; theoretical modeling on mixing processes and application to Pb-Zn deposits in the Harz Mountains, Germany. Mineralium Deposita 28: 79-89 131 Chapter III General Conclusions Geological mapping, geochemistry, drill core logging, petrography, Re-Os dating, fluid inclusion and stable and radiogenic isotope studies were used to constrain the age, physicochemical conditions, and the source of the ore fluid responsible for porphyry Au-Cu-Mo mineralization at Kemess North, north central British Columbia, Canada. A Re-Os date of 201.8 + 1.2 Ma from the main-stage vein shows that mineralization occurred almost simultaneously with pluton emplacement (ca. 202 Ma). The 202.7 ± 1.9 Ma, unmineralized, Sovereign diorite intrudes Takla Group basalt in the south of the deposit with no lithological contacts between the Sovereign and Kemess North plutons observed. Both plutons are coeval, comparable in hand specimen, and have similar trace-element patterns. Toodoggone Formation volcaniclastic rocks (199.1 ± 0.3 Ma) crop out as prominent N-trending ridges or as isolated, fault-bounded, blocks amongst Takla Group basalt. Toodoggone Formation units also occur beneath the Kemess North diorite. Detailed 1:2000 scale field mapping revealed that the central ridge in the study area is mineralized Toodoggone Formation volcaniclastic rocks; this interpretation contrasts with the previous interpretation that these rocks are Takla Group country rock. Mapping also identified several structural features, which included small-scale horst-and- graben style block shuffling between Takla Group country rock and Toodoggone Formation volcaniclastic rock in the east-west headwalls of the cirques. This information was instrumental in determining that the large block of Toodoggone Formation volcaniclastic rock in the center on the deposit, which interrupts the surface gossan, is a large-scale horst-and-graben structure. This block shuffling was also applied to the subsurface and the concept was used when creating cross- sections through the mineralized ore body. The Duncan pluton crops out in the northern areas of 132 the deposit and is surrounded by hornfels contact metamorphism in Takla Group basalt. No contact was observed between the Duncan pluton and Toodoggone Formation rocks. Detailed mapping also revealed that all the rocks, including the Kemess North diorite ore body, are cut by a deposit-scale, E-W striking normal fault that dips steeply (70 to 90°) to the north and extends in strike length for at least 1.4 km and to depths of 500 m below the present surface. The fault marks the contact between Takla Group and Toodoggone Formation rocks. The E-W striking normal faults are commonly cut by NW to NNE striking faults that show normal-dextral displacements. A detailed examination of eight drill holes, with a cumulative length of 4.9 km, revealed seven vein types that were separated into four stages of formation based on cross cutting relationships and with respect to Au-Cu-Mo mineralization (i.e., early-, main-, late-, and post- mineralization-stage). Early-stage veins include magnetite stringer veins and later quartz- magnetite-pyrite + chalcopyrite ± molybdenite veins. These veins are mainly restricted to the diorite, are associated with locally preserved potassic (biotite) alteration, and are considered to be the cause of most Au-Cu-Mo mineralization at Kemess North. Main-stage quartz-pyrite ± chalcopyrite ± molybdenite veins are the most abundant vein type and are present in the diorite and Takla Group basalt within 250 m of the pluton. The veins are associated with phyllic (sericite-quartz) alteration. Late-stage pyrite-chalcopyrite and anhydrite + pyrite + chalcopyrite veins and their associate phyllic (sericite-chlorite-pyrite) alteration occur in diorite and Takla Group country rocks. Lastly, the post-mineralization anhydrite veins and carbonate-zeolite veins cut all rocks. Seven hundred and seventy-four veins were measured with respect to the c-axis of the core. These angles were corrected to the horizontal and revealed a consistent 30 to 40° angle of emplacement. 133 Early-stage biotite alteration is only locally preserved in the diorite due to pervasive replacement by main- and late-stage sericite-quartz + chlorite alteration. Chlorite-epidote (propylitic) alteration occurs in Toodoggone Formation and Takla Group rocks between 350 and 800 meters away from the Kemess North diorite, thus defining an outer halo around phyllic- altered rocks. Fluid inclusion studies from hydrothermal thermal quartz in early- and main-stage veins show that the ore-bearing hydrothermal fluids deposited Au-Cu-Mo at similar temperatures (400°C for early- stage veins; 375°C for main-stage veins) and comparable pressures (0.9 to 2.7 kbar for early-stage veins; 1.2 to 3.0 kbar for main-stage veins). These pressure estimates equate to a broad range of possible crustal depths of 3 to 10 km. These depths support the vein angle data, which also suggest a possible deep formation. Sulfur isotopes were measured in sulfides and anhydrite from mineralized veins. Using fluid inclusion temperature and sulfate-sulfide equilibrium temperature constraints for the late- stage anhydrite-pyrite ± chalcopyrite vein their 45 34SH2s values were calculated. Early-stage veins range from -0.10 to 0.85 per mil, whereas 6 34SH2s values for main-stage veins range from -4.3 to 0.25 per mil. Late-stage anhydrite-pyrite ± chalcopyrite veins have a range of calculated 6 34 SH2s values from -0.83 to -0.19 per mil; these 6 34SH2s values are compatible with values for a mantle fluid source (0 ± 3%o). Radiogenic Pb isotope studies determined that sulfide minerals from the early-stage veins and the Kemess North diorite overlap and suggest that the early-stage fluids were dominantly derived from the Kemess North diorite. In contrast, Pb isotope values for main-stage veins show a greater range, plotting away from the diorite and closer to Pb isotope values for Takla Group country rock. The analysis of these results suggests that the fluid was derived from a magmatic source but interacted with Takla Group country rock and/or other meteoric fluids. 134 By integrating all of the results of the field and laboratory studies a genetic model of Kemess North was created, which characterizes the emplacement of the Kemess North diorite intrusion, the depth of emplacement, age and paragenesis of mineralization, and associated alteration. The model defines the relationships among the different lithologies in the study area, the physical and chemical properties of the ore fluid during metal deposition, and the likely source of metals in the hydrothermal fluid. 135 Further Work A genetic relationship is apparent between the Sovereign diorite and the Kemess North diorite. The two plutons are coeval and have similar mineralogy and trace-element geochemistry, although only the Kemess North diorite hosts economic mineralization at present. The field relations between the Sovereign and Kemess North pluton need to be closely examined, which would require drill-testing because the diorite is unexposed. Most of the samples of veins from the Kemess North diorite were obtained from drill holes located in the centre of the deposit that intersected the high-grade Au-Cu core of the ore body. Future fluid inclusion and isotope studies on veins from more distal areas of the deposit, including Takla Group country rock, may aid in the interpretation of temperature and fluid compositional gradients away from the diorite. This work will require careful documentation owing to the vertical displacement of the Kemess North stratigraphy caused by N-striking faults. Fluid inclusions examined in this study indicate that in situ trapping of a boiling ore fluid did not occur. However, boiling or immiscible phase separation has likely occurred elsewhere in the porphyry system. Further fluid inclusion studies in different parts of the porphyry system might show evidence for boiling and therefore better constrain estimated fluid temperatures and pressures at the time of metal deposition. Lastly, the continuation of the Kemess North diorite and ore body to the east of the east cirque is the focus of current exploration efforts. Geological mapping of the outcrop in this area indicates that Toodoggone Formation rocks are vertically displaced by steep NNW-striking faults. It is likely that these faults vertically disrupt the mineralized stratigraphy. Extending the detailed geological mapping to the east is the first important step required before drill-testing the continuation of the Kemess North ore body. 136 APPENDIX A WHOLE-ROCK AND TRACE ELEMENT COMPOSITIONS FOR SELECTED KEMESS NORTH ROCKS 137 Table A.1: Whole-rock and trace element compositions for selected Kemess North rocks Lab No. N139388 N139375 N139376 N139377 N139378 N139604 N139400 N139601 Location Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Rock type Carbonate unit Sovereign pluton Sovereign pluton Sovereign pluton Sovereign pluton Sovereign Pluton KN Pluton KN Pluton Alteration Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Si°, 70.43 63.63 62.83 63.26 64.35 62.92 62.26 60.39 TiO2 0.2 0.44 0.45 0.44 0.41 0.42 0.48 0.44 Al203 14.56 16.29 16.5 16.6 16.2 16.59 15.91 14.84 Fe 20,T 1 2.15 4.11 5.35 3.99 4.37 4.61 4.69 8.65 FeO' 1.07 1.81 2.46 1.75 1.92 1.79 2.9 3.52 Fe 20,2 0.96 2.10 2.62 2.05 2.24 2.62 1.47 4.74 MnO 0.07 0.07 0.06 0.06 0.06 0.09 0.09 0.09 MgO 0.56 1.45 1.51 1.33 1.39 1.94 2.06 2.45 CaO 2.27 4.13 4.1 4.72 4.02 3.19 2.32 1.29 Na 2O 4.03 4.13 3.78 4.19 3.94 4.01 1.76 2.46 K20 2.96 3.31 2.71 2.39 2.75 2.74 3.34 2.79 P20 , 0.1 0.19 0.2 0.21 0.2 0.2 0.23 0.2 Cr2O3 <0.01 0.01 <0.01 0.01 <0.01 0.01 <0.01 0.01 SrO 0.03 0.06 0.07 0.06 0.06 0.06 0.06 0.04 BaO 0.16 0.19 0.18 0.19 0.19 0.17 0.15 0.09 LOI 2.8 0.94 0.94 0.72 0.79 1.55 4.82 5.05 Total 100.3 98.96 98.66 98.17 98.72 98.5 98.16 98.78 V 30 89 86 83 82 85 97 90 Cr 40 40 10 40 10 50 30 10 Co 2 4 8 3 3 7 5 16 Ni <5 8 <5 5 5 178 8 7 Cu 6 9 7 11 14 16 2630 1265 Zn 57 50 42 48 43 51 154 118 Ga 14 18 18 18 18 18 14 14 Rb 77 56 79 35 43 50 88 72 Sr 300 614 635 575 569 559 564 426 Y 12 18 17 17 17 17 16 15 Zr 108 98 91 106 96 121 84 79 Nb 5 6 6 6 6 6 5 5 Mo <2 <2 <2 <2 <2 4 54 12 Ag <1 <1 <1 <1 <1 <1 1 <1 Sn 1 1 1 1 1 1 2 3 Cs 3 1 2 1 1 1 4 2 Ba 1625 1825 1585 1685 1775 1620 1340 856 La 27 20 18 18 14 18 18 17 Ce 40 38 35 37 30 35 34 32 Pr 4 4 4 4 4 4 4 4 Nd 15 16 16 17 15 16 15 14 Sm 2 3 3 4 3 3 3 3 Eu 1 1 1 1 1 1 1 1 Gd 2 3 3 3 3 3 3 2 Tb 0.3 0.5 0.5 0.5 0.4 0.5 0.4 0.4 Dy 2 3 3 3 3 3 2 2 Ho 0.4 1 1 1 1 1 1 0.5 Er 1 2 2 2 2 2 2 2 Tm 0.2 0.3 0.3 0.2 0.2 0.3 0.2 0.2 Yb 1 2 2 2 2 2 2 2 Lu 0.2 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Hf 3 3 3 3 3 4 3 3 Ta 0.3 1 0.4 1 1 0.4 0.4 0.4 W 7 3 3 1 4 6 2 3 Au <0.001 0.002 0.002 0.001 0.002 0.002 0.796 0.527 TI <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 0.9 0.5 Pb 12 10 11 9 10 8 13 20 Th 5 5 5 4 4 5 5 4 U 2 3 3 3 2 2 2 2 Whole rock data are given in wt%, trace elements are in ppm Abbreviations: Equi., equigranular; Plag., plagioclase: 'measured; 2calculated 138 Lab No. N139602 N139603 N139394 N139395 N139396 N139379 N139380 Location Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Rock type KN Pluton KN Pluton Duncan pluton Duncan pluton Duncan pluton Bladed feldspar porphyry Bladed feldspar porphyry Alteration Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered SiO 2 61.89 61.47 61.31 62.15 61.02 48.92 52.53 Tit), 0.47 0.43 0.54 0.53 0.58 1.12 0.99 AI,0, 15.51 15.56 15.89 15.72 16.16 17.47 15.4 Fe 20,T' 6.75 6.74 5.78 5.49 5.8 8.71 8.47 FeO' 3.67 3.54 2.94 2.75 2.9 5.02 4.7 Fe 20,' 2.67 2.81 2.51 2.43 2.58 3.13 3.25 MnO 0.09 0.07 0.12 0.1 0.12 0.44 0.2 MgO 2.26 1.68 2.18 2.09 2.17 5.62 5.4 CaO 1.56 3.94 4.86 4.76 4.71 8.75 7.59 Na 2O 2.68 2.5 3.31 3.29 3.45 3.02 3.95 K2O 2.73 3.34 2.99 3.13 3 1.74 1.82 P20, 0.23 0.2 0.22 0.21 0.21 0.31 0.29 Cr20, <0.01 <0.01 <0.01 <0.01 0.01 0.02 0.01 Sr0 0.04 0.06 0.06 0.06 0.06 0.06 0.06 BaO 0.09 0.12 0.16 0.16 0.16 0.09 0.05 LOI 3.96 2.37 0.96 0.66 0.81 2.85 1.89 Total 98.25 98.48 98.4 98.35 98.24 99.1 98.64 V 93 90 142 140 140 434 274 Cr 30 10 30 10 40 90 110 Co 14 6 10 10 10 27 26 Ni 7 5 6 5 5 38 26 Cu 1185 93 15 17 10 294 12 Zn 126 85 69 46 61 206 126 Ga 16 17 17 17 17 21 17 Rb 69 65 72 85 71 39 43 Sr 383 550 586 562 563 559 530 Y 18 17 19 17 19 20 22 Zr 79 77 84 89 104 65 102 Nb 6 5 6 6 6 4 6 Mo 13 5 <2 <2 <2 <2 <2 Ag 1 <1 <1 <1 <1 <1 <1 Sn 3 2 1 1 1 1 1 Cs 3 2 2 2 2 3 4 Ba 828 1170 1540 1500 1490 788 481 La 20 12 19 21 20 12 13 Ce 39 26 37 39 38 25 27 Pr 5 3 4 4 4 3 3 Nd 17 13 16 16 17 15 15 Sm 4 3 3 3 3 4 4 Eu 1 1 1 1 1 1 1 Gd 3 3 3 3 3 4 4 Tb 0.5 0.4 0.5 0.5 0.5 1 1 Dy 3 3 3 3 3 3 4 Ho 1 1 1 1 1 1 1 Er 2 2 2 2 2 2 2 Tm 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Yb 2 2 2 2 2 2 2 Lu 0.3 0.3 0.3 0.3 0.3 0.2 0.3 Hf 3 3 3 3 3 2 3 Ta 0.4 0.3 1 1 0.4 0.3 0.4 W 2 1 3 1 1 8 5 Au 0.319 0.020 0.001 <0.001 <0.001 0.022 0.001 TI 0.6 0.5 <0.5 <0.5 <0.5 <0.5 <0.5 Pb 32 17 8 6 7 12 10 Th 5 4 7 6 6 1 2 U 2 2 3 4 3 1 1 Whole rock data are given in wt%, trace elements are in ppm Abbreviations: Equi.. equigranular; Plag.. plagioclase; 'measured; 'calculated 139 Lab No. N139613 N139612 N139605 N139606 N139608 N139609 Location Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Rock type Bladed feldspar porphyry Andesitic augite porphyry Takla Group Takla Group Takla Group Takla Group Alteration Least-altered Least-altered Quartz-sericite-pyrite Quartz-sericite-pyrite Quartz-sericite-pyrite Quartz-sericite-pyrite SiO, 49.52 48.09 56.25 53.62 58.4 55.55 TiO2 0.91 0.72 1.29 1.03 1.07 1.09 Al 20, 16.45 11.01 17.69 18.71 16.88 19.15 Fe20 3T' 9.16 12.29 7.62 9.32 9.18 8.46 FeO' 5.02 7.82 4.54 0.71 0.79 0.51 Fe 20,' 3.58 3.60 2.57 8.53 8.30 7.89 MnO 0.06 0.41 0.05 0.01 0.01 0.01 MgO 4.94 14.49 5.77 2.13 0.89 1.04 CaO 5.04 3.57 0.05 0.08 0.04 0.15 Na20 0.3 0.2 0.27 0.17 0.4 0.23 K2O 2.6 0.32 2.11 2.71 2.71 2.97 P20 5 0.52 0.21 0.38 0.31 0.33 0.34 Cr20, 0.01 0.11 0.01 0.02 0.02 0.01 SrO 0.02 <0.01 <0.01 0.02 0.01 0.05 BaO 0.03 0.01 0.11 0.18 0.03 0.08 LOI 8.51 7.3 6.64 10.15 8.62 9.16 Total 98.07 98.71 98.24 98.45 98.59 98.28 V 327 280 342 419 150 278 Cr 60 970 70 80 70 120 Co 22 36 6 25 31 42 Ni 24 173 23 31 17 30 Cu 532 816 452 121 777 73 Zn 134 331 232 95 65 34 Ga 18 17 22 17 15 12 Rb 72 15 59 66 96 77 Sr 222 19 63 236 2690 81 V 15 15 22 14 18 14 Zr 72 40 112 72 80 78 Nb 7 3 8 5 5 7 Mo 6 8 22 6 84 35 Ag <1 1 <1 <1 <1 1 Sn 7 5 8 16 2 14 Cs 1 1 1 1 4 1 Ba 255 119 997 1690 1595 291 La 14 8 14 11 17 16 Ce 27 16 31 25 34 32 Pr 3 2 4 3 4 4 Nd 14 10 18 17 16 17 Sm 3 3 4 4 4 3 Eu 1 1 1 1 1 1 Gd 3 3 4 3 3 3 Tb 0.5 0.5 1 1 1 0.5 Dy 3 3 4 3 3 3 Ho 1 1 1 1 1 1 Er 2 2 3 1 2 1 Tm 0.2 0.2 0.3 0.2 0.3 0.2 Yb 1 2 2 1 2 1 Lu 0.2 03 0.3 0.2 0.3 0.2 Hf 2 1 3 2 2 2 Ta 0.4 0.3 1 0.4 0.4 1 W 7 3 7 18 7 17 Au 0.174 0.164 0.158 0.089 0.150 0.050 TI 0.6 <0.5 0.7 0.8 0.6 0.8 Pb 8 <5 23 47 10 16 Th 2 1 2 1 3 2 U 2 1 2 1 2 2 Whole rock data are given in wt%, trace elements are in ppm Abbreviations: Equi., equigranular; Plug., plagioclase; 'measured; 'calculated 140 Lab No N139384 N139385 N139607 N139391 N139392 N139393 N139614 N139382 Location Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Rock type Hazelton Group Hazelton Group Hazelton Group Hazelton Group Hazelton Group Hazelton Group Hazelton Group Mafic dyke Alteration Least-altered Least-altered Least-altered Anhydrite Anhydrite Anhydrite Anhydrite Least-altered SiO 2 59.58 60.57 56.65 65.37 59.92 56.53 64.34 47.28 TiO 2 0.56 0.6 0.66 0.64 0.66 0.51 0.63 0.81 Al 20, 17.45 17.45 15.04 26.45 27.27 26.23 23.39 15 Fe20,T 1 5.16 6.85 10.13 0.79 0.92 4.18 1.23 9.21 FeO' 1.72 3.14 3.06 0.28 0.26 0.15 0.31 4.38 Fe20,' 3.25 3.36 6.73 0.48 0.63 4.01 0.89 4.34 MnO 0.15 0.15 0.17 <0.01 <0.01 <0.01 0.01 0.21 MgO 1.69 1.79 1.93 0.03 0.03 0.03 0.16 6.47 CaO 6.58 5.15 2.17 0.03 0.09 0.02 0.09 7.86 Na,O 2.56 3.58 0.97 0.06 0.35 0.05 0.04 1 .42 K20 2.91 0.96 2.91 0.22 0.12 0.05 0.08 5.04 P20, 0.25 0.22 0.26 0.13 0.11 0.18 0.14 0.19 Cr2O 3 <0.01 <0.01 0.01 <0.01 <0.01 <0.01 <0.01 0.01 SrO 0.06 0.07 0.31 0.01 0.07 0.22 0.12 0.05 BaO 0.28 0.12 0.17 0.02 0.05 0.01 0.01 0.22 LOI 1.78 1.22 6.8 4.71 8.9 10.1 8.25 4.6 Total 99 98.73 98.17 98.47 98.5 98.11 98.49 98.34 V 125 166 218 83 99 127 104 277 Cr 30 20 90 10 30 10 20 110 Co 14 14 36 3 1 1 1 41 Ni 7 7 29 <5 <5 <5 5 56 Cu 10 14 913 12 6 <5 10 116 Zn 97 95 68 17 21 11 21 84 Ga 20 19 18 39 33 19 29 15 Rb 62 26 105 6 3 OA 2 128 Sr 522 691 2800 166 677 1855 1115 438 Y 18 20 18 4 2 2 3 20 Zr 106 104 99 129 117 107 106 43 Nb 5 4 6 5 9 4 8 3 Mo <2 <2 93 <2 <2 <2 <2 <2 Ag <1 <1 1 <1 <1 <1 <1 <1 Sn 1 1 4 1 1 1 1 1 Cs 6 2 4 3 1 0.1 0.4 2 Ba 2650 1140 1580 258 562 121 154 1895 La 22 17 18 10 8 13 20 9 Ce 37 34 35 17 11 23 28 18 Pr 4 4 4 2 1 2 2 3 Nd 16 16 18 6 4 8 9 11 Sm 3 4 4 1 1 1 1 3 Eu 1 1 1 0.3 0.2 0.2 0.4 1 Gd 3 3 4 1 1 1 1 3 Tb 0.5 1 0.3 0.1 0.1 0.1 0.1 1 Dy 3 3 3 1 0.3 0.4 0.4 3 Ho 1 1 0.3 0.2 <0.1 0.1 0.1 1 Er 2 2 2 1 0.2 0.3 0.2 2 Tm 0.3 0.3 <0.1 0.1 <0.1 <0.1 <0.1 0.3 Yb 2 2 2 1 0.2 0.3 0.2 2 Lu 0.3 0.3 <0.1 0.1 <0.1 0.1 <0.1 0.3 Hf 3 3 3 3 3 3 3 1 Ta 0.4 03 <0.1 0.4 0.4 0.3 0.4 0.2 W 10 5 11 10 8 4 10 1 Au 0.001 0.001 0.067 0.001 <0.001 <0.001 0.013 0.002 TI <0.5 <0.5 1 <0.5 <0.5 <0.5 <0.5 0.7 Pb 19 10 17 <5 55 10 108 <5 Th 4 4 3 6 1 3 1 1 U 2 2 2 4 0.2 1 0.2 0.5 Whole rock data are given in wt%, trace elements are in ppm Abbreviations: Equi., equigranular; Plag., plagioclase; 'measured 2calculated 141 Lab No N139383 N139387 N139389 N139390 N139397 N139398 N139399 N139610 N139611 Location Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Kemess North Rock type Mafic dyke Aineralized rhyolite dyke Brown dyke Coarse-grained dyke Diorite dyke Diorite dyke Diorite dyke Diorite dyke Diorite dyke Alteration Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered Least-altered SiO 2 45.98 95.85 70.7 64.66 60.24 60.38 60.62 60.26 60.52 TiO, 0.78 0.63 0.21 0.38 0.54 0.5 0.52 0.59 0.49 AI 20, 15 1.05 14.74 15.24 16.36 16.22 16.01 15.94 16.3 Fe 20,1-1 9.1 0.74 2.12 3.75 5.63 5.02 5.47 5.55 5.19 FeO' 4.01 0.51 0.9 1.75 2.44 2.09 2.57 3.2 2.55 Fe,0 3 2 4.64 0.17 1.12 1.81 2.92 2.70 2.61 1.99 2.36 MnO 0.27 0.01 0.06 0.09 0.13 0.11 0.13 0.13 0,14 MgO 5.97 0.11 0.54 1.33 2.36 2.12 2.23 2.19 2.28 CaO 9.14 0.04 0.96 3.55 239 3.38 3.61 3.85 2.49 Na,O 1.5 <0.01 5.08 3.61 4.24 3.31 4.26 4.38 6.33 K,0 3.85 0.26 2.63 2.64 2.93 2.32 2.25 2.66 0.47 P20, 0.17 0.05 0.1 0.12 0.21 0.22 0.17 0.17 0.15 Cr,O, 0.02 <0.01 <0.01 <0.01 0.01 <0.01 <0.01 0.01 0.01 SrO 0.05 <0.01 0.03 0.06 0.03 0.05 0.05 0.02 0.05 BaO 0.2 0.04 02 0.16 0.14 0.16 0.15 0.13 0.17 LOI 6.16 0.23 1.59 3.14 2.99 4.92 3.12 2.21 3.82 Total 98.19 98.99 98.95 98.73 98.2 98.71 98.58 98.08 98.4 V 268 20 19 61 130 110 108 164 128 Cr 120 20 10 30 10 20 10 20 30 Co 38 1 2 7 12 10 12 14 12 Ni 64 10 <5 5 12 7 5 14 14 Cu 78 8 <5 <5 132 65 13 38 23 Zn 92 19 47 47 108 80 61 55 61 Ga 15 4 15 16 17 17 16 19 18 Rb 104 17 66 62 70 51 41 65 14 Sr 433 44 292 538 331 496 476 277 422 Y 19 3 12 12 20 17 17 19 16 Zr 41 121 92 104 106 102 91 113 110 Nb 3 6 5 5 4 4 4 5 4 Mo <2 <2 <2 <2 <2 2 <2 4 2 Ag <1 <1 <1 <1 <1 <1 <1 <1 <1 Sn 1 <1 1 1 1 1 1 1 <1 Cs 2 1 2 2 5 3 2 2 3 Ba 1835 482 1830 1510 1420 1480 1345 1135 1525 La 8 2 22 16 16 13 13 16 14 Ce 17 2 41 30 33 26 26 31 28 Pr 2 <0.1 4 3 4 3 3 4 3 Nd 10 1 15 13 16 12 13 17 14 Sm 3 <0.1 3 3 4 3 3 3 3 Eu 1 <0.1 1 1 1 1 1 1 1 Gd 3 <0.1 2 2 3 3 3 3 3 Tb 0.5 <0.1 0.3 0.4 1 0.5 0.4 0.2 0.1 Dy 3 <0.1 2 2 3 3 3 3 2 Ho 1 <0.1 0.4 0.4 1 1 1 0.4 0.2 Er 2 <0.1 1 1 2 2 2 2 1 Tm 0.3 <0.1 0.2 0.2 0.3 0.3 0.3 <0.1 <0.1 Yb 2 <0.1 1 1 2 2 2 2 2 Lu 0.3 <0.1 0.2 0.2 0.4 0.4 0.3 <0.1 <0.1 Hf 1 3 3 3 3 3 3 4 3 Ta 02 <0.1 03 1 0.3 0.3 0.3 <0.1 <0.1 W 1 11 1 3 1 1 1 6 5 Au 0.004 0.001 <0.001 <0.001 0.001 0.001 0.001 0.001 0.002 TI 0.7 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 0.7 <0.5 Pb <5 14 6 6 7 12 <5 14 7 Th 1 2 5 6 5 5 3 5 5 U 0.5 2 2 3 3 3 2 3 3 Whole rock data are given in we/o. trace elements are in ppm Abbreviations: Equi., equigranular; Plag.. plagioclase; 'measured; 2calculated 142 Sample ID Phenocryst Groundmass Quartz Plagioclase K-feldspar Biotite Amphibole Magnetite SYN Dyke ^Count ^Percent ^ 103 33% 205^67% Whole Rock QAPF ^1 ^,1%^<1% 70 22%^24% 230^71%^76% O 0% 16^5% 5 2% Sample ID X Phenocryst Groundmass Quartz Plagioclase K-feldspar Biotite Amphibole Magnetite FD-2 ^Count ^Percent 203 61% 129^39% Whole Rock QAPF 31^12%^14% 97 37%^45% 88^33%^41% O 0% 43^16% 6 2% m Sample IDPhenocrystGroundmassQuartzPlagioclaseK -feldsparBiotiteAmphiboleMagnetite SOV Plutonount^Percent120 41%171^59%Whole Rock QAPF21^8%^9%83 31%^37%121^45%^54%0 0%29^11%12 5% Duncan Pluton Count^Percent Sample ID Phenocryst Groundmass Quartz Plagioclase K-feldspar Biotite Amphibole Magnetite n/a (equigranular) Whole Rock QAPF 23^15%^19% 63 42%^51% 38^25%^30% 0 0% 16^11% 7% KN 02 07 693.8 A ount^Percent 146 49% 152^51% Whole Rock QAPF 9^3%^4% 115 44%^50% 106^40%^46% 7 3% 5^2% ^20 8% Sample ID, Phenocryst Groundmass Quartz Plagioclase K-feldspar Biotite Amphibole Magnetite FD-1 ^Cou ^Percent 35 14% 209^86% Whole Rock QAPF 4^2%^2% 30 11%^11% 232^87%^87% 1 <1% O 0% O 0%  Sample ID* Phenocryst Groundmass Quartz Plagioclase K-feldspar Biottte Amphibole Magnetite Figure Ai Sample V Phenocryst Groundmass Quartz Plagioclase K-feldspar Biotite Amphibole Magnetite FD-3 ^Count ^Percent 91 21% 349^79% Whole Rock QAPF 105^31%^31% 193 57%^57% 43^12%^12% 0 0% O 0% *2^'<I% " (pyrite) ' !al quartz-rich granitoids quartzolite(quartz • Alkali-feldspar syenite dyke X Quartz-diorite dyke ^ firanodiorite dyke Kemess North Pluton A Sovere ign Pluton Diorite dyke O Duncan Pluton granorliorite 0 tonalite quartz monzodiorite quartz-monzogabbro alkali feldspar granite granite quartz diorite /syeno- / monzot^\ quartz gabbroquartz alkali feldspar sycnite --^/ granito^granite^\ quartz anorthosue la /^35f ^65\ i ^) / quartz I^quartz X morizodiorile / syenite / minzonite^\ alkali feldspar syenite^ 1110117.0gabbro ti monzoliite Alkali Feldspar^ \., Plagioclase Feldspar roid-bearing syenite diorite gabbro anorthosite 143 Figure A.1. The photographs show examples of seven unstained and stained (with sodium- cobalt nitrate) rock slabs of intrusive rocks at Kemess North. For each rock type, mineral percentages are shown based on point-counting of the rock slabs using a 1 mm resolution grid. The data are plotted on the Quartz-Alkali-feldspar-Plagioclase (QAP) ternary diagram and names are given for each rock type. 144 APPENDIX B STRUCTURAL MEASUREMENTS 145 Table B.1: Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636181 6326212 97 9 80 2 1 zeolite vein 636187 6326208 43 4 90 108 1 joint 636183 6326194 43 4 82 262 1 joint 636191 6326193 33 2 90 136 1 contact 636204 6326177 97 9 70 182 1 zeolite vein 636208 6326189 97 9 67 37 1 zeolite vein 636214 6326188 43 4 58 48 1 joint 636216 6326182 43 4 65 143 1 joint 636243 6326263 33 2 54 329 1 contact, BFP 636246 6326245 52 12 90 280 1 fault 636161 6326382 43 4 80 270 1 joint 636164 6326383 43 4 76 165 1 joint 636170 6326377 43 4 61 240 1 joint 636171 6326374 43 4 89 152 1 joint 636184 6326364 97 9 49 295 1 vein 636191 6326331 52 12 73 113 1 fault 636197 6326331 43 4 89 4 1 joint 636201 6326336 43 4 80 54 1 joint 636205 6326338 97 9 78 55 1 vein 636206 6326334 52 12 21 196 1 fault, sinistral 636210 6326335 43 4 59 155 1 joint 636210 6326335 43 4 87 163 1 joint 636213 6326331 43 4 54 190 1 joint 636218 6326329 43 4 60 325 1 joint 636229 6326327 97 9 76 212 1 vein, zeolite-carbonate 636239 6326327 43 4 61 117 1 joint 636239 6326332 43 4 82 118 1 joint 636245 6326327 43 4 78 358 1 joint 636250 6326332 52 12 48 298 1 fault 636250 6326332 78 10 80 90 1 striation 636266 6326331 43 4 71 356 1 joint 636292 6326342 43 4 80 100 1 joint 636296 6326343 43 4 84 348 1 joint 636108 6326619 43 4 90 120 1 joint 636106 6326615 43 4 71 168 1 joint 636112 6326611 43 4 60 110 1 joint 636110 6326607 43 4 47 179 1 joint 636118 6326604 43 4 86 120 1 joint 636118 6326599 43 4 85 142 1 joint 636114 6326597 43 4 75 193 1 joint 636112 6326598 43 4 88 200 1 joint 636126 6326592 43 4 72 122 1 joint 636125 6326584 43 4 85 130 1 joint 636128 6326578 43 4 85 120 1 joint 636133 6326585 43 4 82 188 1 joint 636136 6326579 43 4 72 128 1 joint 636133 6326579 43 4 82 145 1 joint 636190 6326616 52 12 52 172 1 fault 636190 6326618 52 12 50 273 1 fault 636187 6326613 43 4 90 34 1 joint 636186 6326615 52 12 70 183 1 fault 636186 6326615 78 10 10 183 1 striation 636183 6326614 43 4 43 317 1 joint 636179 6326612 43 4 79 287 1 joint 636175 6326612 43 4 78 183 1 joint 636171 6326618 43 4 73 273 1 joint 636171 6326616 43 4 78 173 1 joint 636165 6326620 43 4 83 314 1 joint 636164 6326618 43 4 68 251 1 joint 636155 6326611 43 4 80 110 1 joint 636153 6326609 43 4 72 170 1 joint 636162 6326594 52 12 89 124 1 fault 636168 6326597 52 12 80 178 1 fault 636172 6326584 43 4 75 200 1 joint 636176 6326583 43 4 74 133 1 joint RHR- right hand rule 146 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636190 6326555 43 4 82 13 1 joint 636219 6326554 43 4 80 168 1 joint 636224 6326552 43 4 82 108 1 joint 636210 6326541 43 4 63 328 1 joint 636227 6326538 43 4 80 344 1 joint 636089 6326764 43 4 80 110 1 joint 636093 6326760 43 4 60 9 1 joint 636133 6326775 43 4 23 153 1 joint 636139 6326776 52 12 63 270 1 fault 636140 636145 6326774 6326774 43 52 4 12 72 61 62 358 1 1 joint fault, zeolite-carbonate, dextral 636152 6326754 43 4 62 162 1 joint 636165 6326743 52 12 90 120 1 fault, zeolite 636171 6326744 43 4 77 250 1 joint 636174 6326740 97 9 64 170 1 vein, quartz 636163 6326734 43 4 75 265 1 joint 636168 6326735 43 4 29 110 1 joint 636172 6326713 43 4 42 142 1 joint 636172 6326707 52 12 90 98 1 fault fault, zeolite-epidote- 636174 6326703 52 12 73 47 1 carbonate 636174 6326696 52 12 58 17 1 fault, dextral 636170 6326694 43 4 90 107 1 joint fault, zeolite-epidote- 636154 6326679 52 12 67 342 1 carbonate 636181 6326673 52 12 85 48 1 fault 636183 6326657 97 9 84 26 1 vein, zeolite-carbonate 636186 6326654 43 4 55 29 1 joint 636184 6326652 43 4 70 310 1 joint 636192 6326659 97 9 69 315 1 vein, zeolite-carbonate 636191 6326654 43 4 71 317 1 joint 636185 6326646 43 4 76 310 1 joint 636188 6326644 52 12 78 195 1 fault 636184 6326651 55 42 70 194 1 shear zone 636244 6326664 55 42 90 332 1 shear zone, oxidized 636267 6326650 43 4 60 80 1 joint 636259 6326643 43 4 74 266 1 joint 636264 6326642 43 4 56 3 1 joint 636098 6326702 52 12 80 298 1 fault, zeolite 636099 6326699 43 4 65 160 1 joint 636114 6326692 43 4 77 318 1 joint 636109 6326689 43 4 64 318 1 joint 636095 6326672 43 4 20 278 1 joint 636094 6326669 43 4 88 162 1 joint 636098 6326669 43 4 84 288 1 joint 636090 6326629 43 4 89 120 1 joint fault, dextral-minor 636089 6326626 52 12 74 157 1 reverse 636089 6326626 78 10 20 180 1 striation 636096 6326908 43 4 68 222 1 joint 636096 6326905 43 4 30 135 1 joint 636095 6326905 43 4 80 136 1 joint 636091 6326903 52 12 80 190 1 fault, zeolite-carbonate 636102 6326887 43 4 64 127 1 joint 636101 6326885 43 4 34 162 1 joint 636072 6326804 43 4 79 157 1 joint 636077 6326803 43 4 76 94 1 joint 636128 6326803 52 12 81 290 1 fault, normal, zeolite 636129 6326797 43 4 32 342 1 joint 636134 6326800 43 4 65 163 1 joint 636137 6326801 43 4 50 130 1 joint 635907 6327005 43 4 89 252 1 joint 635917 6327004 43 4 72 28 1 joint 635955 6327016 52 12 80 279 1 fault, zeolite RHR- right hand rule 147 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636047 6326994 43 4 79 270 1 joint 636045 6326990 43 4 37 150 1 joint 636047 6326991 43 4 71 149 1 joint 636063 6326966 43 4 78 59 1 joint 636065 6326957 43 4 60 82 1 joint 635976 6327158 43 4 20 150 1 joint 635988 6327152 43 4 61 150 1 joint 635986 6327151 43 4 68 97 1 joint 635991 6327145 43 4 50 165 1 joint 635992 6327140 43 4 50 225 1 joint 636000 6327133 43 4 72 21 1 joint 635960 6327202 43 4 80 98 1 joint 635959 6327207 43 4 76 78 1 joint 635963 6327210 43 4 45 192 1 joint 635974 6327216 43 4 80 12 1 joint 635975 6327220 43 4 73 107 1 joint 635972 6327223 43 4 89 170 1 joint 635975 6327226 43 4 89 110 1 joint 635963 6327239 52 12 85 130 1 fault 635970 6327238 43 4 61 139 1 joint 635974 6327240 43 4 39 57 1 joint 635972 6327260 43 4 75 125 1 joint 635975 6327260 43 4 71 11 1 joint 635980 6327261 43 4 62 100 1 joint 635985 6327263 43 4 70 147 1 joint 635973 6327295 43 4 89 96 1 joint 635956 6327349 43 4 60 275 1 joint 635958 6327350 43 4 80 340 1 joint 635941 6327379 43 4 52 360 1 joint 635947 6327379 43 4 79 281 1 joint 635958 6327386 43 4 69 120 1 joint 635964 6327375 43 4 84 278 1 joint 635968 6327375 43 4 62 355 1 joint 635930 6327420 33 2 45 185 1 contact? fault, dextral offsets 635955 6327421 52 12 45 154 1 256 joint 635942 6327421 52 12 58 256 1 fault, normal 635941 6327424 43 4 45 281 1 joint 635954 6327428 52 12 60 110 1 fault 635940 6327429 97 9 55 85 1 vein, zeolite-carbonate 635936 6327433 43 4 34 198 1 joint 635933 6327434 55 42 69 117 1 shear zone, chioritic 635914 6327466 43 4 81 266 1 joint 635897 6327494 43 4 80 105 1 joint 635893 6327498 43 4 75 135 1 joint 634963 6327463 43 4 73 121 1 joint 634963 6327200 43 4 70 3 1 joint joint, conjugate with 634914 6327447 43 4 89 189 1 234 joint, conjugate with 634908 6327443 43 4 88 234 1 189 634888 6327404 43 4 46 205 1 joint 634890 6327402 43 4 60 326 1 joint 634840 6327485 43 4 89 290 1 joint 634841 6327486 43 4 64 124 1 joint 634842 6327487 43 4 55 320 1 joint 634843 6327489 43 4 79 330 1 joint joint, conjugate with 634847 6327449 43 4 70 358 1 150 joint, conjugate with 634847 6327449 43 4 70 150 1 358 634847 6327449 43 4 78 80 1 joint 634881 6327414 43 4 68 335 1 joint 634843 6327370 43 4 65 340 1 joint 634844 6327371 43 4 89 205 1 joint RHR- right hand rule 148 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636869 6325892 43 4 76 116 1 joint 636863 6325892 43 4 72 185 1 joint 636875 6325878 43 4 86 241 1 joint 636791 6325812 43 4 77 147 1 joint 636739 6325823 43 4 68 290 1 joint 636739 6325826 43 4 24 60 1 joint 636733 6325825 43 4 69 208 1 joint 636706 6325744 43 4 50 244 1 joint 636702 6325738 43 4 68 132 1 joint 636707 6325740 43 4 68 207 1 joint 636288 6325974 43 4 76 92 1 joint 636289 6325976 52 12 78 327 1 fault 636290 6325975 43 4 87 214 1 joint 636287 6325972 43 4 33 320 1 joint 636308 6325956 33 2 71 122 1 mafic dyke 636308 6325956 43 4 70 19 1 joint 636617 6325969 43 4 90 326 1 joint 636869 6325892 43 4 70 115 1 joint 637013 6325960 43 4 70 183 1 joint 637020 6325959 43 4 86 118 1 joint contact, carbonate 637109 6325981 33 2 80 333 1 dyke? 637126 6325987 43 4 68 162 1 joint 637193 6326027 33 2 80 360 1 contact, syenite dyke 637190 6326048 33 2 80 320 1 contact, mafic dyke 637211 6326082 43 4 74 165 1 joint 637220 6326088 52 12 84 37 1 fault 637294 6326176 43 4 80 197 1 joint 637300 6326186 52 12 58 122 1 fault, dextral fault carbonate 637313 6326204 52 12 80 289 1 alteration 637325 6326222 43 4 88 346 1 joint 637325 6326221 43 4 40 145 1 joint 637339 6326230 43 4 72 238 1 joint 637343 6326278 52 12 40 332 1 fault 637348 6326281 43 4 82 285 1 joint 637346 6326280 97 9 78 167 1 vein, zeolite-carbonate 637388 6326308 43 4 84 103 1 joint 637409 6326326 43 4 81 115 1 joint 637413 6326330 33 2 80 300 1 contact 637427 6326349 97 9 82 46 1 vein, zeolite-carbonate 637441 6326355 97 9 68 6 1 vein, zeolite-carbonate 637433 6326351 43 4 70 297 1 joint 636226 6326099 43 4 78 307 1 joint 636235 6326095 43 4 80 136 1 joint 636238 6326109 52 12 65 157 1 fault 636246 6326112 43 4 82 305 1 joint 636249 6326112 43 4 60 233 1 joint 636255 6326104 52 12 82 340 1 fault 636260 6326109 43 4 55 188 1 joint 636264 6326105 43 4 74 188 1 joint 636266 6326106 43 4 78 140 1 joint 636263 6326081 43 4 60 97 1 joint 636258 6326077 43 4 60 188 1 joint 636268 6326069 43 4 78 116 1 joint 636271 6326070 43 4 88 133 1 joint 636262 6326057 43 4 65 251 1 joint 636267 6326058 33 2 90 219 1 contact, mafic dyke 636276 6326059 52 12 80 306 1 fault 636267 6326036 52 12 85 180 1 fault 636270 6326036 43 4 66 120 1 joint 636268 6326028 43 4 73 2 1 joint 636272 6326026 43 4 85 113 1 joint 636267 6326023 43 4 70 66 1 joint 636543 6326164 43 4 80 230 1 joint RHR- right hand rule 149 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636572 6326092 43 4 64 158 1 joint 636597 6326093 43 4 85 290 1 joint 636581 6326074 43 4 80 155 1 joint 636599 6326031 43 4 82 316 1 joint 636615 6326010 43 4 86 360 1 joint 637360 6326675 43 4 88 121 1 joint 637337 6326698 43 4 84 135 1 joint 637330 6326893 43 4 66 290 1 joint 637330 6326893 33 2 64 316 1 contact, mafic dyke 637323 6326990 43 4 70 20 1 joint 637321 6326996 43 4 70 60 1 joint 637504 6326420 43 4 88 106 1 joint 637300 6327168 43 4 82 103 1 joint 637297 6327179 52 12 88 180 1 fault, cuts E-W faults 637302 6327231 52 12 80 110 1 fault 637302 6327247 52 12 75 180 1 fault 637301 6327256 43 4 76 150 1 joint 637314 6327259 43 4 68 24 1 joint 637323 6327258 44 6 87 281 1 foliation 637305 6327300 43 4 89 360 1 joint 637301 6327308 43 4 85 92 1 joint 637281 6327326 43 4 60 168 1 joint 637286 6327331 43 4 60 195 1 joint 637276 6327335 43 4 69 104 1 joint 637268 6327336 43 4 45 341 1 joint 637274 6327337 43 4 75 147 1 joint 637263 6327400 43 4 75 240 1 joint 637270 6327401 43 4 75 180 1 joint 637258 6327455 97 9 68 284 1 vein, carbonate-epidote 637265 6327461 43 4 74 153 1 joint 637274 6327459 43 4 64 166 1 joint 637267 6327471 43 4 83 288 1 joint 637261 6327474 43 4 80 218 1 joint 634700 6325551 52 12 89 32 1 fault 634699 6325566 97 9 76 50 1 vein, quartz-carbonate 634697 6325569 43 4 88 317 1 joint 634674 6325587 52 12 82 246 1 fault, reverse 634676 6325590 43 4 85 76 1 joint 634670 6325605 43 4 43 302 1 joint 634669 6325610 43 4 46 170 1 joint 634668 6325612 43 4 86 176 1 joint 634685 6325614 43 4 72 200 1 joint 634665 6325611 43 4 85 236 1 joint 634659 6325616 97 9 68 37 1 vein, quartz-magnetite 634654 6325626 43 4 48 166 1 joint 634656 6325626 43 4 75 206 1 joint 634657 6325628 43 4 86 45 1 joint 634635 6325626 43 4 52 140 1 joint, cut mafic dykes 634625 6325632 52 12 71 163 1 fault fault, contact with 634633 6325633 52 12 40 110 1 Takla/TDG 634633 6325633 33 2 40 110 1 contact with Takla/TDG 634624 6325639 52 12 70 334 1 fault 634624 6325639 78 10 25 334 1 striation 634605 6325632 52 12 58 340 1 fault 634605 6325632 78 10 10 160 1 striation 634591 6325648 52 12 76 180 1 fault 634591 6325648 78 10 20 180 1 striation 634592 6325650 43 4 72 316 1 joint 634541 6325678 43 4 50 220 1 joint 634543 6325677 43 4 45 30 1 joint 634498 6325689 43 4 89 144 1 joint 634501 6325693 43 4 80 232 1 joint 634754 6325700 43 4 85 303 1 joint 634754 6325697 52 12 53 167 1 fault RHR- right hand rule 150 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 634754 6325701 43 4 66 340 1 joint 634758 6325702 97 9 89 234 1 vein, quartz-pyrite 634785 6325700 43 4 82 84 1 joint 634786 6325702 97 9 70 64 1 vein, quartz-pyrite 634792 6325709 43 4 80 32 1 joint 634793 6325708 43 4 89 150 1 joint 634796 6325712 43 4 60 325 1 joint 634755 6325713 52 12 70 73 1 fault 634748 6325713 43 4 60 324 1 joint 634750 6325715 43 4 70 64 1 joint 634759 6325717 43 4 60 56 1 joint 634753 6325721 43 4 80 82 1 joint 634756 6325723 43 4 40 4 1 joint 634764 6325779 43 4 85 47 1 joint 634769 6325785 52 12 64 347 1 fault 634777 6325796 52 12 72 56 1 fault 634777 6325796 78 10 20 230 1 striation 634777 6325796 97 9 72 56 1 vein, quartz-pyrite 634782 6325810 97 9 45 44 1 vein, quartz-magnetite 634777 6325829 33 2 88 192 1 mafic dyke 634763 6325832 33 2 66 62 1 mafic dyke 634762 6325836 33 2 85 300 1 mafic dyke 634763 6325847 33 2 82 326 1 mafic dyke 634721 6325880 43 4 80 343 1 joint 634721 6325884 43 4 80 67 1 joint 634734 6325898 52 12 70 246 1 fault, mineralized 634734 6325898 97 9 70 246 1 vein, quartz 634716 6325931 52 12 58 50 1 fault, mineralized 634729 6325952 43 4 65 276 1 joint vein, carbonate-quartz- 634726 6325957 97 9 80 306 1 zeolite vein, carbonate-quartz- 634726 6325955 97 9 74 350 1 zeolite vein, carbonate-quartz- 634745 6325961 97 9 75 10 1 zeolite 634737 6325956 43 4 53 224 1 joint 634714 6325970 43 4 88 316 1 joint 634715 6325975 43 4 78 356 1 joint 634712 6325974 43 4 88 226 1 joint 634690 6326063 43 4 87 80 1 joint 634693 6326070 43 4 89 168 1 joint 635208 6326469 43 4 45 149 1 joint 635234 6326464 43 4 37 120 1 joint 635232 6326460 43 4 70 278 1 joint 635251 6326465 43 4 52 144 1 joint 635253 6326468 43 4 43 314 1 joint 635219 6326439 43 4 64 67 1 joint 635240 6326461 43 4 79 247 1 joint 635275 6326415 52 12 78 221 1 fault 635275 6326415 43 4 76 132 1 joint 635277 6326425 43 4 62 307 1 joint 635294 6326422 43 4 52 161 1 joint 635294 6326422 43 4 52 140 1 joint 635312 6326416 43 4 78 306 1 joint 635295 6326399 43 4 57 26 1 joint 635295 6326399 43 4 82 258 1 joint 635295 6326399 43 4 53 123 1 joint 635295 6326388 43 4 47 138 1 joint 635289 6326377 52 12 62 142 1 fault 635300 6326379 43 4 87 81 1 joint 635300 6326379 43 4 48 12 1 joint 635300 6326379 43 4 62 28 1 joint 635278 6326409 55 42 88 134 1 shear zone, chloritic 635323 6326355 43 4 29 144 1 joint 635323 6326355 43 4 50 129 1 joint RHR- right hand rule 151 Structural Measurements Easting NAD83 Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 635217 6326331 43 4 24 184 1 joint 635209 6326330 43 4 68 122 1 joint 635208 6326303 43 4 51 142 1 joint 635207 6326296 43 4 63 108 1 joint 635201 6326299 43 4 86 218 1 joint 635428 6325996 43 4 88 339 1 joint 635421 6325875 43 4 89 161 1 joint 635418 6325827 43 4 64 337 1 joint 635418 6325827 43 4 86 256 1 joint 635418 6325827 43 4 68 217 1 joint 635393 6325821 43 4 86 104 1 joint 635393 6325821 43 4 86 198 1 joint 635433 6325799 43 4 71 107 1 joint 635430 6325764 43 4 88 111 1 joint 635427 6325729 43 4 88 3 1 joint 635463 6325739 43 4 73 230 1 joint 635463 6325739 43 4 58 309 1 joint 635091 6326006 43 4 69 164 1 joint 635112 6326047 43 4 30 216 1 joint 635112 6326047 43 4 88 136 1 joint 635112 6326047 43 4 63 344 1 joint 635112 6326047 43 4 84 26 1 joint 635149 6326143 43 4 70 135 1 joint 635149 6326143 43 4 85 16 1 joint 635149 6326143 43 4 33 182 1 joint 635142 6326156 43 4 45 209 1 joint 635142 6326156 43 4 88 124 1 joint 635180 6326172 43 4 70 116 1 joint 635180 6326172 43 4 43 221 1 joint 635178 6326209 43 4 72 130 1 joint 635178 6326209 43 4 52 170 1 joint 635178 6326209 43 4 63 261 1 joint 635173 6326232 43 4 44 150 1 joint 635173 6326232 43 4 82 253 1 joint 635162 6326234 43 4 69 260 1 joint 635162 6326234 43 4 88 156 1 joint 635162 6326234 43 4 61 141 1 joint 635162 6326234 43 4 29 158 1 joint 635170 6326243 43 4 90 163 1 joint 635170 6326243 43 4 90 161 1 joint 635179 6326250 97 9 77 255 1 zeolite vein 635170 6326252 43 4 90 133 1 joint 635214 6326261 43 4 77 8 1 joint 635214 6326261 43 4 79 248 1 joint 635214 6326261 43 4 46 158 1 joint 635210 6326270 43 4 80 130 1 joint 635210 6326270 43 4 77 8 1 joint 635210 6326270 43 4 44 230 1 joint 635210 6326270 97 9 68 179 1 zeolite vein 634701 6325581 43 4 53 282 1 joint 634773 6325516 43 4 67 268 1 joint 634773 6325516 43 4 60 18 1 joint 635007 6325479 43 4 81 351 1 joint 635007 6325479 43 4 26 173 1 joint 635035 6325437 43 4 74 306 1 joint 635035 6325437 43 4 63 245 1 joint 635092 6325461 43 4 88 360 1 joint 635092 6325461 43 4 64 288 1 joint 635132 6325456 43 4 85 104 1 joint 635168 6325459 43 4 81 356 1 joint 635242 6325477 43 4 82 344 1 joint 635265 6325479 43 4 61 282 1 joint 636682 6325738 43 4 80 348 1 joint 636682 6325738 43 4 58 215 1 joint 636500 6325703 43 4 64 295 1 joint RHR- right hand rule 152 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code Inclination Strike RHR Weight Information 636466 6325716 52 12 60 360 1 fault zone 636466 6325716 43 4 89 24 1 joint 636448 6325722 52 12 65 360 1 mineralized fault zone 636448 6325722 43 4 66 295 1 joint 636415 6325753 43 4 77 276 1 joint 636409 6325764 43 4 82 324 1 joint 636409 6325764 52 12 82 324 1 mineralized fault zone 636350 6325781 52 12 80 340 1 fault zone 636296 6325820 52 12 77 348 1 fault zone 636205 6325776 43 4 64 326 1 joint 636205 6325776 43 4 85 35 1 joint 636205 6325776 43 4 60 10 1 joint 636162 6325721 52 12 80 4 1 fault 636659 6325708 43 4 70 15 1 joint 636659 6325708 43 4 78 290 1 joint 636659 6325708 43 4 89 182 1 joint contact with 636139 6325719 33 2 82 328 1 Takla/Rhyolite Dyke joints within Rhyolite 636139 6325719 43 4 52 270 1 Dyke fault within Rhyolite 636129 6325687 52 12 78 124 1 Dyke fault contact ending 636074 6325659 52 12 80 2 1 Rhyolite Dyke fault contact ending 636074 6325659 33 2 80 2 1 Rhyolite Dyke fault contact 636061 6325642 52 12 70 200 1 Takla/Toodog 636061 6325642 43 4 78 350 1 joint fault contact 636061 6325642 33 2 70 200 1 Takla/Toodog 636026 6325620 52 12 80 174 1 fault 635999 6325615 43 4 48 295 1 joint 635999 6325615 43 4 52 160 1 joint 635999 6325615 52 12 87 290 1 fault with zeolite veins fault contact 636028 6325615 52 12 80 178 1 Toodog/Takla fault contact 636028 6325615 33 2 80 178 1 Toodog/Takla 635970 6325596 52 12 69 320 1 fault 635970 6325596 43 4 72 314 1 joint 635970 6325596 43 4 82 190 1 joint fault contact 635941 6325604 52 12 83 60 1 Toodog/Takla fault contact 635941 6325604 33 2 83 60 1 Toodog/Takla 635939 6325607 52 12 86 360 1 fault 636651 6325702 43 4 78 39 1 joint 635935 6325607 52 12 73 307 1 fault 635933 6325615 52 12 80 50 1 fault 635933 6325615 52 12 87 60 1 fault 635933 6325615 43 4 73 290 1 joint 635889 6325639 55 42 78 310 1 mineralized shear zone 635880 6325630 52 12 85 124 1 fault 635880 6325630 43 4 82 344 1 joint 635848 6325611 52 12 82 168 1 2m wide fault 635848 6325611 52 12 88 322 1 fault 635848 6325611 43 4 88 247 1 joint 635823 6325607 43 4 78 325 1 joint 635823 6325607 43 4 80 63 1 joint 635823 6325607 43 4 78 172 1 joint 635823 6325607 43 4 78 287 1 joint 635785 6325608 43 4 84 220 1 joint 635785 6325608 43 4 82 171 1 joint 635785 6325608 52 12 65 308 1 sinistral fault RHR- right hand rule 153 Structural Measurements Easting NAD83^Northing NAD83 Structure Code Group Code inclination Strike RHR Weight Information 636642 6325717 52 12 85 130 1 20m long fault 635728 6325588 52 12 75 352 1 fault 50m long, 50cm wide 635703 6325599 52 12 87 357 1 fault 635659 6325595 52 12 86 336 1 fault 635648 6325589 52 12 75 322 1 lm wide fault 635648 6325589 42 4 89 96 1 joint 635648 6325589 42 4 84 353 1 joint 635635 6325583 52 12 70 170 1 80m long, 1m wide 635576 6325621 43 4 89 30 1 joint 635576 6325621 43 4 89 281 1 joint 80m long, 50cm wide 635507 6325648 52 12 89 12 1 fault 635490 6325693 43 4 82 110 1 joint 635490 6325693 43 4 65 354 1 joint chloritic fault, sinistral 636631 6325723 52 12 78 189 1 fault? 636612 6325727 43 4 84 274 1 joint 636612 6325727 43 4 88 280 1 joint 636612 6325727 52 12 87 330 1 fault 636574 6325708 52 12 75 11 1 fault 636559 6325749 43 4 52 110 1 joint 50m long, 10m wide 636527 6325698 52 12 78 216 1 fault 636174 6326581 52 12 64 130 1 fault 636186 6326555 43 4 81 126 1 joint 636038 6327015 43 4 89 92 1 joint 636034 6327013 43 4 44 142 1 joint 634845 6327373 43 4 46 130 1 joint 634846 6327375 43 4 60 338 1 joint 636573 6326110 97 9 80 150 1 vein, zeolite-carbonate 636570 6326108 43 4 89 95 1 joint 634756 6325698 43 4 80 288 1 joint 634752 6325702 43 4 88 245 1 joint 635779 6325605 52 12 70 299 1 fault 635769 6325582 52 12 80 144 1 15m wide fault 636500 6325703 43 4 80 203 1 joint 636466 6325716 43 4 69 300 1 joint 635318 6326344 43 4 86 30 1 joint 635318 6326344 43 4 52 143 1 joint RHR- right hand rule 154 APPENDIX C FLUID INCLUSION ANALYSES 155 N  a w  0  o a w a m m a m  N ^ m m ^ A n c o r  m a w m c o m o c o - w 0 0 ,- 0 - c o  w 0 - N = A - ^ N c 6 6 .- - - A M A r ^ „ 4 6 - = , - - a  N  N N - N N o c A o c o  w O m N N N  N  N N M N N N . - - N  N ^ N N N N ^ N N N  . 4 . N N M N m N N N N N N N N N . - N o A r , N  N m u lo a c o N N N ^ c o = w a , z ▪ z  Z  z z n w N z Z Z  z  Z z w Z  Z Z Z Z • , ^ z z V 0 7 7 0 ' " 0 0 ,0 z Z & " N Z Z Z .Z z z Z Z Z N  N z r, 0 ° N N N  N 0 0 . - 0 N 7 N N N ^ m °  r d ^ 0 N 0 N O N 0 0 . 7 N N O N g N g 0 6 0 0 0  0 0 0 0 0 0 0 0 0 0  0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 X5 0 0 0 0 ' ,  '9 7 0 0 0 '. . . ? . 0 7 '- . • a^ ‘7, V.4) K^ 2N a ^ h " . n 7 15^ 6N ^ 0 0 . - 4 0  6 0 6 0 ^ An  v a s ^ M C O ,j2 0N0 M W 0 ,  m  0  o u 1.N .? 0 .^ T .  1!4 0 6 N o i q r : ^ c i= A - N t- r c o N m o  0) w a A n a c 'm ^ a a m m c o m m m a  a 0 0 0 N 0 0 N O N 7 ' r 7 0 .) 0 0 0 0 0 w 0 6 O p i d , ; 6 0 N 0 0 0 0 , 6 . -- m w 0 m d 0 N O 0 M  0 q M O M , O W 0 ^ , 1 0 , 0  .1 t ■ - - N N N  W M 0 0 • N O ^ M 0 0 . - 0 , N N N 0  W M ■ - 0 0 ,  W . , 7 0 0 " 4 -  0 0 0 7 0  0 , 0 0 0 N . - 0 0  O M N ▪ N N  'M M N  N N N N M M N N . - N ^ M N N N N N E O M , - - 0- O 0 0 0 0 ^ 0 „ , 0 0 0 ° g o = 6  0 0 0 =  0  o  0  0  0  0  = o o 0 0  0 0 0 0  0  0 0 0 - -. 0 0 ', 7 A - 0 0 0 7 o N o o r > 2 2 7 - . 7 8 8 8 - --.N r ,2 O 0 O 6 a .O c ic d o c i.O 6 6 6 6 = = = .  0  . 6 6 6 6 ° ° 6 6 0 0 0 n o v c ,0 -A-c, a N m o ^ O N 0 6 6 A o m w  r- , = A n a  a a ^ m -m o lo E0 o ^ .1 ,:t^ 4 0 . N 7 0 0 0 ,7 , 0 , 1  . 1 N . 0 N N N M N M O N  8 0 0 ^ ° 0  0 0 ' ^ '° . 1^ 0 ^ '4 0 0 ° 0 ^ 0 0 An '' 0 0 , N 0 -N o o 0 N e o = ,  r • -, 0  0  N ^ N  0 , 0  . 0 ^ .0  0  0 ^ A - 10^ A-. a  co 6 ^ 6 ^ 6 ^ 6 , 6 ^ 6 ^ N  6 N ^ C ^ 7 ^ C4^ 6 0 E D O  0  1 0 ^ 0  0 ^ 0 •  N O  P ^ , 0 0 0 , , , M , C q 0 „ 0 0 , 0 0 , , , , C 4 0 . 0 " N  0 0 0 0 , 1 0 C D  0  C D  0  0  0  0  0  0  0  0  0  C D  C D  0  0  0  0  C D  0  C D  C D  0  0  0  C D  0  C P  C D  0  0  a )  0  C D  0  0  0  0  ID  0  0  C D  0  0  0  0  0  0  C D  0  0  0 O C D 0 C D 0 0 , 0 , 0 0 . 0 E X C O 0 O P C 0 0 . 0 0 , M C D 0 o 0 3 0 0 0 0 , C o M M O I r C D O P . 0 / 0 , 0 , M . 0 0 0 0 C A M 0 0 0 , C , 7 1 2 2 2 S V 2 S . A 2 B 2 S B L " B o E B I R S 2 _ M S S 2 . E 1 0. 2 V S . V . B . S e V . V . S S I S B 2 . V . S V ; 5 0 0 0 0 0 T 0 0 0 T 0 0 1 5 , 0 5 0 T 0 0 T 0 T T T T T 0 0 0 T 0 1 4 0 0 v 0  0 T 0 1 , 0 0 T T I ^ I ^ 4 . 1 ^ . 1 1 ^ 4 1 1 = L L L t = L L L L L t L L t = L L L L L= == M M M M M M M M W M M M W M M M M M M M M M I U M M I M M O M M M M C O M M M O I M M M M M M M W M M M W M M M W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W :i 7i i ; i i i '70 Q Q Q Q 1 1 1 1 1 1 M W V V ( 1 4 4 4 - ; ^ ; T. ; ; ; ; ;3, ; ^ r7; T; T . 3^ T ;  N  N  N ^ 4  4  rA ^ 6 6, AAAA^ 66 6  ch  6  d , d , d , 6  6  d , 6  6  d , g g g 8 g g g g g g  8 s 5 g 8 g g g g w v .m w w w q q q q q ,7 , 7„7 -- d O O O c i d c i c i d o O 8 g g g g c g O N o m = = = = „ „ , „ , , , , , „ . , , „ „ , , , , N  N  N  N ' M M 3  o ^ W T T T T T T q i : ^ A aA IIIIIIA A “A A A A A A A A A A ttA ,,,,,,,,,,,,,,,,,,,,^ 0 0 0 0 0 0 0 0 0 0 0 0 = o o = 0 0 0 0 0 0 = o o ,- - ,- N N N N N - - - n n Ao = N N A , N o A N N N N N N N N N N A , N 0 0 0 . . 0 . . . 0 0 0 0 0 0 . . 0 ° ° ° ° ° ° ° ° ° ° ° ° ° ' ZZ 0 0 0 0 0 = 0 0 0 0 0 6 o c l o Z Z Z  z  H . Z  Z  Z z Z Z H H f C f C H ^ H H H H f C H o =^ ” ^ YYYY 4EttUttEttttEtttttttfAttttAttttttttEtttttttttttEttt Zvi O E E E E E E E g V E E E E E E E E E E E E E E E E E E E E E V E E E g E E E E E E E E E E E E E E 156 Fluid Inclusion Analyses Stack^Sample Inclusion Vein-type Length (ym) Width (ym) Tm ice ('Cl Tm NaCI (°C) VolFrac yap (%) Th L-V ('C) Th to NaCt/(NaCI+KCI) Ta ('C) Molal NaCI Wt% NaCI X(NaCI) Cht.Temp. ('C) Cnt.Press. (bars) Bulk Den Bulk MV I-120-NaCI-(KCI) Kemess North KNO209-418.28 418.28-A1-1 Main-stage 18.75 25 -6 0.1 171^L 1^-28.3 1.7 9.2 0.0 459 446 1,0 20.0 Kemess North KNO209-418,28 418.28-At-2 Main-stage 8.75 11 378.1 0.05 264^L 1 14.1 45.1 0.2 NA. N.A. 1.2 21.8 Kemess North KNO209-418.28 418.28-A1-3 Main-stage 9 7 0.1 284^L 1 Kemess North KNO209-418.28 418.28-A1-4 Main-stage 11.25 8 415.1 0.1 279^L 1 16.5 49.1 0.2 NA. NA. 1,2 222 Kemess North KNO209-418.28 418.28-A1-5 Main-stage 7,5 5 351.3 0.1 264^L 1 12.7 42.5 0.2 N.A. N.A. 1,2 22.0 Kemess North KNO209-418,28 418,28-A1-6 Main-stage 8.75 4 0.15 L 1 Kemess North KNO209-418.28 418.28-A3-1 Main-stage 12.5 15 382.9 0.1 286^L 1 14.4 45.6 0.2 N.A. NA, 1.2 22.4 Kemess North KNO209-418.28 418.28-A3-2 Main-stage 8.75 6 388 0.05 245^L 1 14.7 46.2 0.2 N.A. NA. 12 21.6 Kemess North KNO209-418.28 418,28-A3-3 Main-stage 5 11 0.05 L 1 Kemess North KNO209-418.28 418.28-A3-4 Main-stage 12.5 13.5 440.2 0.05 298^L 1 18.6 52.1 0.3 N.A. N.A. 1.2 22.6 Kemess North KNO209-418.28 418.28-A3-5 Main-stage 25 30 -5.2 0.05 77^L 1^-24 1.5 8.1 0.0 449 419 1.0 19,0 Kemess North KNO209-418.28 418.28-A5-1 Main-stage 12.5 11 267 0.1 333^L 1 -27.7 9.5 35.8 0.2 N.A. NA. 1.0 23.3 Kemess North KNO209-418.28 418.28-A5-2 Main-stage 13 4 0.4 L 1 Kemess North KNO209-418.28 418,28-A8-1 Main-stage 11.25 11 0.1 220^L 1 Kemess North KNO209-418.28 418.28-A6-2 Main-stage 11.25 11 419.9 0,1 266^L 1 18.9 49.7 0.2 N.A. NA. 1.2 21.9 Kemess North KNO209-418.28 418.28-A6-3 Main-stage 6.25 16.25 0.05 183^L 1 Kemess North KNO209-418.28 418.28-A6-4 Main-stage 8.75 16.25 392 095 270^L 1 14,9 46.6 0.2 N.A. N.A. 12 21.9 Kemess North Kemess North Kemess North KNO209-418.28 KNO209-418.28 KNO209-418.28 418.28-A6-5 418,28-A6-6 418.28-A6-7 Main-stage Main-stage Main-stage 11.25 10 7.25 14.75 6.25 8.75 403.1 346.8 381,9 0.2 0.05 0.05 264^L 197^L 245^L 1 1 1 15,7 12,4 14.3 47.8 42.1 45.5 0.2 0.2 0.2 N.A. N.A., N.A. N.A. NA. N.A. 2 1.2 1.2 21.9 20.7 21.4 Kemess North KNO209-418.28 418,213-A8-8 Main-stage 6.25 11.25 450.9 0.05 185^L 1 19.6 53.4 0.3 N.A. NA. 1.3 21.2 Kemess North KNO209-399 399-A1-2 Main-stage 12.5 13 356.3 0.1 257^L 1 12.9 43.0 0.2 N.A. N.A. 1.2 21.8 Kemess North KNO209-399 399-A1-8 Main-stage 16.5 16 410.8 0.1 272^L 1 16,2 48,6 0.2 NA, N.A. 1,2 22.2 Kemess North KNO209-399 399-A1-10 Main-stage 11.25 5 450 0,1 271^L 1 19.5 53.3 0.3 N.A. N.A. 1.3 22.2 Kemess North KNO209-399 399-A1-11 Main-stage 11.8 10 407.4 0.05 242^L 1 16.0 48,3 0.2 N.A. NA, 1.3 21.5 Kemess North KNO209-399 399-A1-12 Main-stage 16 12 390,6 0.1 242^L 1 14.8 46.4 0.2 NA, N.A. 1,2 21.5 ,...., Kemess North KNO209-399 399-A1-13 Main-stage 14.3 9.3 438.9 0.1 L 1 18.5 51,9 03 furl Kemess North KNO209-399 399-A1-14 Main-stage 12.5 16 0.05 248^L 1 20.4 54.4 0.3 N.A. N.A. 1.3 22.0 ---1 Kemess North KNO209-399 399-A1-18 Main-stage 10 10 440585.98 0.05 261^L 1 15.9 48.1 0.2 N.A. NA, 12 21.8 Kemess North KNO209-399 399-A1-19 Main-stage 12.5 12.5 405 0.05 286^L 1 15.8 48.0 0.2 N.A. N.A. 1,2 22.3 Kemess North KNO209-399 399-A3-3 Main-stage 16 12 0.05 71 L 1 Kemess North KNO209-399 399-A3-4 Main-stage 8.6 10 352.7 0.1 234^L 1 12,7 42.7 0,2 NA, N.A. 1.2 21,5 Kemess North KNO209-399 399-A3-5 Main-stage 10 11.2 0.8 394^L 1 Kemess North 010209-399 399-A3-7 Main-stage 8.75 6.25 0.5 412^L 1 Kemess North KNO209-399 399-A3-8 Main-stage 12.5 10 0,8 405^L 1 Kemess North KNO209-399 399-A3-9 Main-stage 4 6.25 0.6 405^L 1 Kemess North KNO209-399 399-A3-10 Main-stage 6.25 10 326.6 0.1 L 1 11,6 40.3 0,2 Kemess North KNO209-399 399-A3-11 Main-stage 12 12 315.6 0.05 213^L 1 11,1 39.4 0.2 N.A. N.A. 1.2 21.0 Kemess North KNO103-503.7 503.7-A1-1 Main-stage 14 7.8 -4.7 0,6 381^L 1 1.4 7.4^• 09 442 401 0.6 29.7 Kemess North KNO103-503.7 503.7-A1-2 Main-stage 12.5 11 -3.4 0,6 360^L 1 1.0 5.5 0.0 425 352 0.8 29.2 Kemess North KNO103-503.7 503.7A1-4 Main-stage 9.3 9.3 0.6 389^L 1 0.0 0.0 0.0 0.4 41.3 Kemess North KNO103-503,7 503.7-A1-6 Mein-stage 18.7 9.3 -5.5 0.5 431^L 1 1.6 8.5 0.0 453 429 0.5 36.4 Kemess North KNO103-503.7 503.7-A1-7 Main-stage 11 9.3 -3.1 0.2 254^L 1 0.9 5.0 0.0 420 340 0.8 22.4 Kemess North KNO103-503.7 503.7-A1-10 Main-stage 23 26 -4.1 0.6 369^L 1 1,2 6.5 0.0 434 378 06 29.2 Kemess North KNO103-503.7 503.7-A2-1 Main-stage 15.6 22 0,6 429^V 1 0.0 0.0 0,0 62.20.3 Kemess North KN0103-503.7 503.7-A2-2 Main-stage 18.7 12.5 0.6 424^V 1 0.0 0.0 0.0 0.3 58.2 Kemess North KN0103-503.7 503.7-A2-6 Main-stage 6.24 7.8 0.6 439^V 1 0.0 0,0 0.0 0.2 724 Kemess North KNO103-503.7 503.7-A3-1 Main-stage 28.1 31.2 -9.3 0.35 471^V 1 2.6 13.2 0.0 495 545 0.5 36.1 Kemess North KNO103-503.7 503.7-A3-2 Main-stage 18.7 17.2 -9.2 0.6 467^V 1 2.6 13,1 0.0 494 542 0,6 35.5 Kemess North KNO103-503.7 503.7-A3-3 Main-stage 23.4 26.5 -8.3 0.5 486^V 1 2.4 12.1 0.0 0.5 41.8 Kemess North KNO103-503.7 503.7-A3-7 Main-stage 15.6 10.9 0.6 404^V 1 0.0 0.0 0.0 0.4 46.9 Kemess North KNO209-399 399-A2-5 Main-stage 9.3 6.8 359.5 0,1 257^L 1 13.1 43.3 0.2 N.A. N.A. 1.2 21.7 Kemess North KNO209-399 399-A2-6 Main-stage 5 7.5 292.2 0.1 202^L 1 10,3 37,8 0.2 N.A. N.A. 1.2 20.9 Kemess North KNO209-399 399-A2-8 Main-stage 10 6.8 385 0.1 222^L 1 14.5 45.9 0.2 NA. NA. 1,2 21.4

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