Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
DSpace
UBCV
Celis, Antonio
Master of Science - MSc
University of British Columbia
Exploration success in large parts of the Quesnel and Stikine terranes in south-central British Columbia (BC) has been limited due to extensive coverage by glacial sediments (Ward et al., 2009), where traditional geophysical and geochemical exploration methods have proven to be limited or impractical (Gent et al., 2011). The occurrence of resistate minerals such as apatite, epidote, garnet, magnetite, rutile and titanite as alteration products in porphyry deposits suggests that they could be utilized as porphyry indicator minerals (PIMs) to provide a new tool to increase exploration success in covered terrains (Bouzari et al., 2011). Titanite (CaTiSiO5) is a common accessory mineral in alkalic Cu-Au porphyry deposits that is known to record various magmatic and hydrothermal processes in its texture and chemical composition (). In this research, titanite hosted in bedrock from the Mount Polley, Mount Milligan and Copper Mountain alkalic porphyry Cu-Au deposits of south-central BC, as well as in surrounding till sediments, was characterized based on petrography, heavy mineral separation, and Electronic Microprobe (EMP) and Laser Ablation Inductively Coupled-Plasma Mass Spectrometry (LA-ICP-MS) chemical analyses. The main objective is to determine key diagnostic features of titanite that are related to alkalic porphyry alteration and mineralization. Titanite typically forms as replacement of mafic minerals, such as augite, biotite and magnetite during K-silicate and Na-Ca alterations. Thus, four types of titanite were defined based on key petrographic and chemical features: primary magmatic (MAG), metasomatic (MET), secondary (SEC) and altered (ALT) titanites. Titanite recovered from till sediments near studied alkalic deposits preserve the texture and chemical signatures obtained in the rock, despite surficial weathering. Therefore, the above classification of titanite constitutes a useful mineralogical tool for exploration for alkalic Cu-Au porphyry deposits in covered terrains
TITANITE AS AN INDICATOR MINERAL FOR ALKALIC PORPHYRY CU-AU DEPOSITS IN SOUTH-CENTRAL BRITISH COLUMBIA by Antonio Celis BSc, Universidad de Concepción, 2010 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in The Faculty of Graduate and Postdoctoral Studies (Geological Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) November 2015 © Antonio Celis, 2015 ii Abstract Exploration success in large parts of the Quesnel and Stikine terranes in south-central British Columbia (BC) has been limited due to extensive coverage by glacial sediments (Ward et al., 2009), where traditional geophysical and geochemical exploration methods have proven to be limited or impractical (Gent et al., 2011). The occurrence of resistate minerals such as apatite, epidote, garnet, magnetite, rutile and titanite as alteration products in porphyry deposits suggests that they could be utilized as porphyry indicator minerals (PIMs) to provide a new tool to increase exploration success in covered terrains (Bouzari et al., 2011). Titanite (CaTiSiO5) is a common accessory mineral in alkalic Cu-Au porphyry deposits that is known to record various magmatic and hydrothermal processes in its texture and chemical composition (). In this research, titanite hosted in bedrock from the Mount Polley, Mount Milligan and Copper Mountain alkalic porphyry Cu-Au deposits of south-central BC, as well as in surrounding till sediments, was characterized based on petrography, heavy mineral separation, and Electronic Microprobe (EMP) and Laser Ablation Inductively Coupled-Plasma Mass Spectrometry (LA-ICP-MS) chemical analyses. The main objective is to determine key diagnostic features of titanite that are related to alkalic porphyry alteration and mineralization. Titanite typically forms as replacement of mafic minerals, such as augite, biotite and magnetite during K-silicate and Na-Ca alterations. Thus, four types of titanite were defined based on key petrographic and chemical features: primary magmatic (MAG), metasomatic (MET), secondary (SEC) and altered (ALT) titanites. MAG titanite is typically euhedral, colourless, exhibits concentric compositional zoning and has intermediate (1-1.5) Fe/Al ratios, low V and F, high REE (∑ REE = 5000 -7000 ppm), high HFSE (Y, Nb, Ta, Th/U) and REE patterns with LREE convex upwards and strong negative Eu anomalies. MET titanite has euhedral to subhedral habit, distinctive caramel brown colour, abundant microfractures, amorphous high contrast zoning, and is chemically similar to MAG titanite but has higher concentrations of REE and HFSE (Y, Nb, Ta, Th/U). SEC and ALT titanites are typically blond to honey brown colour and exhibit anhedral habit with fine cavities, dissolved edges, patchy/sector compositional zoning and significant degree of rutile replacement. Chemically, they have low (< 1.0) Fe/Al ratios if affected by Na-Ca alteration, high (> 1.5) Fe/Al ratios if affected by K-silicate alteration, V enrichment when texturally associated with Cu mineralization and are typically depleted in REE (∑ REE < 5000 ppm) and HFSE. Titanite recovered from till sediments near studied alkalic deposits preserve the texture and chemical signatures obtained in the rock, despite surficial weathering. Therefore, the above classification of titanite constitutes a useful mineralogical tool for exploration for alkalic Cu-Au porphyry deposits in covered terrains. iii Preface This research is part of the Porphyry Indicator Minerals (PIMs) Project led by Dr. Farhad Bouzari at Mineral Deposit Research Unit (MDRU), with financial support from Geoscience BC. My research contribution was focused on the study of titanite in alkalic Cu-Au porphyry deposits of south-central BC. The author benefited from discussion with supervisors and other faculty members at the Department of Earth, Ocean and Atmospheric Sciences. Travis Ferbey from the British Columbia Geological Survey (BCGS) provided field assistance for the till survey component of this research. Although this project has benefited from discussion with many people, the major findings are based on the author’s personal endeavors. The following constitutes a list of publications arising from work presented in this research: Celis, M.A., Hart, C.J.R., Bouzari, F., Bissig, T. and Ferbey, T. (2013): Porphyry Indicator Minerals (PIMs) from alkalic porphyry Cu-Au deposits in south-central British Columbia (NTS 092, 093); in Geoscience BC Summary of Activities 2012, Geoscience BC, Report 2013-1, p.37–46. This publication largely is based on data from Chapter 1. Celis, M.A., Bouzari, F., Bissig, T., Hart, C.J.R. and Ferbey, T. (2014): Petrographic characteristics of porphyry indicator minerals from alkalic porphyry Cu-Au deposits in south-central British Columbia (NTS 092, 093); in Geoscience BC Summary of Activities 2013, Geoscience BC, Report 2014-1, p. 53–62. This publication largely is based on data from Chapter 4. Celis, M.A., Bouzari, F., Hart, C.J.R., , Bissig, T. and Ferbey, T. (2015): Titanite as a Porphyry Indicator Mineral for alkalic Cu-Au porphyry deposits in south-central British Columbia, abstract for 27th International Applied Geochemistry Symposium, 2015, Tucson, AZ, USA. This publication largely is based on data from Chapter 4 and 5. iv Table of Contents Abstract ........................................................................................................................................... ii Preface............................................................................................................................................ iii Table of Contents ........................................................................................................................... iv List of Tables ...................................................................................................................................x List of Figures ................................................................................................................................ xi List of Abbreviations…………………………………………………………………………….xv Acknowledgements……………………………………………………………………………..xvii Dedication .................................................................................................................................. xviii Chapter 1: Introduction……………………………………………………………………………1 1.1. Objectives ........................................................................................................................... 3 1.2. Porphyry Indicator Minerals (PIMs) ................................................................................... 4 1.3. The significance of titanite as an indicator mineral ............................................................ 7 1.3.1. Titanite types and occurrences .................................................................................. 8 1.3.2. Titanite chemical substitutions ................................................................................ 11 1.3.3. Titanite chemistry as an indicator of source ............................................................ 12 1.4. Overview of thesis ............................................................................................................ 16 1.4.1. Chapter 1: Introduction ........................................................................................... 16 1.4.2. Chapter 2: Materials and Methods .......................................................................... 17 1.4.3. Chapter 3: Geological Setting ................................................................................. 16 1.4.4. Chapter 4: Petrography of Titanite .......................................................................... 16 1.4.5. Chapter 5: Chemistry of Titanite............................................................................. 17 1.4.6. Chapter 6: Titanite in Till Sediments ...................................................................... 18 v 1.4.7. Chapter 7: Discussion and Conclusions .................................................................. 18 Chapter 2: Materials and Methods ................................................................................................19 2.1. Study sites ......................................................................................................................... 19 2.2. Field work . ....................................................................................................................... 20 2.3. Analylitical methods ........................................................................................................ 27 2.3.1. Petrographic analysis ............................................................................................... 27 2.3.2. Heavy mineral separation ........................................................................................ 27 2.3.3. Binocular microscope study .................................................................................... 29 2.3.4. Titanite chemical analysis ....................................................................................... 29 2.3.4.1. Major element analysis ....................................................................................... 29 2.3.4.2. Trace element analysis........................................................................................ 30 2.3.5. Till survey ............................................................................................................... 31 2.3.5.1. Till matrix geochemistry .................................................................................... 31 Chapter 3: Geological Setting .......................................................................................................32 3.1. Alkalic porphyries ............................................................................................................ 32 3.2. Alkalic porphyries in British Columbia ........................................................................... 34 3.3. Mount Polley .................................................................................................................... 35 3.3.1. Lithology ................................................................................................................. 35 3.3.2. Alteration................................................................................................................. 43 3.3.3. Mineralization ......................................................................................................... 47 3.4. Mount Milligan ................................................................................................................ 48 3.4.1. Lithology ................................................................................................................. 48 3.4.2. Alteration ................................................................................................................. 53 vi 3.4.3. Mineralization ......................................................................................................... 58 3.5. Copper Mountain ............................................................................................................. 59 3.5.1. Lithology ................................................................................................................. 59 3.5.2. Alteration................................................................................................................. 67 3.5.3. Mineralization ......................................................................................................... 71 Chapter 4: Petrography of Titanite ...............................................................................................72 4.1. Paragenesis of titanite in alkalic porphyry deposits .......................................................... 72 4.1.1. Titanite at Mount Polley deposit ............................................................................. 73 4.1.2. Titanite at Mount Milligan deposit ......................................................................... 74 4.1.3. Titanite at Copper Mountain deposit ...................................................................... 75 4.2. Titanite types ..................................................................................................................... 77 4.2.1. Magmatic titanite .................................................................................................... 77 4.2.1.1. Magmatic recrystallized titanite ........................................................................ 78 4.2.2 . Secondary titanite .................................................................................................... 79 4.2.2.1. Secondary titanite after magnetite ..................................................................... 80 4.2.2.2. Secondary titanite after augite ........................................................................... 81 4.2.2.3. Secondary titanite after biotite ........................................................................... 82 4.2.3. Altered titanite ......................................................................................................... 83 4.2.3.1. Altered magmatic titanite ................................................................................... 84 4.2.3.2. Altered Secondary Titanite ................................................................................ 84 4.2.3.3. Altered unknown titanite .................................................................................... 86 4.3. Titanite binocular study .................................................................................................... 87 4.3.1. Titanite colour ......................................................................................................... 87 vii 4.3.2. Titanite size and relative abundance ....................................................................... 89 4.4. Summary .......................................................................................................................... .91 Chapter 5: Chemistry of Titanite ..................................................................................................93 5.1. Titanite major element composition ................................................................................. 93 5.1.1. Titanite composition at Mount Polley ..................................................................... 93 5.1.2. Titanite composition at Mount Milligan ................................................................. 95 5.1.3. Titanite composition at Copper Mountain .............................................................. 96 5.1.4. Interpretation ........................................................................................................... 98 5.2. Titanite trace element composition and REE patterns ...................................................... 99 5.2.1. Titanite composition at Mount Polley ..................................................................... 99 5.2.2. Titanite composition at Mount Milligan ............................................................... 101 5.2.3. Titanite Composition at Copper Mountain ........................................................... 103 5.2.4. Interpretation ......................................................................................................... 106 5.3. Chemistry of titanite concentrates from bedrocks .......................................................... 107 5.3.1. Titanite HMC major element composition ........................................................... 107 5.3.2. Titanite HMC trace element composition ............................................................. 108 5.3.3. Interpretation ......................................................................................................... 110 5.4. Summary of titanite chemistry ........................................................................................ 111 Chapter 6: Titanite in Till Sediments ..........................................................................................116 6.1. Till geology ..................................................................................................................... 116 6.2. Heavy mineral concentrates (HMC) in till sediments at Mount Milligan ...................... 120 6.2.1. Detrital titanite in till sediments ............................................................................ 120 6.2.1.1. Physical characterization of detrital titanite ................................................. 121 viii 6.2.1.2. Chemistry of detrital titanite ........................................................................... 124 6.2.1.3. Interpretation..................................................................................................... 127 6.2.1.4. Detrital titanite in till sediments at Mount Polley ........................................ 129 6.2.2. Distribution and relative abundance of heavy mineral concentrates (HMC) ........ 132 6.2.2.1. Titanite ............................................................................................................... 132 6.2.2.2. Distribution and relative abundance of other PIMs ..................................... 136 6.3. Till geochemistry at Mount Milligan .............................................................................. 142 6.3.1. Results ................................................................................................................... 142 6.3.1.1. Deposit scale metal dispersion ....................................................................... 142 6.3.1.2. Regional scale metal dispersion ..................................................................... 147 6.4. Summary ......................................................................................................................... 150 Chapter 7: Discussions and Conclusions ....................................................................................153 7.1. Discussion ....................................................................................................................... 153 7.2. Conclusions ..................................................................................................................... 158 7.3. Guidelines for the use of titanite in exploration.............................................................. 163 References ....................................................................................................................................167 Appendices ...................................................................................................................................177 Appendix A. ................................................................................................................................ 178 A.1 Hand and core samples listing ................................................................................ 179 A.2 Petrographic data .................................................................................................... 186 Appendix B. Electron Microprobe (EMPA) Analytical Data ..................................................... 213 B.1 EMPA analyses in thin sections .............................................................................. 214 B.2 EMPA analyses in bedrock concentrates ................................................................ 223 ix B.3 EMPA analyses in till concentrates ........................................................................ 225 Appendix C. Laser Ablation ICP-MS analytical data ................................................................ 229 C.1 LA-ICP-MS analyses in thick sections ................................................................... 230 C.2 LA-ICP-MS analyses in bedrock concentrates ....................................................... 234 C.3 LA-ICP-MS analyses in till concentrates ............................................................... 235 Appendix D. Heavy Mineral Concentrates (HMC) Quantitative Data.…..…………………….239 D.1 Titanite & PIMs HMC from bedrocks. ................................................................... 240 D.2 Titanite HMC from till sediments ........................................................................... 240 D.3 PIMs HMC from till sediments............................................................................... 242 Appendix E. Till matrix Geochemical Data ............................................................................... 243 E.1 Till matrix geochemistry at Mount Milligan. ......................................................... 246 E.2 Till matrix geochemistry at Mount Polley .............................................................. 247 x List of Tables Table 1.1 Characteristics of PIMs occurring in porphyry copper deposits……………………….4 Table 1.2 Summary of titanite types in intrusive rocks ……………….………………………...10 Table 1.3 Titanite common chemical substitutions and their significance…………….………...15 Table 4.1 Physical characterization of titanite grains from SELFRAG bedrock………………...90 Table 4.2 Titanite petrographic classification.……………….………………………………......92 Table 5.1 Representative titanite major and trace element composition.……………….……...114 xi List of Figures Figure 1.1 Portion of titanite crystal structure ………………………...………………………..11 Figure 2.1 Location map showing selected study sites………………...………………………..20 Figure 2.2 Geology map of Mount Polley showing location of rock samples ……………….....22 Figure 2.3 Geology map of Mount Milligan showing location of rock samples ……………….23 Figure 2.4 Geology map of Copper Mountain showing location of rock samples ……………..24 Figure 2.5 Location of till samples……………………………...………………...…………….26 Figure 2.6 Heavy mineral separation method……………………………...……………………28 Figure 2.7 Till sampling……………………………...………………...………………………..31 Figure 3.1 Schematic model of alkalic igneous complexes……………………………………..34 Figure 3.2 Geological map of the Mount Polley Intrusive Complex……………………………36 Figure 3.3 Photomicrographs of Augite-biotite diorite (PD1) at Mount Polley………………...37 Figure 3.4 Photomicrographs of K-feldspar-bearing diorite (PMdu) at Mount Polley…………39 Figure 3.5 Photomicrographs of K-feldspar monzonite porphyry (Pkm) at Mount Polley……..41 Figure 3.6 Photomicrographs of Fragmental Breccia (FBx) at Mount Polley…………….……42 Figure 3.7 Alteration map of the Mount Polley Intrusive Complex…………………………....44 Figure 3.8 Photomicrographs of potassic alteration at Mount Polley…………………………...45 Figure 3.9 Photomicrographs of calc-Potassic alteration at Mount Polley……………………..46 Figure 3.10 Photomicrographs of propylitic alteration at Mount Polley………………………..47 Figure 3.11 Geology of the Mount Milligan deposit……………………………………………49 Figure 3.12 Photomicrographs of basaltic trachyandesite from the Witch Lake succession at Mount Milligan…………………………………………………………………………………..50 Figure 3.13 Photomicrographs of the Lower Trachyte at Mount Milligan…………….……….51 xii Figure 3.14 Photomicrographs of the MBX and SS stocks at Mount Milligan…………….…..52 Figure 3.15 Alteration map of the Mount Milligan deposit……………………………………..54 Figure 3.16 Photomicrographs of potassic alteration at Mount Milligan……………………….55 Figure 3.17 Photomicrographs of sodic-calcic alteration at Mount Milligan…………………..56 Figure 3.18 Photomicrographs of propylitic alteration at Mount Milligan……………………...60 Figure 3.19 Geology of the Copper Mountain deposit………………………………………….60 Figure 3.20 Photomicrographs of the Nicola Group at Copper Mountain District……………..61 Figure 3.21 Photomicrographs of the CMS and Voight Stock at Copper Mountain District…...63 Figure 3.22 Photomicrographs of LHIC at Copper Mountain District………………………….65 Figure 3.23 Alteration map of the Copper Mountain deposit…………………………………...67 Figure 3.24 Photomicrographs of sodic-calcic alteration at Copper Mountain…………………69 Figure 3.25 Photomicrographs of potassic alteration at Copper Mountain……………………..70 Figure 4.1 Photomicrographs of titanite at Mount Polley ………………………………………73 Figure 4.2 Photomicrographs of titanite at Mount Milligan ……………………………………74 Figure 4.3 Photomicrographs of titanite at Copper Mountain …………………………………76 Figure 4.4 a. MAG titanite viewed under TL. b. Same view under SEM………………………78 Figure 4.5 a. MAG-RCX titanite viewed under TL. b. Same view under SEM………………..79 Figure 4.6 a. SEC-Mgt titanite viewed under RL. b. Same view under SEM………………......81 Figure 4.7 a. SEC-Aug titanite viewed under TL. b. Same view under SEM…………………..82 Figure 4.8 a. SEC-Biot titanite viewed under TL. b. Same view under SEM…………………..83 Figure 4.9 a. ALT-MAG titanite viewed under TL. b. Same view under SEM…………….......84 Figure 4.10 a. ALT-SEC-Aug titanite viewed under RL. b. Same view under TL......................85 Figure 4.11 a. ALT-SEC-Biot titanite viewed under TL. b. Same view under SEM……….......86 xiii Figure 4.12 a. ALT-UNK titanite viewed under TL. b. Same view under SEM………………..86 Figure 4.13 Photomicrographs of titanite grains examined under binoculars and SEM………..88 Figure 4.14 Photomicrographs of titanite grains from SELFRAG bedrocks……………………89 Figure 5.1 Titanite composition at Mount Polley ………………………………………………94 Figure 5.2 Titanite composition at Mount Milligan …………………………………………….96 Figure 5.3 Titanite composition at Copper Mountain …………………………………………..97 Figure 5.4 Titanite REE patterns at Mount Polley……………………………………………..100 Figure 5.5 Titanite trace elements concentration (ppm) vs ∑REE (ppm) at Mount Polley …...101 Figure 5.6 Titanite REE patterns at Mount Milligan…………………………………………..102 Figure 5.7 Titanite trace elements concentration (ppm) vs ∑REE (ppm) at Mount Milligan…103 Figure 5.8 Titanite REE patterns at Copper Mountain………………………………………...104 Figure 5.9 Titanite trace elements concentration (ppm) vs ∑REE (ppm) at Copper Mountain.105 Figure 5.10 Titanite HMC composition at Mount Polley……………………………………...108 Figure 5.11 Titanite HMC REE patterns at Mount Polley……………………………………..109 Figure 5.12 Titanite HMC trace elements concentration (ppm) vs ∑REE (ppm) at Mount Polley…………………………………………………………………………………………...110 Figure 6.1 Till sediments overlying the Mount Milligan deposit ……………………………..118 Figure 6.2 Location of till samples ……………………………………………………………119 Figure 6.3 Photomicrographs of detrital titanites in tills from Mount Milligan ………………122 Figure 6.4 Photomicrograph of titanite grains from bedrock ………………………………….123 Figure 6.5 Chemistry of detrital titanites in tills from Mount Milligan ……………………….125 Figure 6.6 REE patterns of detrital titanites in tills from Mount Milligan ……………………126 xiv Figure 6.7 Trace elements concentration vs ∑REE (ppm) in detrital titanites in tills from Mount Milligan…………………………………………………………………………………………127 Figure 6.8 Photomicrographs of detrital titanites in tills from Mount Polley …………………129 Figure 6.9 Chemistry of detrital titanites in tills from Mount Polley …………………………130 Figure 6.10 REE patterns and trace elements contents in detrital titanites in tills from Mount Polley…………………………………………………………………………………………...131 Figure 6.11 Detrital titanite deposit-scale footprint in till sediments at Mount Milligan ……..133 Figure 6.12 Detrital titanite deposit-scale footprint in till sediments at Mount Polley…..........135 Figure 6.13 Chalcopyrite and gold grain deposit-scale footprints in tills at Mount Milligan.....137 Figure 6.14 Garnet and epidote deposit-scale footprints in tills at Mount Milligan …………..138 Figure 6.15 Chalcopyrite and gold grain deposit-scale footprints in tills at Mount Polley……138 Figure 6.16 Garnet and epidote deposit-scale footprints in tills at Mount Polley …………….141 Figure 6.17 Deposit-scale vanadium (V) anomalies in the till fine fraction relative to the V content in titanite at Mount Milligan…………………………………………………………...143 Figure 6.18 Deposit-scale copper (Cu) and gold (Au) anomalies in the till fine fraction at Mount Milligan ………………………………………………………………………………...............145 Figure 6.19 Deposit-scale antimony (Sb) and arsenic (As) anomalies in the till fine fraction at Mount Milligan …………………………………………………………...................................146 Figure 6.20 Regional scale Copper (Cu) and gold (Au) anomalies in till at Mount Milligan....148 Figure 6.21 Regional scale antimony (Sb) and arsenic (As) anomalies in till at Mount Milligan ………………………………………………………………......................................................149 Figure 6.22 Regional scale vanadium (V) anomalies (ppm) in till at Mount Milligan………...150 Figure 7.1 Summary diagram of titanite in alkalic porphyry deposits ……………...................163 xv List of Abbreviations a.p.f.u. ……………………………………………………………………..Atoms per formula unit ALT…………………………………………………………………………………Altered titanite ALT-MAG………………………………………………………………Altered Magmatic titanite ALT-SEC……………………………………………………………….Altered Secondary titanite ALT-SEC-Aug……………………………………………Altered Secondary titanite after Augite ALT-SEC-Biot……………………………………………Altered Secondary titanite after Biotite ALT-UNK……………………………………………………………….Altered Unknown titanite BSE……………………………………………………………...Back-Scattered Electron detector EDS……………………………………………………….Energy-Dispersive X-ray Spectroscopy EMP…………………………………………………………………………..Electron Microprobe fO2………………………………………………………………………………..Oxygen Fugacity HFSE………………………………………………………………..High Field Strength Elements HMC…………………………………………………………………Heavy Mineral Concentrates HREE………………………………………………………………….Heavy Rare Earth Elements INAA…………………………………………………..Instrumental Neutron Activation Analysis LA-ICP-MS……………………………..Laser Ablation Inductive Coupled Plasma Spectroscopy LREE…………………………………………………………………...Light Rare Earth Elements MAG……………………………………………………………………………..Magmatic titanite MAG-RCX………………………………………………………Magmatic Recrystallized titanite MET…………………………………………………………………………..Metasomatic titanite PIMs………………………………………………………………….Porphyry Indicator Minerals REE…………………………………………………………………………...Rare Earth Elements xvi RL……………………………………………………………………..Reflected Light microscopy SEC……………………………………………………………………………...Secondary titanite SEC-Aug…………………………………………………………...Secondary titanite after Augite SEC-Biot…………………………………………………………...Secondary titanite after Biotite SEC-Mgt………………………………………………………..Secondary titanite after Magnetite SELFRAG………………………………………………………………...Selective Fragmentation SEM……………………………………………………………...Scanning Electronic Microscopy T……………………………………………………………………………………….Temperature TL…………………………………………………………………..Transmitted Light microscopy XN……………………………………………………………………..Crossed Nicols microscopy xvii Acknowledgements First, I would like to acknoledge my sponsors Geoscience BC and the Mineral Deposit Research Unit (MDRU) of UBC for the generous financial contribution and support of this project. I would like to give special thank to my supervisors Dr. Farhad Bouzari and Dr. Craig Hart for their good will and constant supervision during all the stages of my thesis. In addition, I would like to give special thanks to Travis Ferbey (British Columbia Geological Survey) for his great collaboration and guidance during fieldwork, as well as Peter Holbek (Copper Mountain Mining Corp.), Graeme Roper (Thompson Creek Metals Co.) and Gary Roste (Imperial Metals Corp.) for all their support during fieldwork at Copper Mountain, Mount Milligan and Mount Polley mine sites respectively. Finally, I would like to thank Edith Czech (UBC), Marghaleray Amini (UBC), Albert Ding (UBC), Tom Ver Hoeve (UBC) and Dr. James Scoates (UBC) for their support and use of facilities during analylitical work, as well as Dr. Lee Groat (UBC) and Dr. Jan Cempirek (UBC) for their guidance during mineralogical data interpretation. xviii Dedication To my parents Rodrigo and Teresa… 1 Chapter 1: Introduction Alkalic systems include some of the world’s highest grade porphyry gold resources (e.g., Ridgeway, New South Wales, 53 Mt grading 2.5 g/t Au (4.26 million oz) and 0.77% Cu; Cadia Far East, New South Wales, 290 Mt grading 0.98 g/t Au (9.13 million oz) and 0.36% Cu), and some of the largest gold accumulations in epithermal settings (e.g., Lihir, Papua New Guinea, 44.7 million oz Au: Chamberlain et al., 2006). The Quesnel and Stikine terranes in south-central BC comprise Late Triassic–Early Jurassic magmatic arcs that host several porphyry Cu±Mo and Cu-Au deposits. However, exploration success in large parts of these terranes has been limited due to extensive coverage by veneers of till and related glacial sediments (Ward et al., 2009), especially between the Mount Milligan and Mount Polley alkalic porphyry deposits (Bouzari et al., 2011). During the last three decades, exploration for porphyry copper deposits has been very successful in terrains with rock outcrops because of use and interpretation of alteration mineral assemblages (Sillitoe, 2010). But most of these alteration minerals, such as biotite and muscovite, are not stable in weathering environment and transported cover sediments. In addition, traditional geochemical exploration methods based on the analysis of rock, sediments, water and vegetation are a long established means of detecting and localizing most types of mineralization. However, their application to identify buried ore bodies in terrains with thick cover (glacial, alluvial, colluvial, lateritic, etc.) can be limited or impractical (Gent et al., 2011). Geophysical methods are commonly used in covered terrains to identify favourable host intrusive bodies but their effectiveness in identifying small mineralized zones are limited due to factors such as geology, size and depth of the orebody. 2 Nevertheless, geophysical and geochemical surveys in south-central BC (e.g., Jackaman et al., 2009; Farr et al,, 2008; Kowalczyk, 2009) suggest a broad correlation between the surficial glacial sediments geochemistry and the underlying bedrock geology (Barnett and Williams, 2009), indicating that sediments are not far transported and are broadly representative of the underlying bedrock. Therefore, identifying a more direct link between surficial sediments and the underlying bedrock source can potentially be used as an exploration tool in covered terrains. Resistate indicator minerals generated or affected by alteration and ore-forming processes can provide such link to vector towards underlying ore deposits. The large alteration footprint of porphyry deposits (4 to 10 km radius) and the common occurrence of resistate indicator minerals such as apatite, rutile, garnet, epidote, magnetite and titanite as alteration products, suggest that these minerals could be used as porphyry indicator minerals (PIMs) by providing a tool that increases exploration targeting success in covered terrains (Bouzari et al., 2011). Previous works (Deer et al., 1982; Gromet & Silver, 1983; Green & Pearson, 1986; Paterson & Stephens, 1992; McLeod, 2007) have documented titanite’s ability to record a large variety of petrogenetic information, both in terms of its chemistry and mineralogical properties such as colour, habit, texture and compositional zoning. Moreover, the crystallization of significant amounts (4%) of titanite in alkalic Cu-Au porphyry deposits of south-central BC and its common occurrence as alteration product from selective alteration of mafic minerals (i.e. augite, magnetite, biotite) during strong hydrothermal alteration + mineralization events, suggests that titanite is a strong PIMs candidate for exploration in covered terrains. 3 1.1. Objectives The main purpose of this research is to evaluate the potential of titanite as PIMs and provide a new exploration tool for the discovery covered alkalic Cu-Au porphyry deposits in south-central B.C. The objectives of this research include: • Characterization and classification of various titanite types on the basis of paragenesis and physical properties in intrusive rocks from selected alkalic deposits. • Chemical characterization of various titanite types based on their major and trace element compositions. • Physical and chemical characterization of titanite in heavy mineral concentrates (HMC) from till sediments overlying/proximal from selected alkalic deposits. • Establish key physical and chemical indicators of titanite associated with hydrothermal alteration and mineralization. • Define parameters for the use of titanite as PIMs for exploration in covered terrains. 1.2. Porphyry Indicator Minerals (PIMs) Indicator minerals are defined as those resistate minerals that persist through weathering in supergene environments, possess distinctive features that allow them to be traced back to their source and have sufficient abundance and grain size to be recovered as heavy mineral concentrates (Averill, 2001, Bouzari et al., 2011, McClenaghan, 2011). During the last three decades, kimberlite indicator minerals (KIMs) have successfully been applied to kimberlite and diamond exploration in arctic regions vastly covered by till sediments (McClenaghan, 2011). However, indicator minerals have rarely been used as exploration tool for other ore deposit 4 types, including porphyry deposits. The large alteration footprint of porphyry deposits (4 to 10 km radius) and the common occurrence of resistate minerals such as apatite, rutile, garnet, epidote, magnetite and titanite as alteration products, suggest that these minerals could be utilized as porphyry indicator minerals (PIMs) by providing a tool that increases exploration targeting success in covered terrains (Bouzari et al., 2011). The following table (from Bouzari et al., 2011) summarizes the occurrence and characteristic features of various PIMs. Table 1.1. Characteristics of PIMs occurring in porphyry copper deposits. (D = density, PCD = porphyry copper deposits), from Bouzari et al., 2011. Mineral D Occurrence in PCD Characteristic features in porphyry deposits south-central BC example Selected References Rutile 4.2 Occurs in potassic and phyllic zones as altera- tion product of biotite, il- menite, titanomagnetite, titanite and amphibole. Red color due to high copper content; crystal length:width ratio increases outward the deposit; grains proximal to the mineralized center are larger and zoned; abundance and grain size follows the Cu grade; high concentration of V, Ta and Sc; Cr+V:Nb+Ta is high; V-Sb-W-rich rutile defines the Au-rich zone. Mt. Milligan, Babine Lake, Highland Valley Williams and Cesbron, 1977; Desborough and Sharp, 1978; Czamanske et al., 1981; Harris, 1989; Nelson and Bellefontaine, 1996; Scott, 2005; Rabbia et al, 2009 Apatite 3.2 Occurs in hostrock and with early potassic alteration but records a history of dissolution and precipitation during subsequent alterations. Fluoresce bright orange color in the UV; shows complicated history of corrosion and redeposition with a characteristic zoning (Liesegang rings); rings can often be detected 600-1000 m laterally away from the intrusive; commonly displays sulphur-rich cores abruptly changing to sulphur-poor rims; it is chlorine-rich. Mt. Polley, Galore Creek, Lorraine, Granisle, Highland Valley Carson and Jambor, 1974; Williams and Cesbron, 1977; Streck and Dilles, 1998; Tepper and Kuehner, 1999; Belousova et al., 2002; Kempe and Götze, 2002; Bath et al., 2006; Liaghat and Tosdal, 2008 Garnet ~3.9 Occurs in the periphery of porphyry deposits Displays zoning, dissolution and change in composition. Ti-rich andradite commonly reported; hydrothermal titanian andradite can have as much Ti-Si as igneous varieties, but has zero or negative amounts of TiMg[Fe3+] -2 Mt. Polley, Galore Creek, Lorraine Watson, 1969; Russell et al., 1999; Nixon and Peatfiled, 2003; Micko 2010 Zircon 4.6 Commonly magmatic, occurring with the host intrusion but few studies report distinct hydro- thermal zircon hosted in hydrothermal veins. Rose zircon commonly reported; hydrothermal, spongy, inclusion-rich zircon may show complex internal textures in which secondary domains cut across primary growth zones; porphyry copper deposits are associated with intrusions with zircon having Ce(IV)/Ce(III)>300 and EuN/EuN*>0.4 Mt. Milligan, Mt. Polley, Ajax Mortensen et al., 1995; Nelson and Bellefontaine, 1996; Ballard et al., 2002; Hoskin, 2005; Pettke et al., 2005; Schaltegger, 2007 5 Table 1.1. Characteristics of PIMs occurring in porphyry copper deposits. (D = density, PCD = porphyry copper deposits), from Bouzari et al., 2011 (continuation). Monazite ~5.1 Commonly magmatic occurring with the host intrusion Hydrothermal monazite is characterized by its low ThO content (0–1 wt %) and is distinct from that of 2 igneous monazite (3 to >5 wt %). Endako Schand and Gorton, 2004; Villeneuve et al., 2001 Titanite ~3.5 Commonly magmatic occurring with the host intrusion Blond titanite reported. Composition of zoned titanite is used to examine, magma oxidation state and mixing and compatibility of Mo and W in felsic intrusions. Secondary titanite rims on magnetite contain higher Cr, Zn and Mo, and lower REE, rela- tive to magmatic titanite. Mt. Milligan; Mt. Polley; Copper Mountain Nakada, 1991; Mortensen et al., 1995; Nelson and Bellefontaine, 1996; Piccolie et al., 2000 Tourmaline ~3 Commonly with transi- tional phyllic or breccia bodies. Dravite is more common; associated with or without mineralization. Megabuck, Highland Valley Panteleyev et al., 1996; Slack, 1996 Jarosite ~3 Supergene oxidation May occur with goethite and/or copper oxides Mt. Milligan Magnetite 5.1 Magmatic and as- sociated with K-silicate alteration Can form resistate phase especially when aggre- gated with rutile, titanite and quartz. Hydrothermal magnetite has less Ti than magmatic magnetite. Geochemistry of magnetite is used to discriminate Fe-oxide occurring in various deposit types. Mt. Polley; Mt. Milligan; Highland Valley Arancibia and Clark, 1996; Dupuis and Beaudoin, 2011 Several case studies tested the use of various PIMs occurring in regolith soils, gravels, and till sediments overlying and surrounding porphyry deposits. Force et al. (1984) showed that rutile grains within 100 m of the Tangse Cu porphyry in northeast Sumatra are larger than grains further out from the deposit. Scott (2005) demonstrated key physical and chemical features of rutile in saprolite soils overlying and proximal to the Northparkes alkalic Cu-Au porphyry in southwest Australia. Rutile grains associated with hydrothermal alteration and mineralization are larger and typically display a complex zonation characterized by areas enriched in vanadium. Such effects of hydrothermal alteration survive weathering and can be readily seen in saprolite and soils (Scott, 2005). Averill (2011) studied various PIMs in gravels overlying and surrounding the Quebrada Blanca Cu porphyry deposit in northern Chile’s Atacama Desert. The footprint of a various PIMs clearly outlines an outer propylitic zone, indicated by high amounts of andradite garnet, and a more central advanced argillic alteration zone, characterized by high 6 amounts of jarosite + alunite + turquoise grains. The andradite grains are typically yellow or red-orange in colour and may have adhering silica (quartz) alteration. The supergene minerals jarosite and alunite are particularly useful indicators because they elucidate the sulphur and iron from hypogene pyrite, together with advanced argillic alteration (Averill, 2011). Kelley et al. (2011) demonstrated that PIMs are an effective exploration tool to vector towards the concealed Pebble Cu-Mo porphyry deposits in southwest Alaska, USA. Till sediments up to 7 km down-ice of the deposit contain abundant gold and jarosite grains. The presence of jarosite in the tills suggests the existence of supergene mineralization and indicates that the level of erosion by glacial processes was probably shallow. This has significant exploration implications in such that it reflects to which degree the deposit has been preserved and whether or not it is enriched in Cu due to supergene processes. Lastly, the occurrence of andradite and epidote grains in till, could reflect the presence of porphyry and/or skarn mineralization related to porphyry Cu deposits (Kelley et al., 2011). Bouzari et al. (2011) showed that yellow and brown cathodoluminescence (CL) of apatite is characteristic of specimens hosted in fresh host rocks. Apatites in K-silicate altered rocks have green CL, whereas grey CL apatites are characteristics of sericite alteration. Recent till surveys at the Mount Polley alkalic Cu-Au porphyry deposit, confirmed that andradite garnet, apatite, chalcopyrite, gold, epidote and jarosite are abundant PIMs (compared to background values) in till down-ice from the deposit (Hashmi et al., 2015). More recently, Pisiak et al. (2015) studied key characteristics of hydrothermal magnetite associated with ore mineralization in till sediments surrounding the Mount Polley deposit. Magmatic or primary magnetite tends to show ulvöspinel exsolution lamellae, high Ti content and low Ni/Cr ratio, whereas hydrothermal magnetite is more depleted in Ti and shows higher Ni/Cr ratio. In general, 7 the ratio of hydrothermal magnetite grains over magmatic counterparts increases with proximity to the deposit (Pisiak et al., 2015). 1.3. The significance of titanite as an indicator mineral Titanite (CaTiSiO5) is named after its titanium content, but it is also known as sphene due to its characteristic sphenoid shape. Titanite chemical formula has also been reported as CaTiO(SiO4) (Deer W.A. 1992) and CaTi(SiO4)(O,OH,F) (Della Ventura, Bellatreccia et al. 1999). There are several different varieties and analogues of titanite: Grothite is the Al-rich variety; Yttrotitanite is the Y-rich variety; Malayite, is the Sn analogue; Keilhauite is the REE-rich variety; and Greenovite is the Mn analogue (Deer W.A. 1992). Titanite occurs in different colors such as gray, brown, green, yellow, black, orange, colourless; yellow or light brown. It has resinous to adamantine luster and small sphenoid/wedge shaped crystal habit. Titanite is a common accessory mineral in a wide range of rocks formed in various geological environments including: igneous rocks, low to medium grade metamorphic rocks and low-temperature hydrothermal veins (Deer et al., 1992). Titanite hosted in rocks from alkalic Cu-Au porphyry deposits has up to 4% modal abundance and commonly occurs after hydrothermal alteration of mafic Ti-bearing minerals such as augite, primary Ti-magnetite and biotite. It also occurs as discrete accessory crystals in the groundmass of porphyritic intrusive rocks. The following section describes the role of titanite as a petrogenetic and metasomatic indicator, in terms of its type/occurrence and chemistry. 8 1.3.1. Titanite types and occurrences Previous works (Deer et al., 1982; Gromet & Silver, 1983; Green & Pearson, 1986; Paterson & Stephens, 1992; McLeod, 2007) have documented titanite’s ability to record a large variety of petrogenetic information, both in terms of its chemistry and mineralogical properties such as colour, habit, texture and compositional zoning. Exley (1980) has shown that magmatic titanite represents crystallization from REE-rich residual magmatic fluids at late stage of intrusion consolidation. Morad et al. (2009) noted different titanite types hosted in granitic rocks from southeastern Sweden. Secondary titanite is Al, F-rich and occurs as fine (< 0ȝm) lenticular to rod-like crystals with poorly defined boundaries, disposed along relict cleavages of chloritized biotite. Magmatic titanite is commonly euhedral, coarse (up to 800 ȝm) and zoned due to REE enrichment. Che et al. (2013) also observed similar differences in titanite hosted in intrusive rocks of the Boss Mountain and Ray Gulch Mo deposits. Hydrothermal titanite is Al, F enriched and Ti depleted, exhibits high microporosity, gradual rutile replacement and typically occurs along cleavages of muscovite and/or chlorite. Magmatic titanite euhedral or subhedral, up to 500 ȝm long and occurs in planar contact with magmatic K-feldspar, plagioclase, or quartz. It distinguishes from hydrothermal titanite by higher concentrations of Ti, REE, Th, U, Nb, Ta, Zr, Hf, and high Th/U ratio, and lower Al and F. Pan & Fleet (1993) observed significant alteration features in blond and dark-coloured titanites from a wide variety of geological environments, including granitic rocks of the Lac du Bonnet batholith, Manitoba, Canada. Blond to honey brown altered titanite is partly replaced by fine aggregates of REE-rich minerals (i.e. allanite, monazite, and bastnasite) and/or by rutile, minor calcite or apatite. The aggregates of REE-rich minerals are bordered by an irregular zone of altered titanite that is depleted in REEs, U, and Th than the adjacent unaltered titanite matrix. These replacements and textural features apparently 9 postdate crystallization of titanite and are likely related to subsequent hydrothermal activity. Lee (2008) observed two titanite types hosted in granodiorites from the El Salvador calc-alkalic Cu-Mo porphyry deposit in northern Chile, one Al-rich and another Al-poor, suggesting either the mixing of two different melts or influence of hydrothermal alteration. Table 1.3 summarizes various titanite types and occurrences previously documented in literature. 1 0 Table 1.2. Summary of titanite types in intrusive rocks. Titanite type Occurrence Characteristic features Chemistry Example Selected ReferencesMagmatic titaniteaccesory rock-forming mineral; discrete crystals in planar contact with magmatic K-feldspar, plagioclase, and quartz.euhedral, coarse (up to 800 mm) and concentrically zoned due to REE enrichment. Represents crystallization from REE-rich residual magmatic fluids.Enriched in REE, Ti, Th, U, Nb, Ta, Zr, Hf. High Th/U ratio, and lower Al and F.Skye Granite, northwest Scotland; Smaland Granite, southeastern Sweden; Boss Mountain and Ray Gulch Mo deposits, BC, Canada.Exley, 1980; Morad et al., 2009; Groat et al., 2013Secondary titanitedisposed along the traces of the cleavage planes of chloritized biotite.fine (2–15 mm) lenticular to rod-like crystals with poorly defined boundaries.Enriched in Al, Fe, F; depleated in REE.Smaland Granite, southeastern Sweden.Morad et al., 2009; Hydrothermal titanite along cleavages of muscovite and/or chlorite and also in contact with pyrite.high microporosity together with rutile replacement. Enriched in Al, F; depleted in Ti.Boss Mountain Mo and the Ray Gulch Mo deposits in BC, Canada.Che et al., 2013Altered titanite no petrographic description available.dark-coloured; partly replaced along fractures and boundaries by secondary REE minerals (allanite, monazite, and bastnasite), as well as rutile, quartz, calcite, apatite, and chlorite.lower in REEs, U, and Th.Granite with K-fedspar + biotite alteration from Lac du Bonnet batholith, MB, Canada.Pan & Fleet (1993) 1 1 1.3.2. Titanite chemical substitutions Titanite is known to be stable in a wide variety of geological environments and therefore is likely to incorporate various elements into its structure that are representative of the system where it crystallizes (McLeod, 2007). Thus, there are three main sites in the titanite crystal structure (Figure 1.1) that participate for isomorphous substitution: • (4)-fold coordinated Oxygen site • (7)-fold coordinated Calcium polyhedron site • (6)-fold coordinated Titanium octahedron site Figure 1.1. Portion of titanite crystal structure. From (King et al., 2013). In addition, non-isovalent cation substitutions are common in the titanite structure, where the charge balance often occurs through coupled substitutions involving multiple substitution sites. Substitution mechanisms vary according to the availability and relative abundance of elements, which both rely on the host rock composition. Thus, the common substitutes for 6-fold coordinated Ti site and 7-fold coordinated Ca site are: Ca2+ = REE3+, Y3+, U3+, Th3+, Pb2+, Fe2+, Sr2+, Mn2+, Na+, K+ 1 2 Ti4+ = Al3+, Fe3+, V5+, Ta5+, Nb5+, Zr4+, Sb5+, Cr3+ To summarize, the following list comprises common titanite coupled and uncoupled chemical substitutions: Ca2+ + Ti4+ ļ REE3+ + (Al, Fe) 3+ (Green and Pearson, 1986; Enami, Suzuki et al., 1993) Ca2+ + Th4+ ļ REE3+ (Gromet and Silver, 1983) (Al, Fe)3+ ļ Ti4+ + (OH, F)í (Franz and Spear, 1985) 2 Ti4+ ļ (1E Ta) 5+ + (Al, Fe) 3+ (Cerny, Novak et al., 1995; Vuorinen and Halenius, 2005) Ti4+ + Al3+ ļ =r4+ + Fe3+ (Seifert and Kramer, 2003) Ti4+ + Ca2+ + Th4+ ļ REE3+ + Zr4+ + Al3+ (Seifert, 2005) Ti4+ ļ =r4+ (Della Ventura, Bellatreccia et al., 1999) 2 Ti4+ ļ ($l &r Mn )e)3+ + Sb5+ (Perseil and Smith, 1995) 2Ca2+ ļ REE3+ + Na+ (Tiepolo, Oberti et al. 2002) Ti4+ + Ca2+ ļ (8 TK)4+ + Mg2+ (Tiepolo, Oberti et al. 2002) 2 Ti4+ ļ V5+ + (Al, Fe)3+ (Bernau & Franz, 1987) 1.3.3. Titanite chemistry as an indicator of source As previously mentioned, substitution mechanisms are regulated by the availability and relative abundance of elements, which depend upon the host rock composition and affecting alteration processes. Therefore, a review of previous works regarding the various possible chemical variations of titanite constitutes a key step for the chemical characterization of specimens from studied alkalic deposits. The following section summarizes relevant findings concerning the meaning of titanite composition as an indicator of its geological environment. Major element 1 3 composition is first discussed, followed by trace element composition. A summary of the main titanite chemical substitutions is presented at the end (Table 1.2). Kowallis et al. (1997) proposed that the Fe/Al molar ratio can be used to distinguish titanite from different sources: 0.1-0.25 for metamorphic rocks, 0.1-0.5 for hydrothermal veins, 0.5-1.0 for quartz-bearing intrusive igneous rocks, 1.0 for intermediate to silicic igneous rocks and >2.0 for silica-undersaturated igneous rocks. The Aluminum and Fe3+ substitutions are regulated by three main factors: (1) Variations in oxygen fugacity ( fO2 ), which controls the abundance of Fe3+ substituting in the Ti-site, (2) Pressure (P); high pressure increases Al3+ substituting in the Ti-site and (3) silica activity, which increases light rare earth element (LREE) substituting in the Ca-site. In addition, Morad et al. (2009) suggested that the (Al, Fe)3+ coupled substitution in the Ti-site results from calc-silicate alteration, where Al3+ is derived from adjacent plagioclase and Fe3+ from adjacent magnetite. Che et al., (2013) suggested that hydrothermal titanite is Al3+ and F- enriched, whereas magmatic titanite is depleted in these elements and enriched in Ti. Bernau and Franz (1987) reported that V5+ substitution in the Ti-site occurs under highly oxidizing conditions above the hematite-magnetite buffer during calc-silicate alteration. This also agrees with the fact that V is more soluble and mobile under high fO2 oxidizing conditions (Micko, 2010), which increases the oxidation state from V3+ to V5+ and facilitates V incorporation into the titanite structure. At last, fluorine (F) substituting in the O-site is associated with magmatic fluids separating from a crystallizing melt (Bailey, 1977; Harris, 1981). LREE substituting in the Ca-site is associated with magmatic differentiation given that LREE-rich titanite represents crystallization from REE-rich residual magmatic fluids during late stage of intrusion consolidation ( Exley, 1980). In addition, magmatic titanite serves as a sink for 1 4 various trace elements of petrogenetic significance, such as REE and high-field-strength elements (HFSE), and resists the diffusion of these elements out of its crystal structure due to its refractory nature ( McLeod, 2007) In addition, Che et al. (2013) suggested that magmatic titanite has high concentrations of LREE, Th, U, Nb, Ta, Zr, Hf and high Th/U ratio compared to hydrothermal titanite, and that such concentrations tend to be more elevated in crystal cores rather than rims. In addition, Russel et al. (1994) stated that magmatic titanite originating from alkaline systems shows average CeN/LaN ratios near 1, whereas values near zero reflect an origin from subalkaline intrusions. Pan & Fleet (1993) demonstrated that titanite typically exhibits REE chondrite-normalized patterns LREE-enriched relative to HREE, together with a pronounced negative Eu anomaly. In contrast, the overall depletion of REE with respect to chondrite values reflects the influence of hydrothermal fluids leaching and remobilization of REE at a microscale into adjacent REE-rich minerals such as allanite, bastnaesite and monazite (Pan & Fleet, 1993). A negative Eu anomaly reflects the existence of Eu as Eu3+ rather than Eu3+and therefore does not incorporate into the Ca-site of titanite (Pan & Fleet, 1993). In addition, Mazdab et al. (2007) argued that Eu anomalies can fluctuate from negative to positive with decreasing temperature. Horie et al. (2008) discussed that positive Eu anomalies result from the incorporation of Eu2+ together with Ca2+ into altered titanite due to Eu reduction from Eu3+ to Eu2+. At last, fluctuations of the Eu anomaly tend to correlate with variations of fO2 enhanced by metasomatism (Lottermoser, 1992 in Micko, 2010), where a positive Eu anomaly reflects a decrease of fO2 due to oxidizing hydrothermal fluids interacting with a buffering host rock (Micko, 2010). 1 5 Table 1.3. Titanite common chemical substitutions and their significance. Titanite chemical substitution Significance Selected ReferencesFe/Al molar ratio Indicator of differente sources: 0.1-0.25 for metamorphic rocks, 0.1-0.5 for hydrothermal veins, 0.5-1.0 for quartz-bearing intrusive igneous rocks, 1.0 for intermediate to silicic igneous rocks >2.0 for silica-undersaturated igneous rocks.Kowallis et al. (1997) Al3+ ↔ Ti-site Controled by pressure (P). High P increases the Al substitution.Kowallis et al. (1997) Fe2+ ↔ Ti-site Controled by variations in oxygen fugacity (f O2). High f O2 increases Fe substitution.Kowallis et al. (1997) LREE 3+ ↔ Ca-site Controled by the silica activity during magmatic differentiation, which increases LREE substitution.Kowallis et al. (1997) Al, Fe2+ ↔ Ti-site Product of calc-silicate alteration, where Al and Fe2+ are derived from adjacent albite and biotite respectively.Morad et al. (2009)V3+↔ Ti-site Product of calc-silicate alteration, during high f O2 conditions.Bernau & Franz (1987) F-↔ O-site Product of degassing of late stage magmatic fluids and/or the fractionation of the magma.Bailey (1977); Harris (1981)1 6 Table 1.3. Titanite common chemical substitutions and their significance (continuation). 1.4. Overview of thesis This thesis is structured into the following seven chapters: 1.4.1. Chapter 1: Introduction The main purpose of this research and related objectives are described at the beginning of this chapter. Other topics include a brief reference to the economic importance of alkalic Cu-Au porphyry deposits and discussion regarding the limitations for their exploration in covered terrains. In addition, the concept of porphyry indicator minerals (PIMs) is described with reference to previous case studies. Lastly, the mineralogy, chemistry and role of titanite as a petrogenetic recorder are discussed with reference to relevant previous works. LREE 3+ ↔ Ca-site Product of magmatic differentiation. LREE-enrichment represents crystallization from REE-rich residual magmatic fluids. Exley (1980)CeN/LaN ratio CeN/LaN ≈ 1 indicates an origin from alkalic systems CeN/LaN ≈ 0 indicates an originin from subalkalic Russel, Groat et al., (1994) REE ↔ Ca-site Controled by selective hydrothermal alteration. Secondary REE-rich inclusions leach LREE, whereas hydrothermal fluids remove HREE.Pan & Fleet (1993) Eu/Eu* Controlled by host rock effect. Eu/Eu* ≤ 1 Eu3+ incorporates into plagioclase. Pan & Fleet (1993) Eu/Eu* Controlled by temperature (T) Eu/Eu* ≤ 1 high T conditions Eu/Eu* ≥ 1 lower T conditionsMazdab et al. (2007) Eu/Eu* Controled by f O2 conditions. Eu/Eu* ≤ 1 high f O2 conditions Eu/Eu* ≥ 1 lower f O2 conditions (hostrock acting as buffer during metasomatism).Horie et al. (2008) 1 7 1.4.2. Chapter 2: Materials and Methods The first half of this chapter provides a description of the study sites, sampling and field work. The second half describes analytical methods and techniques including: petrography, heavy mineral separation, electron microprobe (EMP) and laser ablation inductive-coupled plasma spectroscopy (LA-ICP-MS) analyses and till sediments geochemistry. 1.4.3. Chapter 3: Geological Setting This chapter introduces alkalic Cu-Au porphyry deposits, describing tectonic setting, geochemical affinity and other geologic aspects, with particular emphasis in deposits of the North American Cordillera. The core of this chapter describes various lithologies and alteration types of the Mount Polley, Mount Milligan and Copper Mountain selected study sites. 1.4.4. Chapter 4: Petrography of Titanite This chapter presents a classification of titanite based on key mineralogical features (i.e. colour, habit, texture and paragenesis) observed in thin sections and heavy mineral concentrates (HMC). Various titanite types and subtypes are discussed and summarized in a table at the end of the chapter. 1.4.5. Chapter 5: Chemistry of Titanite This chapter describes the chemistry of the various titanite types defined in Chapter 4 in terms of their major and trace element composition determined with EMP and LA-ICP-MS spot analyses 1 8 respectively. Analytical results are presented and discussed through multiple bivariate plots, diagrams and REE patterns. 1.4.6. Chapter 6: Titanite in Till Sediments This chapter briefly refers to the glacial sediments covering selected study sites (i.e. Mount Milligan and Mount Polley deposits) and describes physical and chemical features of titanite recovered from these sediments. In addition, titanite relative abundance and footprint around deposit centres relative to the ice flow direction is also discussed. Additionally, the footprint and relative abundance of other PIMs (i.e. chalcopyrite, gold grains, garnet and epidote) is also described. A comparison between the footprint of PIMs (including titanite) and metal (i.e. Cu and Au) dispersion in the till fine fraction is discussed at the end of the chapter. 1.4.7. Chapter 7: Discussion and Conclusions This first half of this chapter presents a discussion on the key physical and chemical features of titanite and their ability to reflect and record alteration + mineralization signs. In addition, all titanite types are graphically summarized in a single diagram that depicts their key physical and chemical features. The second half of this chapter includes a list of guidelines for exploration using titanite as an indicator mineral tool while exploring for alkalic Cu-Au porphyry deposits in covered terrains. 1 9 Chapter 2: Materials and Methods This chapter describes field and laboratory methods. Fieldwork was carried out at Mount Polley, Copper Mountain and Mount Milligan alkalic Cu-Au porphyry deposits, located in South-Central British Columbia, during the 2012 and 2013 summer seasons. Analytical methods included petrography, preparation and study of heavy mineral concentrates (HMC), till and mineral geochemistry. 2.1. Study sites The study sites include three, Late Triassic to Middle Jurassic, alkalic Cu-Au porphyry deposits located in South-Central British Columbia, namely Mount Polley (silica-undersaturated), Copper Mountain and Mount Milligan (silica-saturated). These deposits formed either during or after Late Triassic arc formation in the Quesnel and Stikine terranes (Figure 2.1), and prior to terrane accretion onto the North American continent (McMillan et al., 1995). These alkalic porphyry systems typically host high-grade ore associated with small volume pipe-like intrusions with surface expressions of only a few hundred square meters (Lueck and Russell, 1994; Lang et al., 1995; Lickfold et al., 2007; Holliday and Cooke, 2007) and small alteration footprint (Bailey and Hampton, 1990; Sillitoe, 2002), which make these deposits difficult exploration targets (Holliday and Cooke, 2007). Alkalic porphyry deposits commonly host gold mineralization making them attractive exploration targets (Copper Mountain Mine 22,100 oz Au, Mount Polley Mine 25,900 oz Au, Mount Milligan Mine 181,500 oz Au and New Afton 102,700 oz Au) (Clarke et al., 2014). However, the geomorphological setting of these deposits, underlying a thick and extensive morainal till blanket from the Late Wisconsinan glaciation between 25940 ± 380 and 2 0 10100 ± 90 years B.P. (Clague, 1981 in Sibbick et al., 1996) has resulted in lack of exploration success and the urgent need to develop new exploration methods to increase discoveries. 2.2. Field work During field work, rock (core and hand specimen) and till samples were collected at each studied site. The main objective of the sampling survey was to collect various rock types (unaltered and altered) and till sediments (proximal up/down ice from the deposits) in order to provide a variety of geological scenarios to characterize titanite. A total of 100 rock samples of drilled-core (~30 cm long average) and hand specimens (2 to 4 kg) were collected from outcrops and benches of altered and unaltered rock units at each mine site (Figure 2.2 to 2.4). The rock sampling criteria consisted in the selection of least altered and altered specimens representing various alteration types (i.e. potassic, sodic and propylitic) from each deposit. A description of all lithologies and Figure 2.1 Location map showing selected study sites, major tectonic terranes and other associated porphyry deposits (redrafted from del Real, 2012; modified from McMillan et al., 1995) 2 1 alteration types of each deposit is provided in Chapter 3. All core and hand samples are listed and briefly described in Appendix A1, together with their correspondent UTM location. 2 2 Figure 2.2 Geology map of Mount Polley (from Rees et al., 2014) showing location of rock samples (core and hand specimens). 2 3 Figure 2.3 Geology map of Mount Milligan (modified from LeFort, 2011) showing location of rock samples (core and hand specimens). 2 4 Figure 2.4 Geology map of Copper Mountain (modified from Preto, Nixon et al., 2004.) showing location of rock samples (core and hand specimens). 2 5 Surficial (≈1.5 m deep) and basal (≈10 m deep) till samples were collected at marginal portions of the Mount Polley (n=5) and Mount Milligan (n=21) open pits, as well as in roadcuts within 0.1 - 20 km of deposit centres (Figure 2.5). Till samples were identified according to their composition such of a dense, compacted sand-silt-clay matrix with poorly sorted, polymictic angular to well-rounded pebbles to cobbles clasts. 2 6 Figure 2.5. Location of till samples. a. Till samples at Mount Milligan (from Kerr, 1991). b. Till samples at Mount Polley (Bichler & Bobrowsky, 2003). 2 7 2.3. Analytical methods Analytical methods used in this research include: i) Petrographic analysis, ii) Heavy mineral separation and binocular study, iii) Titanite EMP and LA-ICP-MS chemical analysis and iv) Till geochemistry of the fine fraction. 2.3.1. Petrographic analysis A total of 66 thin sections were prepared by Vancouver Petrographics Labs. Petrographic study was conducted at Mineral Deposit Research Unit (MDRU) in order to characterize titanite in least altered and altered-mineralized rock samples from each study site. A selection of three to four key thin sections from each deposit representing least altered rock and various alteration types (i.e. potassic, sodic and propylitic) was performed in order to characterize different titanite types and occurrences. Thus, titanite specimens were examined under transmitted light (RL) and reflected light (RL) microscopy, scanning electronic microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The petrographic description of the key thin sections is included in Appendix A2. 2.3.2. Heavy mineral separation Heavy mineral concentrates (HMC) were recovered from least altered and altered rocks (n=16) from all three study sites. Heavy mineral separation method is depicted in Figure 2.6 and includes Selective Fragmentation (SELFRAG) rock disaggregation, sieving, heavy liquids and electromagnetic separation. The SELFRAG method was performed at Queen’s University and was chosen over the traditional rock crushing method, due to its capability of obtaining 2 8 morphologically intact grains and decreasing the cross-contamination between samples. Each rock sample was submitted to an average of 480 electric pulses at an average of 172 volts until complete rock disaggregation. Next, disaggregated rock samples were sieved using W.S. Tyler Standard Test Sieves of 8" diameter, mesh No.10, No. 60 and No.140 for separation into the > 2 mm, 0.25 – 2 mm and 0.1 - 0.25 mm size fractions. An equal amount of 300 g of material from each sample was run through a hand magnet for the extraction of magnetic material, followed by heavy liquid (Methylene Iodide) for the extraction of the dense (S.G > 3.2 g/cm2), and moderately dense (S.G= 2.8 - 3.2 g/cm2) fractions. Subsequently, samples were electromagnetically separated into non-paramagnetic (> 1.0 A), weakly paramagnetic (0.8-1.0 A), moderately paramagnetic (0.6-0.8 A) and strongly paramagnetic (0.0-0.6 A) fractions using a Frantz isodynamic separator. The same technique above described (except for SELFRAG) was performed by ODM Ltd. in Ottawa to recover titanite grains from till samples from Mount Milligan and Mount Polley deposits. Figure 2.6 Heavy mineral separation method: 1. Selective Fragmentation (SELGRAG) of rock samples. 2. Size separation using W.S. TYLER Standard Test Sieves. 3. Magnetic separation using hand magnet. 4. Density separation using heavy liquid. 5. Electromagnetic separation using Frantz isodynamic separator. 2 9 2.3.3. Binocular microscope study: Heavy mineral concentrates were examined under a Nikon SMZ1500 binocular lens equipped with a Cool Pix 995 Nikon digital camera and Dolan Jenner Fiber Light MI-150 high intensity illuminator. Titanite grains were identified on the basis of their characteristic size (i.e. 0.1-0.25 mm), habit (i.e. lozenge to wedge shape) and colour (i.e. colourless, blond to honey brown). Grains were carefully hand-picked and mounted on a thin section slab for photomicrography at 100 x scale. Thus, grains were examined under SEM for characterization of their texture and morphology followed their mineral verification using EDS. Thus, grains were mounted in epoxy pucks for EMP and LA-ICP-MS chemical analysis. The relative abundances of all heavy mineral separated are listed in Appendix D1. 2.3.4. Titanite chemical analysis A total of 233 titanite specimens were analyzed for their major and trace element composition using EMP and LA-ICP-MS analytical techniques at The Pacific Centre for Isotopic and Geochemical Research (PCIGR) of the University of British Columbia. Analyzed specimens include 96 grains identified in the key selected thin sections, 48 grains from correspondent offcuts, 35 grains recovered from SELGRAG samples and 54 grains recovered from till samples. All EMP analytical results are documented in Appendix B and LA-ICP-MS results in Appendix C. 2.3.4.1. Major elements analysis Major element chemical analyses were performed using a Cameca SX100 EMP at The University of British Columbia, operated at 15 kV and using a 1µm diameter beam in order to 3 0 evaluate fine-scale compositional zoning at the core and rim of titanite specimens. Spot analyses were performed 96 specimens from key thin sections of each deposit, 35 grains recovered from SELGRAG samples and 54 grains recovered from till sediments samples. Major elements analysed include Al, Ca, Cr, F, Fe, Na, Mg, Mn, O, OH, Si, Sn, Ti, V and Zr, as well as Ce, Nb, Nd and Y. Detection limit for all elements is less than 0.1 wt.%, except for Ce (0.3 wt.%) and F (0.2 wt.%). Chemical concentrations are expressed as atoms per formula unit (a.p.f.u.) based on stoichiometries calculated on basis of 2 M+T cations (octahedral + tetrahedral = everything except alkalis and REE's), where OH is calculated as 5-(O+F) and all iron as Fe3+. 2.3.3.2. Trace elements analysis Trace elements were analysed with a Quadruple Agilent 7700 Series LA-ICP-MS, operated at 10 J/cm2 energy fume, 5 Hz repetition rate and using a 24 µm diameter beam. Spot analyses were performed on 48 specimens from offcuts of key thin sections of each deposit, 27 grains recovered from SELFRAG samples and 54 grains recovered from till samples. Quality control/quality assurance (QA/QC) was assessed introducing standards NIST612 and NIST610 every 5 spot analyses. The analyzed trace element suite includes REE (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), HFSE (Y, Zr, Nb, Hf, Ta, Th, and U), as well as Al, Na, K, Si, Fe, Ti, V, and Cu. All concentrations are expressed as part per million (ppm) and the detection limit for all elements is less than 0.01ppm. 2.3.5. Till survey Surficial (≈1.5 m deep) and basal (≈10 m deep) till samples of 10-15 kg each were collected at outer borders of the Mount Polley (n=5) and Mount Milligan (n=21) open pits, as well as in roadcuts of access roads within 0.1 - 20 km of each deposit (Figure 2.7). Heavy mineral 3 1 separation of till samples was performed by ODM Ltd. in Ottawa, Canada using the same method described above (see section 2.3.2.). Relative abundances of all HMC from till sediments are listed in Appendix D2. Figure 2.7. Till sampling. a. Till sampling at marginal portions of the Wight pit, North East Zone at Mount Polley mine. b. Till sample MT-14 at marginal eastern portions of the 66 Zone at Mount Milligan mine. 2.3.5.1. Till matrix geochemistry Geochemical analysis of the fine fraction of 26 till samples was performed by Acme Analytical Labs Ltd. in Vancouver, using 1:1 Aqua Regia/ICP-MS and Instrumental Neutron Activation Analysis (INAA) analytical methods. Till samples were oven dried at 60° C prior to size separation of the fine sand (< 0.25 mm) and very fine sand (< 0.074 mm) fraction using W.S. Tyler Standard Test Sieves mesh No. 60 and No. 200 respectively. Approximately 45 g of sieved material of each size fraction per each till sample was shipped to Acme Analytical Labs Ltd. (Vancouver, BC) chemical analyses. QAQC was assessed by using 1 duplicate per 10 samples 3 2 and 1 certified control standard (i.e. CANMET till standard, Canada Centre for Mineral and Energy Technology) per 20 samples. All till analytical results are listed in Appendix E. 3 2 Chapter 3: Geological Setting Cordilleran porphyry deposits in British Columbia have a diverse anatomy, mineralization and alteration styles. These deposits formed during two separate time intervals: Late Triassic to Middle Jurassic and Late Cretaceous to Eocene. The Early Mesozoic deposits formed either during or after Late Triassic arc formation in the Quesnel and Stikine terranes, and prior to terrane accretion onto the North American continent (McMillan et al., 1995) (see Chapter 2, Figure 2.1). They include associations with both calc-alkalic and alkalic igneous rocks. Examples of Calc-alkalic varieties include the Island Copper, Highland Valley, Kemess and Gibraltar Cu-Mo porphyry deposits. Examples of the alkalic Cu-Au deposits include Galore Creek, Mount Milligan, Mount Polley, and Copper Mountain (McMillan et al., 1995). Younger Late Cretaceous to Eocene porphyry deposits formed in an intracontinental arc setting after the accretion and assembly of the Cordilleran terranes. They are mostly related to calc-alkaline magmatism. Examples include the Granisle Cu-Au ± Mo porphyry deposit and Endako Cu-Mo porphyry deposits. 3.1. Alkalic porphyries Alkalic porphyry systems are typically gold-rich deposits associated with small volume pipe-like intrusions (Figure 3.1) that have surface expressions of only a few hundred square meters (Lueck and Russell, 1994; Lang et al., 1995; Lickfold et al., 2007; Holliday and Cooke, 2007). Alkalic melts generally contain higher CO2 and SO4 compared to their calc-alkaline equivalents and generate mineralization typically with smaller alteration footprint relative to their calc-alkalic 3 3 counterparts (Bissig & Cook, 2014; Jensen & Barton, 2000). This small footprint makes them difficult exploration targets, so practical guides and accurate deposit models are required to assist exploration (Holliday and Cooke, 2007). Unlike calc-alkalic porphyry systems, alkalic deposits do not usually have associated advanced argillic alteration assemblages, phyllic alteration demonstrates to be restricted to fault zones and evidence of connection to high sulphidation epithermal deposits is not commonly observed (Chamberlain et al., 2007). These features are attributed to the high neutralization capacities of the alkaline host rocks, which reduce the lateral mobility of acidic fluids (Bissig & Cook, 2014; Jensen & Barton, 2000). Phyllic alteration in alkalic porphyry systems is typically restricted to late fault and vein zones that penetrate the waning hydrothermal system. 3 4 Figure 3.1 Schematic model of alkalic igneous complexes, associated ore deposit and alteration patterns (from Jensen and Barton, 2000). 3.2. Alkalic porphyries in British Columbia A Late Triassic to Early Jurassic magmatic arc in the Canadian Cordillera of British Columbia defines two suites of alkalic intrusions, silica-saturated and silica-undersaturated, both hosting Cu-Au porphyry deposits. Silica-undersaturated intrusions suites are locally zoned with composition vary between pyroxenite to syenite. Their mineralogy is characterized by variable 3 5 amounts of aegirine-augite, K-feldspar, biotite, titanite, apatite, garnet, hornblende, plagioclase and magnetite (Lueck and Russell, 1994). The silica-saturated intrusions suites vary from diorite to monzonite and their mineralogy is characterized by variable amounts of augite, biotite, magnetite, plagioclase, K-feldspar and apatite. Hornblende and titanite are less common and quartz is rare (Lueck and Russell, 1994). Two silica-saturated alkalic porphyry deposits (Mount Milligan and Copper Mountain) and one silica-undersaturated (Mount Polley) were selected for this study. 3.3. Mount Polley 3.3.1. Lithology The Mount Polley Cu-Au porphyry deposit is located in the Quesnel Terrane along the eastern margin of the Intermontane Belt of the Canadian Cordillera (Lang et al, 1995). The deposit is hosted within the Mount Polley Intrusive Complex (MPIC), a 5km long, multiphase intrusive complex composed of monzonites, monzodiorites, diorites and syenites, which intrudes Late Triassic volcanic rocks of the Nicola Group (Figure 3.2), Imperial Metals, 2007). Geochronological U/Pb and Ar/Ar studies have constrained intrusive activity between 209.4 and 196.7 million years (Ma), indicating a Late Triassic to Early Jurassic age (Bailey and Archibald, 1990; Mortensen et al., 1995; Logan et al., 2007). The core of the system consists of the Cariboo, Bell and Springer ore bodies, which are truncated in the west by the north-northwest striking Polley Fault. Finally, the Northeast Zone discovered in 2003, the Wight Pit, lies 1.5 km to the northeast of the main deposits, near the northern boundary of the MPIC (Jackson, 2008).. 3 6 Figure 3.2 Geological map of the Mount Polley Intrusive Complex. From Rees et al., 2014.3 7 1. Augite-biotite diorite (PD1) It corresponds to the oldest generation of intrusive units and consists of an equigranular diorite, dominated by augite (15-20%) and plagioclase (30%) but containing up to 20% K-feldspar, minor biotite (7-12%), hornblende (5%), and magnetite (< 5%) (Figure 3.3). Disseminated pyrite and chalcopyrite are rare and occur within the Springer pit and adjacent to the Bell pit (Jackson, 2008). 2. K-feldspar-bearing diorite (PD2) The K-feldspar-bearing diorite intrudes PD1 with gradational contacts and has variable textures, ranging from fine to coarse porphyritic diorite with up to 5% disseminated pyrite. Several PD1 Figure 3.3 Photomicrograph of Augite-biotite diorite (PD1) at Mount Polley. a. Hand sample P-3 of dark green colour and medium grain equigranular texture with 25% of mafic minerals. Note the cross-cutting calcite vein in the centre of the picture. b. Same sample under TL microscopy showing coarse biotite and relict augite phenocrysts in a K-feldspar + plagioclase groundmass. c. Same view under cross nicols (XN). Note the high birefringence of relict augite. 3 8 mafic xenoliths can be found in this unit, contributing to textural and compositional heterogeneity (Jackson, 2008). 3. Undifferentiated Monzodiorite (PMdu) Undifferentiated monzodiorite intrudes PD1 and represents the bulk of the MPIC. It encompasses various lithological types ranging from equigranular augite-bearing monzonite, lesser K-feldspar-bearing diorite, monzodiorite, and K-feldspar-phyric monzonite porphyry. It displays a fine- to coarse-grained, equigranular to microporphyritic texture, with abundant augite, local hornblende with primary biotite, albite and K-feldspar phenocrysts and large elongated accessory titanite up to 1mm and 3-4% modal abundance. In addition, disseminated and thin veinlets of pyrite generally compose <1% of the rock. PMdu differentiates from PD2 by the presence of primary K-feldspar, and by its albite alteration that causes plagioclase phenocrysts to stand out (Figure 3.4), resulting in the identification of this unit as plagioclase porphyry by other authors (e.g. Fraser, 1994). Finally, PMdu contains up to 25% of mafic, angular, xenoliths from adjacent PD1 and PD2 units (Jackson, 2008). 3 9 4. Monzonite (PMz) Monzonite intrudes PMDu and displays a medium to coarse grained equigranular texture. It differentiates from PMdu by its coarser grained texture and higher content of mafic phenocrysts (>10% augite ± primary biotite) and absence of hornblende (Jackson, 2008). 5. K-feldspar monzonite porphyry (Pkm) K-feldspar monzonite porphyry consists of a series of north-northwest trending, steeply dipping, few tens of meters long, porphyritic dykes that cross-cut locally PMz and PMdu units. Two distinctive Pkm dykes can be recognized based on textural features (Rees and Ferriera, 2006): a) Coarse (Pkm-c) is distinguished by 1-4 cm long, subparallel, K-feldspar phenocrysts in a medium-grained groundmass composed of plagioclase and K-feldspar in subequal amounts. Figure 3.4 Photomicrograph of K-feldspar-bearing diorite (PMdu) at Mount Polley. a. Hand sample P-12 of whitish colour and medium grain inequigranular texture characterized by abundant coarse tabular albite (40%) and fine acicular mafic minerals (10%). b. Same sample under TL microscope showing a salmon colour K-feldspar groundmass with relict augite phenocrysts on the left hand side and minor opaque minerals (5%). c. Same view under cross nicols (XN). 4 0 Other phenocrysts include biotite, augite and minor hornblende. Euhedral accessory titanite up to 1mm constitute up to 3-4% modal abundance. Fine disseminated pyrite and local chalcopyrite are also present, but are of sub-economic importance. b) Fine (Pkm-f) is distinguished by abundant, subparallel, small phenocrysts ranging only from 0.1 to 1 cm long, and composing near 25% of the rock. Plagioclase phenocrysts are smaller (1-2mm) and less abundant than coarser (3-5mm) K-feldspar phenocrysts. In addition, the groundmass is finer than that of Pkm-c, and xenoliths from PMdu, PD1 and PD2 units are more abundant ( Jackson, 2008). 4 1 Figure 3.5 Photomicrograph of K-feldspar monzonite porphyry (Pkm) at Mount Polley. a. Coarse K-feldspar monzonite porphyry (Pkm-c) represented by hand sample P-6 of megacrystic porphyritic texture characterized by coarse tabular K-feldspar megacrysts (15%) in an intensively altered salmon colour groundmass. . b. Same sample under TL microscope showing coarse K-feldspar and minor plagioclase 4 2 phenocrysts in the K-feldspar groundmass. c. Same view under cross nicols (XN). d. Fine K-feldspar monzonite porphyry (Pkm-f) represented by hand sample P-7 of porphyritic texture characterized by abundant K-feldspar phenocrysts (20%) and minor mafic minerals (8%) in an intensively altered salmon colour K-feldspar groundmass. e. Same sample under TL microscopy showing a cross cutting calcite vein and minor opaque minerals (4%). f. Same view under cross nicols (XN). 6. Fragmental Breccias (FBx) Fragmental breccias occur within the Central and North East Zones of the MPIC. Fragmental breccias are polymictic or oligomictic and consist on subrounded to subangular undifferentiated monzodiorite ( PMdu), monzonite (PMz) and K-feldspar monzonite porphyry (Pkm) partly resorbed clasts in a cognate igneous cement (igneous breccia) and/or a clastic matrix of fine to coarse rock flour. Contacts with adjacent rock units are gradational into variably brecciated (monomictic jigsaw-fit type) diorite to monzonite. A common characteristic of this unit is pervasive calc-potassic alteration ( K-feldspar ± biotite ± albite ± magnetite ± actinolite/diopside ± garnet), which obliterates and replaces the igneous groundmass/breccia matrix. In addition, potassic alteration occurs at lithostatic pressure, but may be punctuated by brief episodes of elevated fluid pressure resulting in brecciation and explosive escape of volatiles (McMillan and Panteleyev, 1988 in Lang et al., 1998). Fragmental breccias within the Central and North East Zone are typically moderately to highly mineralized with disseminated and interstitial chalcopyrite ± bornite or pyrite, up to 10% modal abundance (Rees et al., 2014). Figure 3.6 Photomicrograph of Fragmental Breccia (FBx) at Mount Polley represented by core sample SD0981_92.3m. Note the coarse, salmon colour fragments of intensively altered Pkm unit in a pinkish K-feldspar matrix.. Abundant fractures and cracks partially filled with white calcite patches and dark magnetite veins. 4 3 7. Augite Porphyry (AP) It consists of a series of chaotically oriented, mafic to intermediate augite-phyric porphyry dykes that crosscut mineralized breccias and are generally unaffected by hydrothermal mineralization (Rees et al., 2005). They are characterized by a fine-grained, pale-green to pinkish-green groundmass containing 20-60% augite phenocrysts, and local olivine phenocrysts replaced by iddingsite (Rees et al., 2005). 3.3.2. Alteration Alteration at the MPIC (Figure 3.7) is dominated by four alteration zones, a central potassic core surrounded by an intermediate potassic-sodic alteration, which limits with a calc-potassic zone in the northeast, and with an outer potassic-propylitic zone in the southeast (Rees et al., 2014). 4 4 Figure 3.7 Alteration map of the Mount Polley Intrusive Complex. From Rees et al., 2014. 4 5 The Central Zone (Springer, Bell and Cariboo pits) is dominated by weak to strong, fractured-controlled potassic-sodic alteration (Figure 3.8) characterized by a K-feldspar + biotite + albite + magnetite + diopside/actinolite assemblage (Rees et al., 2014). In the centre of the deposit, a potassic core extends as a circular zone (0.8 km2) characterized by a K-feldspar flooding, where pervasive potassic alteration has destroyed primary textures and fine-grained disseminated hematite imparts a salmon-pink colouration to the rocks (Logan et al., 2004). Figure 3.8 Photomicrograph of potassic alteration at Mount Polley. a. Augite-biotite diorite (PD1) represented by hand sample P-3 cross cut by a magnetite vein with a pinkish K-feldspar envelope. Note the two calcite veins cross cutting the K-feldspar envelope. b. Same sample under TL microscope showing relict diopside and biotite in a K-feldspar groundmass, cross cut by a calcite vein. c. Fragmental Breccia (FBx) represented by core sample SD0981-92.3m showing a salmon colour K-feldspar groundmass cross cut by two magnetite veins. Note the white calcite patch replacing the groundmass on the left hand side. d. Same sample under RL microscope showing massive magnetite intergrowth with chalcopyrite and minor bornite. 4 6 The North East Zone (Wight pit) and local margins of the Central Zone are dominated by a calc-potassic alteration (Figure 3.9), also described as skarn alteration by some authors (e.g. Fraser et al., 1995). It consists on pink veinlets of secondary K-feldspar, green veinlets of very fine epidote-clinozoisite ± calcite (clinozoisite is an Al-rich epidote mineral), massive and fine veinlets of andradite garnet, magnetite and fine disseminated pyrite and chalcopyrite (Rees et al., 2014). In addition, this alteration has been described as a texturally destructive K-feldspar metasomatic event that predated or coincided with the formation of Fragmental breccias (Rees et al., 2014). Figure 3.9 Photomicrograph of calc-potassic alteration at Mount Polley. a. Fragmental Breccia (FBx) represented by core sample SD12132_309m showing clotty garnet + epidote + calcite assemblage (right hand side) overprinting a K-feldspar groundmass. Note the thin garnet vein in a K-feldspar envelope (left hand side) cross cutting the groundmass. b. Same sample under TL microscope showing massive garnet and epidote overprinting the groundmass. c. Same sample under TL microscope showing relict biotite phenocrysts in K-feldspar groundmass. d. Same sample under RL showing magnetite intergrowth with chalcopyrite. 4 7 The South East Zone and East margin of the MPIC are dominated by potassic-propylitic alteration (Figure 3.10) characterized by an albite + epidote + pyrite assemblage (Rees et al., 2014). Argillic and phyllic alteration are absent (Jackson, 2008). Figure 3.10 Photomicrograph of propylitic alteration at Mount Polley. a. K-feldspar-phyric monzonite porphyry (PMdu) represented by core sample PM1113_265m cross cut by an epidote vein. b. Same sample under TL microscope showing an epidote patch in K-feldspar groundmass. 3.3.3. Mineralization Since the Mount Polley mine opened in 1997, until 2013 it has produced more than 226.3 thousand tonnes (t) of Cu, 21.5 t of Au, and 65.1 t of Ag from several ore zones. Overall, the various deposits constitute proven and probable reserves of 59.9 million tonnes (Mt) of ore containing 0.36% Cu, 0.27 g/t Au and 0.73 g/t Ag, Measured and indicated resources include 73.6 Mt of ore at 0.36% Cu, 0.30 g/t Au, and 1.43 g/t Ag (Imperial Metals, 2007). Most of the ore is breccia hosted, with lesser Cu sulfide mineralization occurring in veins and disseminations. Across the MPIC, porphyry-style mineralization is associated dominantly with K-feldspar and albite alteration and subordinate calc-potassic alteration. Chlorite-epidote (commonly mapped as propylitic) alteration is widespread across the property whereas argillic 4 8 alteration is absent. Mineralization and alteration are constrained to a 5 Ma window from approximately 209 to 204 Ma (Logan et al., 2007). 3.4. Mount Milligan 3.4.1. Lithology The Mount Milligan Cu-Au porphyry deposit is located in the Quesnel terrane in the Intermontane Belt of the Canadian Cordillera and is known as one of the youngest of the seven major mineralized alkalic porphyry systems in British Columbia, dated at 183 ± 4 Ma, excluding the Heidi Lake stock (Mortensen et al., 1995; Nelson and Bellefontaine, 1996; Jago, 2008). Regional structures exerted significant control over the emplacement of the plutonic bodies (Nelson et al., 1991; Jago 2008). There are four main pre-mineralization alkalic intrusions: Magnetite Breccia (MBX), Southern Star (SS), Goldmark and North Slope intrusions (Figure 3.11). Goldmark and North Slope intrusions are marginally economic and are not discussed here further. All intrusions are hosted within the Witch Lake Succession of the Takla Volcanic Group, made up of augite-, hornblende- and plagioclase- phyric basalts, andesites, latites, and trachytes (Ditson, 1997; Jago, 2008). Also part of the Witch Lake Succession is the Lower Trachyte, defined as a thick stratiform unit of intensely altered trachytic rock, which overlies the Rainbow Dike at 66 Zone of the deposit. Finally, the Main and South Star (SS) ore bodies are centred on two the MBX and SS stocks, respectively. 4 9 Figure 3.11 Geology of the Mount Milligan Deposit. From LeFort et al., 2011. MBX=Magnetite Breccia, DWBX= Deep Western Breccia. 5 0 Witch Lake succession The Witch Lake succession is comprised of a moderately northeast dipping/facing panel of alternating coherent- and clastic porphyritic basaltic-trachyandesites (Figure 3.12) (Barrie, 1993; Lang, 1992, Jago, 2008). Rocks from this unit are composed of coarse (~2.5 mm in diameter) clinopyroxene (augite) phenocrysts (15-30%) that are commonly altered to actinolite ± pyrite, plagioclase phenocrysts (25-40%), cryptocrystalline K-feldspar (20%) and a trachytic-textured feldspar groundmass (30%) (Jago, 2008). Figure 3.12 Photomicrograph of basaltic trachyandesite from the Witch Lake succession at Mount Milligan. a. Core sample 06957_217.7m of green colour and porphyritic texture characterized by 15% dark green clinopyroxene in a light green groundmass. Note the cross cutting thin epidote veining (left hand side). b. Same sample under cross nicols (XN) microscope showing high birefringence clinopyroxene phenocrysts in a trachytic groundmass characterized by fine K-feldspar microlites. Lower Trachyte This subunit of the Witch Lake succession is defined after its very fine trachytic texture (Figure 3.13) that consists of a groundmass (20-30%) of subparallel arrangement of acicular feldspar microlites, strongly altered augite phenocrysts (15-25%) replaced by actinolite ± chlorite and pyrite (5-15%) that has replaced some mafic phenocrysts and has precipitated in the partings (Jago, 2008). Other minor rock-forming minerals include microcline, adularia, albite, muscovite, phengite, and illite (Jago, 2008). 5 1 Figure 3.13 Photomicrograph of the Lower Trachyte at Mount Milligan. a. Hand sample Milligan-1 of porphyritic texture characterized by 10% of augite phenocrysts entirely replaced by pyrite + an actinolite rim in dark green groundmass. b. Same sample under cross nicols (XN) microscope showing coarse subhedral augite phenocrysts with actinolite rims in a trachytic groundmass characterized by very fine subparallel K-feldspar microlites. Magnetite Breccia (MBX) and Southern Star (SS) stocks The Magnetite Breccia (MBX) stock consists of a moderately west-dipping, sub-rounded, 400 m in diameter, body of monzonite. In its southeast portion, it limits with the Rainbow Dyke, a large 50 m wide dyke that intrudes basaltic-trachyandesites from the Witch Lake succession (Takla Group) forming an elongated bowl with gently-dipping sides open to the southeast ( Jago, 2008). The Southern Star (SS) stock consists of a moderately west-dipping, northwest striking, 800 m x 300 m, tabular body of monzonite, with more irregular margins than those of the MBX stock (Jago, 2008). Both stocks exhibit a porphyritic texture with up to 30% subparallel plagioclase phenocrysts within a fine-grained groundmass composed of K-feldspar, plagioclase, minor quartz, hornblende, biotite, and accessory magnetite. The SS stock differs from the MBX stock by its coarser plagioclase phenocrysts and common cross-cutting, synmineral monzonite dykes (Jago, 2008). 5 2 Figure 3.14 Photomicrograph of the MBX and SS stocks at Mount Milligan. a. MBX Stock represented by core sample 06938_303m of porphyritic texture characterized by 30% of white plagioclase phenocrysts in dark green groundmass. b. Same sample under TL microscope showing sericite alteration in tabular plagioclase 5 3 phenocrysts in a K-feldspar groundmass with 5% of opaque minerals. c. Sample under cross nicols (XN). d. SS stock represented by core sample 06957_130.6m of porphyritic texture characterized by 10% of plagioclase phenocrysts and 10% of light green phenocrysts in a dark green groundmass. Note a 7% of finely disseminated chalcopyrite. e. Same sample under RL microscopy showing 10% of opaque minerals, abundant plagioclase + K-feldspar phenocrysts in a K-feldspar groundmass. f. Sample under cross nicols (XN). Note the cluster of K-feldspar phenocryst (right hand side). Post-mineral dykes, generally unaltered and barren, cross-cut the Main and SS ore bodies. These are: Trachytic dykes: are 15 m wide, north-strike, dip moderately to the northwest, and concentrate in the southwestern portion of the Main ore body, and northern portion of the SS ore body. They display a grey colour and aphanitic texture with minor content of magnetite. Monzonitic dykes: formed after the trachytic dykes and occur throughout the Main and SS ore bodies. They are up to 10 m wide, north-strike, and dip moderately to the northwest. They exhibit a porphyritic texture characterized by abundant coarse plagioclase and augite phenocrysts, with minor magnetite in a fine-grained, K-feldspar-rich groundmass. Dioritic dykes: are typically 5 m wide and constitute the youngest intrusive rocks of the deposit. They have a northwest orientation, with steep dip to the northeast, and typically distribute in the northern portion of the Main ore body. These dykes exhibit a porphyritic texture characterized by abundant coarse plagioclase and hornblende phenocrysts, minor quartz eyes, in a fine-grained K-feldspar groundmass with carbonate alteration patches. 3.4.2. Alteration Alteration at Mount Milligan includes potassic, sodic-calcic and propylitic alterations (Figure 3.15), which mainly occur throughout the MBX and SS stocks. Early in the alteration sequence, most augite is replaced by pseudomorphic actinolite ± pyrite. In addition, selective sericitic 5 4 alteration overprints the potassic alteration. Finally, late, post-mineralization carbonate alteration occurs locally (Sketchley et al., 1995). Figure 3.15 Alteration map of the Mount Milligan deposit. Redrafted from Sketchley et al., 1995 & LeFort et al., 2011. 5 5 Potassic alteration Potassic alteration is represented by a K-feldspar, biotite and magnetite assemblage. It locally obliterates original texture, resulting in the crystallization of fine-grained, patchy aggregates of K-feldspar, usually with magnetite and very fine acicular actinolite. It generally distributes along the outer margins of the monzonitic rocks, with most intense expressions occurring in the contact between the Rainbow dike and the MBX stock (Sketchley et al., 1995). Figure 3.16 Photomicrograph of potassic alteration at Mount Milligan. a. Core sample 06946_64.8m showing pervasive potassic alteration characterized by a pinkish K-feldspar groundmass with 10% white albite phenocrysts and minor cross cutting dark chlorite veinlets. . b. Same sample under TL microscope showing selective plagioclase alteration by sericite. c. Same view under cross nicols (XN). d. Same sample under TL microscopy showing relict biotite ± actinolite in K-feldspar groundmass. Sodic-Calcic alteration Sodic-calcic surrounds the potassic alteration zone and is more developed at the 66 Zone. It is characterized by albite replacement of acicular K-feldspar microlites in the groundmass of the 5 6 Lower Trachyte, and selective replacement of augite phenocrysts by actinolite + pyrite. Accessory alteration minerals include epidote, chlorite, calcite, apatite, titanite, and quartz (Jago, 2008). )ine (00 ȝm) secondar\ titanite commonl\ occurs along cleavage planes of strongly altered augite phenocrysts and has up 2-3% modal abundance. Figure 3.17 Photomicrograph of sodic-calcic alteration at Mount Milligan. a. Core sample 07992_81.5m showing moderate sodic-calcic alteration characterized by 10% of dark clinopyroxene phenocrysts in dark green groundmass partly replaced by white albite and calcite patches. b. Same sample under TL microscope showing calcite and albite patches replacing a trachytic groundmass of fine subparallel K-feldspar microlites. c. Hand sample Milligan-1 showing selective augite replacement by pyrite + actinolite rims. d. Same sample under cross nicols (XN) microscope showing fine acicular actinolite rims around augite phenocrysts. Propylitic alteration Propylitic alteration has a widespread peripheral distribution up to 5 km outward from the deposit and is best developed in basaltic host rocks of the Takla Group (e.g. Nelson and Bellefontaine, 1996; Jago et al., 2014; Vaca, 2012), that in some cases resemble latite volcanic rocks due to an alteration effect (Figure 3.17a-b). In addition, propylitic alteration shows 5 7 significant overprint in sodic and potassic altered rocks of the MBX and SS stocks, where it is represented by an epidote, albite, calcite, chlorite, and pyrite assemblage (Sketchley et al., 1995). Epidote is the most common and widespread propylitic mineral and occurs either as narrow alteration envelopes around fractures and pyrite-calcite veins, as veinlets with chlorite and calcite, as irregular aggregates in the groundmass, or as selective replacement of plagioclase and mafic minerals. Chlorite typically occurs, replacing primary biotite, on the edges of pyrite, or as irregular disseminations in the groundmass. Albite presents as coarse tabular phenocrysts in the groundmass of porphyritic monzonite and locally displays intergrowth with minor epidote. Calcite occurs either as patches replacing the groundmass, as selective replacement of actinolite and augite, or as veinlets with epidote, chlorite and pyrite (Sketchley et al., 1995). Minor accessory alteration minerals include secondary titanite ± rutile after biotite, which commonly display skeletal texture along cleavage planes of altered biotite phenocrysts. 5 8 Figure 3.18 Photomicrograph of propylitic alteration at Mount Milligan. a. Hand sample Milligan-4 showing moderated propylitic alteration characterized by a green groundmass with dark green coarse mafic phenocrysts. b. Same sample under XN microscope showing coarse subhedral olivine, augite and plagioclase phenocrysts. c. Core sample 06946_64.8m showing potassic alteration overprinted by propylitic alteration characterized by white albite phenocrysts and cross cutting dark chlorite veins. d. Same sample under TL and XN microscope showing chlorite veins cross cutting a K-feldspar groundmass. Sericite alteration Sericite alteration consists of a selective-pervasive plagioclase replacement by sericite ± epidote ± chlorite ± calcite (Figure 3.15b). It occurs in the MBX and SS stocks, as well as in the Rainbow dike (Sketchley et al., 1995). 3.4.3. Mineralization The Mount Milligan Cu-Au porphyry deposit contains proven reserves of 482 million tonnes (Mt) averaging 0.20% Cu and 0.39 (g/t) Au (Terrane Metals Corp., 2009) and is relatively 5 9 enriched in Au when compared to other alkalic Cu-Au porphyry deposits of British Columbia (Sketchley et al., 1995). Mineralization is primarily hosted in five ore zones: the Magnetite Breccia (MBX), the Western Breccia (WBX), the Deep Western Breccia (DWBX), the Southern Star (SS), and the 66 Zone. Copper and gold mineralization consists of chalcopyrite ± bornite ± magnetite in areas of potassic alteration, and pyrite in areas of propylitic alteration. It is best in the footwall and to a lesser extent in the hanging wall of the stocks, as well as within the Rainbow Dyke and trachytic volcanic country rocks. On the other hand, Au-rich, Cu-poor mineralization is associated with sericite-carbonate-pyrite alteration (Jago et al., 2014), which is best developed in the 66 Zone. Thus, the highest copper-gold grades are related to chalcopyrite adjacent to the MBX and SS stocks, whereas the highest gold grades are associated with abundant pyrite and distributed in the 66 Zone. In addition, high gold grades are also associated with local intense albitization in basaltic rocks and clots of pyrite, carbonate, and chlorite in trachyte. Finally, supergene enrichment consisting of sporadic occurrences of chalcocite is restricted to MBX and WBX Zones and does not form a well-defined zone (Terrane Metals Corp., 2009). 3.5. Copper Mountain 3.5.1. Lithology Copper Mountain is hosted by an alkaline volcanic‐intrusive complex in a rift‐related volcanic arc setting. Main intrusive units consists of Copper Mountain Stock (CMS) to the south, Voight and Smelter Lake Stocks to the north and the Lost Horse Intrusive complex (LHIC) in the central part which is more closely associated with mineralization. These intrude the volcanic rocks of the Nicola Group. All of these rocks are nearly coeval (Late Triassic to Early Jurassic) and 6 0 probably co‐magmatic. Chemically, the rocks are quartz‐normative but free quartz is absent (with rare exceptions) in all rock types (Cromwell et al., 2015).. Cretaceous aged felsic dykes cut the above units and Tertiary volcanoclastic rocks of the Princeton Group unconformably overlie the Mesozoic rocks to the north (Holbek & Joyes, 2013). The following map (Figure 3.18) depicts all lithologies, followed by their correspondent description. Figure 3.19 Geology of the Copper Mountain deposit. From Nixon et al., 2004. 6 1 Nicola Group Volcanics The Nicola Group is an approximately 7.5 km average thick assemblage of volcanic and sedimentary rocks occurring as a north-trending belt approximately 25 km wide, extending from the U.S. border to north of Kamloops Lake (Schau, 1968; Preto, 1972, 1979; Mortimer, 1987 in Stanley et al., 1995). It is composed predominantly of augite-phyric andesites and intermediate to felsic pyroclastic rocks with subordinate amounts of sedimentary rocks. Four predominant Nicola Group rock types occur in the open pits: (1) Poorly-sorted fragmental volcanic breccia consisting of surrounded andesite and monzodiorite clasts in an andesite matrix, (2) Fine-grained, aphanitic to porphyritic andesite flows, (3) Thinly bedded, felsic tuffaceous epiclastic sedimentary rocks and (4) Clast-supported slump breccia with a mudstone matrix and clasts of felsic tuffaceous epiclastic sedimentary rocks ( Stanley et al., 1995). The volcanic and sedimentary facies of these rocks indicate that the depositional environment for the Nicola Group in the Copper Mountain district was probably tectonically active, shallow and subaqueous, possibly on the margin of an emergent or submergent island arc volcano (Stanley et al., 1995). Figure 3.20 Photomicrograph of the Nicola Group at Copper Mountain District. a. Porphyritic andesite represented 6 2 by hand sample CMT-12 located at Pit 2 characterized by 10% fine dark green mafic minerals in whitish groundmass partly replaced by light green epidote. b. Same sample under RL microscope showing 30% of K-feldspar phenocrysts. c. Sample under cross nicols (XN) showing 5% high birefringence prismatic augite phenocrysts, 30% K-feldspar phenocrysts in a fine groundmass. d. Epiclastic tuff represented by hand sample Bottom Pit 1 showing a white greyish aphanitic groundmass with 10% of dark mafic minerals. e. Same sample under TL microscope showing relict mafic phenocrysts. f. Sample under cross nicols (XN) showing porphyritic texture characterized by 10% of subhedral plagioclase phenocrysts in a trachytic groundmass of very fine subparallel K-feldspar microlites. Copper Mountain Stock (CMS) The CMS is not known to host important mineralization and consists of a concentrically zoned alkalic intrusion that grades from outward to inward as follows: Outer Diorite Phase It corresponds to the outer-most phase of the CMS and consists of a foliated, equigranular to subporphyritic, medium grain diorite (Figure 3.20), with relatively equal amounts of augite and plagioclase phenocrysts, lesser K-feldspar, biotite, magnetite, as well as accessory apatite and titanite (Montgomery, 1968; Stanley et al., 1995). Intermediate Monzonite Phase Intermediate Monzonite lies several hundred meters inward from the CMS. It differs from the Outer Diorite Phase by its coarser grain size, higher plagioclase/augite ratio, higher content of K-feldspar, hornblende rims on augite phenocrysts, and more abundant apatite and titanite (Lang, 1993). Syenite Core Syenite core situates approximately two thirds of the way into the CMS and limits abruptly with the Intermediate Monzonite Phase. It characterizes by its perthitic texture, coarser grain, and leucocratic colouration. In addition, it is the only phase of CMS that exhibits minor amounts of disseminated sulphides. 6 3 Lastly, the CMS hosts several small intrusive bodies of gabbro and pyroxenite, as well as late, cross-cutting quartz-monzodiorite dykes. Voigt stock (VS) and Smelter Lake stock (SLS) These stocks are smaller than the CMS and are texturally similar to each other and to the Outer Diorite Phase of the CMS (Montgomery, 1968 in Stanley et al., 1995). Both stocks have been locally subjected to pervasive potassic alteration associated with pyrite + chalcopyrite mineralization. Only the Voigt Stock (VS) is known to host economically feasible Cu-Au mineralization (Lang, 1993; Stanley et al., 1995). Figure 3.21 Photomicrograph of the CMS and Voight Stock at Copper Mountain District. a. Outer diorite phase of the CMS represented by hand sample CMT-9 of porphyritic texture characterized by 10% of dark subparallel mafic phenocrysts in grey K-feldspar groundmass. b. Voight Stock represented by hand sample CMT-13 of equigranular texture with 40% plagioclase, 20% dark green mafic phenocrysts . c. Same sample under TL microscope showing a coarse prismatic augite phenocrysts surrounded by relict biotite and 5% opaque 6 4 minerals in a K-feldspar groundmass. d. Same sample under cross nicols (XN) showing the prismatic augite phenocrysts of high birefringence. Lost Horse Intrusive Complex (LHIC) Lost Horse Intrusive Complex is defined as a multiphase suite of diorite to monzonite and minor syenite intrusions with pencil shape and irregular-boundary (Figure 3.21). It intrudes Nicola Group volcanic rocks and has Upper Triassic age dated 205.5±1.1 Ma by U-Pb zircon geochronology (Milhalynuk et al., 2009). In addition, it is interpreted to have been emplaced after the previously mentioned stocks because: 1) clasts from these stocks are recognizable in the LHIC rocks; 2) small LHIC dykes cut both the VS and SLS stocks (Montgomery, 1968; Preto, 1972 in Stanley et al., 1995). The LHIC is comprised of three distinctive intrusive phases: 6 5 Figure 3.22 Photomicrograph of LHIC at Copper Mountain District. a. LH1 diorite phase represented by hand sample CMT-5showing equigranular texture characterized by coarse tabular whitish plagioclase, pinkish K-feldspar and abundant dark green mafic phenocrysts. b. Same sample under RL microscopy showing white prismatic augite phenocrysts, biotite relicts and 5% of opaque minerals. c. Same sample under cross nicols (XN) showing abundant plagioclase and K-feldspar phenocrysts and high birefringence 6 6 augite phenocrysts. d. LH2 monzonite phase represented by core sample CM12AB10_31.5m showing porphyritic texture characterized by white albite and green chlorite phenocrysts in a salmon colour K-feldspar groundmass. e. Same sample under RL microscopy showing coarse tabular plagioclase phenocrysts in a K-feldspar groundmass. f. Sample under cross nicols (XN) showing selective sericite alteration of plagioclase phenocrysts. LH1 phase LH1 consists of dioritic dykes with equigranular texture and similar mineral assemblage to CMS, VS and SLS stocks, but contain fewer amounts of K-feldspar and biotite. Cross-cutting relations indicate that these dykes were emplaced prior to main-stage alteration and mineralization of the Copper Mountain porphyry deposit (Lang, 1993; Stanley et al., 1995). LH2 phase LH2 phase consist of monzonite dykes that differ from LH1 phase by its seriate porphyritic texture with coarser, commonly aligned plagioclase phenocrysts, as well as its significant content of accessory titanite up to 2% modal abundant. In addition, xenoliths of LH1 can be found within this unit, determining LH1 to be an older phase (Cromwell, 2014). LH2a phase LH2a phase also consists of monzonite and is distinguished from LH2 by its coarse plagioclase phenocrysts up to 9mm contained in a fine-grained grey/green microcrystalline feldspar groundmass (Cromwell, 2014). The LH2a phase constitutes the youngest phase of the LHIC (Lang, 1993; Stanley et al., 1995). Regardless the phase of LHIC, both plagioclase and clinopyroxene are consistently euhedral and thus are interpreted to be the first major minerals to crystallize in this intrusive complex (Stanley et al., 1995). 6 7 3.5.2. Alteration Alteration pattern and assemblages at Copper Mountain consist of an early stage pre-mineralization biotite-albite (mapped as hornfels) which is overprinted by sodic-calcic and potassic alterations (Figure 3.22). Early biotite-albite alteration occurs as recrystallization of mafic to intermediate volcanic host rocks, which is evidenced by the presence of fine-grained diopside + biotite + plagioclase + magnetite (Preto, 1972; Stanley et al., 1995). Figure 3.23. Alteration map of the Copper Mountain deposit. From Holbek & Joyes, 2013. 6 8 Early Hornfels alteration In the south part the district, rocks from the Nicola Group adjacent to the CMS display varying degrees of hornfels alteration related to the emplacement of the CMS, with textural preservation in some rocks and textural destruction in others. The more ferro‐magnesium rich rocks have been, partially to wholly, recrystallized into fine‐grained, brittle, biotite‐magnetite rich rocks, whereas the thinly laminated volcanic siltstones have retained their colour banding, but have been recrystallized, such that they break with a conchoidal fracture, giving the rocks a very chert‐like aspect in spite of whole‐rock silica contents below 50% (Holbek & Joyes, 2013). Sodic-calcic alteration Sodic-calcic, also known as “albitic alteration”, largely occurs to the south-central portion of the deposit and dominated by albite with variable amounts of diopside, chlorite and epidote, and minor pyrite and chalcopyrite (Lang et al., 1998). It is represented by pale greyish-green or mottled-white alteration of the host rock (Figure 3.23). Selective alteration of augite by actinolite ± titanite ± magnetite is a distinctive feature. 6 9 Figure 3.24 Photomicrograph of sodic-calcic alteration at Copper Mountain. a. Core sample CM12P223-179.5m showing pervasive sodic-calcic alteration characterized by abundant white albite replacement, disseminated chalcopyrite and green epidote replacement. b. Same sample under TL microscope showing relicts of altered augite phenocrysts partially replaced by secondary titanite and patches of epidote. c. Same view under cross nicols (XN). d. Same sample under RL microscope showing abundant disseminated chalcopyrite partly intergrowth with subhedral secondary titanite. Potassic alteration Potassic alteration locally cross-cuts zones of earlier sodic alteration and is widely distributed in the deposit. It is characterized by K-feldspar replacing plagioclase, secondary biotite, magnetite, calcite and minor chlorite replacing mafic minerals (Figure 3.24). In general, potassic alteration affects a larger total volume of rock than sodic alteration and both alterations are characterized by high amounts of K-feldspar and mafic mineral replacement (Stanley et al., 1995). 7 0 Figure 3.25 Photomicrograph of potassic alteration at Copper Mountain. a. Core sample CM12AB12-92m showing strong potassic alteration characterized by a salmon colour K-feldspar groundmass accompanied with disseminated chalcopyrite. b. Same sample under TL microscope showing selective biotite chloritization in K-feldspar + magnetite groundmass. c. Same view under cross nicols (XN). d. Same sample under RL microscope showing massive magnetite with hematite replacement and partly intergrowth with chalcopyrite. Chlorite-Actinolite-Epidote alteration Chlorite-epidote, mapped as propylitic, alteration is represented by a dark to light green colour of the host rock. It mainly distributes in the periphery of the deposit and in less extent in central portions of the deposit. It consists of chlorite + actinolite + epidote ± pyrite ± calcite replacing mafic minerals, and local hematite replacing magnetite (Figure 3.24d). Plagioclase and K-feldspar replacement by albite + epidote + calcite are also common (Stanley et al., 1995). Selective biotite chloritization is a distinctive feature together with minor titanite ± rutile replacement along cleavage planes. 7 1 Kaolinite and Sericite-Chlorite-Clay (SCC) alterations These alteration types occur only locally, are structurally controlled and considered to be late stage (post-mineralization). Texturally destructive kaolinite alteration consists of kaolinite + sericite + calcite + pyrite ± epidote ± chlorite ± minor quartz. SCC alteration typically displays a pale green colour due to green clays content and does not obliterate original textures (Stanley et al., 1995). 3.5.3. Mineralization Mineralization is strongly controlled by concentric and radial structures developed peripheral to the pre‐mineral CMS and by dikes and “pipes” of the syn‐mineral LHIC. Styles of mineralization range from: fracture fill, micro‐veins and vein stockworks, through to coarse veins, breccias, pods or pipe‐like bodies and disseminations (Holbek & Joyes, 2013). Sulfide mineral assemblages vary across the camp; with predominantly bornite (± chalcocite)‐chalcopyrite‐pyrite and chalcopyrite‐bornite‐pyrite in the south and central area between the CMS and LHIC (Fig. 7), a chalcopyrite‐pyrite‐magnetite assemblage in the north, centered on the LHIC, and a magnetite‐hematite‐chalcopyrite assemblage at the Voigt zone in the northeast (Stanley, et al, 1995). Similarly, silver and gold values vary with high silver‐low gold grades in the south and the inverse in the north (Giroux and Holbek, 2009). Total production at Copper Mountain accounts for 765,000 tonnes of Cu @ 0.5%, 21.2 tonnes of Au @ 0.13 g/t and 289 tonnes of Ag @ 1.7 g /t (Stanley, et al, 1995). 72 Chapter 4: Petrography of Titanite Titanite (CaTiOSiO5) is a common accessory mineral in a wide range of rocks formed in various geological environments including: calc-alkalic and alkalic igneous rocks, volcanic rocks, low to medium grade metamorphic rocks and low-temperature hydrothermal veins (Deer et al., 1992). In addition, titanite has the ability to record petrogenetic information within its texture, crystal habit and compositional zoning (McLeod, 2007). This chapter presents a characterization of titanite according to its colour, texture, habit, size, relative abundance and occurrence in fresh and altered rocks from Copper Mountain, Mount Polley and Mount Milligan alkalic porphyry copper deposits. Petrographic examination of 66 thin sections under transmitted light (TL), reflected light (RL), and scanning electronic microscopy (SEM), as well as binocular examination of 32 titanite grains recovered from 16 SELFRAG bedrock samples. The first section briefly describes titanite occurrence in various host rocks and alteration types from selected deposits. This is followed by classification of various titanite types. 4.1. Paragenesis of titanite in alkalic porphyry deposits In order to understand the common paragenesis of titanite in selected alkalic porphyry deposits, it is of relevance to consider that magmatic differentiation, magma mixing, hydrothermal alteration and ore precipitation are known occurring processes during the genesis of these deposits, which have demonstrated to be recorded in titanite crystals (McLeod, 2007). Therefore, an essential step for the petrographic characterization and classification of titanite is to identify 73 its different occurrences and paragenesis in rocks from selected alkalic deposits. The following section describes different occurrences of titanite at each studied alkalic deposit 4.1.1. Titanite at Mount Polley deposit Titanite occurs as colourless, euhedral, discrete accessory crystals (Figure 4.1a) in the groundmass of K-feldspar-phyric monzonite porphyry (Pkm) and Augite-bearing monzonite (PMdu) (see Chapter 3, section 3.3.1). In potassic (K-feldspar + magnetite) altered rocks, anhedral titanite rims and replaces cracked magnetite ± ilmenite phenocrysts (Figure 4.1b), whereas in pervasive potassic and calc-potassic mineralized rocks, particularly Fragmental Breccias (FBx), anhedral titanite and chalcopyrite is a common paragenesis evidenced by a close textural association (Figure 4.1c). Figure 4.1. Photomicrographs of titanite at Mount Polley. a. Discrete euhedral titanite in the groundmass of K-feldspar-phyric monzonite porphyry (Pkm) under TL microscope. b. Titanite rim replacing magnetite in K-feldspar-phyric monzonite porphyry (Pkm) under RL microscope. c. Anhedral titanite intergrowth with chalcopyrite in mineralized Fragmental Breccia (FBx) under RL microscope. 74 4.1.2. Titanite at Mount Milligan deposit Most titanite (3%) occurs after selective augite replacement by actinolite ± titanite, characteristic during early, high temperature (T= 400°- 600°C) sodic-calcic alteration affecting the MBX and SS stocks. Titanite commonly occurs as clustered anhedral crystals along cleavages of relict actinolite phenocrysts (Figure 4.2a-b). To a lesser extent, titanite also occurs as recrystallized or regrowth, coarse (> 500 ȝm) euKedral cr\stals in tKe Jroundmass oI tKe least altered rocks from the Heidi Lake Stock (Figure 4.2c-d). Lastly, there is no petrographic evidence of titanite texturally associated with chalcopyrite. Figure 4.2. Photomicrographs of titanite at Mount Milligan. a. Augite phenocrysts entirely replaced by actinolite + titanite in sodic-calcic alteration of the porphyritic monzonite from the SS stock, under TL microscope. b. Same view under RL microscope, note ilmenite inclusions in titanite. c. Coarse discrete euhedral titanite in the groundmass of peripheral, unmineralized, weakly altered, Heidi Lake Stock under TL microscope. d. Same view under RL microscope. 75 4.1.3. Titanite at Copper Mountain deposit The majority of titanite (4%) occurs as clustered subhedral crystals replacing relict augite phenocryst during sodic-calcic alteration (Figure 4.3a-b). In altered and mineralized rocks (chalcopyrite > 5%), anhedral titanite is commonly and texturally associated with chalcopyrite. During potassic (K-feldspar + biotite) alteration, anhedral, fine, elongated titanite commonly replaces biotite phenocrysts along cleavage planes and exhibits gradual rutile replacement during subsequent oxidation (Figure 4.3c-d). To a less extent, titanite also occurs as discrete euhedral crystals in the groundmass of marginal portions of the Lost Horse Intrusive Complex (LHIC) and peripheral Voight Stock, where it commonly displays significant rutile replacement due to oxidation during superimposed and marginal chlorite + calcite alteration (Figure 4.3e-f). 76 Figure 4.3. Photomicrographs of titanite at Copper Mountain. a. Relict augite phenocrysts partly replaced by titanite in sodic-calcic-altered porphyritic monzonite at central portions of the LHIC, under TL microscope. b. Same view under RL microscopy. c. Elongated titanite along cleavage planes of biotite in potassic altered porphyritic monzonite from the LHIC under TL microscopy. d. Same view under RL microscopy. e. Discrete subhedral titanite in the groundmass of peripheral portions of the LHIC under TL microscopy. d. Same view under SEM, note the partly preserved concentric zoning and high reflectance of rutile over titanite. 77 4.2. Titanite types The characterization of titanite in thin section and grains from SELFRAG bedrocks was performed according to key mineralogical features of colour, texture, habit, compositional zoning, and type hosting paragenesis (i.e. augite, biotite or magnetite). This section describes three titanite types and subtypes defined herein as Magmatic (MAG), Secondary (SEC) and Altered (ALT) titanites. 4.2.1. Magmatic titanite Magmatic (MAG) titanite typically occurs as discrete euhedral, colourless, 300µm size phenocrysts (Figure 4.4a) in the groundmass of least altered rocks. Concentric compositional zoning is a characteristic disequilibrium texture of this titanite type, which consists of concentric alternated light and dark contrast bands observed in BSE images (Figure 4.4b). Titanite zoning typically reflects melt fractionation and/or magmatic differentiation, while the melt cools and equilibrates to a new temperature (T) and/or oxygen fugacity (fO2) regime (McLeod, 2007). On the other hand, specimens with homogenous texture scarce and strictly crystallized when true physicochemical equilibrium is achieved (McLeod, 2007). Generally, pristine MAG titanite is rare given that it commonly exhibits recrystallization (see section 4.2.1.1.) and/or some degree of hydrothermal alteration represented by minor cavities and/or slightly dissolved crystal edges. 78 Figure 4.4. a. MAG titanite viewed under the microscope in TL. b. Same view under SEM. Sample P-6: least altered (K-Silicate), megacrystic porphyritic monzonite, North East Zone (NEZ), Mount Polley Deposit. 4.2.1.1. Magmatic recrystallized titanite Magmatic Recrystallized (MAG-RCX) titanite is also common in least altered rocks and occurs as discrete, euhedral, coarse (> 500 µm) crystals in the groundmass. Its presence indicates that successive changes in T and fO2 that modified original MAG specimens (McLeod, 2007). Thus, variations in T result in marginal crystal dissolution, represented by serrated edges (Figure 4.5a), whereas decreasing fO2 promotes ilmenite inclusions crystallization (Figure 4.5b). Once T decreases and fO2 restores to more oxidized conditions, crystallizing of ilmenite ceases and titanite growth resumes around the original MAG titanite. Lastly, these successive changes in T and fO2 are recorded as solution horizons between the inner MAG titanite of light contrast in BSE images and the outer, darker contrast MAG-RCX (Figure 4.5c). 79 Figure 4.5. a. MAG-RCX titanite viewed under the microscope in TL. b. Same view under SEM. c. Zoomed area viewed under SEM, showing solution horizons and fine ilmenite inclusions. Sample PTB045: strong sodic-calcic altered, megacrystic porphyritic monzonite, South Zone, Mount Polley Deposit. 4.2.2. Secondary titanite Secondary (SEC) titanite represents titanite crystallization after the alteration and/or destabilization of another mineral known as the hosting paragenesis. Three distinctive SEC titanite subtypes are distinguished depending hosting paragenesis (i.e. magnetite, augite or biotite): 80 4.2.2.1. Secondary titanite after magnetite Secondary titanite after magnetite (SEC-Mgt) results from primary, Ti-bearing magnetite (i.e. titanomagnetite) destabilization. The magnetite + ilmenite lamellae + anhedral SEC titanite ± pyrite assemblage (Figure 4.6) suggests variations in T and fO2 possibly enhanced by the melt cooling and superimposed potassic (K-feldspar) alteration. Thus, the increasing oxidation state of the cooling melt results in ilmenite and magnetite exsolution lamellae crystallization after Ti-bearing magnetite (Lindsley, 1991): 6 Fe2TiO4 + O2 = 6 FeTiO3 + 2 Fe3O4 Ti-magnetite ilmenite magnetite Alternatively, during potassic alteration, residual magnetite ± ilmenite can interact with S-rich hydrothermal fluids to form SEC titanite + secondary magnetite ± sulphide phases (Lindsley, 1991), where the calcium for titanite is likely scavenged from adjacent clinopyroxene or plagioclase: KAlSi3O8 + FeTiO3 + Fe3O4 + 2(H2S) = CaTiSiO5 + Fe3O4 + FeS2 + 2 H2O K-feldspar ilmenite/magnetite fluid titanite magnetite pyrite Lastly, the occurrence of SEC-Mgt is particularly common in the K-feldspar monzonite porphyry (Pkm) at North East Zone of the Mount Polley Instrusive Complex (MPIC). Moreover, the silica-undersaturated affinity of the Mount Polley deposit is inferred to be responsible for large amounts of magnetite from which SEC titanite crystallizes. 81 Figure 4.6. a. SEC-Mgt titanite viewed under the microscope in RL. b. Same view under SEM. Sample P-6: least altered K-feldspar monzonite porphyry (Pkm), North East Zone, Mount Polley Deposit. 4.2.2.2. Secondary titanite after augite Secondary titanite after augite (SEC-Aug) is particularly common in silica-saturated alkalic deposits (i.e. Mount Milligan and Copper Mountain), where it typically occurs as clustered crystals with fine cavities that distribute along cleavage planes of relict augite (Figure 4.7b). Thus, SEC-Aug titanite results from selective augite replacement during early, high temperature (T = 400° -600°C) sodic or “albitic” alteration: 7 Ca(Fe,Ti)Si2O6 + 9 SiO2 + 2 H2O = 2 Ca2(Mg,Fe)5Si8O22(OH)2 + 3 CaTiSiO5 augite quartz actinolite titanite The subsequent oxidation of relict augite phenocrysts can also form titanite with secondary magnetite: 3 Ca(Fe,Ti)Si2O6 + O2 = 3 CaTiSiO5 + 2 Fe3O4 + 3 SiO2 augite titanite + magnetite + quartz 82 Figure 4.7. a. SEC-Aug titanite viewed under the microscope in TL. b. Same view under SEM, showing patchy zoning and fine cavities. Sample CM12P223-352m: pervasive sodic-calcic altered – mineralized , porphyritic monzonite, LHIC, Copper Mountain Deposit. 4.2.2.3. Secondary titanite after biotite Secondary titanite after biotite (SEC-Biot) is a common SEC subtype during potassic (K-feldspar) alteration overprinted by a marginal chlorite ± calcite assemblage (also locally referred to as propylitic alteration). Thus, SEC-Biot results from which selective biotite chloritization (Morad et al., 2009): K(Mg,Fe)5O2TiAl2Si5O2(OH,F) + CaAl2Si2O8 + SiO2 + 2H2O  Ca(Ti,Al)(OH,F)SiO4 + Biotite + Plagioclase Titanite + (Mg,Fe)9Al5Si5(OH)16 + KAlSi3O8 Chlorite + K-feldspar Specimens typically occur as fine (< 100 µm) elongated crystals along cleavages of chloritized biotite (Figure 4.8a). Late oxidation stage during superimposing chlorite alteration promotes gradual to complete rutile replacement from borders to centre of titanite crystals (Figure 4.8b). 83 Figure 4.8. a. SEC-Biot titanite viewed under the microscope in TL. b. Same view under RL showing gradual rutile replacement. Sample CMT-7: strong K-Silicate/Propylitic altered – barren, subporphyritic syenite, LHIC, Copper Mountain Deposit. 4.2.3. Altered titanite Altered (ALT) titanite forms when pre-existing crystals of MAG or SEC type are affected by a significant degree of hydrothermal alteration. Moreover, ALT titanite and chalcopyrite paragenesis with textural association is common in intensively altered and mineralized (chalcopyrite > 5%) rocks. ALT titanite diagnostic feature consists of anhedral habit comparable to Emmental swiss cheese, characterized by highly dissolved edges and numerous cavities. Another alteration feature consists of a gradual to complete rutile replacement from borders to centre of the original titanite specimen. The following ALT titanite subtypes are defined depending on the origin of the affected titanite crystal (i.e. MAG or SEC): 4.2.3.1. Altered magmatic titanite Altered Magmatic (ALT-MAG) titanite occurs when MAG specimens are significantly replaced by rutile during late stage oxidation of superimposed chlorite alteration. Thus, ALT-MAG 84 subhedral crystals exhibit partly dissolved edges with rutile replacements (Figure 4.9a) and preservation of original concentric zoning typical from MAG specimens (Figure 4.9b). Figure 4.9. a. ALT-MAG titanite viewed under the microscope in TL. b. Same view under SEM, showing preserved concentric zoning and rutile replacement around crystal edges. Sample CMAB015-13.4m: strong K-Silicate – mineralized, megacrystic porphyritic syenite (LHIC), Copper Mountain Deposit. 4.2.3.2. Altered secondary titanite Depending on the hosting paragenesis (i.e. augite or biotite) and type of hydrothermal alteration, there are two Altered Secondary (ALT-SEC) titanite subtypes that can be distinguished: Altered Secondary titanite after augite (ALT-SEC-Aug), which results from the complete augite obliteration during pervasive sodic alteration carrying Cu-mineralization (Figure 4.10a), 3 Ca(Fe,Ti)Si2O6 + (H2S,Cu)  3 CaTiSiO5 + CuFeS2 + 9 SiO2 augite fluid titanite chalcopyrite quartz ALT-SEC-Aug titanite is characterized by a distinctive skeletal texture composed of an arrangement of anhedral titanite crystals distributed along relicts of augite (Figure 4.10b). 85 Figure 4.10. a. ALT-SEC-Aug titanite viewed under the microscope in RL, showing texture association with sulphurs. b. Same view under TL, depicting skeletal texture. Sample CM12P223-352m: pervasive sodic-calcic altered – mineralized , porphyritic monzonite, LHIC, Copper Mountain Deposit. On the other hand, Altered Secondary titanite after biotite (ALT-SEC-Biot) results from the entire replacement of SEC-Biot titanite by rutile during late stage oxidation of a superimposed chlorite + calcite alteration (Figure 4.11a-b): CaTiSiO5 + 2 (H2CO3)  CaCO3 + SiO2 + TiO2 titanite + fluid calcite + quartz + rutile Figure 4.11. a. ALT-SEC titanite viewed under the microscopy in TL. b. The same view under SEM. Sample CMT-13: least altered (sodic-calcic) monzonite, North East Zone, Copper Mountain Deposit. 86 4.2.3.3. Altered unknown titanite The classification of titanite into the defined types becomes problematic when specimens are highly modified and the hosting paragenesis has been entirely obliterated by pervasive hydrothermal alteration (Figure 4.12). Therefore, a third ALT titanite type defined as Altered Unknown (ALT-UNK) titanite is introduced. The occurrence of ALT-UNK titanite is particularly common in pervasively altered and mineralized (chalcopyrite > 5%) rocks, where chalcopyrite and titanite are texturally associated. Diagnostic features of ALT-UNK specimens include extremely anhedral habit characterized by highly dissolved edges and multiple cavities (Figure 4.12b). Figure 4.12. a. ALT-UNK titanite viewed under the microscope in TL. b. Same view under SEM. Sample CM12P223-352m: pervasive sodic-calcic altered – mineralized, porphyritic monzonite, LHIC, Copper Mountain Deposit. 87 4.3. Titanite binocular study Titanite heavy mineral concentrates (HMC) were recovered in the 0.1-0.25 mm size, S.G > 3.2 g/cm2 and E.M > 1.0 A fraction of 16 least altered and altered SELFRAG rock samples. An average of 5 titanite grains per 300g of processed material were carefully hand-picked and examined under binoculars and SEM for physical characterization and estimated abundance. 4.3.1. Titanite colour The majority of grains collected from least altered rocks (Figure 4.13a) are colourless, euhedral to subhedral and exhibit homogenous texture without inclusions or cavities (Figure 4.13b). These physical features suggest a correspondence with MAG titanite. On the other hand, grains obtained from altered ± mineralized rocks display a translucent to cloudy blond colour, subhedral habit (Figure 4.13.c) and patchy/sector compositional zoning (Figure 4.13d). These physical features suggest a correspondence with ALT and/or SEC titanites. Lastly, grains recovered from intense to pervasive altered ± mineralized rocks exhibit dark honey brown colour and highly anhedral habit (Figure 4.13f). In addition, BSE images (Figure 4.13e) reflect noticeable rutile replacement around borders, together with coarse calcite inclusions. These physical features suggest a correspondence with ALT titanite and depict a higher degree of alteration than that of blond grains. Therefore, the colour of titanite observed under binoculars could be used as an indicator of the intensity of the affecting hydrothermal alteration. 88 Figure 4.13. Photomicrographs of titanite grains examined under binoculars and SEM. a. Colourless, subhedral MAG titanite without cavities or inclusions. b. Same view under SEM showing no compositional zoning. c. Blond, subhedral ALT titanite. d. Same view under SEM showing patchy compositional zoning, partly dissolved edges and minor cavities. e. Dark honey brown, anhedral ALT titanite. f. Same view under SEM showing rutile replacement around edges and multiple cavities filled with calcite + rutile. 89 4.3.2. Titanite size and relative abundance Thirty-four titanite grains were recovered in half of the SELFRAG rock samples. Approximately 60% of the total recovered grains correspond to subhedral to anhedral ALT titanite with blond and/or dark honey brown colour (Figure 4.14) and 250 ȝm average size (Table 4.1). The remaining 40% of grains corresponds to colourless MAG titanite of euhedral to subhedral habit (Figure 4.14) and 300 ȝm average size (Table 4.1). Lastly, the chemical signature of these titanite grains is discussed in the next chapter and documented in Appendices B2 (major element composition) and C2 (trace element composition). Figure 4.14. Photomicrographs of titanite grains from SELFRAG bedrocks of Mount Polley and Copper Mountain. Colourless euhedral to subhedral grains correspond to MAG titanites and blond to honey brown subhedral to anhedral grains correspond to ALT titanites. 90 Table 4.1. Physical characterization of titanite grains from SELFRAG bedrock. Aug= augite; cal= calcite; ccp= chalcopyrite; ep= epidote; n/a= no inclusions; rt= rutile. Deposit SELFRAG sample Grain Colour Habit Inclusions length (µm) width (µm)P3-1 honey brown anhedral ep + ccp 300 175P3-2 colourless anhedral ep + ccp 295 230P3-3 colourless anhedral ep + ccp 270 180P3-5 honey brown anhedral ep + ccp 280 240P3-9 honey brown anhedral ep + ccp 185 135P6-1 blond subhedral n/a 180 150P6-2 blond subhedral ep + ccp 300 200P6-3 colourless subhedral ep + ccp 220 130P6-4 colourless subhedral n/a 470 150P6-5 colourless subhedral n/a 260 195P6-6 colourless subhedral rt 250 170P6-7 colourless subhedral rt 340 180P4-1 colourless euhedral n/a 220 140P4-2 colourless euhedral n/a 220 130CMT-13 M13-1 honey brown anhedral rt + cal 160 115M65-1 colourless subhedral ep + ccp 240 200M65-2 honey brown subhedral rt + cal 180 140M65-3 honey brown subhedral rt + cal 250 200M65-4 honey brown subhedral rt + cal 270 250M65-5 blond subhedral rt + cal 270 180M65-6 blond subhedral rt + cal 340 230M65-7 blond subhedral rt + cal 170 70M65-8 blond subhedral rt + cal 220 170M65-9 colourless subhedral n/a 430 290M65-10 colourless subhedral rt + cal 375 275M7-1 honey brown anhedral rt + cal 600 400M7-2 honey brown anhedral rt + cal 130 90M7-3 honey brown anhedral aug + rt + cal 180 150M7-5 honey brown anhedral rt + cal 150 100M217-1-1 blond subhedral ccp 300 250M217-2-1 honey brown anhedral ep 240 200M217-3-1 blond subhedral n/a 230 230M238-1-1 colourless subhedral ep + ccp 230 225M238-2-1 colourless euhedral aug + ccp 270 17006957_217m111015_238.5mMt.MilliganP4Mt.PolleyCopper Mt.P3P6CM12P221-65.5mCMT-7 91 4.4. Summary The majority of titanite (60%) from studied alkalic deposits has a secondary (SEC) origin as it crystallizes after alteration of other minerals (i.e. augite, biotite and magnetite). Sodic or “albitic” alteration affecting augite-bearing monzonites to diorites is particularly common in silica-saturated alkalic deposits (i.e. Mount Milligan and Copper Mountain) and is responsible for the crystallization of large amounts of secondary titanite (3-4%) after augite alteration. To a lesser extent, potassic or K-silicate alteration affecting magnetite and/or biotite bearing monzonites also generates noticeable amounts of secondary titanite (1-2%) after biotite and magnetite alteration. In addition, titanite replacement of Ti-bearing magnetite is particularly common in rocks of the silica-undersaturated Mount Polley deposit, where large volumes of Ti-bearing magnetite favour SEC titanite crystallization. Pervasive rock alteration accompanied by significant mineralization (chalcopyrite > 5%) produces altered (ALT) titanite, which commonly exhibits a close textural association with disseminated chalcopyrite blebs. Superimposing, late stage chlorite ± calcite assemblage promotes biotite chloritization and gradual to complete rutile replacement of pre-existent titanite. The remaining 40% of titanite in alkalic deposits consist of discrete euhedral, colourless, crystals in the groundmass least altered to moderately altered rocks. These specimens are considered to have magmatic (MAG) origin as they crystallize from melt fractionation into a rock-forming accessory mineral. Finally, a binocular study reveal that more than half titanite in studied deposits is ALT type and has blond / honey brown colour, subhedral to anhedral habit and 0.25 mm average size. The remaining specimens correspond to colourless, euhedral MAG crystals. These observations, together with titanite textural characterization under SEM suggest that colour could be used as an indicator of the alteration intensity, where blond grains represent moderately altered titanite and dark honey brown grains represent highly altered titanite. 92 To conclude, all titanite types and subtypes are described in classification Table 4.2. Table 4.2. Titanite petrographic classification. Class Diagnostic Criteria Subclass Diagnostic Criteria Processes involved Magmatic (MAG)colourless; euhedral habit; well-preserved concentric compositional zoning; Fractional crystallization and magmatic differentiation.Magmatic Recrystallized (MAG-RCX)pale yellow; subhedral habit; ilmenite inclusions; solution horizons; partly dissolved margins; sector compostional zoning / no zoning.Fluctuations in T and f O2 related to magmatic differentiation and/or magma mixing.Secondary after augite (SEC-Aug)pale honey brown; coarse subhedral crystal clusters along cleavage planes of Augite; patchy compositional zoning.Selective augite replacement during sodic-calcic (albite + actinolite + epidote) alteration of augite-bearing host rocks.Secondary after biotite (SEC-Biot)honey brown; anhedral habit; crystallization along cleavage planes of biotite; patchy compositional zoning.Selective magnetite replacement during potassic (K-feldspar) alteration of biotite-bearing host rocks.Secondary after magnetite (SEC-Tmgt)honey brown; anhedral habit; ilmenite inclusions; filling fractures and surrounding magnetite.Selective magnetite replacement during potassic (K-feldspar) alteration of magnetite-bearing host rocks.Altered Magmatic (ALT-MAG)colourless to pale yellow; subhedral habit; rutile replacement; partly preserved concentric compositional zoning.Pervasive sodic-calcic / potassic alteration overprinted by propylitic (chlorite + calcite ± rutile) alteration.Altered Secondary (ALT-SEC)a) after biotite: honey brown colour crystals partly replaced by rutile, with strong anhedral elongated habit, disposed along cleavages of chloritized biotite. b) after augite: strongly anhedral crystals with skeletal texture along relict augite phenocrysts; common integrowth with disseminated sulphides.a) Pervasive potassic alteration overprinted by propylitic (chlorite + calcite ± rutile) alteration. b) Sodic-calcic alteration overprinted by pervasive potassic alteration carrying H2S,Cu -rich fluids. Altered Unknown (ALT-UNK)no recognizable hosting paragenesis; colourless/pale yellow, strongly anhedral crystals with mutiple cavities and dissolved edges; commonly intergrowth with disseminated Sodic-calcic alteration overprinted by pervasive potassic alteration carrying H2S,Cu -rich fluids. Magmatic (MAG)discrete, colourless, euhedral crystals with concentric compositional zoningAltered (ALT)strongly anhedral crystals characterized by multiple cavities, inclusions and dissolved edges; selective rutile replacementsubhedral to anhedral crystals with patchy compositional zoning along relict mafic mineralsSecondary (SEC)9 3 Chapter 5: Chemistry of Titanite This chapter describes the chemical composition of titanite hosted in least altered and altered bedrocks from studied deposits based on Electron Microprobe (EMP) and Laser Ablation Inductive Coupled Plasma Spectroscopy (LA-ICP-MS) analyses of specimens in thin / thick sections and heavy mineral concentrates. Results are presented through various major and trace element bivariate plots and diagrams. Major element contents are first described, followed by trace element and REE patterns. 5.1. Titanite major element composition Major elements were analysed in 100 grains from 9 thin sections (Appendix B1) using EMP. Trace elements were analysed in 33 grains from 8 thick sections (off cuts from thin section mentioned above) (Appendix C1) using LA-ICP-MS. Analytical results are discussed in the following 3 subsections, which included titanite chemistry at each deposit. 5.1.1. Titanite composition at Mount Polley Spot analyses of 24 MAG and ALT grains from three thin sections are shown in Figure 5.1. MAG titanite hosted in least altered K-feldspar-phyric monzonite porphyry (Pkm-c) is characterized by KiJK ∑LREE and intermediate (1.0-1.5) Fe/Al ratios (Figure 5.1a). MAG titanite occurring with moderate propylitic (epidote + albite) alteration hosted in Augite-bearing monzonite (PMdu) is characterized by low (< 1.0) Fe/Al ratios (Figure 5.1a) and low ∑ LREE relative to MAG specimens. In addition, the high Al contents responsible for low (< 1.0) Fe/Al ratios are also observed in Figure 5.1c, while comparing Al2O3 contents with other common substitutions (i.e. ∑ LREE and V2O3). ALT titanites hosted in Fragmental Breccia 9 4 (FBx) with pervasive potassic (K-feldspar + magnetite) alteration and mineralization are characterized by high (> 1.5) Fe/Al ratios and V enrichment particularly at rims (Figure 5.1b). Finally, fluorine (F) concentration is significantly higher in ALT titanites relative to MAG titanites (Figure 5.1d). Figure 5.1. Titanite composition at Mount Polley. a. Bivariate plot of Fe/Al ratio vs ∑LREE (ppm) b. Bivariate plot of Fe/Al ratio vs V3+ (a.p.f.u.). c. Ternary diagram of ∑LREE- Al2O3- V2O3. d. Probability plot of F- (a.p.f.u.). a.p.f.u = atoms per formula unit (a.p.f.u.). Dashed lines separate low (<1.0), intermediate (1.0-1.5) and high (>1.5) Fe/Al ratios. D.L = detection limit. 5.1.2. Titanite composition at Mount Milligan Spot analyses of 22 MAG and ALT grains from three thin sections are shown in Figure 5.2. Results show that MAG titanites hosted in least altered monzonite (Heidi Lake Stock) have 9 5 intermediate (1.0-1.5) Fe/Al ratios and are enriched in ∑LREE (Figure 5.2a). ALT titanites hosted in monzonite (SS Stock) have two distinctive populations depending on the alteration type. The sample with strong potassic (K-feldspar + magnetite) alteration contains titanite with high (> 1.5) Fe/Al ratios and low ∑ LREE (Figure 5.2a), whereas the sample affected by strong sodic-calcic (albite + actinolite + epidote) alteration contains titanites with low (< 1.0) Fe/Al ratios, low ∑ LREE and V enrichment (Figure 5.2b). ALT titanite hosted in the Lower Trachyte unit affected by strong propylitic (epidote + albite + actinolite + pyrite) alteration and mineralization shows very low (< 0.75) Fe/Al ratios and V enrichment, particularly at crystals rims (Figure 5.2b). In addition, the high Al contents responsible for low (< 1.0) Fe/Al ratios are also observed in Figure 5.2c, while comparing Al2O3 contents with other common substitutions (i.e. ∑ LREE and V2O3). Lastly, high fluorine (F) contents are observed in ALT specimens hosted in monzonite (SS Stock) affected by strong sodic-calcic alteration and mineralization (Figure 5.2d). 9 6 Figure 5.2. Titanite composition at Mount Milligan. a. Bivariate plot of Fe/Al ratio vs ∑LREE (ppm) b. Bivariate plot of Fe/Al ratio vs V3+ (a.p.f.u.). c. Ternary diagram of ∑LREE - Al2O3 - V2O3. d. Probability plot of F- (a.p.f.u.). a.p.f.u = atoms per formula unit (a.p.f.u.). Dashed lines separate low (<1.0), intermediate (1.0-1.5) and high (>1.5) Fe/Al ratios. D.L = detection limit. 5.1.3. Titanite composition at Copper Mountain Spot analyses in 21 MAG, SEC and ALT grains from three thin sections are shown in Figure 5.3. MAG titanites show intermediate (1.0 – 1.5) Fe/Al ratios and strong LREE enrichment irrespective of the host rock / alteration type where they occur (Figure 5.3a). ALT titanites hosted in monzonite (LHIC, LH2) affected by strong potassic alteration (K-feldspar + magnetite) and mineralization are characterized by high (> 1.5) Fe/Al ratios (Figure 5.3b), whereas grains in diorite (LHIC, LH1) affected by pervasive sodic-calcic (albite + actinolite + epidote) alteration and mineralization have low (< 1.0) Fe/Al ratios and strong V enrichment 9 7 particularly at rims (Figure 5.3b). SEC titanite hosted in least altered rock (Voight Stock) is characterized by low (< 1.0) Fe/Al ratios and low ∑ LREE depletion, with no V enrichment (Figure 5.3a-b). Finally, the F concentration is most elevated in ALT titanites hosted in diorite (LHIC, LH1) with pervasive sodic-calcic (albite + actinolite + epidote) alteration and mineralization (Figure 5.3d). Figure 5.3. Titanite composition at Copper Mountain. a. Bivariate plot of Fe/Al ratio vs ∑LREE (ppm) b. Bivariate plot of Fe/Al ratio vs V3+ (a.p.f.u.). c. Ternary diagram of ∑LREE - Al2O3 - V2O3. d. Probability plot of F- (a.p.f.u.). a.p.f.u = atoms per formula unit (a.p.f.u.). Dashed lines separate low (<1.0), intermediate (1.0-1.5) and high (>1.5) Fe/Al ratios. D.L = detection limit. 9 8 5.1.4. Interpretation Spot analyses in titanite specimens from thin sections confirm that MAG titanite is characterized by intermediate (1.0-1.5) Fe/Al ratios and high ∑ LREE contents compare to ALT and SEC titanites. These observations agree with previous work (Morad et al., 2009), which describes MAG titanite as being REE-enriched and Al, F, Fe depleted. ALT titanite has either high (> 1.5) Fe/Al ratios when affected by intense potassic (K-feldspar + magnetite) alteration or low (< 1.0) Fe/Al ratios when affected intense sodic-calcic (albite + actinolite + epidote) alteration. These observations agree with previous work (Kowallis et al., 1997; Morad et al., 2009) and can be explained by the remobilization of Fe3+ and Al3+ at microscale during metasomatism. Titanite with high (> 1.5) Fe/Al ratios reflect an increase of Fe3+ substituting the Ti-site, typically enhanced by high fO2 conditions (Kowallis et al., 1997) during potassic (K-feldspar + biotite + magnetite) alteration. Excess of Fe3+ is likely remobilized from adjacent magnetite by hydrothermal fluids (Morad et al., 2009). On the other hand, titanite with low (< 1.0) Fe/Al ratios reflects an increase of Al3+ substituting the Ti-site, where excess of Al3+ is likely remobilized from adjacent plagioclase (Morad et al., 2009) during high temperature (T = 400 - 600°C) fluids from deep (1 - 2 km) sodic-calcic alteration. Alternatively, low Fe/Al ratios may be attributed to Fe3+ leaching during strong sodic or “albitic” alteration from the Copper Mountain deposit (Holbek and Joeys, 2013). The following equation represents the common (Al, Fe) 3+ coupled substitution in the Ti-site of the titanite structure: Ca2+ + Ti4+ ļ REE3+ + (Al, Fe) 3+ (Green and Pearson, 1986; Enami, et al., 1993) In addition, ALT titanite hosted in strongly altered rocks with significant Cu mineralization (chalcopyrite > 5%) is enriched in V particularly at rims. This agrees with the fact that V-9 9 enrichment is associated with high fO2 conditions typical during strong calc-silicate alteration (Bernau and Franz, 1987). Thus, V is interpreted to increase its oxidation state from V3+ to V5+ (Micko, 2010) and therefore is likely to incorporate in the Ti-site of the titanite structure. 2 Ti4+ ļ V5+ + (Al, Fe)3+ (Bernau & Franz, 1987) Lastly, ALT titanite also has high F concentrations compared to specimens from unmineralized host rocks. The excess of F is interpreted to be derived from a magmatic fluid phase separating from the crystalizing melt (Bailey, 1977), which typically takes place during high T (> 350 C°) and/or high fO2 (log fO2 > -25) conditions. The following equation represents F- substitution in the O-site of the titanite structure: (Al, Fe)3+ ļ Ti4+ + (OH, F)í (Franz and Spear, 1985) 5.2. Titanite trace element composition and REE patterns This section describes the trace element composition, including REE patterns of 33 titanite grains from 8 thick sections (off cuts from thin sections previously discussed) on the basis LA-ICP-MS spot analyses (Appendix C1). Analytical results are presented in the following three subsections describing titanite trace element composition at each deposit, followed by an interpretation at the end. 5.2.1. Titanite trace element composition at Mount Polley REE analyses demonstrated that MAG titanite has REE patterns characterized by LREE enrichment convex upwards relative to HREE (> 1000 times that of chondrite) and pronounced negative Eu anomalies (Figure 5.4a-b) irrespective of the host rock alteration. In contrast, ALT titanite hosted in Fragmental Breccia (FBx) affected by pervasive potassic (K-feldspar + 1 00 magnetite) alteration and mineralization shows a marked decrease of LREE from La to Sm and absent to strongly positive Eu anomalies (Figure 5.4c). Figure 5.4. Titanite REE patterns at Mount Polley. a. REE patterns of MAG titanites hosted in least altered K-feldspar-phyric monzonite porphyry (Pkm-c). b. REE patterns of MAG titanites hosted in Augite-bearing monzonite (PMdu) with moderate propylitic alteration. c. REE patterns of ALT titanites hosted in Fragmental Breccia (FBx) with pervasive potassic alteration + mineralization. All values are normalized to chondrite after Sun and McDonough, 1995. More importantly, trace element (Y, Nb, Ta, Th/U) contents relative to ∑ REE (Figure 5.5) depict that MAG titanite is highly enriched in REE and HFSE (Y, Nb, Ta, Th/U) irrespective of the host rock alteration, whereas ALT titanite is depleted in these elements. 1 01 Figure 5.5. Titanite trace elements concentration (ppm) vs ∑ REE (ppm) at Mount Polley. a. Tantalum (Ta) concentration (ppm). b. Niobium (Nb) concentration (ppm). c. Yttrium (Y) concentration (ppm). d. Thorium/Uranium (Th/U) ratio. 5.2.2. Titanite trace element composition at Mount Milligan Scarce MAG titanite hosted in monzonite (SS Stock) affected by moderate sodic-calcic (albite + actinolite + epidote) alteration shows LREE enrichment convex upwards relative to HREE and absent to positive Eu anomalies (Figure 5.6a). The positive Eu anomalies suggest that these specimens have been affected by some degree of sodic-calcic alteration. Spot analyses in MAG titanite hosted in least altered rock are not included given the unavailability of a representative sample (i.e. missing offcut from thin section MTM91-1074). 1 02 Most REE patterns of ALT titanite hosted in monzonite (SS Stock) affected by intense propylitic (epidote + albite + actinolite + pyrite) are chaotic (Figure 5.6b) and show LREE depletion (< 1000 times that of chondrite) relative to HREE and absent to weak positive Eu anomalies. Lastly, ALT titanite hosted in the Lower Trachyte unit affected by intense potassic (K-feldspar + biotite) alteration and mineralization a marked decrease of LREE from La to Sm and strongly positive Eu anomalies (Figure 5.6c). Figure 5.6. Titanite REE patterns at Mount Milligan. a. REE patterns of MAG titanites hosted in monzonite (SS Stock) with moderate sodic-calcic alteration. b. REE patterns of ALT titanites hosted in monzonite (SS Stock) with strong propylitic alteration + mineralization. c. REE patterns of ALT titanites hosted in Lower Trachyte with strong potassic alteration + mineralization. All values are normalized to chondrite after Sun and McDonough, 1995. Trace element (Y, Nb, Ta, Th/U) contents relative to ∑ REE (Figure 5.7) show that MAG titanite is significantly enriched in REE and HFSE (Y, Nb, Ta, Th/U) compared to ALT specimens. An exemption applies for those ALT specimens hosted in the Lower Trachyte 1 03 affected by strong potassic alteration and mineralization, which show higher Th/U ratios than MAG titanite (Figure 5.7c). Figure 5.7. Titanite trace elements concentration (ppm) vs ∑REE (ppm) at Mount Milligan. a. Tantalum (Ta) concentration (ppm). b. Niobium (Nb) concentration (ppm). c. Yttrium (Y) concentration (ppm). d. Thorium/Uranium (Th/U) ratio. 5.2.3. Titanite trace element composition at Copper Mountain The majority of analyzed specimens are considered to be ALT titanite given their significant REE depletion (ie ∑ REE < 1000 times that of chondrite), with one exemption in least altered rock (Voight Stock) (Figure 5.8a). Petrographic observations of these specimens (see Appendix A2, sample CM12P223-352m, plate 10c-d) reveal the effects of attacking hydrothermal fluids 1 04 (i.e. specimens with cavities and embayments), which likely leached and remobilized REE into adjacent accessory minerals such as apatite and allanite (Pan & Fleet, 1993). In addition, the strong positive Eu anomalies of specimens affected by pervasive sodic-calcic (albite + actinolite + epidote) alteration and mineralization (Figure 5.8b) are also a characteristic sign of ALT titanite at the other deposits. Lastly, minor SEC titanite hosted in least altered rock (Voight Stock) is highly depleted in Ce (Figure 5.8a), suggesting the existence of Ce as Ce4+ characteristic during high fO2 conditions (e.g. Henderson 1980, Gianetti & Luhr 1983; Carlier & Lorand, 2008), associated with hydrothermal alteration phases. Figure 5.8. Titanite REE patterns at Copper Mountain. a. REE patterns of MAG and SEC titanites hosted in least altered diorite (Voight Stock). b. REE patterns of ALT titanites hosted in diorite (LHIC, LH1) with pervasive sodic-calcic alteration + mineralization. c. REE patterns of ALT titanites hosted in monzonite (LHIC, LH2) with strong potassic alteration. All values are normalized to chondrite after Sun and McDonough, 1995. 1 05 Trace element (Y, Nb, Ta, Th/U) contents relative to ∑ REE (Figure 5.9) also confirm that most specimens are ALT titanite depleted in REE (ie ∑ REE < 5000 ppm). Lastly, the concentration of trace elements (Y, Ta, Nb, Th/U) in SEC and ALT titanite affected by pervasive sodic-calcic alteration is significantly lower than in rest of specimens. Figure 5.9. Titanite trace elements concentration (ppm) vs ∑REE (ppm) at Copper Mountain. a. Tantalum (Ta) concentration (ppm). b. Niobium (Nb) concentration (ppm). c. Yttrium (Y) concentration (ppm). d. Thorium/Uranium (Th/U) ratio. 1 06 5.2.4. Interpretation Results of LA-ICP-MS spot analyses reveal that MAG titanite has higher REE and HFSE (Y, Ta, Nb, Th/U) contents than ALT and SEC specimens, irrespective of the host rock alteration. Moreover, REE patterns of MAG specimens are characterized by LREE enrichment convex upwards and strong negative Eu anomalies. A negative Eu anomaly represents the existence of Eu as Eu3+ rather Eu2+, which does not incorporate into the Ca-site of titanite (Pan and Fleet, 1993). In addition, the LREE enrichment represents titanite crystallization from LREE-rich residual magmatic fluids at late stage of intrusion consolidation (Exley, 1980). On the other hand, REE patterns of ALT titanites are characterized by decreasing LREE from La to Sm and absent to positive Eu anomalies. A positive Eu anomaly represents reduction of Eu3+ to Eu2+ and subsequent incorporation of Eu2+ in the Ca-site of titanite (Horie et al., 2008). The reduction of Eu is likely to be caused by metasomatism of highly oxidizing fluids interacting with a buffering host rock (Micko, 2010) ,n addition siJniIicant REE depletion (∑ REE < 1000 times that of chondrite) of ALT titanite is inferred to be caused by hydrothermal fluids leaching and remobilizing these elements into adjacent accessory REE-bearing minerals such as apatite and allanite (Pan & Fleet, 1993). Trace element (Y, Nb, Ta, Th/U) contents in MAG titanite are significantly than those of SEC and ALT specimens, irrespective of the host rock alteration. This agrees with the description of MAG titanite been REE and HFSE enriched (Che et al., 2013) and reflects its behaviour as a “sink or trap” for trace elements when crystallizing from intermediate to acidic melts (McLeod, 2007). 1 07 5.3. Chemistry of titanite concentrates from bedrocks This section describes the chemical composition of 12 titanite grains recovered from SELFRAG bedrocks from Mount Polley deposit, based on EMP (Appendix B2) and LA-ICP-MS (Appendix C2) spot analyses. Altered (ALT) and secondary (SEC) titanites are not distinguishable in heavy mineral concentrates (HMC) and therefore herein referred as ALT/SEC grains. Analytical results are presented through the same bivariate plots and diagrams used for the chemical characterization of titanites in thin and thick sections. Major element composition is first discussed, followed by trace element and REE patterns. An interpretation of the relation between titanite chemistry and colour (under natural light) is presented at the end. 5.3.1. Titanite HMC major element composition Colourless grains recovered from least altered rock have intermediate (1.0 - 1.25) Fe/Al ratios and high ∑ LREE contents, which confirm the chemistry of MAG titanite (Figure 5.10a). Blond grains recovered from a sample with moderate potassic (K-feldspar + magnetite) alteration and mineralization (chalcopyrite < 5%) have similar Fe/Al ratios but are enriched in vanadium (V), suggesting the chemistry of ALT/SEC titanite (Figure 5.10b). Lastly, honey brown grains recovered from the same rock sample are considered strongly altered ALT/SEC titanite given their high (> 1.5) Fe/Al ratios, higher V enrichment (Figure 5.10b) and F enrichment (Figure 5.10c). 1 08 Figure 5.10. Titanite HMC composition at Mount Polley. a. Bivariate plot of Fe/Al ratio vs ∑LREE (ppm) b. Bivariate plot of Fe/Al ratio vs V3+ (a.p.f.u.). c. Ternary diagram of ∑LREE - Al2O3- V2O3. d. Probability plot of F- (a.p.f.u.). a.p.f.u = atoms per formula unit (a.p.f.u.). Dashed lines separate low (<1.0), intermediate (1.0-1.5) and high (>1.5) Fe/Al ratios. D.L = detection limit. 5.3.2. Titanite HMC trace element composition The REE patterns of colourless MAG specimens show the characteristic LREE enrichment convex upwards and strong negative Eu anomalies (Figure 5.11a). On the other hand, blond ALT/SEC specimens recovered from a sample with moderate potassic alteration (K-feldspar + magnetite) and mineralization (chalcopyrite < 5%) show similar REE patterns but absent to weak Eu anomalies (Figure 5.11b). Lastly, honey brown ALT/SEC grains from the same 1 09 sample are near half REE depleted with respect to the chondrite and decreasing LREE from La to SM and even weaker to absent Eu anomalies (Figure 5.11c). Figure 5.11. Titanite HMC Rare Earth Elements (REE) composition at Mount Polley. a. REE concentrations of colourless MAG titanites in least altered K-feldspar-phyric monzonite porphyry (Pkm-c). b. REE concentrations of blond ALT titanites in Augite-biotite diorite (PD1) with moderate potassic alteration + mineralization. c. REE concentrations of honey brown ALT titanites in Augite-biotite diorite (PD1) with moderate potassic alteration + mineralization. Spider diagrams normalized to chondrite after Sun and McDonough, 1995. Trace element (Nb, Ta) contents relative to ∑ REE reveal that the colourless MAG grains are significantly more enriched in Nb and Ta than ALT/SEC blond and honey brown specimens (Figure 5.12). 1 10 Figure 5.12. Titanite HMC trace elements concentration (ppm) vs ∑REE (ppm) at Mount Polley. a. Tantalum (Ta) concentration (ppm). b. Niobium (Nb) concentration (ppm). 5.3.3. Interpretation The chemistry of titanite HMC from SELFRAG bedrocks from Mount Polley demonstrates to be coincident with that of specimens in thin/thick sections. Colourless, euhedral grains without cavities or inclusions have equivalent chemistry to that of MAG titanite, characterized by intermediate (1 – 1.5) Fe/Al ratios, V and F depletion, Nb, Ta and REE enrichment, with REE patterns showing strong negative Eu anomalies. Blond subhedral grains show a similar chemistry of that of ALT titanite, characterized by intermediate (> 1.5) Fe/Al ratios, V and F enrichment, and Nb, Ta and REE depletion, with REE patterns showing absent to positive Eu anomalies. Dark honey brown anhedral grains have a similar chemistry than blond grains but show high (> 1.5) Fe/Al ratios and REE patterns with a marked decrease of LREE. This suggests that honey brown specimens were probably submitted to a higher degree of alteration than blond grains and that excess of Fe3+ responsible for the high Fe/Al ratios could be associated with the dark brown colouration. 1 11 To conclude, the chemical composition of titanite HMC from SELFRAG bedrocks revealed that the colour of titanite could be linked to particular titanite types. Thus, colourless grains are considered MAG titanite and blond and/or honey brown grains are associated with ALT/SEC titanite. 5.4. Summary of titanite chemistry The chemical composition of various titanite specimens hosted in least altered and strongly altered, mineralized rocks from studied deposits confirmed that the Fe/Al ratio and the V, F, REE and HFSE (Y, Ta, Nb, Th/U) contents are key components of the titanite chemical signature. In addition, the physical and chemical characterization of titanite HMC from SELFRAG bedrock samples reveal that grain colour can be linked to a specific titanite type, where colourless grains represent MAG titanite and blond/honey brown represent ALT or SEC titanite. Thus, honey brown titanite grains can be indicative of Cu-mineralization given their close chemical similarity to ALT titanite hosted in strongly altered and mineralized (chalcopyrite > 5%) rocks. A description of each titanite chemical indicator is herein presented, together with their relation to titanite colour. Fe/Al ratio The Fe/Al ratio in titanite reflects the remobilization of Fe3+ and Al3+ at microscale during metasomatism (Kowallis et al., 1997; Morad et al., 2009). Thus, the Fe/Al ratio ranges from a) low (< 1.0) in ALT specimens affected by intense sodic (albite) alteration and mineralization, b) intermediate (1.0 - 1.5) in MAG specimens and c) high (> 1.5) in ALT specimens affected by intense potassic (K-feldspar + magnetite) alteration and mineralization. High (> 1.5) Fe/Al 1 12 ratios reflect Fe3+ substitution in the Ti-site during high fO2 conditions (Kowallis et al., 1997), where excess of Fe3+ is remobilized from adjacent magnetite (Morad et al., 2009). Low (< 1.0) Fe/Al ratios reflect an increase of Al3+ substituting the Ti-site (Kowallis et al., 1997), where excess of Al3+ is remobilized from adjacent plagioclase (Morad et al., 2009). Lastly, the honey brown titanite grains have higher Fe/Al ratios compare to blond specimens, suggesting that the brown colour is likely to be caused by an increase of Fe3+ in the titanite structure. Vanadium (V) Vanadium (V) enrichment is characteristic of ALT titanite hosted in strongly altered rocks with significant Cu mineralization (chalcopyrite > 5%), particularly at crystal rims. This agrees with the fact that V-enrichment is associated with high fO2 conditions during calc-silicate alteration (Bernau and Franz, 1987), where V tends to increase its oxidation state from V3+ to V5+ (Micko, 2010) and therefore is expected to be incorporated in titanite. Fluorine (F) Fluorine (F) enrichment is also typical in ALT titanite hosted in strongly altered rocks with significant Cu mineralization (chalcopyrite > 5%). High F concentrations suggest high T (> 350 C°) and/or high fO2 (log fO2 > -25) metasomatism of magmatic fluids (Bailey, 1977). Rare Earth Elements (REE) The REE concentration of titanite allows to distinguish MAG specimen, which typically have ∑ REE ! 5000 ppm Irom $/T 6E& specimens tKat Kave ∑ REE < 5000 ppm Moreover the REE patterns of titanite also reveal these differences and can reflect the degree of alteration affecting the mineral. Thus, MAG titanite typically shows LREE enrichment convex upwards 1 13 and strong negative Eu anomalies, whereas ALT titanite shows decreasing LREE from La to Sm and absent to strong positive Eu anomalies. The LREE enrichment represents crystallization from LREE-rich residual magmatic fluids at late stage of intrusion consolidation (Exley, 1980), whereas LREE depletion reveals leaching or remobilization of LREE into adjacent REE-bearing accessory minerals (i.e. apatite, allanite) during metasomatism (Pan & Fleet, 1993). In the addition, a negative Eu anomaly indicates absence of Eu in the titanite structure (Pan and Fleet, 1993), whereas a positive Eu anomaly reflects metasomatism of oxidizing fluids interacting with a buffering host rock (Micko, 2010), where Eu3+ reduces to Eu2+ and incorporates into the Ca-site of titanite (Horie et al., 2008). High Field Strength Elements (HFSE) MAG titanite tends to incorporate Yttrium (Y), Niobium (Nb), Tantalum (Ta) in the Ti-site of and Uranium (U) and Thorium (Th) in the Ca-site. This agrees the fact that MAG titanite acts as a “sink or trap” for these elements when crystallizing from intermediate to acidic melts (McLeod, 2007; Che et al., 2013). Previous work (Corfu & Muir, 1989; Mezger et al., 1993; Verts et al., 1996) documented that dark brown translucent titanite tends to incorporate more U than light brown, cloudy specimens. However, this observation could not be verified given that U contents where not analyzed in titanite HMC from SELFRAG bedrocks. The following table 5.1 includes representative major and trace element contents of various titanite types, based on EMP and LA-ICP-MS spot analyses respectively. EMP and LA-ICP-MS were not measured from the exact same grain given that EMP were performed in thin sections, whereas LA-ICP-MS were performed in the equivalent offcuts (i.e. thick sections). However, both analyses represent the same titanite type hosted in the same sample. 1 14 Table 5.1. Representative titanite major and trace element composition. Sample # P-6 P-6 PTB045 PTB045 WB04109-269m WB04109-269m MTM91-1074 MTM91-1074 06948-63.4m 06948-63.4m 111015-238m 111015-238m CMT-13 CMT-13 CMT-13 CMT-13 CM12P223-352m CM12P223-352m CMAB015-13.4m CMAB015-13.4mDeposit Mt. Polley Mt. Polley Mt. Polley Mt. Polley Mt. Polley Mt. Polley Mt. Milligan Mt. Milligan Mt. Milligan Mt. Milligan Mt. Milligan Mt. Milligan Copper Mt. Copper Mt. Copper Mt. Copper Mt. Copper Mt. Copper Mt. Copper Mt. Copper Mt.Host rock KMzPh KMzPh AMz AMz FBx FBx MzHLS MzHLS MzSS MzSS LTc LTc DiVS DiVS DiVS DiVS DiLHIC DiLHIC MzLHIC MzLHICAlteration LA LA P P KS+M KS+M LA LA KS KS P+M P+M LA LA LA LA NC+M NC+M KS+M KS+MTitanite type MAG MAG MAG MAG ALT ALT MAG MAG ALT ALT ALT ALT MAG MAG SEC SEC ALT ALT ALT ALTSpot core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim(wt.%) D.L.CaO 0.24 26.92 27.16 26.77 26.47 27.12 27.15 26.11 26.84 28.08 28.09 27.51 27.35 27.73 26.56 28.48 27.95 28.08 27.99 26.23 26.44SiO2 0.02 29.47 29.81 29.46 29.67 29.93 29.97 29.47 29.73 29.83 29.81 30.41 30.36 30.12 31.79 30.58 30.42 30.60 30.67 28.88 29.31TiO2 0.14 38.23 37.11 36.30 35.94 35.93 36.03 35.38 36.27 37.64 38.26 37.72 37.50 35.43 36.36 36.74 36.25 34.34 34.48 35.67 36.56ZrO2 0.12 0.26 0.26 0.23 0.17 0.67 0.13 0.31 - 0.97 0.26 0.50 0.16 - - - - - - 0.15 -SnO2 0.11 - - - - - - - - - - - - - - - - 0.08 - - -Al2O3 0.02 1.06 1.16 1.20 0.98 0.98 0.84 0.95 0.89 0.28 0.41 0.94 0.98 1.39 1.83 1.82 1.85 2.45 1.75 0.34 0.46V2O3 0.08 0.32 0.18 0.18 0.13 0.18 0.40 0.15 0.17 0.16 0.29 0.34 0.56 0.18 0.15 0.25 0.29 0.49 1.58 0.21 0.30Cr2O3 0.04 - - - - - - - - - 0.06 0.09 0.09 0.09 - - - - - 0.43 0.29Fe2O3 0.08 2.00 2.10 1.52 2.01 2.60 2.25 1.65 1.57 1.04 1.37 0.72 0.87 3.04 1.92 1.84 2.16 2.35 1.12 2.06 1.59MgO 0.03 - - 0.03 0.04 - - - - - - - - 0.03 - - - - - 0.02 -MnO 0.07 0.11 0.12 0.19 0.19 0.09 - 0.15 0.17 - - 0.07 0.09 - - 0.05 - - - - 0.14Nb2O5 0.12 0.11 - - - - - 0.50 0.25 0.26 0.38 0.10 - - - - - - - - 0.20Y2O3 0.11 0.18 0.29 0.33 0.25 - - 0.67 0.39 - - - - 0.33 0.24 - - - 0.09 - 0.10Ce2O3 0.27 - 0.27 0.40 0.27 0.27 - 0.64 0.45 - - - - 0.40 - - - - - - -Nd2O3 0.33 0.33 - - 0.26 - - 0.41 - - - - - - 0.28 - - - - - -Na2O 0.04 0.08 0.05 0.04 0.07 0.03 0.04 - - 0.03 0.03 - - - 0.23 - - - - 0.07 0.07K2O 0.03 0.02 0.09 - 0.10 0.08 0.30 - - 0.05 0.11 0.08 0.16 0.04 0.35 0.02 0.02 - - 0.02 0.15F 0.34 0.35 0.71 0.41 0.52 1.11 0.87 - 0.29 - - - - - 0.38 0.28 - 1.51 0.87 - 0.53H2O 0.78 0.49 0.49 0.56 0.46 0.18 0.51 0.36 0.15 0.30 0.53 0.64 0.75 1.09 0.60 0.84 0.31 0.32 0.58 0.43F=O -0.23 -0.30 -0.17 -0.22 -0.23 -0.23 0.00 -0.12 0.00 -0.01 -0.05 -0.07 -0.04 -0.16 -0.12 -0.06 -0.64 -0.37 -0.09 -0.22Total 97.14 99.41 97.31 97.12 97.14 97.14 98.76 99.23 98.89 99.24 99.53 99.20 100.16 101.47 101.02 100.31 100.09 98.82 97.22 98.23(a.p.f.u.)Ca site 0.935 0.950 0.957 0.946 0.932 0.982 0.947 0.964 1.001 0.993 0.963 0.958 0.970 0.902 0.981 0.967 0.974 0.985 0.963 0.956Si site 0.955 0.973 0.983 0.989 0.984 0.992 0.998 0.997 0.992 0.983 0.993 0.993 0.983 1.008 0.984 0.983 0.990 1.007 0.990 0.989Ti site 0.932 0.911 0.911 0.902 0.889 0.897 0.901 0.915 0.942 0.949 0.927 0.922 0.870 0.867 0.889 0.881 0.836 0.852 0.920 0.928Zr 0.004 0.004 0.004 0.003 0.011 0.002 0.005 - 0.016 0.004 0.008 0.002 - - - - - - 0.003 -Sn - - - - - - - - - - - - - - - - 0.001 - - -Al 0.041 0.045 0.047 0.039 0.038 0.033 0.038 0.035 0.011 0.016 0.036 0.038 0.053 0.068 0.069 0.070 0.093 0.068 0.014 0.018V 0.008 0.005 0.005 0.004 0.005 0.011 0.004 0.005 0.004 0.008 0.009 0.015 0.005 0.004 0.006 0.007 0.013 0.042 0.006 0.008Cr - - - - - - - - - 0.001 0.002 0.002 0.002 - - - - - 0.012 0.008Fe 0.054 0.057 0.042 0.056 0.071 0.062 0.042 0.040 0.029 0.038 0.020 0.024 0.083 0.051 0.049 0.058 0.064 0.031 0.053 0.040Mg - - 0.002 0.002 - - - - - - - - 0.002 - - - - - 0.001 -Mn 0.003 0.003 0.005 0.005 0.001 - 0.004 0.005 - - 0.002 0.003 - - 0.001 - - - - 0.004Nb 0.002 - - - - - 0.008 0.004 0.002 0.000 0.002 - - - - - - - - 0.003Y 0.003 0.005 0.006 0.004 - - 0.012 0.007 - - - - 0.006 0.004 - - - 0.002 - 0.002Ce - 0.003 0.005 0.003 0.000 - 0.008 0.005 - - - - 0.005 - - - - - - -Nd 0.004 - - 0.003 - - 0.005 - - - - - - 0.003 - - - - - -Na 0.005 0.003 0.003 0.004 0.001 0.003 - - 0.002 0.002 - - - 0.014 - - - - 0.004 0.004K 0.001 0.004 - 0.004 0.027 0.006 - - 0.002 0.005 0.003 0.007 0.002 0.014 0.001 0.001 - - 0.001 0.007F- 0.036 0.073 0.044 0.055 0.111 0.092 - 0.031 - - - - - 0.038 0.028 - 0.154 0.091 - 0.056OH- 0.169 0.106 0.108 0.125 0.100 0.040 0.115 0.080 0.034 0.066 0.116 0.139 0.163 0.230 0.129 0.180 0.067 0.070 0.133 0.097Structural formula calculated on the basis of O = 5 atoms1 15 Table 5.1. Representative titanite major and trace element composition (continuation). V (ppm) 0.332 1613 1218 1027 1017 2188 1464 n/a n/a 1175 1504 5060 4890 1810 n/a 795 n/a 7930 9610 3394 n/aCu 0.900 2 3 - 1 148 186 n/a n/a 9 - 21 35 4 n/a - n/a 6 2 - n/aY 0.025 2451 1450 2369 2152 1397 436 n/a n/a 2188 877 380 158 1220 n/a 93 n/a 444 453 429 n/aZr 0.061 1584 950 1479 1366 2480 1770 n/a n/a 204 2250 167 143 191 n/a 50 n/a 264 171 1624 n/aNb 0.003 465 267 424 356 264 109 n/a n/a 1614 2370 80 79 253 n/a 21 n/a 129 110 167 n/aHf 0.005 60 36 55 52 107 32 n/a n/a 8 64 5 5 8 n/a 1 n/a 21 13 81 n/aTa 0.005 39 22 34 31 8 4 n/a n/a 17 60 1 2 14 n/a - n/a 9 9 13 n/aTh 0.001 68 36 59 49 110 49 n/a n/a 171 345 9 4 174 n/a 12 n/a 18 11 30 n/aU 0.007 18 13 19 17 107 96 n/a n/a 32 172 54 18 192 n/a 25 n/a 38 35 11 n/aLa 0.005 940 550 729 599 544 612 n/a n/a 510 748 22 25 247 n/a 47 n/a 59 29 78 n/aCe 0.013 2848 1610 2183 1883 1450 1052 n/a n/a 2105 2050 76 63 1010 n/a 165 n/a 191 97 436 n/aPr 0.005 424 234 335 303 212 121 n/a n/a 372 275 11 8 171 n/a 25 n/a 31 16 80 n/aNd 0.001 2098 1170 1675 1596 1002 475 n/a n/a 1891 1166 51 35 890 n/a 122 n/a 158 93 411 n/aSm 0.045 507 288 436 437 273 96 n/a n/a 498 229 20 14 262 n/a 30 n/a 52 38 85 n/aEu 0.007 112 61 108 110 86 63 n/a n/a 130 94 10 5 41 n/a 13 n/a 66 86 49 n/aGd 0.017 471 279 435 429 279 87 n/a n/a 436 193 25 12 253 n/a 22 n/a 66 58 73 n/aTb 0.001 74 44 69 66 44 13 n/a n/a 70 28 7 5 36 n/a 3 n/a 11 10 11 n/aDy 0.025 477 288 455 433 299 80 n/a n/a 468 181 63 35 224 n/a 21 n/a 75 79 72 n/aHo 0.003 94 55 91 85 58 16 n/a n/a 92 35 17 7 44 n/a 3 n/a 17 17 15 n/aEr 0.053 259 157 253 232 166 46 n/a n/a 278 105 35 24 126 n/a 10 n/a 51 52 44 n/aTm 0,001 36 21 36 31 24 6 n/a n/a 44 16 6 3 18 n/a 2 n/a 7 7 7 n/aYb 0.005 205 126 215 185 144 33 n/a n/a 295 105 42 17 113 n/a 11 n/a 49 46 44 n/aLu 0.006 24 14 26 22 15 3 n/a n/a 37 15 6 1 14 n/a 1 n/a 6 6 4 n/a 5EE 8569 4898 7045 6410 4597 2704 n/a n/a 7225 5238 390 253 3449 n/a 475 n/a 838 633 1409 n/a /5EE 6310 3564 4922 4381 3208 2260 n/a n/a 4878 4239 160 131 2318 n/a 359 n/a 439 235 1006 n/a 05EE 1641 960 1503 1475 982 339 n/a n/a 1104 495 105 57 816 n/a 89 n/a 270 271 290 n/a +5EE 618 374 621 554 407 105 n/a n/a 746 275 105 51 315 n/a 27 n/a 130 127 113 n/a"-"= value below detection limits; D.L.=detection limit; n/a= data not availableALT=altered titanite; MAG=magmatic titanite; SEC=secondary titanite;  5EE total 5EE content  /5EE light 5EE from /a to 1d  05EE medium 5EE from 6m to 'y  +5EE heaYy 5EE from +o to /uAmz=augite-bearing monzonite; DiLHIC=diorite from Lost Horse Intrusive Complex; DiVS=diorite from Voight Stock; FBx=fragmental breccia; KMzPh=K-feldspar monzonite porphyry; LTc=Lower Trachyte; MzHLS=monzonite from Heidi Lake Stock; MzSS=monzonite from South Star Stock. LA=least altered rock; KS=K-Silicate alteration; NC=sodic-calcic alteration; P=propylitic alteration; M=mineralization1 16 Chapter 6: Titanite in Till Sediments Titanite has been previously suggested as potential indicator mineral in covered terrains (e.g., Averill, 2011). This research attempts to characterize titanite in alkalic deposits and in overlying/proximal till sediments. This chapter presents the physical and chemical characterization of titanite grains recovered from till sediments overlying/proximal to the Mount Milligan and Mount Polley deposits. The main purpose is to assess mineralization potential in covered terrains by tracing detrital dispersion of titanite and other PIMs (i.e. gold, chalcopyrite, apatite, epidote and garnet) back to bedrock source, in conjunction with identifying metals (i.e. Cu and Au) anomalies within the till fine fraction. Thus, the till survey presented herein includes a) a mineralogical component (i.e. analyses of heavy mineral concentrates) and b) till matrix geochemistry component. A description of till sediments overlying and surrounding the Mount Milligan and Mount Polley deposits is first presented, followed by the physical and chemical characterization of detrital titanite. The last two sections describe the distribution and relative abundance titanite and various PIMs concentrates, followed by analytical results of till geochemistry. Detrital titanite physical and chemical indicators of alteration and mineralization and titanite footprint relative to the distribution of Cu and Au anomalies are discussed at the end of this chapter. 6.1. Till geology Surficial sediments of the Mount Milligan area include morrainal till, glaciofluvial, fluvial and colluvial sediments (Kerr, 1991). Two surficial media predominate in the Mount Milligan district: an extensive morainal till blanket and a large glaciofluvial outwash complex of the 1 17 Rainbow Creek (Figure 6.2). Till is commonly hummocky, drumlized and was deposited during the Late Wisconsinan glaciation between 25940 ± 380 and 10100 ± 90 years B.P. (Sibbick et al., 1996). It consists of a dense matrix-supported diamicton composed of very poorly sorted, angular to well-rounded pebbles to cobbles in a sand-silt-clay matrix (Figure 6.1) (Sibbick et al., 1996). The surficial geology at the Mount Polley district is mostly attributed to the Fraser Glaciation of the Late Wisconsinan. Over the plateau, morainal till is the most dominant surficial material and typically occurs as a thick blanket (>1 m thick) that masks local topography. It is poorly sorted, moderate to well-compacted, silty clay diamicton. At surface, tills are often heavily washed, with the fine-grained component removed by weathering and erosion. Less common, glaciofluvial sediments are concentrated within the major valleys and typically consist on moderately sorted, weak to moderately compacted, cobble or boulder gravel with a sand matrix. The rest of sediments within the Mount Polley district consist of minor amounts of glaciolacustrine sediments, organic material (i.e., fens and bogs), colluvium, modern fluvial deposits and anthropogenically disturbed stratum (Bichler & Bobrowsky, 2003). Two pilot till surveys, one at Mount Milligan (n=21 samples) and another at Mount Polley (n=5 samples) were performed in order to determine the distribution and relative abundance of titanite and various PIMs concentrates, as well as to identify geochemical anomalies. Results are presented in deposit and district scale maps showing surficial geology (Kerr, 1991; Bichler & Bobrowsky, 2003), historical till geochemistry (Sibbick et al., 1996; Hashmi et al., 2015) and ice flow direction (Ferbey et al., 2013). Details regarding till sampling methods are provided in Chapter 2. 1 18 Figure 6.1 Till sediments overlying the Mount Milligan deposit characterized by a dense matrix-supported diamicton composed of poorly sorted, angular to well-rounded pebbles to cobbles in a sand-silt-clay matrix. 1 19 Figure 6.2 Location of till samples. a. Till samples at the Mount Milligan from Kerr, 1991. b. Till samples at the Mount Polley from Bichler & Bobrowsky, 2003. 1 20 6.2. Heavy mineral concentrates (HMC) in till sediments at Mount Milligan Heavy mineral concentrates (HMC) is an important component for exploration in covered terrains. Some significant advantages of HMC over traditional glaciofluvial/till sediments geochemistry analyses include: i) better detection and more revealing dispersal patterns for elements with low background values (e.g., PGEs, Ag, W and Au), ii) more representative data (reduced nugget effect) since they are extracted from larger volumes than regular geochemical samples and iii) dispersal patterns can be interpreted almost entirely in terms of clastic dispersal processes given that HMC are clastic monominerals without hydromorphic component (Maurice, 1991). The main disadvantage of this technique consists of higher costs of sampling and processing compared to traditional glaciofluvial/till sediments analysis, which typically translates into a lower sample density (Maurice, 1991). Heavy mineral concentrates (HMC) were recovered from basal till samples (≈ 10m deep) at the bottom line of marginal benches of the Mount Milligan open pit and surficial till samples (≈ 1.5m deep) in roadcuts within 3 to 15 km distal from the mine site. Titanite grains are firsts described, followed by other PIMs concentrates (i.e., chalcopyrite, gold, epidote and garnet). All HMC are listed and documented in Appendix D. 6.2.1. Detrital titanite in till sediments Detrital titanites were reported by ODM Labs in 13 out of 21 till samples (10-15 kg each) overlying and proximal (< 3 km) down ice of the Mount Milligan deposit. This section describes the physical and chemical characterization of 50 titanite grains recovered largely from 2 surficial and 3 basal till samples proximal (< 1 km) and overlying the Mount Milligan 1 21 deposit. Specimens in more distal (> 3km down ice) till sediments are not abundant (< 40 grains/per sample) and most of them are less than 500 ȝm in size. Physical description of various titanite grains is first provided, followed by their correspondent chemical characterization. 6.2.1.1. Physical characterization of detrital titanite Detrital titanites were recovered from the same size (0.1-0.25 mm), density (> 3.52 g/cm2) and non-paramagnetic (> 1.0 A) fraction. Subsequently, specimens were examined under binoculars, SEM and were characterized based on their colour, habit and texture (cavities, inclusions, replacement, compositional zoning). Appendix D2 provide a summary of collected data. Three distinctive titanite types were identified based on colour and texture: Caramel brown detrital titanite Grains are typically euhedral, 520 × 420 ȝm averaJe si]e and display caramel brown colour (Figure 6.3a), together with high contrast amorphous compositional zoning (Figure 6.3b and c). More importantly, they show no replacement textures (i.e., rutile and calcite), which suggests a different origin than those dark honey brown grains occurring in strongly altered host rocks (Figure 6.4a, b and c). Therefore, the caramel brown colour of these specimens is probably not indicative of hydrothermal alteration and is rather attributed to metamictic effects, which usually turns the mineral original colour into green, brown or even black (Woodhead, 1991,). Thus, caramel brown titanite is herein defined as metamictic (MET) titanite. 1 22 Blond titanite These grains are typically subhedral, 570 x 400 ȝm averaJe size, display translucent blond colour (Figure 6.3g), together with textures characterized by minor fine cavities and weak contrast sector zoning (Figure 6.3h and i). These physical features indicate a close resemblance to blond ALT/SEC titanite (Figure 6.4e-f) derivate from bedrocks. Figure 6.3 Photomicrographs of detrital titanites in tills from Mount Milligan. a. MET titanite from till sample S1303-14m viewed under binoculars showing honey brown colour. b. Same view under SEM showing euhedral habit. c. Transect view under SEM showing distinctive dark contrast amorphous zoning. d. ALT/SEC titanite from till sample MT-16 viewed under binoculars showing clear translucent yellow colour. e. Same view under SEM showing subhedral habit. f. Transect view under SEM showing weak contrast patchy zoning and multiple fine cavities. 1 23 Figure 6.4 Photomicrographs of titanite grains from bedrock. a. Dark honey brown ALT/SEC titanite from strong potassic alteration and mineralization (sample CMT-7). b. Same view under SEM showing significant calcite and rutile replacement around borders. c. Blond ALT/SEC titanite from moderate potassic alteration (sample P-3). d. Same view under SEM showing multiple cavities and partly dissolved edges. e. Colourless MAG titanite from moderate to least altered rock (sample P-6). f. Same view under SEM showing euhedral rhombic habit and homogenous texture with no zoning and minor fine microfractures. 1 24 6.2.1.2. Chemistry of detrital titanite From bedrock study (see 4.2.4, Chapter 4), titanite grains were initially classified as colourless, blond and dark honey brown. From the titanite grains in till sediments a fourth type was added namely caramel brown titanite of metamictic (MET) origin (Figure 6.5). Results shows that the majority of caramel brown titanites Kave ∑ LREE > 7000 ppm and plot within intermediate (1-1.5) Fe/Al range (Figure 6.5a). Moreover, almost all grains are V-depleted as reflected by V3+ < 0.01 a.p.f.u. (Figure 6.5b). This indicates that most detrital titanites correlate with the chemical signature of MAG titanite from bedrocks (see Chapter 5, Figure 5.2a-b). Blond titanites typically display ∑ /REE < 7000 ppm and specimens with ∑ LREE < 5000 ppm show particularly low (< 1.2) Fe/Al ratios (Figure 6.5a) due to Al-enrichment (Figure 6.5c). These grains have a strong chemical similarity with ALT/SEC titanite occurring with Al-rich sodic-calcic and/or propylitic alterations (see Chapter 5, Figure 5.2c). Most grains have fluorine enrichment (F- > 0.05 a.p.f.u), particularly caramel brown grains over blond specimens (Figure 6.5d) compared to specimens from bedrock (F- < 0.05 a.p.f.u) (see Chapter 5, Figure 5.2d). 1 25 Figure 6.5. Chemistry of detrital titanite in tills from Mount Milligan. a. Bivariate plot of Fe/Al ratio (a.p.f.u.) vs ∑/REE (ppm) b. Bivariate plot of Fe/Al ratio (a.p.f.u.) vs V3+ (a.p.f.u). c. Ternary diagram of Al2O3 – ∑/REE - V2O3 (ppm). d. Probability plot of F - (a.p.f.u.). Dashed lines separate medium (1.0-1.5) and very low (<1.0) Fe/Al ratios. a.p.f.u. = atoms per formula unit. D.L = detection limit. REE patterns of detrital titanite in tills at the Mount Milligan deposit show that caramel brown MET specimens and MAG titanite from least altered bedrocks have similar REE patterns characterized by LREE enrichment convex upward (> several 1000’s that of chondrite) and pronounced negative Eu anomalies (Figure 6.6a). On the other hand, blond ALT/SEC grains have similar REE patterns than those of ALT/SEC titanite from bedrocks, characterized by decreasing LREE from La to Sm and absent to positive Eu anomalies (Figure 6.6b). 1 26 Figure 6.6. REE patterns of detrital titanites in tills from Mount Milligan. a. REE patterns of caramel brown MET grains. b. REE patterns of blond ALT/SEC grains. All values are normalized to chondrite after Sun and McDonough, 1995. Trace element (Y, Ta, Nb and Th/U) contents relative ∑ REE (Figure 6.7) show that caramel brown MET grains have significantly higher ∑ REE (10,000 - 20,000 ppm), Y (2000 - 5000 ppm), Ta (100 – 400 ppm), Nb (1000 – 3500 ppm) and Th/U (4 to 6.5) contents than blond specimens. 1 27 Figure 6.7 Trace elements concentration vs ∑REE (ppm) in detrital titanites in tills from Mount Milligan. a. Yttrium (Y) concentration (ppm). b. Niobium (Nb) concentration (ppm). c. Tantalum (Ta) concentration (ppm). d. Thorium/Uranium (Th/U) ratio. 6.2.1.3. Interpretation Physical and chemical characterization of detrital titanites in tills overlying the Mount Milligan deposit identifies the blond titanite and suggests existence of a new titanite type namely, metamictic (MET). The fact that MET grains display subtle colour and textural differences relative to bedrock counterparts suggests that their caramel brownish colouration and amorphous features are associated with metamictization rather than alteration. Previous work 1 28 by Vance et al. (1985) has documented that titanite is two to three times more sensitive than zircon to radiation damage by alpha decay of U and Th impurities. Moreover, metamictization of titanite consists of a gradual and ultimately complete destruction of the crystalline structure into a quasi-amorphous state similar to glass (Bismayer et al., 2010; McLeod, 2007). Thus, the amorphous dark contrast zoning observed in caramel brown specimens (Figure 6.3c) also correlates with the above description of metamictization effects in titanite. Results show that bulk of MET titanites plot within the intermediate (1-1.5) Fe/Al ratio and their concentration of REE (∑ REE = 10,000 - 20,000 ppm) and trace elements (Y= 2000 - 5000 ppm; Ta= 100 – 400 ppm; Nb= 1000 – 3500 ppm; Th/U= 4 to 6.5) are significantly higher than MAG titanites from bedrocks, suggesting that these grains are allochthonous from the porphyry related suites and are likely originated from a different magmatic source. On the other hand, translucent blond ALT/SEC detrital titanites show a similar chemistry to that of ALT/SEC titanite from bedrocks, characterized by relativel\ loZ (<) )e$l ratios and ∑ REE < 5000 ppm. Therefore, these grains probably were originated or modified during sodic-calcic and/or propylitic alteration from the Mount Milligan deposit. Detrital titanites in more distal (up to 2 km down ice) till sediments are not abundant (< 20 grains/per sample) and the majority (3/4) of them correspond to small (< 500 ȝm) suEKedral to anhedral ALT/SEC translucent blond grains. Only one till sample (MT-17) reported significant amounts (1/3) of caramel brown MET specimens. Finally, the fact that till samples containing MET specimens are located at deeper levels (≈10 m deep) and less than 1 km down ice east of the deposit suggest that MET titanite could be originated from a deeper level igneous phase, probably older than the Mount Milligan deposit, considering that metamictization by radiation 1 29 damage typically occurs over a longer period of geologic time than that of a porphyry alteration and mineralization (Vance et al., 1985). 6.2.1.4. Detrital titanite in till sediments at Mount Polley Only four grains were analyzed and recovered from limited till samples (n=5) containing traces of titanite grains (n < 20). Most grains are colourless (Figure 6.8a) small (< 00 ȝm) with subhedral habit and weak-contrasted sector zoning (Figure 6.8b and c). Only one translucent blond grain (Figure 6.8d) with subhedral habit and concentric zoning (Figure 6.8e and f) was recognized. Figure 6.8 Photomicrographs of detrital titanite in tills from Mount Polley. a. Colourless titanite from till sample PT-4 viewed under binoculars. b. Same view under SEM showing euhedral habit. c. Transect view under SEM showing sector zoning. d. Blond translucent titanite from till sample PT-2 viewed under binoculars. e. Same view under SEM showing subhedral habit. f. Transect view under SEM showing minor cavities and concentric zoning. 1 30 The chemical signature of these grains shows that the blond titanite has low (< 1.0) Fe/Al ratio, low ∑ /REE ()iJure  a) and rims enricKed in 93+ (Figure 6.9b), which coincides with the chemistry of ALT/SEC specimens from bedrocks. In contrast, colourless grains correlate with the chemistry of MAG specimens from bedrock. Figure 6.9. Chemistry of detrital titanite in tills from Mount Polley. a. Bivariate plot of Fe/Al ratio (a.p.f.u.) vs ∑/REE (ppm) b. Bivariate plot of Fe/Al ratio (a.p.f.u.) vs V3+ (a.p.f.u). c. Ternary diagram of Al2O3 – ∑/REE - V2O3 (ppm). d. Probability plot of F - (a.p.f.u.). Dashed lines separate medium (1.0-1.5) and very low (<1.0) Fe/Al ratios. a.p.f.u. = atoms per formula unit. D.L = detection limit. In addition, REE patterns and trace element (Y, Ta and Nb) contents in colourless grains confirm a close chemical similarity with MAG titanite from bedrocks, characterized by LREE 1 31 enrichment, strong negative Eu anomalies (Figure 6.10a) and high ∑ REE (> 10,000 ppm), Y (> 2000 ppm) and Nb (> 700 ppm) contents (Figure 6.10b-c). Lastly, blond grains show a close chemical resemblance with ALT/SEC titanite from bedrocks. Figure 6.10. REE patterns and trace element content in detrital titanite in tills from Mount Polley. a. REE patterns normalized to chondrite after Sun and McDonough, 1995. b. Yttrium (Y) concentration (ppm). b. Niobium (Nb) concentration (ppm). d. Tantalum (Ta) concentration (ppm). 1 32 6.2.2. Distribution and relative abundance of heavy mineral concentrates (HMC) 6.2.2.1. Titanite Detrital titanite at Mount Milligan Detrital titanites were recovered in 13 till samples of 10-15 kg each, overlying and proximal (< 3 km) down ice of the Mount Milligan deposit. Till samples (n=3) with the highest amounts of titanite (139 - 3451grains) correspond to basal till from the northern margins of the MBX Zone (Figure 6.11a). The remaining (n=10) till samples contain only traces (< 20 grains) of titanite and correspond to surficial till located 1 to 2 km down ice of the SS Zone (Figure 6.11a). The estimated ratio between colourless and coloured specimens indicates that 60% of total recovered grains are blond, 40% are caramel brown, whereas colourless grains are absent or rare. Moreover, basal till from the northern margin of the MBX Zone contain 36% to 100% of blond grains and 0% to 64% of caramel brown specimens (Figure 6.11b). Most grains contained in more distal (1-2 km down ice) till samples are blond, with only one sample (MT-17) containing caramel brown specimens. Finally, titanite was not reported in till samples (n=3) located up ice and/or more than 2 km distal down ice from the Mount Milligan deposit. Additional basal till samples are required in order to fully establish the titanite footprint of mineralization down ice. 1 33 Figure 6.11. Detrital titanite deposit-scale footprint in tills at Mount Milligan. a. Titanite distribution and relative abundance. b. Relative proportions of titanite as function of colour. 1 34 Detrital Titanite at Mount Polley The majority (3/4) of till samples overlying and proximal (1 – 4 km) of the Mount Polley deposit contain only traces (< 20 grains / 10-15 kg) of titanite. Till sample PT1 contains the highest amount of titanite (n=123 grains) and corresponds to basal till from the west margin of Wight Pit at the North East Zone of the Mount Polley Intrusive Complex. In addition, till sample PT2 located in the same area is the only sample that reported blond titanite specimens. The rest of till samples only contain traces of colourless grains (Figure 6.12a). Thus, additional till samples are required in order to correctly estimate the footprint extension and relative abundance of blond grains interpreted as ALT/SEC titanite derivate from the deposit. 1 35 Figure 6.12. Detrital titanite deposit-scale footprint in tills at Mount Polley. a. Titanite distribution and relative abundance. b. Relative proportions of titanite as function of colour. 1 36 6.2.2.2. Distribution and relative abundance of other PIMs Mount Milligan Distribution and relative abundance of other PIMs (i.e. chalcopyrite, gold, garnet and epidote) reveal that chalcopyrite (Figure 6.13a) and gold grains (Figure 6.13b) share a similar footprint to that of titanite (Figure 6.11a), which restricts to less than 1 km down ice from the Mount Milligan deposit. In addition, chalcopyrite and gold grains are interpreted to best represent bedrock mineralization from the deposit. High amounts of chalcopyrite (up to 100 grains/10-15 kg) are concentrated at the east margin of the 66 Zone (Figure 6.13a), whereas high amounts of gold grains (up to 290 grains/10-15 kg) are concentrated in the northern margin of the MBX Zone (Figure 6.13b). Garnet relative abundance and distribution mimics that of gold grains, with high amounts (up to 200 grains/10-15 kg) also located at northern margins of the MBX Zone (Figure 6.14a). Till samples (n=2) located 0.5 to 1.5 km up ice west of the deposit contain anomalous amounts of garnet (up to 1000 grains/10-15 kg) and are considered to be unrelated to the deposit given their location (up ice) and hosting material (glaciofluvial sediments). Lastly, traces (< 5 grains/10-15 kg) of epidote were detected mostly up ice from the deposit (Figure 6.14b), which were likely transported by glaciofluvial sediments. Other PIMs such as apatite and rutile were not detected and/or examined. 1 37 Figure 6.13. Chalcopyrite and gold grain deposit-scale footprints in tills at Mount Milligan. a. Chalcopyrite distribution and relative abundance. b. Gold grain distribution and relative abundance. 1 38 Figure 6.14. Garnet and epidote deposit-scale footprints in tills at Mount Milligan. a. Garnet distribution and relative abundance. b. Epidote distribution and relative abundance. 1 39 Mount Polley Data from Hashmi (2015) complement the dataset presented in this thesis in order to get a better interpretation of the distribution and relative abundance of various PIMs (i.e. chalcopyrite, gold, garnet and epidote). Chalcopyrite footprint and abundance (Figure 6.15a) mimics that of detrital titanite (Figure 6.12a), with amounts up 49 grains/10-15 kg in basal till samples from the west margin of the Wight Pit at the North East Zone, and absence in till samples located up ice from the deposit. Gold grains (Figure 6.15b) and garnet (6.16a) have a similar footprint, with high amounts (73 gold grains/10-15 kg and 20,000 garnet grains/10-15 kg) in till samples located 1 km down ice from the Central Zone, trace amounts (< 10 grains/10-15 kg) in till samples located up ice from the deposit. Lastly, the epidote footprint (Figure 6.16b) is similar to that from Mount Milligan and is also interpreted to be unrelated to the deposit because of its chaotic distribution (i.e. higher amounts of grains in till up ice), which does not match that of more indicative PIMs, such as chalcopyrite. Other PIMs such as apatite and rutile were not detected and/or examined. 1 40 Figure 6.15. Chalcopyrite and gold grain deposit-scale footprints in tills at Mount Polley. a. Chalcopyrite distribution and relative abundance. b. Gold grain distribution and relative abundance.1 41 Figure 6.16. Garnet and epidote deposit-scale footprints in tills at Mount Polley. a. Garnet distribution and relative abundance. b. Epidote distribution and relative abundance. 1 42 6.3. Till geochemistry at Mount Milligan Geochemical analyses of the fine sand (< 0.25 mm) and very fine sand (< 0.074 mm) fractions of till sediments overlying/proximal to the Mount Milligan deposit were performed to detect Cu and Au metal anomalies and validate their significance relative the previously described titanite and PIMs footprints. Thus, historical data of surficial geology (Kerr, 1991), ice flow direction (Ferbey et al., 2013) and till geochemistry of the silt + clay (< 0.063mm) fraction (Sibbick et al., 1996) were integrated in order to detect potential metal dispersal trends. Metal (i.e. Cu, Au, Sb, As, and V) anomalies were defined over background values (i.e. median of metal concentration) obtained from a regional till survey ( Lett, 2008) including over 5000 till samples. Metal anomalies are presented in deposit and regional scale surficial geological maps and showing ice flow direction and filtered background values. All till geochemical data obtained for this research is included in Appendix E. 6.3.1. Results 6.3.1.1. Deposit scale metal dispersion Metal dispersion vs titanite footprint and chemistry Results show that vanadium (V) anomalies in the till fine fraction (Figure 6.17a) mimic those of V concentrations in detrital titanite (Figure 6.17b). Moreover, the V concentration in titanite is higher (V= 700 – 800 ppm) to that of the till fine fraction (V= 75 - 270 ppm). Lastly, the fact that V and Au (Figure 6.18b) share a similar dispersion suggests that the V-enrichment in titanite may serve as a path finder for Au-mineralization. 1 43 Figure 6.17. Deposit-scale vanadium (V) anomalies in the till fine fraction relative to the V content in titanite from Mount Milligan. a. Vanadium (V) anomalies (ppm). b. Vanadium (V) concentration (ppm) in titanite. Background values are not shown. 1 44 Metals dispersion vs PIMs footprint Analysed metals (i.e. Cu, Au, As, Sb, V, and Zn) demonstrated to be best concentrated in the silt + clay (< 0.063mm) fraction relative to the very fine sand (< 0.074mm) fraction of till sediments from Mount Milligan. The fine sand fraction (< 0.25mm) showed metal concentrations 10 times lower than those of the silt + clay fraction and is therefore dismissed for this interpretation. These observations agree with McClenaghan et al. (2014), which stated that metal anomalies are best traced within the silt + clay fraction of till sediments. Results show that copper (Cu) anomalies at deposit scale (Figure 6.18a) correlates the garnet footprint (Figure 6.14a), showing high concentrations (Cu = 500 - 700 ppm) less than 1 km down ice to the eastern margin of the MBX and 66 Zones. Gold (Au) anomalies (Figure 6.18b) are also higher (Au = 100 – 300 ppb) down ice to the eastern margin of the 66 Zone, but do not correlated to the gold grain footprint that shows higher amounts (200 - 300 grains/10-15 kg) to the northern margin of the MBX Zone (Figure 6.13b). Lastly, Cu anomalies correlate with those of antimony (Sb) and arsenic (As) (Figure 6.19a-b), whereas Au anomalies correlate best with that of vanadium (V) (Figure 6.17a). 1 45 Figure 6.18. Deposit-scale copper (Cu) and gold (Au) anomalies in the till fine fraction at Mount Milligan. a. Copper (Cu) anomalies (ppm). b. Gold (Au) anomalies (ppm). Background values are not shown. 1 46 Figure 6.19. Deposit-scale antimony (Sb) and arsenic (As) anomalies in the till fine fraction at Mount Milligan. a. Antimony (Sb) anomalies (ppm). b. Arsenic anomalies (ppm). Background values are not shown. 1 47 6.3.1.2. Regional scale metal dispersion Two metal dispersion trends are interpreted at regional scale (> 1:50.000) surrounding the Mount Milligan deposit based on the interpretation of historical a till geochemistry survey by Sibbick et al. (1996). A main copper (Cu) and gold (Au) trend lies at central latitudes of the study area, moving to the east of the deposit down ice (Figure 6.20 to 6.22). The trend is defined from Cu anomalies (up to 1026 – 2182 ppm) and Au anomalies (343-732 ppb) in till overlying and proximal to the east margin of the Mount Milligan deposit, moving 10 km east down ice through an area without anomalies ( non-sampled glaciofluvial sediments from the Rainbow Creek outwash complex), into a morrainal till blanket with anomalies of Cu (200 - 400 ppm) and Au (120 - 343 ppb) (Figure 6.20a-b). This Cu-Au trend is best represented by antimony (Sb) and arsenic (As) anomalies (Figure 6.21a-b). Another trend is interpreted from Au anomalies of 343 to 732 ppb overlying and proximal to the east margin of the Mount Milligan deposit, moving 15 km northwest down ice, into a morrainal till blanket with Au anomalies of 120 to 343 ppb (Figure 6.20b). This trend is best represented by vanadium (V) anomalies (Figure 6.22). Lastly, zinc (Zn) did not represent the trends above mentioned and is therefore not discussed. 1 48 Figure 6.20. Regional scale Copper (Cu) and gold (Au) anomalies in till at Mount Milligan. a. Copper (Cu) anomalies (ppm). b. Gold (Au) anomalies (ppm). 1 49 Figure 6.21. Regional scale antimony (Sb) and arsenic (As) anomalies in till at Mount Milligan. a. Antimony (Sb) anomalies (ppm). b. Arsenic (As) anomalies (ppm). 1 50 Figure 6.22. Regional scale vanadium (V) anomalies (ppm) in till at Mount Milligan. 6.4. Summary Detrital titanite in till sediments The titanite footprint demonstrates to extend less than 3 km down ice from the at Mount Milligan and Mount Polley deposits. The majority of recovered grains in tills from Mount Milligan are blond and considered to be ALT/SEC titanite derivate from the deposit. In addition, 1 51 a fourth type of titanite with caramel brown colour and metamictic origin was also identified and interpreted to be allochthonous to the Mount Milligan deposit. In fact, metamictic (MET) titanite has siJniIicantl\ KiJKer ∑ REE (0000 - 20,000 ppm) and Y (2000 - 5000 ppm), Ta (100 – 400 ppm), Nb (1000 – 3500 ppm) and Th/U (4 to 6.5) contents than specimens from bedrocks (see Chapter 5), suggesting that MET grains are likely originated from a different magmatic source, not from the Mount Milligan porphyry related suites. On the other hand, blond grains share similar chemistry than those ALT/SEC specimens from bedrocks, characterized by low (< 1.2) Fe/Al ratios and low ∑ REE (< 5000 ppm). This suggests that blond grains are related to hydrothermal alteration of the Mount Milligan deposit. Lastly, most titanite grains recovered from till sediments overlying and less than 4 km to the Mount Polley deposit are in trace amounts (< 20 grains/10-15 kg) and considered as MAG titanite due to their chemistry and colourless feature. Blond grains are rare and were only identified in one till sample at the eastern margin of the North East Zone. PIMs distribution The footprint and relative abundance of titanite and various PIMs (i.e., garnet, epidote, chalcopyrite and gold grains) in till sediments from Mount Milligan and Mount Polley deposits revealed that, 1) Chalcopyrite and gold grains best represent the footprint of bedrock mineralization at a deposit scale (< 1 km down ice from both deposits), 2) The footprint and abundance of blond titanite at Mount Milligan mimics that of chalcopyrite and 3) Gold grains and garnet share a similar deposit scale footprint in till sediments from both deposits. 1 52 Till Geochemistry (Mount Milligan) Analyzed metal (i.e. Cu, Au, As, Sb, V, and Zn) contents prove to be best concentrated in the silt + clay fraction of till sediments at Mount Milligan. At deposit scale, copper (Cu) anomalies are best represented by antimony (Sb) and arsenic (As) anomalies, and also by the garnet footprint. Gold (Au) anomalies correlate with those of vanadium (V) and with the V concentration in titanite. Moreover, the fact that V best concentrates in titanite grains (V = 700-800 ppm) relative to the till fine fraction (V= 75- 300 ppm) suggests that titanite could be used as a path finder for Au-mineralization. Finally, metal anomalies at regional scale depict the existence of 1) a main Cu-Au trend that is best traced by arsenic (As) and antimony (Sb) anomalies, and 2) an Au trend that is best traced by vanadium (V) anomalies. 1 53 Chapter 7 Discussion and Conclusions 7.1. Discussion The identification of a more direct link between detrital components in sediments and source rock can potentially be used as exploration tool in covered terrains. Thus, resistate minerals generated or modified during hydrothermal alteration and ore forming processes can be used as pathfinders to vector towards ore deposits covered by glacial or fluvial sediments. The common occurrence (4%), high specific gravity (> 3.2 g/cm2) and sufficient grain size (> 0.1 mm) of titanite in alkalic porphyry Cu-Au deposits, combined with its ability to record a large variety of petrogenetic information, both by its chemistry and mineralogical properties, makes this mineral a useful PIMs for exploration in covered terrains. Titanite hosted in rocks from studied alkalic Cu-Au porphyry deposits has 3 to 4% modal abundance, where approximately in average two thirds consist of SEC and ALT titanites formed or modified as a result of hydrothermal alteration of mafic minerals such as augite, biotite and magnetite, and one third is considered MAG titanite as it crystallizes from fractionating alkalic melts as discrete euhedral, colorless crystals in the groundmass of diorites to monzonites. Host rocks geochemical affinity play an important role in controlling titanite modal abundance. Thus, alkalic melts are particularly Fe-Ti–rich (Francis, 2013; Winter, 2001) and capable of generating abundant mafic silicates (i.e., augite 10-20%) can be partly replaced by titanite during alteration (i.e., SEC titanite). In addition, higher contents of Ti (TiO2 > 1.2 wt.%), particularly at early stages of alkalic melts fractionation, in conjunction with relatively low fO2 and considerable silica (SiO2 ≈ 45%), promote crystallization of mafic silicates over oxides (Francis, 2013). Thus, 1 54 titanite prevails as primary Ti-bearing mineral phase (i.e., MAG titanite) over other common Ti-bearing minerals such as rutile, which crystallize under more oxidizing conditions (Morad et al., 2009). On the other hand, increasing Si contents (SiO2 > 50 wt.%) and lack of Fe and Ti enrichment during fractionation of calc-alkaline melts results in early crystallization of Fe-Ti oxides (i.e., magnetite/titanomagnetite, ilmenite), which deplete the residual melt in Fe and Ti (Winter, 2001) and therefore crystallization of titanite decreases. Moreover, the occurrence of secondary titanite and ilmenite after magmatic magnetite reflects a history of variations in temperature and fO2 conditions due to cooling and/or magma mixing processes (McLeod, 2007). The classification of titanite into defined types (i.e., MAG, SEC and ALT) constitutes a practical approach towards identifying those grains directly associated with hydrothermal alteration and mineralization of an alkalic porphyry system. Previous work by Che et al. (2013) has documented that magmatic titanite can reflect high concentrations of W and Mo in the source melt, suggesting a potential use for identifying intrusions fertile for W or Mo mineralization. More importantly, SEC and ALT titanites are originated from hydrothermal alteration of bedrocks and are therefore of particular interest in this study. Thus, identification of these different titanite types becomes critical while tracing hydrothermal alteration and mineralization from an alkalic deposit in covered terrains. Because there is no observable paragenesis in heavy mineral concentrates, ALT and SEC specimens must be considered as one type namely ALT/SEC, which can be distinguish from colourless euhedral MAG titanite by their cloudy blond to honey brown colour and subhedral to anhedral shapes, with curved edges and fine inclusions. Therefore, only ALT titanites constitute useful PIMs given their ability to record hydrothermal alteration and mineralization, both in terms of its physical and chemical properties. 1 55 Titanite is known to be stable in a wide variety of geological environments and therefore is likely to incorporate various elements into its structure, which are representative of the system where it crystallizes (Deer et al., 1982; Gromet & Silver, 1983; Green & Pearson, 1986; Paterson & Stephens, 1992; McLeod, 2007). Chemical characterization of the various titanite types based on EMP and LA-ICP-MS spot analyses revealed that variations in the Fe/Al ratios, V, F, REE and HFSE (Y, Ta, Nb, Th/U) contents are indicative of their origin and history of alteration. Thus, MAG titanite is characterized by intermediate (1-5) )e$l ratios loZ 9 and ) and KiJK REE (∑ REE = 5000-7000 ppm) and HFSE (Y, Nb, Ta, Th/U), with REE patterns of LREE convex upwards and strong negative Eu anomalies. This correlates with the fact that magmatic titanite serves as a “sink or trap” for REE and various HFSE (Y, Ta, Th, U, Nb, Zr, Hf) of petrogenetic significance (McLeod, 2007), where progressive depletion of these trace elements mirrors late- stage fractional crystallization of the melt (Prowatke & Klemme, 2005). Che et al. (2013) proposed that the Th/U ratio can potentially be used to distinguish magmatic from hydrothermal titanite, with the former having low Th/U (although, more details on melt and fluid compositions, degree of fractionation etc. are needed to test this hypothesis ( Che et al., 2013)). This hypothesis only agrees with analyzed titanites from Mount Polley, where MAG titanite shows average Th/U = 2.8 and ALT titanite shows Th/U = 0.5. Analyzed specimens from the rest of studied deposits show ALT titanite with higher average Th/U ratios over MAG specimens, probably due to the fact that a large portion of ALT specimens represent altered magmatic titanite (ALT-MAG, see Chapter 4, section 4.2.3.1.). Particularly, LREE enrichment represents titanite crystallization from LREE-rich residual magmatic fluids at late stage of intrusion consolidation (Exley, 1980), whereas negative Eu anomalies indicate existence of Eu as Eu3+ rather Eu2+, which does not incorporate into titanite (Pan and Fleet, 1993). On the other 1 56 Kand $/T and 6E& titanites are t\picall\ REE (∑ REE < 5000 ppm) and +)6E depleted and have absent to positive Eu anomalies, which reflect metasomatism infused by highly oxidizing fluids carrying Cu-mineralization interacting with buffering host rocks (Micko, 2010), where available Eu3+ gets reduced to Eu2+ and incorporates in the Ca-site of the titanite structure (Horie et al., 2008). Moreover, ALT and SEC titanite have either low (< 1.0) Fe/Al ratios when affected by sodic-calcic alteration, or high (> 1.0) Fe/Al ratios if affected by potassic alteration. These findings agree with Kowallis et al. (1997), who suggested that Al commonly substitutes the Ti-site of titanite, where available Al is likely leached from adjacent plagioclase during metasomatism at a microscale (Morad et al., 2009). On the other hand, an increase of Fe substituting the Ti-site typically under high fO2 conditions (Kowallis et al., 1997) during strong potassic alteration accompanied by significant Fe metasomatism. Vanadium (V) enrichment is characteristic of ALT titanite hosted in strongly altered and mineralized (chalcopyrite > 5%) rocks and increases particularly at crystal rims. The fact that V-contents are particularly high at crystal rims and that ALT titanite reflects interaction with highly oxidizing fluids responsible for Cu-mineralization (i.e. dissolved edges and cavities) suggests that these fluids might have also carried soluble V. This agrees with the fact that V is highly mobile during increasing fO2 conditions of calc-silicate alteration (Bernau and Franz, 1987), where it changes its oxidation state from V3+ to V5+ (Micko, 2010) and is therefore likely for incorporate into ALT titanite. Lastly, fluorine (F) enrichment is also common in ALT titanite and indicates magmatic fluids separating from a crystalizing melt during high T (> 350 C°) and/or high fO2 conditions (log fO2 > -25) (Bailey, 1977). Titanite has been previously suggested as potential porphyry indicator mineral in covered terrains (e.g., Averill, 2011). However, the footprint extension of blond ALT titanite grains 1 57 recovered from till sediments extends less than 3 km down ice from studied deposit centres and appears smaller than that of other PIMs such as garnet and epidote. Excess of garnet and epidote are interpreted to be allochthonous from studied porphyry system and likely derivate from other rock units within the region. These observations suggest that titanite would be more practical for tracing metal dispersion at a deposit scale (up to 1:25.000) rather than at regional scale (1:50.000 to 1:200.000). In addition, titanite abundance demonstrates to be higher (200 – 3000 grains / 10-15 kg of till) in proximal, Easal (§ 0 m) till sediments rather than in peripheral (1-3 km) surIicial (§  – 2 m) samples. This agrees with the recommended sampling media of basal till, which represents detrital first derived from bedrocks and therefore can be traced back to bedrock source relative to ice flow direction (Ferbey, pers. commun.). However, in order to correctly determine the footprint extension of titanite in surficial till sediments it is necessary to perform additional till surveys given the limited number of till samples collected for this research. The As, Sb and V anomalous concentrations in the silt + clay fraction of till sediments best correlate with dispersion of mobile metals such as Cu and metals with low background values such as Au, suggesting that As, Sb and V are useful pathfinders in terrains covered by glacial till. Nevertheless, only Sb and V have been reported as common substitutions in the Ti-site of titanite (see Chapter 1, section 1.3.2.) because of their similar atomic radius and electric charge to Ti (McLeod, 2007). Moreover, V content in detrital ALT titanite is significantly higher than that of the silt + clay fraction of till sediments. Therefore, V-rich ALT titanite could be used as a reliable pathfinder to trace Cu and Au in covered terrains. This interpretation is also supported by the fact that heavy mineral concentrates (HMC) typically have better detection and more revealing dispersion patterns for elements with low background values (e.g., PGEs, Ag, W and Au) (Maurice, 1991). In addition, these dispersal patterns can be interpreted almost entirely in 1 58 terms of clastic dispersal processes because HMC are clastic monominerals without hydromorphic component (Maurice, 1991). Finally, despite the fact that the Sb content in titanite was not analyzed during this study, its analysis is highly recommended in future studies given Sb well-known reputation as a pathfinder for Cu and Au and because of its ability to incorporate into the titanite structure. 7.2. Conclusions Titanite types in Alkalic Cu-Au Porphyry Deposits The majority of titanite (60%) hosted in alkalic porphyry deposits studied herein is considered to be secondary (SEC) because it formed or was modified as a result of hydrothermal alteration of mafic minerals such as augite, biotite and magnetite. The sodic-calcic (albite + epidote) alteration of augite-bearing monzonites to diorites produces selective augite replacement by actinolite, epidote and various amounts of titanite (3% to 4% modal abundance). To a lesser extent, potassic (K-feldspar) alteration of primary biotite and/or magnetite bearing monzonites also generates titanite crystallization (1-2%) from partial biotite and magnetite replacement by titanite. Subsequent overprinting of fluids forming chlorite + calcite alteration produces altered titanite as evidenced by gradual to complete replacement by rutile. Pervasive alteration accompanied by oxidizing fluids carrying Cu-mineralization is responsible for textural obliteration of the host rock, which translates in relict or skeletal texture of the titanite host (i.e., augite, biotite) and occurrence of strongly anhedral ALT specimens with multiple cavities and dissolved edges. The remaining (40%) of titanite in studied alkalic porphyry deposits is considered to have a magmatic origin (i.e. MAG titanite) as it crystallizes from melt fractionation in the form of discrete euhedral, colorless crystals (2-3%) in the groundmass of porphyritic 1 59 monzonites to diorites. Lastly, a fourth type named metamictic (MET) titanite occurs in till sediments overlying and peripheral to the Mount Milligan deposit and is interpreted to be unrelated to the porphyry system. More details regarding this titanite type is provided in the last of the sections below. Titanite physical properties Titanite Size, Shape and Texture Titanite hosted in bedrocks from studied alkalic deposits displays 0.1-0.3 mm average size, but can be up to 1 mm in specimens that have experienced regrowth or recrystallization during magmatic processes (i.e., MAG-RCX titanite, see chapter 4 section 4.2.1.1.). Moreover, blond subhedral ALT titanite grains recovered from till sediments are typically 0.2-0.4 mm, whereas caramel brown, euhedral MET grains are 0.3-0.5 mm. Titanite crystals are typically euhedral to subhedral with rhombic and/or wedge shaped crystal habits. Anhedral specimens (i.e., ALT and SEC titanites) are common in strongly altered host rocks. These grains exhibit curve-shaped dissolution features such as embayments and multiple cavities, which reflect a history of metasomatism. They differ from larger, more euhedral MAG-RCX grains, which typically exhibit serrated edges. Titanite texture is characterized by distinctive compositional zoning, consisting of alternate areas of lower and higher reflectancy observed under the SEM. Thus, a distinctive concentric compositional zoning is typical from MAG titanite, whereas sector or patchy compositional zoning is representative of ALT and SEC specimens. Moreover, strongly ALT titanite typically displays replacement textures of rutile ± calcite and/or fine inclusions (e.g., chalcopyrite, epidote). Finally, amorphous, high contrast zoning together with abundant microfractures are characteristic textural features of MET titanite. 1 60 Titanite Color The colour of titanite grains recovered from SELFRAG bedrocks ranges from colourless, to translucent blond, to dark honey brown. Colourless specimens account for approximately 1/3 of total recovered grains and represent MAG titanite lacking impurities such as Fe, Al, and U in their structure. The remaining grains range from translucent blond to dark honey brown colour and are interpreted as ALT / SEC titanites due to their higher Fe contents over colourless grains. Thus, the increasing Fe content is interpreted to be ultimately responsible for the blond and brown colouration. Lastly, a distinctive caramel brown colour is characteristic of MET titanite. The more euhedral habit of MET grains and lack of textural alteration features (see previous section) suggest that the caramel brown colour is a consequence of metamictization rather than alteration given the high susceptibility of titanite to radiation damage by alpha decay of U and Th impurities (Vance et al., 1985). To conclude, additional features of titanite grains, such as habit, texture (i.e., cavities, inclusions, microfractures) and type of compositional zoning (i.e., concentric, sector, patchy) need to be considered prior to the classification of titanite grains. Titanite chemical properties Chemical characterization on the basis of EMP and LA-ICP-MS spot analyses in various titanites hosted in least altered and strongly altered, mineralized host rocks from studied alkalic deposits confirms that variations in the Fe/Al ratios, V, F, REE and HFSE (Y, Ta, Nb, Th/U) contents are indicative of titanite origin and history of alteration. First, the Fe/Al ratio varies from intermediate (1.0-1.5) in MAG and MET specimens hosted in least altered rocks, to high (> 1.5) in ALT titanites hosted in potassic altered (K-feldspar + magnetite) rocks, to low (<1.0) in ALT 1 61 specimens hosted in sodic-calcic (albite + actinolite + epidote) altered rocks. Secondly, vanadium (V) enrichment is characteristic in ALT titanites hosted in strongly altered rocks with significant mineralization (chalcopyrite > 5%) and increases particularly at crystal rims. Fluorine enrichment is also representative in ALT titanites hosted in strongly altered rocks with significant mineralization (chalcopyrite > 5%) relative to specimens hosted in unmineralized host rocks. In decreasing order of magnitude, titanites from Mount Polley, Copper Mountain and Mount Milligan demonstrated to have REE concentrations 100-4000 times than that of chondrite, where different titanite types show distinctive REE patterns. MAG and MET titanites show LREE convex upwards and pronounced negative Eu anomalies, whereas ALT and SEC titanites hosted in strongly altered and mineralized (chalcopyrite > 5%) rocks show decreasing LREE and absent to strongly positive Eu anomalies. Finally, MET titanites have similar REE patterns but siJniIicantl\ KiJKer REE (∑ REE 0000 - 20,000 ppm) and trace element (Y= 2000 - 5000 ppm; Ta= 100 – 400 ppm; Nb= 1000 – 3500 ppm; Th/U= 4 to 6.5) concentrations than of MAG specimens, suggesting that these grains are allochthonous from the porphyry system and are likely originated from a different magmatic source. Titanite preservation and distribution in Till Sediments The footprint extension of preserved titanite grains in till sediments overlying/surrounding the Mount Milligan deposit is less than 3 km down ice of the deposit centre and is comparable to that of chalcopyrite and gold heavy mineral concentrates. Till samples (n=3) with the highest amounts of titanite (139 – 3451 grains / 15 kg) correspond to basal tills overlying northern margins of the deposit, whereas surficial till samples (n=10) located 1 - 2 km down ice from the deposit only contain traces of grains (< 20 grains / 15 kg). Physical examination of grains (n= 1 62 48) recovered from till samples (n=21) confirms that 60% correspond to blond ALT/SEC titanite, 40% correspond to caramel brown MET specimens, whereas colourless MAG specimens are rare or absent. Till samples overlying the deposit contain 36% to 100% of blond ALT/SEC grains and 0% to 64% of caramel brown MET specimens. More distal (1-2 km down ice) samples contain almost 100% blond ALT/SEC specimens, with only one sample (MT-17) containing 1/3 of caramel brown MET grains. The source of caramel brown titanite is not known but probably is related to an older rock unit occurring in the region given that metamictization by radiation damage occurs over considerable geologic time. In terms of detrital titanite chemistry relative to till geochemistry of the silt + clay fraction, vanadium (V) best concentrates in titanite (V= 700 – 800 ppm) relative to tills (V= 75 - 270 ppm). This observation combined with the fact that the V and Au dispersion correlate suggest that V-rich detrital titanite could be used as a path finder for Au-mineralization. Nevertheless, additional basal till samples are required in order to estimate the footprint extension of titanite and Au-mineralization down ice. Lastly, till samples (n=5) overlying and distal (2 - 4 km) up/down ice of the Mount Polley deposit revealed that most grains are colourless MAG specimens and only one till sample contains blond ALT/SEC titanite. Caramel brown MET grains were not identified. To summarize and conclude, magmatic (MAG) titanite is a common accessory mineral in alkalic intrusive rocks and occurs as zoned colorless grains. Metamictic (MET) titanite occurs as euhedral grains with significant radiation damage (i.e. microfractures, amorphous zoning) by alpha particles during U and Th decay. Secondary (SEC) titanite forms after magmatic magnetite, biotite or silicate phases such as augite during potassic or sodic-calcic alterations. Dark honey brown titanite with abundant cavities and rutile replacements occurs during 1 63 superimposing chlorite alteration. The main conclusions of this study are graphically shown below in Figure 7.1. Figure 7.1. Summary diagram of titanite in alkalic porphyry deposits. 7.3. Guidelines for use of titanite in exploration This research has contributed to validate the utility of titanite as PIMs for the exploration of alkalic Cu-Au porphyries in covered terrains. The main attempt of this research was to physically and chemically characterize titanite hosted in alkalic deposits in order to provide a new tool within the known suite of PIMs – i.e., apatite, garnet, epidote, magnetite, etc. Thus, analytical results of titanite grains recovered from till sediments overlying and proximal to the studied 1 64 deposits suggest a capability of this mineral to serve an indicator mineral to explore alkalic porphyry deposits in covered terrains. However, additional till surveys are required to support this statement. The following list of guidelines represents a practical approach towards the application of titanite as an indicator mineral for exploration of alkalic Cu-Au deposits in covered terrains. 1. Sampling: A preliminary understanding of the ice flow history within the explored region is required before hand in order to adequately sample and interpret detrital dispersion relative to the ice flow (Hashmi et al., 2015). Moreover, the recommended sampling spacing must be ideally 0.5 - 1 km and follow a fan-shape grid down ice further with respect of identified metal anomalies in the fine fraction of till sediments (Lehtonen et al., 2005). Lastly, a minimum of 10 to 20 till samples of 10 kg each must be collected in order to have a meaningful interpretation of detrital dispersal relative to the ice flow direction (Averill, 2001; McClenaghan & Kjarsgaard, 2007; Lehtonen et al., 2005; Ferbey, pers. commun.) 2. Sample Media: The adequate sampled media must consist of morrainal till, which is defined as a dense matrix-supported diamicton composed of very poorly sorted, angular to well-rounded pebbles to cobbles in a sand-silt-clay matrix. In addition, basal till (≈ 10 m deep) is the recommended sampling media given that it represents detritus first derived from bedrocks and can be traced back to bedrock source relative to ice flow direction (Ferbey, pers. commun.). However, surficial tills between 1 to 4m deep are also useful samples (Hashmi et al., 2015). 3. Sample Processing: The collected till samples must be dried and sieved in the 0.1-0.5mm, 0.5-1mm and 1-2mm size fractions using ASTM standard meshes. Subsequent heavy mineral concentration consists of: i) filtration of magnetic material, ii) recovery of dense minerals 1 65 (specific gravity > 3.2 g/cm2) using heavy liquids and iii) electromagnetic mineral separation into non-paramagnetic (> 1 A), weakly paramagnetic (0.8-1 A), moderately paramagnetic (0.6-0.8 A) and strongly paramagnetic (< 0.6 A) fractions. Lastly, titanite grains should preferentially be handpicked from the 0.1-0.5mm, > 3.2 g/cm2 and > 1 A fraction. 4. Binocular Study: Grain hand-picking should be done under binoculars with at least 10x magnification power and using very fine professional microscopy tweezers. Grains should be selected based on colour (colourless, blond and honey brown), shape (i.e., rhombic, lozenge shape) and texture (i.e. visible inclusions). Thus, a special attention should be put in blond and honey, subhedral to anhedral specimens, which represent ALT titanite. 5. Abundance: Modal abundancy of titanite grains within the 0.1-0.5mm, > 3.2 g/cm2 and > 1 A fraction can be estimated by multiplying the total weight (g) of this fraction by the estimate percentage of visible grains under binoculars and by a factor of 10,000 (i.e., estimated number of grains of 0.1 to 0.5 mm present in 1 g of sampled material). Special emphasis should be put in estimating the ratio of MAG colourless grains relative to ALT/SEC blond, honey brown grains. Thus, a higher proportion of ALT over MAG grains would indicate proximity to a mineralized porphyry system. 6. Chemical Characterization: Selected titanite grains should then be verified under SEM using EDS, in order to disregard erroneous picked grains (i.e. non titanite grains). The verified titanite grains must then be mounted into epoxy pucks for chemical analysis of major (Ca, Ti, Si, Al, Fe, V, F, O, OH) and trace element (REE, HFSE, Sb) contents using EMPA and LA-ICP-MS respectively. Recommended EMPA instrument settings are 15 kV excitation voltage, 20 nA Eeam current and  ȝm diameter Eeam Recommend /$-ICP-MS settings are 10 J/cm2 energy 1 66 fume, 5 Hz repetition rate and 24 µm diameter beam. Each titanite type has a distinctive chemistry, which reflects alteration and mineralization effects of the host rock. MAG titanite has intermediate (1-5) )e$l ratios loZ 9 and ) and KiJK REE (∑ REE 5000-7000 ppm) and HFSE (Y, Nb, Ta, Th/U), with REE patterns of LREE convex upwards and strong negative Eu anomalies. MET titanite has a similar chemical signature than MAG titanite, but shows even higher concentrations of REE and HFSE (Y, Nb, Ta, Th/U). ALT and SEC types have either low (< 1.0) Fe/Al ratios if affected by sodic-calcic alteration or high (> 1.5) Fe/Al ratios if affected E\ potassic alteration ,n addition tKe\ are REE (∑ REE < 5000 ppm) and +)6E depleted and show F and V enrichment when hosted in mineralized (chalcopyrite > 5%) altered rocks. 1 67 References Averill S.A., 2001: The application of heavy indicator mineralogy in mineral exploration with emphasis on base metal indicators in glaciated metamorphic and plutonic terrains: In: McClenaghan, M.B., Bobrowsky P.T., Hall, G.E.M. & Cook, S.J. (eds) Drift Exploration in Glaciated Terrains. Geological Society, London, Special Publications, Vol. 185, pp. 69–81. 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Location Lithology Intensity Alteration Min.P-1 Mt. Polley 5823413 591588 1024 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 4%P-2 Mt. Polley 5823413 591588 1024 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 4%P-3 Mt. Polley 5823621 591675 1024 Central Zone, Springer PitAugite-biotite diorite (PD1) with equigranular texturestrongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veinsP-4 Mt. Polley 5823781 591489 1003 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivecalc-potassic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 4%P-5 Mt. Polley 5823781 591489 1003 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivecalc-potassic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 4%P-6 Mt. Polley 5825240 592860 921 North East Zone, Wight PitK-feldspar-phyric monzonite porphyry (Pkm-c)moderatepotassic alteration characterized by a K-feldspar + biotite + magnetite P-7 Mt. Polley 5825236 592827 912 North East Zone, Wight PitK-feldspar-phyric monzonite porphyry (Pkm-f)strongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veinsP-8 Mt. Polley 5825307 592742 917 North East Zone, Wight PitK-feldspar-phyric monzonite porphyry (Pkm-c)strongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veinsP-9 Mt. Polley 5825370 592677 910 North East Zone, Wight Pit Fragmental Breccia (FBx) pervasivecalc-potassic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 4%P-10 Mt. Polley 5822071 592687 890 South ZoneAugite-bearing monzonite (PMdu) with equigranular texture weakpotassic-propylitic zone characterized by albite + epidote + pyriteP-11 Mt. Polley 5825506 584459 948 Northwest of Central ZoneK-feldspar-bearing diorite (PMdu) with porphyritic texture weakpotassic-propylitic zone characterized by albite + epidote + pyriteP-12 Mt. Polley 5825173 590993 1052 Northwest of Central ZoneK-feldspar-bearing diorite (PMdu) with porphyritic texture weakpotassic-propylitic zone characterized by albite + epidote + pyritePTB045* Mt. Polley 5822150 593585 1049 South ZoneK-feldspar-bearing diorite (PMdu) with porphyritic texture weakpotassic-propylitic zone characterized by albite + epidote SD0981_92.3m Mt. Polley 5823324 591717 1140 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 4%1 80 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.SD0981_109.5m Mt. Polley 5823324 591717 1140 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + magnetite + albite + epidote ± calcite veins ccp 4%SD0981_236m Mt. Polley 5823324 591717 1140 Springer PitK-feldspar-phyric monzonite porphyry (Pkm-f)pervasivepotassic-sodic alteration characterized by a K-feldspar + magnetite + albite + epidote ± calcite veinsSD0981_463m Mt. Polley 5823324 591717 1140 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 5%SD0981_818m Mt. Polley 5823324 591717 1140 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 5%SD12132_29m Mt. Polley 5823639 591612 1207 Central Zone, Springer PitK-feldspar-phyric monzonite porphyry (PMdu)strongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veinsSD12132_43m Mt. Polley 5823639 591612 1207 Central Zone, Springer PitK-feldspar-phyric monzonite porphyry (PMdu)strongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veinsSD12132_91m Mt. Polley 5823639 591612 1207 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ccp 7%SD12132_309m Mt. Polley 5823639 591612 1207 Central Zone, Springer Pit Fragmental Breccia (FBx) pervasivecalc-sodic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 5%PM1113_220m Mt. Polley 5823896 592694 1190 East of Central ZoneK-feldspar-bearing diorite (PMdu) with porphyritic texture moderatepotassic-propylitic alteration characterized by a K-feldspar + magnetite + albite + epidote ± calcite veins±pyritePM1113_265m Mt. Polley 5823896 592694 1190 East of Central ZoneK-feldspar-bearing diorite (PMdu) with porphyritic texture moderatepotassic-propylitic alteration characterized by a K-feldspar + magnetite + albite + epidote ± calcite veins±pyriteWB04102_42.5m Mt. Polley 5825526 592581 986 North East Zone, Wight PitK-feldspar-phyric monzonite porphyry (PMdu)strongpotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ± pyrite ccp 4%WB04102_237m Mt. Polley 5825526 592581 986 North East Zone, Wight PitK-feldspar-phyric monzonite porphyry (PMdu)strongcalc-potassic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 6%WB04109_135.5m Mt. Polley 5825443 592529 1000 North East Zone, Wight Pit Fragmental Breccia (FBx) pervasivepotassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite veins ± pyrite ccp 4%WB04109_269m Mt. Polley 5825443 592529 1000 North East Zone, Wight Pit Fragmental Breccia (FBx) pervasivecalc-potassic-sodic alteration characterized by a K-feldspar + biotite + magnetite + albite + epidote ± calcite i ccp 10%1 81 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.WB06230_882m Mt. Polley 5825422 592802 964 Wight Pit, NE Zone Fragmental Breccia (FBx) pervasivecalc-potassic alteration characterized by a K-feldspar + albite + andradite garnet + epidote ± calcite veins ccp 6% ± bn (1%)06938_92.6m Mt. Milligan 6109468 434124 1137 WBX Zone Quartz monzonite (MBX Stock) with porphyritic texturestrongpotassic alteration (k-feldspar + biotite + magnetite) overprinted by sericitic alteration (sericite ± epidote ± chlorite ± l i ) ccp 6% ± bn (1%)06938_192.6m Mt. Milligan 6109468 434124 1137 WBX Zone Monzonite (MBX Stock) with porphyritic texture strongpotassic alteration (k-feldspar + biotite + magnetite) overprinted by sericitic alteration (sericite ± epidote ± chlorite ± 06938_303m Mt. Milligan 6109468 434124 1137 WBX Zone Monzonite (MBX Stock) with porphyritic texture strongpotassic alteration (k-feldspar + biotite + magnetite) overprinted by sericitic alteration (sericite ± epidote ± chlorite ± 06946_64.8m Mt. Milligan 6108269 434086 1178 SS Zone Monzonite (SS Stock) with porphyritic texture moderatesodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i )06946_154.7m Mt. Milligan 6108269 434086 1178 SS Zone Monzonite (SS Stock) with porphyritic texture moderatesodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± 06948_63.4m Mt. Milligan 6108572 434114 1161 SS Zone Monzonite (SS Stock) with porphyritic texture weaksodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± 06961_157m Mt. Milligan 6109277 434737 1111 MBX Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i )06957_100m Mt. Milligan 6109277 434737 1111 SS Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± 06957_217.7m Mt. Milligan 6108494 433945 1184 SS Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± ccp (4%)07992_47m Mt. Milligan 6109035 434799 1077 66 Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i )07992_81.5m Mt. Milligan 6109035 434799 1077 66 Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± 111015_18.2m Mt. Milligan 6109468 433978 1150 DWBX Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± 111015_238.5m Mt. Milligan 6109468 433978 1150 DWBX Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i ) ccp (5%)1 8 2 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.111015_270.3m Mt. Milligan 6109468 433978 1150 DWBX Zone Lower Trachyte (Witch Lake Succesion - Takla Group)strongsodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i )111015_286.1m Mt. Milligan 6109468 433978 1150 DWBX Zone Monzonite (MBX Stock) with megracrystic porphyritic texturestrongpotassic alteration (k-feldspar + biotite + magnetite) overprinted by sericitic alteration (sericite ± epidote ± chlorite ± 111016_505m Mt. Milligan 6109320 433853 1151 DWBX Zone Lower Trachyte (Witch Lake Succesion - Takla Group)weaksodic-calcic (albite + actinolite ± chlorite ± pyrite) overprinted by propylitic (epidote + albite + calcite + actinolite ± hl i )Milligan_1 Mt. Milligan 6109039 434929 1074 66 ZoneLower Trachyte (Witch Lake Succesion - Takla Group)strongpropylitic alteration (epidote + albite + calcite + actinolite) Milligan_2 Mt. Milligan 6101784 434254 1126 Surroundings Basaltic trachyandesite with porphyritic texture moderatepropylitic alteration (epidote + chlorite + calcite + actinolite ± pyrite) Milligan_3 Mt. Milligan 6094872 433125 1209 Surroundings Basaltic trachyandesite with porphyritic texture moderatepropylitic alteration (epidote + chlorite + calcite + actinolite ± pyrite) Milligan_4 Mt. Milligan 6095035 434327 1237 Surroundings Basaltic trachyandesite with porphyritic texture moderatepropylitic alteration (epidote + chlorite + calcite + actinolite ± pyrite) MTM91-1074* Mt. Milligan Heidi Lake ZoneMonzonite (Heidi Lake Stock) with porphyritic texturemoderatesodic-calcic alteration (albite + actinolite + titanite) overprinted by sericite alteration (sericite ± epidote ± chlorite ± CMT-1 Copper Mt. 5468232 680840 1100 Virginia Pit Nicola Group Volcanics strongpotassic alteration (K-feldspar) overprinted by propylitic (chlorite + epidote + calcite veins + pyrite) ccp (3%)CMT-2 Copper Mt. 5468232 680840 1100 Virginia Pit Nicola Group Volcanics strongpotassic alteration (K-feldspar) overprinted by propylitic (chlorite + epidote + calcite veins + pyrite) ccp (4%)CMT-3 Copper Mt. 5468232 680840 1100 Virginia Pit Monzonite (LHIC, LH2) with equigranular texture strongpotassic alteration (K-feldspar) overprinted by propylitic (chlorite + epidote + calcite veins + pyrite) ccp (4%)CMT-4 Copper Mt. 5467705 679511 1162 Pit 1 Monzonite (LHIC, LH2) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) ccp (4%)CMT-5 Copper Mt. 5468282 680081 1163 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + i )CMT-6 Copper Mt. 5467578 679571 1168 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + ccp 3% CMT-7 Copper Mt. 5467578 679571 1168 Pit 2 Syenite (LHIC, LH2) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + i )ccp 4% CMT-8 Copper Mt. 5467578 679571 1168 Pit 2 Monzonite (LHIC, LH2) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + ccp 5% 1 83 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.CMT-9 Copper Mt. 5466695 679400 1175 Pit 3 Diorite (CMS) with equigranular texture weaksodic-calcic alteration (albite + actinolite + titanite) overprinted by propylitic alteration (epidote ± chlorite ± calcite)CMT-10 Copper Mt. 5467003 679459 1183 Between Pit 1 and Pit 3 Nicola Group Volcanics moderatesodic-calcic alteration (albite + actinolite + titanite) CMT-11 Copper Mt. 5467159 679585 1209 Pit 1 Nicola Group Volcanics moderatesodic-calcic alteration (albite + actinolite + titanite) CMT-12 Copper Mt. 5466845 680058 1187 Pit 3 Nicola Group Volcanics moderatesodic-calcic alteration (albite + actinolite + titanite) CMT-13 Copper Mt. 5468302 681500 1034 Voight Stock Diorite (Voight Stock) with equigranular texture weakLeast altered - potassic alteration (K-feldspar ± biotite ± magnetite)CMT-14 Copper Mt. 5469730 677490 943 Voight Stock Diorite (Voight Stock) with equigranular texture weakLeast altered - potassic alteration (K-feldspar ± biotite ± magnetite)Bottom Pit 1 Copper Mt. 5467170 679150 1000 Pit 1 Nicola Group Volcanics strongsodic-calcic alteration (albite + actinolite + titanite) Oriole3 Copper Mt. 5465883 680622 1400 1km from Pit3 Nicola Group Volcanics weaksodic-calcic alteration (albite + actinolite + titanite) overprinted by propylitic alteration (epidote ± chlorite ± calcite)CM14-15* Copper Mt. Virginia Pit Monzonite (LHIC, LH2) with porphyritic texture strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + i ) ccp (3%)CM12AB3_68m Copper Mt. 5468743 679802 1229 Alabama PitMonzonite (LHIC, LH2) with porphyritic texture partially obliterated strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + CM12AB10_31.5m Copper Mt. 5468641 679827 1236 Alabama Pit Monzonite (LHIC, LH2) with porphyritic texture moderatepotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + i ) ccp (4%)CM12AB10_104m Copper Mt. Alabama Pit Diorite (LHIC, LH1) with equigranular texture moderatepotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + i ) ccp (6%)CM12AB12_19m Copper Mt. 5468600 679960 1242 Alabama Pit Diorite (LHIC, LH1) with equigranular texture strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + CM12AB12_65.5m Copper Mt. 5468600 679960 1242 Alabama Pit Diorite (LHIC, LH1) with equigranular texture strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + i ) ccp (8%)CM12AB12_92m Copper Mt. 5468600 679960 1242 Alabama Pit Monzonite (LHIC, LH2) with porphyritic texture moderatepotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + ccp (3%)CMAB015_13.4m* Copper Mt. Alabama Pit Monzonite (LHIC, LH2) with porphyritic texture strongpotassic alteration (K-feldspar + biotite + magnetite) overprinted by propylitic (chlorite + epidote + calcite veins + 1 84 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.CM12P219_181.5mCopper Mt. 5467810.05 679783 1196 Pit 2 Monzonite (LHIC, LH2) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P219_219m Copper Mt. 5467810.05 679783 1196 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P219_350.5mCopper Mt. 5467810.05 679783 1196 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P219_352.5mCopper Mt. 5467810.05 679783 1196 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P219_415.5mCopper Mt. 5467810.05 679783 1196 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P219_607m Copper Mt. 5467810.05 679783 1196 Pit 2 Diorite (LHIC, LH1) with equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite)CM12P221_45m Copper Mt. 5467839 679745 1193 Pit 2 Monzonite (LHIC, LH2) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (3%)CM12P221_65.5m Copper Mt. 5467839 679745 1193 Pit 2 Diorite (LHIC, LH1) with equigranular texture partially obliterated moderatesodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)CM12P221_73m Copper Mt. 5467839 679745 1193 Pit 2 Diorite (LHIC, LH1) with equigranular texture entirely obliterated strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (5%)CM12P221_84.5m Copper Mt. 5467839 679745 1193 Pit 2 Diorite (LHIC, LH1) with equigranular texture partially obliterated strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)CM12P221_125.5mCopper Mt. 5467839 679745 1193 Pit 2 Syenite (LHIC, LH2) with equigranular texture entirely obliterated strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (4%)CM12P221_144.5mCopper Mt. 5467839 679745 1193 Pit 2 Diorite (LHIC, LH1) equigranular texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)CM12P221_241m Copper Mt. 5467839 679745 1193 Pit 2 Syenite with porphyritic texture (LHIC, LH2) strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (5%)CM12P221_413m Copper Mt. 5467839 679745 1193 Pit 2 Syenite (LHIC, LH2) with porphyritic texture entirely obliterated strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)1 85 Sample Deposit UTM N UTM E ELEV. Location Lithology Intensity Alteration Min.CM12P223_136m Copper Mt. 5467739 679869 1205 Pit 2 Diorite (LHIC, LH1) with equigranular texture moderatesodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)CM12P223_179.5mCopper Mt. 5467739 679869 1205 Pit 2 Monzonite (LHIC, LH2) with porphyritic texture partially obliterated strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (5%)CM12P223_352m Copper Mt. 5467739 679869 1205 Pit 2 Diorite (LHIC, LH1) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite) ccp (7%)CM12P223_504m Copper Mt. 5467739 679869 1205 Pit 2 Diorite (LHIC, LH1) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)CM12P223_505m Copper Mt. 5467739 679869 1205 Pit 2 Diorite (LHIC, LH1) with porphyritic texture strongsodic-calcic alteration (albite + epidote + actinolite + titanite) overprinted by potassic alteration (K-feldspar + biotite + magnetite)1 86 A2. Petrographic Data 1 87 Sample: PTB045 Lithology: Augite-bearing monzonite (PMdu) District: Mount Polley Igneous Complex (MPIC) Location: South East Zone UTME or Longitude: 593585 UTMN or Latitude: 5822150 Elevation: 1049 m.a.s.l. Summary Augite-bearing monzonite (PMdu) with porphyritic texture. K-feldspar (30%) as groundmass, plagioclase (45%), augite (8%) and magnetite (< 5%). Plates a-b. Weak potassic (K-feldspar) alteration overprinted by propylitic (epidote + albite) alteration and subsequent sericite alteration. Titanite occurs as discrete subhedral, large, elongated crystals in the K-feldspar groundmass. Plates c-d. Plate 1. 1 88 Thin section description Mineral Occurrence Abundance % Ap altered crystals with cavities + inclusions, adjacent to mafic minerals 1 Aug relict phenocryst 11 Cal patches and veinlets in the groundmass 10 Ccp fine disseminated trz Kfs groundmass 30 Mag finely disseminated 5 Ab large tabular phenocrysts altered to sericite 40 Py fine disseminated trz Ttn discrete large elongated subhedral crystals 3 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 89 Sample: P-6 Lithology: K-feldspar-phyric monzonite porphyry (Pkm-c) District: Mount Polley Igneous Complex (MPIC) Location: North East Zone, Wight Pit UTME or Longitude: 592860 UTMN or Latitude: 5825240 Elevation: 921 m.a.s.l. Summary K-feldspar-phyric monzonite porphyry. K-feldspar megacrysts (22%), K-feldspar groundmass (30%), plagioclase phenocrysts (25%), biotite (12%) and magnetite (7%). Plates a-b. Moderate potassic (K-feldspar) alteration. Titanite occurs as discrete subhedral, large, elongated crystals in the K-feldspar groundmass. Plates c-d. Plate 2. 1 90 Thin section description Ttn subhedral to anhe dral cry st als replac ing Mag in Bnde rs 3 Mineral Occurrence Abundance % Ap altered crystals with c av it ies + inclusio ns adjace nt to mafic mine rals 1 Bt altered to Chl 12 Kfs megacrysts 22 Kfs groundmass 30 Mag finely disseminated in the Kfs gro undmas s. Ilm lam e llae and Ttn replac em e nt on the edge s 7 Pl tabular phenocrysts altered to Ser 25 Py finely disseminated trz Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 91 Sample: WB04109_269m Lithology: Fragmental Breccia (FBx) District: Mount Polley Igneous Complex (MPIC) Location: North East Zone, Wight Pit UTME or Longitude: 592529 UTMN or Latitude: 5825443 Elevation: 1000 m.a.s.l. Summary Fragmental Breccia (FBx). K-feldspar (50%) as groundmass, albite phenocrysts (20%), biotite (8%) and magnetite (<5%). Plates a-b. Pervasive potassic (K-feldspar + magnetite) alteration and mineralization. Mineralization is characterized by massive/veinlets of chalcopyrite (7%) and minor bornite (<1%). Titanite intergrowth with massive chalcopyrite. Plates c-d. Plate 3. 1 92 Thin section description Mineral Occurrence Abundance % Ap very fine euhedral crystals disseminated in the groundmass 1 Bt disseminated phenocrysts 8 Bn disseminated + intergrowth Mag-Ccp-Bn trz Ccp massive and veinlets 7 Kfs groundmass 50 Ab disseminated; veinlets; intergrowth with Ccp 20 Mag replaced with Ilm lamellae, Hem and Ttn along fractures and edges 2 Mag II secondary Mag disseminated and veinlets, intergrowth with Ccp 10 Ttn (a) discrete subhedral crystals; (b) anhedral crystals replacing Mag 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 93 Sample: P-3 Lithology: Diorite (PD1) District: Mount Polley Igneous Complex (MPIC) Location: Central Zone, Springer Pit UTME or Longitude: 591675 UTMN or Latitude: 5823621 Elevation: 1024 m.a.s.l. Summary Diorite with equigranular texture. K-feldspar groundmass (35%); plagioclase phenocrysts (20%); augite (15%); biotite (10%); magnetite (8%). Plates a-b. Weak potassic (K-feldspar) alteration overprinted by propylitic (chl + calc) alteration. Mineralization characterized by minor chalcopyrite (2%) Titanite occurs as discrete euhedral crystals in the groundmass. Plates c. Plate 4. 1 94 Thin section description Mineral Occurrence Abundance % Ap grains with cavities & inclusions 2 Aug relict phenocryst 6 Bt disseminated phenocrysts 15 Cal veinlets filling cavities 10 Ccp disseminated 2 Kfs groundmass 35 Mag replaced with Ilm lamellae, Hem and Ttn around borders 8 Pl disseminated phenocrysts 20 Ttn discrete euhedral crystals 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 95 Sample: 06948-63.4m Lithology: Monzonite (SS Stock) District: Mount Milligan Location: SS Zone UTME or Longitude: 6108572 UTMN or Latitude: 434114 Elevation: 1161 m.a.s.l. Summary Monzonite subporphyritic texture. K-feldspar + plagioclase groundmass (20%); plagioclase phenocrysts (20%); augite (20%); biotite (10%). Plates a-b. Strong potassic (K-feldspar + magnetite) alteration overprinted by sodic-calcic (albite + epidote) alteration with selective augite replacement by actinolite ± titanite ± magnetite assemblage. Secondary titanite occurs along cleavage planes of relict augite phenocrysts. Plates c-d. Plate 5. 1 96 Thin section description Mineral Occurrence Abundance % Ap adjacent to mafic min, with cavities and inclusions 2 Aug relict textured; replace by Mag ± Ttn ± Py 20 Bt replaced by chl 10 Ms replacing mafic minerals and groundmass 10 Ccp disseminated, association with Ttn trz Kfs + Pl groundmass 20 Mag replacing aug, relic textures 5 Pl tabular phenocrysts 30 Ttn interstitial crystals along relict aug cleavage planes; interlocked with Ccp 3 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 97 Sample: 111015_238.5m Lithology: Lower Trachyte District: Mount Milligan Location: DWBX Zone UTME or Longitude: 6109468 UTMN or Latitude: 433978 Elevation: 1150 m.a.s.l. Summary Lower Trachyte characterized by trachytic texture consisting on a groundmass of very fine subparallel acicular K-feldspar microlites (30%); augite (20%); muscovite (15%); epidote patches (15%). Plates a-b. Pervasive propylitic (epidote-albite-actinolite-pyrite) alteration overprinting potassic (K-feldspar) alteration + mineralization. Mineralization consists on disseminated pyrite (8%) and minor chalcopyrite (5%). Strongly anhedral secondary titanite occurs along cleavages planes of chloritized biotite phenocrysts. Plates c-d. Plate 6. 1 98 Thin section description Mineral Occurrence Abundance % Ap crystals with cavities + inclusions; adjacent to mafic minerals 1 Bt entirely replaced by Chl 30 Ep coarse patches 10 Ccp disseminated + intergrowth Ccp-Py 5 Kfs + Pl trachytic groundmass 30 Ab tabular phenocrysts 5 Ms disseminated in the groundmass 10 Py replacing Aug 8 Ttn replacing relict Aug; interlock with Ccp 1 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 1 99 Sample: MTM91-1074* Lithology: Monzonite District: Mount Milligan Location: Heidi Lake Stock *Sample from Lang J.R., 1992, Geochemistry of igneous rocks in the Mount Milligan district, Central British Columbia, Section 1, MDRU Annual Technical Report Year 1 Summary Monzonite with porphyritic texture. K-feldspar +plagioclase groundmass (30%); plagioclase phenocrysts (25%); augite (15%); biotite (10%); magnetite (7%). Plates a-b. Weak propylitic (chlorite ± calcite) alteration. Titanite occurs as discrete, coarse, recrystallized crystals in the groundmass. Plates c-d. Plate 7. 2 00 Thin section description Mineral Occurrence Abundance % Aug relict textured; replace by Act 15 Ap disseminated 1 Bt highly chloritized 10 Ccp disseminated trz Kfs + Pl groundmass 35 Mag disseminated 7 Pl large phenocrysts with sericite alteration 25 Py disseminated 5 Ttn coarse discrete recrystallized crystals 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 01 Sample: CMT-13 Lithology: Diorite (Voight Stock) District: Copper Mountain Location: northeast of Copper Mountain mine UTME or Longitude: 5468302 UTMN or Latitude: 681500 Elevation: 1034 m.a.s.l. Summary Diorite with equigranular texture. Plagioclase phenocrysts (45%); augite (30%); biotite (15%); magnetite (6%). Plates a-b. Weak propylitic (chlorite + calcite) alteration characterized by selective biotite chloritization and minor calcite replacement of the groundmass. Titanite occurs as subhedral discrete crystals in the groundmass, which are partly replaced by rutile. Plates c-d. Plate 8. 2 02 Thin section description Mineral Occurrence Abundance % Ap crystals with cavities + inclusions adjacent to mafic minerals 2 Aug disseminated phenocrysts 30 Bt disseminated phenocrysts 15 Ccp disseminated trz Mag fine grained; Ilm lamellae; Ttn replacement on edges 6 Pl disseminated phenocrysts 45 Ttn discrete crystals in the groundmass partly replaced by Rt 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 03 Sample: CM14-15* Lithology: Monzonite (LHIC, LH2) District: Copper Mountain Location: Virginia Pit *Sample from Murray Allan, 2014. Summary Monzonite with porphyritic texture. Albite phenocrysts (15%); K-feldspar groundmass (50%); Augite (15%). Plates a-b. Strong potassic (K-feldspar) alteration characterized by a K-feldspar flooding of the groundmass, overprinted by weak propylitic alteration (chlorite + calcite). Titanite occurs as discrete subhedral crystals in the groundmass and is partly replaced by rutile. Plate 9. 2 04 Thin section description Mineral Occurrence Abundance % Ab tabular phenocrysts 15 Ap discrete crystals adjacent to mafic minerals 1 Aug relict phenocrysts 15 Bt replaced by Chl 10 Kfs groundmass 50 Mag disseminated coarse crystals with Ilm lamellae 7 Ttn discrete subhedral crystals partly replaced by Rt 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 05 Sample: CM12P223-352m Lithology: Diorite (LHIC, LH1) District: Copper Mountain Location: Pit 2 UTME or Longitude: 679869 UTMN or Latitude: 5467739 Elevation: 1205 m.a.s.l. Summary Diorite with porphyritic texture. Albite phenocrysts (30%); Plagioclase + K-feldspar groundmass (30%); augite (22%). Plates a-b. Pervasive sodic-calcic (albite + epidote) alteration overprinted by potassic alteration (K-feldspar) + mineralization. Selective augite replacement by actinolite ± titanite is characteristic. Mineralization consists on disseminated chalcopyrite (5%) and minor pyrite (<1%). Secondary titanite occurs as subhedral clusters along relict augite phenocrysts and is locally intergrowth with chalcopyrite. Plates c-d. Plate 10. 2 06 Thin section description Mineral Occurrence Abundance % Ap subhedral crystals with cavities + inclusions; adjacent to mafic minerals 2 Aug relict phenocrysts 22 Cal crosscutting veinlets 5 Ccp disseminated 7 Kfs + Pl groundmass 30 Ab tabular phenocrysts 30 Py disseminated 1 Ttn subhedral clusters along relict Aug phenocrysts; locally intergrowth with Ccp 3 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 07 Sample: CM12P221-65m Lithology: Diorite (LHIC, LH1) District: Copper Mountain Location: Pit 2 UTME or Longitude: 679745 UTMN or Latitude: 5467839 Elevation: 1193 m.a.s.l. Summary Diorite with equigranular texture. Albite phenocrysts (20%); Plagioclase + K-feldspar groundmass (27%); biotite (15%); augite (7%). Plates a-b. Strong sodic-calcic (albite + epidote) alteration overprinted by potassic alteration (K-feldspar + biotite). Secondary titanite occurs as fine elongated crystals along biotite cleavages. Plates c-d. Plate 11. 2 08 Thin section description Mineral Occurrence Abundance % Ab sericite altered phenocrysts 15 Ap grains with cavities + inclusions, adjacent to Act / Chl grains 1 Aug relict phenocrysts 7 Bt disseminated Chloritized phenocryst 15 Cal disseminated and veinlets 8 Ccp disseminated 1 Kfs groundmass 20 Kfs + Pl groundmass 27 Py disseminated 3 Ttn replacing Bt along cleavage planes; minor rutile replacement 3 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 09 Sample: CMAB015-13.4m* Lithology: Monzonite (LHIC, LH2) District: Copper Mountain Location: Alabama Pit *Sample from Edward Cromwell Bachelors Thesis 2014 Summary Monzonite with megacrystic porphyritic texture. K-feldspar groundmass (40%); albite megacrysts (20%); K-feldspar phenocrysts (15%); augite (15%); magnetite (5%). Plates a-b. Strong potassic (K-feldspar + magnetite) alteration + minor mineralization (chalcopyrite < 3%). Titanite occurs as discrete subhedral to anhedral crystals replaced by ilmenite. Plates c-d Plate 12. 2 10 Thin section description Mineral Occurrence Abundance % Ab megacrysts 20 Aug relict phenocrysts altered to Act + Chl 15 Ccp disseminated 3 Kfs phenocrysts 15 Kfs groundmass 45 Mag disseminated 5 Ttn discrete subhedral to anhedral crystals replaced by ilmenite 2 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 11 Sample: CMT-7 Lithology: Syenite (LHIC, LH2) District: Copper Mountain Location: Pit 2 UTME or Longitude: 679745 UTMN or Latitude: 5467578 Elevation: 1168 m.a.s.l. Summary Syenite with porphyritic texture. K-feldspar groundmass (45%); hornblende (12%); biotite (8%); magnetite (7%). Plates a-b. Pervasive potassic alteration characterized by K-feldspar flooding of the groundmass, overprinted by propylitic alteration (Calcite + chlorite). Secondary titanite occurs as fine elongated crystals along biotite cleavages and is commonly replaced by relict rutile. Plates c-d. Plate 13. Thin section description 2 12 Mineral Occurrence Abundance % Ap altered crystals with cavities + inclusions; adjacent to mafic minerals 4 Bt altered to Chl 8 Cal patches replacing the groundmass 15 Ccp disseminated 4 Hlb disseminated phenocrysts 13 Kfs groundmass 45 Mag Hem replacement; interlocked with Ccp 7 Ttn replacing Bt along cleavages; relict texture replaced by Rt 4 Ab= albite; Ap= apatite; Act= actinolite; Aug= augite; Bt= biotite; Cal=calcite; Chl= chlorite; Ccp= chalcopyrite; Ep= epidote; Gt= garnet; Ilm= ilmenite; Kfs= K-feldspar; Mag= magnetite; Ms= muscovite; Pl= plagioclase; Py= pyrite; Rt= rutile; Ser= sericite; Trz= traces; Ttn= titanite. 2 13 Appendix B Electron microprobe (EMPA) Analytical Data Tables B1. EMPA analyses in thin sections Tables B2. EMPA analyses in bedrock concentrates Table B3. EMPA analyses in till concentrates 2 14 Table B1.1. Electron microprobe analyses of titanite from Mount Polley Spot No. s10-1a s1-1a s1-1b s2-1a s2-1b s3-1a s3-2a s3-2b s4-1a s5-1a s6-1a s6-1b s7-1a s7-2a s7-2b s9-1a s9-1bLocation core core rim core rim core core rim rim core core rim core core rim core rim(wt.%)CaO 26.93 26.75 26.78 26.85 26.94 26.84 26.77 26.47 26.72 26.86 27.22 26.89 26.64 27.11 26.98 26.60 26.64SiO2 29.55 29.50 29.33 29.41 29.55 29.45 29.46 29.67 29.06 29.53 29.44 29.50 29.03 29.79 29.43 29.42 29.13TiO2 36.47 36.17 35.68 37.01 36.14 36.11 36.30 35.94 36.04 35.25 35.91 35.81 36.54 36.36 36.30 36.64 35.70ZrO2 0.21 0.21 0.19 - 0.15 0.17 0.23 0.17 0.20 0.14 - 0.18 - - 0.14 0.25 -SnO2 - - - - - - - - - - - - - 0.12 - - -Al2O3 1.22 1.22 1.20 1.15 1.18 1.30 1.20 0.98 1.21 1.16 1.26 1.16 1.21 1.25 1.13 1.10 1.15V2O3 0.14 0.21 0.17 0.22 - 0.27 0.18 0.13 0.19 0.12 0.19 0.21 0.13 0.14 0.15 0.15 0.14Cr2O3 - 0.05 - - - - - - 0.04 - - - - - - - -Fe2O3 1.62 1.48 1.60 1.33 1.49 1.68 1.52 2.01 1.60 1.49 1.43 1.63 1.57 1.51 1.28 1.56 1.62MgO - 0.04 - 0.04 - 0.04 0.03 0.04 - - - - - - - - -MnO 0.19 0.17 0.19 0.20 0.24 0.14 0.19 0.19 0.13 0.19 0.12 0.22 0.16 0.15 0.16 0.19 0.18Nb2O5 0.13 - - - 0.09 - - - - - - - - - - - -Y2O3 0.33 0.22 0.16 0.29 0.21 0.20 0.33 0.25 0.22 0.18 0.17 0.37 0.29 0.24 0.31 0.29 0.32Ce2O3 0.28 0.28 - 0.38 0.24 - 0.40 0.27 0.26 - - 0.32 - 0.22 0.34 0.38 0.23Nd2O3 - - - - - - - 0.26 0.33 - - - - - - - 0.29Na2O - - - - 0.03 - 0.04 0.07 - 0.05 - - 0.04 - 0.06 0.03 0.03K2O 0.02 - 0.04 - 0.03 - - 0.10 0.03 - - 0.03 - - 0.04 - 0.03F 0.56 0.50 0.88 0.61 0.47 0.76 0.41 0.52 0.57 0.59 0.61 0.40 0.49 0.41 0.55 0.40 0.60H2O 0.45 0.50 0.27 0.41 0.44 0.46 0.49 0.56 0.37 0.31 0.28 0.46 0.46 0.48 0.24 0.57 0.29F=O -0.24 -0.21 -0.37 -0.26 -0.20 -0.32 -0.17 -0.22 -0.24 -0.25 -0.26 -0.17 -0.23 -0.27 -0.16 -0.33 -0.25Total 97.72 97.02 96.42 97.60 96.84 97.09 97.31 97.12 96.59 95.88 96.57 96.96 97.14 97.33 96.73 98.19 96.07(a.p.f.u.)Ca site 0.958 0.957 0.966 0.956 0.966 0.958 0.957 0.946 0.964 0.974 0.981 0.965 0.958 0.965 0.971 0.949 0.968Si site 0.981 0.985 0.988 0.978 0.989 0.981 0.983 0.989 0.979 1.000 0.990 0.988 0.975 0.989 0.989 0.980 0.988Ti site 0.911 0.908 0.904 0.926 0.910 0.905 0.911 0.902 0.913 0.898 0.908 0.902 0.923 0.908 0.917 0.918 0.910Zr 0.003 0.003 0.003 - 0.002 0.003 0.004 0.003 0.003 0.002 - 0.003 - - 0.002 0.004 -Sn - - - - - - - - - - - - - 0.002 - - -Al 0.048 0.048 0.047 0.045 0.046 0.051 0.047 0.039 0.048 0.046 0.050 0.046 0.048 0.049 0.045 0.043 0.046V 0.004 0.006 0.004 0.006 - 0.007 0.005 0.004 0.005 0.003 0.005 0.006 0.004 0.004 0.004 0.004 0.004Cr - 0.001 - - - - - - 0.001 - - - - - - - -Fe 0.045 0.041 0.045 0.037 0.042 0.047 0.042 0.056 0.045 0.042 0.040 0.046 0.044 0.042 0.036 0.044 0.046Mg - 0.002 - 0.002 - 0.002 0.002 0.002 - - - - - - - - -Mn 0.005 0.005 0.005 0.006 0.007 0.004 0.005 0.005 0.004 0.005 0.003 0.006 0.004 0.004 0.005 0.005 0.005Nb 0.002 - - - 0.001 - - - - - - - - - - - -Y 0.006 0.004 0.003 0.005 0.004 0.004 0.006 0.004 0.004 0.003 0.003 0.007 0.005 0.004 0.006 0.005 0.006Ce 0.003 0.003 - 0.005 0.003 - 0.005 0.003 0.003 - - 0.004 - 0.003 0.004 0.005 0.003Nd - - 0.003 - - - - 0.003 0.004 - - - - - - - 0.003Na - - - - 0.002 - 0.003 0.004 - 0.003 - - 0.003 - 0.004 0.002 0.002K 0.001 - 0.002 - 0.001 - - 0.004 0.001 - - 0.001 - - 0.002 - 0.001F- 0.059 0.053 0.094 0.064 0.050 0.080 0.044 0.055 0.061 0.063 0.064 0.042 0.052 0.043 0.058 0.043 0.064OH- 0.100 0.112 0.061 0.092 0.098 0.101 0.108 0.125 0.083 0.070 0.062 0.104 0.104 0.106 0.054 0.126 0.066"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsThin section: PTB0452 15 Table B1.2. Electron microprobe analysis of titanite from Mount Polley Thin section: P-6Spot No. s1-1c s1-1d s1-2c s1-2d s18-1b s18-1c s18-1d s18-2c s2-1c s2-1e s4-1d s4-1d2 s4-1e s7-1c s7-1d s7-1eLocation rim core rim core core rim rim rim rim rim core core rim rim core rim(wt.%)CaO 26.74 26.96 26.89 27.18 27.56 27.38 27.53 27.03 27.02 26.89 27.13 27.20 27.03 27.16 26.92 27.10SiO2 29.73 29.59 29.76 29.97 29.69 29.64 29.88 30.17 29.76 29.61 29.78 29.82 29.48 29.81 29.47 29.99TiO2 36.16 37.12 36.74 37.31 38.11 37.11 36.90 36.89 37.08 36.93 36.01 37.13 36.67 37.11 38.23 37.28ZrO2 0.28 - 0.21 0.14 0.20 0.15 0.17 0.21 - 0.24 0.23 - - 0.26 0.26 0.34SnO2 - - - - - - - - - - - - - - - -Al2O3 1.05 0.98 1.10 0.92 0.96 1.08 1.10 1.09 1.07 1.17 1.42 0.99 1.27 1.16 1.06 1.13V2O3 0.22 0.16 0.30 0.29 0.30 0.27 0.29 0.46 0.25 0.27 0.32 0.22 0.17 0.18 0.32 0.31Cr2O3 - - - - 0.05 - 0.06 0.08 - - - - - - - -Fe2O3 1.80 1.61 2.08 1.51 1.81 1.64 1.85 1.72 1.60 1.62 2.31 1.68 1.97 2.10 2.00 2.41MgO - - 0.03 0.04 0.03 - 0.04 0.05 - 0.04 - 0.04 - - - -MnO 0.15 0.08 0.12 0.18 0.13 0.13 0.16 0.17 0.19 0.13 0.13 0.17 0.10 0.12 0.11 0.21Nb2O5 - - - - - 0.11 - 0.09 - - - - - - 0.11 -Y2O3 0.25 0.36 0.33 0.29 0.21 0.29 0.32 0.34 0.27 0.33 0.23 0.31 0.28 0.29 0.18 0.22Ce2O3 0.49 0.35 0.36 - 0.26 0.30 0.30 0.27 0.45 0.38 - 0.50 0.41 0.27 - 0.41Nd2O3 - - - 0.28 - 0.36 - - - 0.47 0.27 0.29 - - 0.33 -Na2O 0.03 - 0.04 0.05 - 0.04 - 0.04 - 0.04 - 0.05 - 0.05 0.08 -K2O 0.06 - 0.12 0.02 - 0.03 - 0.06 0.12 0.08 0.10 0.04 0.03 0.09 0.02 0.09F 0.53 0.55 0.41 0.42 0.45 0.65 0.64 0.48 0.32 0.48 0.63 0.41 0.68 0.71 0.35 0.93H2O 0.45 0.35 0.66 0.50 0.51 0.25 0.36 0.65 0.56 0.47 0.61 0.42 0.44 0.49 0.78 0.59F=O -0.22 -0.23 -0.17 -0.18 -0.19 -0.27 -0.27 -0.20 -0.13 -0.20 -0.16 -0.17 -0.33 -0.30 -0.23 -0.27Total 97.79 98.01 98.68 98.73 100.01 99.12 99.41 99.36 98.53 98.81 96.73 99.00 98.19 99.41 97.14 97.33(a.p.f.u.)Ca site 0.953 0.959 0.945 0.956 0.960 0.967 0.967 0.943 0.954 0.950 0.953 0.959 0.956 0.950 0.935 0.936Si site 0.989 0.982 0.976 0.984 0.965 0.977 0.979 0.982 0.980 0.976 0.976 0.981 0.973 0.973 0.955 0.967Ti site 0.904 0.927 0.906 0.921 0.932 0.920 0.910 0.903 0.919 0.915 0.888 0.919 0.911 0.911 0.932 0.904Zr 0.005 - 0.003 0.002 0.003 0.002 0.003 0.003 - 0.004 0.004 - - 0.004 0.004 0.005Sn - - - - - - - - - - - - - - - -Al 0.041 0.038 0.043 0.036 0.037 0.042 0.042 0.042 0.042 0.045 0.055 0.038 0.049 0.045 0.041 0.043V 0.006 0.004 0.008 0.008 0.008 0.007 0.008 0.012 0.007 0.007 0.008 0.006 0.005 0.005 0.008 0.008Cr - - - - 0.001 - 0.002 0.002 - - - - - - - -Fe 0.050 0.045 0.057 0.042 0.049 0.045 0.051 0.047 0.044 0.045 0.063 0.046 0.054 0.057 0.054 0.065Mg - - 0.002 0.002 0.002 - 0.002 0.002 - 0.002 - 0.002 - - - -Mn 0.004 0.002 0.003 0.005 0.004 0.004 0.004 0.005 0.005 0.004 0.004 0.005 0.003 0.003 0.003 0.006Nb - - - - - 0.002 - 0.001 - - - - - - 0.002 -Y 0.004 0.006 0.006 0.005 0.004 0.005 0.006 0.006 0.005 0.006 0.004 0.005 0.005 0.005 0.003 0.004Ce 0.006 0.004 0.004 - 0.003 0.004 0.004 0.003 0.005 0.005 - 0.006 0.005 0.003 - 0.005Nd - - - 0.003 - 0.004 - - - 0.006 0.003 0.003 - - 0.004 -Na 0.002 - 0.002 0.003 - 0.002 - 0.002 - 0.003 - 0.003 - 0.003 0.005 -K 0.002 - 0.005 0.001 - 0.001 - 0.003 0.005 0.003 0.004 0.002 0.001 0.004 0.001 0.004F- 0.056 0.057 0.043 0.044 0.046 0.068 0.066 0.049 0.033 0.050 0.065 0.042 0.071 0.073 0.036 0.095OH- 0.099 0.078 0.145 0.109 0.111 0.056 0.078 0.141 0.122 0.104 0.134 0.093 0.098 0.106 0.169 0.127"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 16 Table B1.3. Electron microprobe analysis of titanite from Mount Polley Thin section: WB04109-269mSpot No. s1-1c s1-1d s1-2a s1-2b s1-2c s2-1a s2-1b s2-1c s2-2a s2-2b s2-2c s3-1a s3-1b s3-1c s3-1d s3-2b s3x-1b s3x-1d s4-1b s4-1c s4-2b s4-2c s4-2d s5-1b s5-2b s5-2cLocation rim rim core rim rim core rim rim core rim rim core core rim rim rim rim core rim rim rim core rim rim core rim(wt.%)CaO 27.29 27.66 27.78 27.77 27.50 27.66 27.88 27.78 28.22 27.05 27.91 28.04 27.41 28.12 27.79 27.37 27.68 27.62 26.46 27.70 27.53 27.12 27.15 27.96 26.81 27.84SiO2 30.30 30.35 30.21 30.27 30.11 29.85 30.06 29.91 29.65 30.54 29.71 29.86 29.88 29.92 30.29 29.85 30.30 30.52 31.16 30.38 30.06 29.93 29.97 29.98 29.73 30.33TiO2 37.52 37.38 37.58 36.37 37.57 37.85 37.76 37.80 38.34 38.07 38.83 38.01 35.68 38.53 38.04 37.61 37.42 39.10 36.35 36.96 36.98 35.93 36.03 37.17 35.04 37.40ZrO2 0.38 - 0.23 0.47 0.32 0.49 0.52 0.79 - 0.31 0.13 0.14 2.28 - 0.17 0.25 - 0.32 0.33 0.49 0.16 0.67 0.13 0.55 0.30 0.39SnO2 - - - - - - - - - - - - - - - - - - - - - - - - - -Al2O3 0.65 0.62 0.58 0.75 0.68 0.75 0.60 0.73 0.50 0.74 0.40 0.45 0.76 0.56 0.68 0.66 0.68 0.42 1.13 0.69 0.85 0.98 0.84 0.59 1.14 0.84V2O3 0.36 0.40 0.63 0.18 0.50 0.15 0.11 0.16 0.15 0.20 0.17 0.16 0.10 0.17 0.49 0.35 0.37 0.11 0.33 0.31 0.46 0.18 0.40 0.48 0.18 0.29Cr2O3 - - - - - - - - - - - - - - - - - - - - - - - - - -Fe2O3 1.99 1.58 1.43 2.38 1.72 1.68 1.48 1.78 1.11 1.36 1.22 1.16 1.52 1.53 1.59 1.48 2.42 1.09 2.03 2.08 2.48 2.60 2.25 2.16 2.89 1.94MgO - - - - - 0.03 - - - 0.06 - - - - - - - - - - - - - - 0.08 0.04MnO 0.07 0.16 - 0.12 - 0.15 0.07 0.08 0.09 0.14 0.08 0.08 0.10 0.07 - - 0.11 0.12 - 0.10 0.10 0.09 - - 0.18 0.10Nb2O5 - - - 0.09 0.11 - - - - - - - 0.12 - - - - - - - - - - - - -Y2O3 0.16 0.20 0.16 - 0.11 - - - 0.09 - - 0.15 - - 0.13 0.13 - 0.11 - - 0.13 - - - 0.23 0.15Ce2O3 - - - 0.24 - - - - - - - - - - 0.24 - - 0.39 - - - 0.27 - - 0.46 -Nd2O3 - - - - - - - - - - - - - - - - - - 0.33 - - - - - 0.54 -Na2O 0.06 0.04 - - 0.05 0.03 - - - - 0.03 - 0.04 - 0.04 - 0.05 - - 0.05 0.03 0.03 0.04 0.04 0.04 0.04K2O - 0.09 0.04 0.03 0.08 - 0.06 - - 0.04 - 0.04 0.11 0.09 - 0.05 0.10 - 0.64 0.15 0.15 0.08 0.30 0.05 - -F 0.68 0.81 0.76 0.96 0.70 - 0.33 0.38 0.59 0.59 0.40 0.53 0.56 0.64 0.79 0.89 0.83 0.44 1.07 0.88 0.99 1.11 0.87 0.56 0.65 0.95H2O 0.42 0.43 0.61 0.27 0.36 0.19 0.10 0.42 0.11 0.12 0.05 0.16 0.25 0.34 0.73 0.08 0.46 0.20 0.78 0.31 0.26 0.46 0.18 -0.03 0.28 0.41F=O -0.29 -0.14 -0.25 -0.29 -0.39 -0.32 -0.25 -0.17 -0.29 -0.41 -0.34 -0.23 -0.16 -0.14 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23Total 100.18 99.29 99.19 99.62 100.05 99.64 99.66 100.07 98.28 100.55 99.35 97.14 99.06 99.53 97.14 97.14 97.14 97.14 97.14 97.14 97.14 97.14 97.14 97.14 97.14 97.14(a.p.f.u.)Ca site 0.958 0.978 0.947 0.978 0.961 0.975 0.993 0.976 0.971 0.966 0.975 0.975 0.988 0.979 0.960 0.993 0.950 0.945 0.960 0.966 0.954 0.932 0.982 0.966 0.978 0.945Si site 0.985 0.994 0.987 0.993 0.980 0.978 0.987 0.976 0.985 0.991 0.977 0.991 0.992 0.980 0.982 0.984 0.982 0.985 1.004 0.990 0.973 0.984 0.992 0.976 0.986 0.986Ti site 0.917 0.921 0.923 0.898 0.919 0.933 0.933 0.928 0.958 0.929 0.961 0.949 0.891 0.949 0.927 0.933 0.912 0.950 0.881 0.906 0.901 0.889 0.897 0.911 0.874 0.914Zr 0.006 - 0.004 0.008 0.005 0.008 0.008 0.013 - 0.005 0.002 0.002 0.037 - 0.003 0.004 - 0.005 0.005 0.008 0.003 0.011 0.002 0.009 0.005 0.006Sn - - - - - - - - - - - - - - - - - - - - - - - - - -Al 0.025 0.024 0.022 0.029 0.026 0.029 0.023 0.028 0.020 0.028 0.015 0.018 0.030 0.022 0.026 0.025 0.026 0.016 0.043 0.026 0.033 0.038 0.033 0.023 0.044 0.032V 0.009 0.010 0.016 0.005 0.013 0.004 0.003 0.004 0.004 0.005 0.004 0.004 0.003 0.005 0.013 0.009 0.010 0.003 0.008 0.008 0.012 0.005 0.011 0.013 0.005 0.007Cr - - - - - - - - - - - - - - - - - - - - - - - - - -Fe 0.054 0.043 0.039 0.065 0.047 0.046 0.041 0.048 0.031 0.037 0.034 0.032 0.042 0.042 0.043 0.041 0.066 0.029 0.055 0.057 0.067 0.071 0.062 0.059 0.080 0.053Mg - - - - - 0.000 - - - 0.000 - - - - - - - - - - - - - - 0.001 0.000Mn 0.002 0.004 - 0.001 - 0.001 0.002 0.002 0.002 0.003 0.005 0.003 0.002 0.002 - - 0.001 0.002 - 0.003 0.004 0.001 - - 0.003 0.001Nb - - - 0.001 0.002 - - - - - - - 0.002 - - - - - - - - - - - - -Y 0.002 0.000 0.000 - 0.000 - - - 0.003 - - 0.001 - - 0.000 0.000 - 0.001 - - 0.002 - - - 0.002 0.001Ce - - - 0.001 - - - - - - - - - - 0.000 - - 0.003 - - - 0.000 - - 0.000 -Nd - - - - - - - - - - - - - - - - - - 0.000 - - - - - 0.000 -Na 0.003 0.000 - - 0.000 0.001 - - - - 0.002 - 0.001 - 0.002 - 0.002 - - 0.003 0.000 0.001 0.003 0.002 0.002 0.003K - 0.001 0.002 0.002 0.000 - 0.000 - - 0.001 - 0.005 0.001 0.002 - 0.004 0.002 - 0.001 0.004 0.002 0.027 0.006 0.004 - -F- 0.072 0.035 0.061 0.071 0.095 - 0.061 0.041 0.071 0.099 0.085 0.059 0.040 0.034 0.011 0.067 0.091 0.121 0.011 0.085 0.148 0.111 0.092 0.171 0.103 0.089OH- 0.091 0.094 0.133 0.059 0.077 0.042 0.022 0.092 0.024 0.026 0.011 0.036 0.055 0.075 0.158 0.016 0.100 0.043 0.167 0.067 0.057 0.100 0.040 - 0.062 0.088"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 17 Table B1.4. Electron microprobe analysis of titanite from Mount MilliganThin section: 06948-63.4mSpot No. s11-1a s11-1b s1-1a s1-1b s2-1a s2-1b s3-1a s3-1b s5-1a s5-1b s7-1a s7-1b s7-2a s7-2b s8-1a s8-1b s9-1a s9-1b s9-2a s9-2bLocation core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim(wt.%)CaO 28.14 28.05 27.20 28.09 26.42 27.18 27.86 27.85 28.08 28.09 28.01 27.78 28.05 28.13 28.44 28.00 28.02 28.05 27.67 27.87SiO2 29.51 29.60 29.62 30.07 28.95 29.49 29.79 29.53 29.83 29.81 29.72 29.74 29.82 30.10 30.13 29.97 29.74 29.70 29.45 29.70TiO2 36.42 38.04 37.53 37.52 37.34 37.19 37.32 36.52 37.64 38.26 33.90 37.68 36.27 37.26 37.36 34.66 36.92 39.24 36.10 36.84ZrO2 - - - - - - - - 0.97 0.26 - - - - - - - - - -SnO2 - - - - - - - - - - - - - - - - - - - -Al2O3 1.12 0.77 0.61 0.56 0.39 0.46 1.15 1.24 0.28 0.41 1.43 1.23 1.27 0.85 1.62 1.93 0.65 0.33 1.48 1.32V2O3 0.62 0.38 0.17 0.18 0.17 0.25 0.34 0.31 0.16 0.29 0.69 0.47 0.49 0.31 - 0.22 0.39 0.31 0.45 0.24Cr2O3 0.04 - - - - - - - - 0.06 0.06 0.06 - - - - - 0.04 - -Fe2O3 1.43 0.84 1.81 1.38 1.38 1.66 1.50 1.49 1.04 1.37 1.94 1.17 1.84 1.28 1.56 2.01 2.17 0.82 1.11 1.25MgO - - - 0.03 - - - - - - - - - - - - - - - -MnO - - - - - - 0.09 0.09 - - - - - - - - 0.07 - - -Nb2O5 - 0.13 0.23 - 0.21 - - - 0.26 0.38 - - - - - - - - 0.25 -Y2O3 - - - - 0.56 - - - - - - - - - - - - - 0.15 -Ce2O3 - - - - - - - - - - - - - - - - - - - -Nd2O3 - - 0.34 - 0.42 - - - - - - - - - - - - - - -Na2O - - - - 0.04 - - - 0.03 0.03 - - - - - - - - - -K2O - 0.07 - - - 0.12 - 0.06 0.05 0.11 - 0.07 0.04 0.20 - 0.04 - 0.09 - 0.07F 0.37 0.31 - 0.34 - - - - - - 0.34 0.28 0.28 0.28 0.43 0.24 0.29 - 0.43 0.27H2O 0.25 0.13 0.49 0.17 0.32 0.38 0.52 0.36 0.15 0.30 0.31 0.49 0.44 0.21 0.37 0.55 0.38 0.14 0.25 0.38F=O -0.16 -0.23 -0.06 -0.14 -0.04 -0.10 -0.09 -0.09 0.00 -0.01 -0.14 -0.12 -0.12 -0.12 -0.27 -0.16 -0.16 -0.16 -0.16 -0.16Total 98.07 97.14 98.84 98.67 96.99 97.30 99.08 98.20 98.89 99.24 96.53 99.16 98.62 98.90 97.33 96.73 96.73 96.73 96.73 96.73(a.p.f.u.)Ca site 1.004 0.998 0.964 0.996 0.958 0.976 0.980 0.993 1.001 0.993 1.014 0.976 0.993 0.996 0.990 0.996 0.993 0.991 0.992 0.991Si site 0.983 0.983 0.980 0.996 0.980 0.988 0.979 0.982 0.992 0.983 1.004 0.975 0.985 0.994 0.979 0.995 0.983 0.979 0.986 0.986Ti site 0.913 0.950 0.934 0.934 0.951 0.938 0.922 0.914 0.942 0.949 0.862 0.930 0.901 0.926 0.913 0.865 0.918 0.973 0.909 0.919Zr - - - - - - - - 0.016 0.004 - - - - - - - - - -Sn - - - - - - - - - - - - - - - - - - - -Al 0.044 0.030 0.024 0.022 0.016 0.018 0.044 0.049 0.011 0.016 0.057 0.047 0.049 0.033 0.062 0.075 0.025 0.013 0.058 0.051V 0.017 0.010 0.005 0.005 0.005 0.007 0.009 0.008 0.004 0.008 0.019 0.012 0.013 0.008 - 0.006 0.010 0.008 0.012 0.006Cr 0.001 - - - - - - - - 0.001 0.002 0.001 - - - - - 0.001 - -Fe 0.040 0.023 0.050 0.038 0.039 0.046 0.041 0.041 0.029 0.038 0.055 0.032 0.051 0.035 0.042 0.056 0.060 0.023 0.031 0.035Mg - - - 0.002 - - - - - - - - - - - - - - - -Mn - - - - - - 0.003 0.003 - - - - - - - - 0.002 - - -Nb - 0.001 0.005 - 0.006 - - - 0.002 0.000 - - - - - - - - 0.002 -Y - - - - 0.010 - - - - - - - - - - - - - 0.003 -Ce - - - - - - - - - - - - - - - - - - - -Nd - - 0.004 - 0.005 - - - - - - - - - - - - - - -Na - - - - 0.003 - - - 0.002 0.002 - - - - - - - - - -K - 0.003 - - - 0.005 - 0.002 0.002 0.005 - 0.003 0.002 0.009 - 0.002 - 0.004 - 0.003F- 0.039 0.033 - 0.036 - - - - - - 0.037 0.029 0.030 0.029 0.044 0.026 0.031 - 0.046 0.029OH- 0.055 0.029 0.109 0.038 0.072 0.084 0.113 0.080 0.034 0.066 0.069 0.108 0.096 0.046 0.079 0.121 0.083 0.030 0.057 0.083"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 18 Table B1.5. Electron microprobe analysis of titanite from Mount MilliganThin section: 111015-238mSpot No. A1-1a A1-1b A2-1a A2-1b A4-1b B1-1a B1-1b B2-1a B2-1b B3-1a B3-1b B3-2a B3-2bLocation core rim core rim rim core rim core rim core rim core rim(wt.%)CaO 27.51 27.35 27.89 27.84 27.15 27.53 27.79 27.73 27.72 27.87 28.07 28.43 27.53SiO2 30.41 30.36 29.78 30.52 30.14 29.86 30.06 30.23 30.26 30.05 30.47 30.14 30.14TiO2 37.72 37.50 36.73 37.16 36.46 36.67 37.52 37.13 38.53 38.10 34.11 34.90 38.47ZrO2 0.50 0.16 0.53 - - - - 0.14 0.25 - - - -SnO2 - - - - - - - - - - - 0.08 -Al2O3 0.94 0.98 0.96 0.92 1.11 1.45 1.27 1.38 0.76 1.23 3.13 2.28 0.94V2O3 0.34 0.56 0.24 0.41 0.75 0.47 0.19 0.51 0.66 0.48 0.35 0.28 0.16Cr2O3 0.09 0.09 0.08 0.18 0.31 0.21 0.04 0.09 0.10 0.13 - 0.19 -Fe2O3 0.72 0.87 0.84 0.80 0.61 1.10 0.84 0.93 0.43 0.94 1.26 1.09 0.65MgO - - - 0.17 - - - - - - 0.08 - -MnO 0.07 0.09 0.07 - - - - - 0.07 - - 0.05 -Nb2O5 0.10 - - - - - - - - - - - -Y2O3 - - - - - - - 0.09 0.15 - - - -Ce2O3 - - - - - - - - - 0.25 - - -Nd2O3 - - - - - - - - - - - - -Na2O - - - - - - - - - - - - -K2O 0.08 0.16 - 0.03 0.11 0.05 0.10 - - 0.03 0.13 - -F - - - 0.50 - 0.30 0.48 0.39 0.41 0.59 1.68 1.05 0.48H2O 0.53 0.64 0.27 0.33 0.63 0.48 0.34 -14.76 -15.85 0.33 0.13 0.04 0.34F=O -0.05 -0.07 -0.05 -0.21 -0.04 -0.16 -0.17 -1.41 -1.36 -0.33 -0.71 -0.44 -0.20Total 99.53 99.20 97.91 98.97 97.56 99.22 99.66 29.55 32.08 98.19 98.90 98.27 98.72(a.p.f.u.)Ca site 0.963 0.958 0.998 0.979 0.966 0.973 0.981 0.972 0.969 0.971 0.982 1.008 0.968Si site 0.993 0.993 0.994 1.001 1.000 0.985 0.991 0.989 0.987 0.977 0.994 0.997 0.989Ti site 0.927 0.922 0.922 0.917 0.910 0.910 0.930 0.913 0.945 0.932 0.837 0.868 0.950Zr 0.008 0.002 0.009 - - - - 0.002 0.004 - - - -Sn - - - - - - - - - - - 0.001 -Al 0.036 0.038 0.038 0.035 0.043 0.056 0.049 0.053 0.029 0.047 0.120 0.089 0.036V 0.009 0.015 0.007 0.011 0.020 0.012 0.005 0.013 0.017 0.013 0.009 0.007 0.004Cr 0.002 0.002 0.002 0.005 0.008 0.006 0.001 0.002 0.002 0.003 - 0.005 -Fe 0.020 0.024 0.023 0.022 0.017 0.030 0.023 0.025 0.012 0.025 0.034 0.030 0.018Mg - - - 0.008 - - - - - - 0.004 - -Mn 0.002 0.003 0.002 - - - - - 0.002 - - 0.002 -Nb 0.002 - - - - - - - - - - - -Y - - - - - - - 0.002 0.003 - - - -Ce - - - - - - - - - 0.003 - - -Nd - - - - - - - - - - - - -Na - - - - - - - - - - - - -K 0.003 0.007 - 0.001 0.005 0.002 0.004 - - 0.001 0.005 - -F- - - - 0.051 - 0.031 0.050 0.040 0.042 0.061 0.174 0.109 0.050OH- 0.116 0.139 0.06 0.072 0.139 0.128 0.058 0.104 0.074 0.071 0.028 0.009 0.074"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 19 Thin section: MTM91-1074Spot No. s1-1a s1-1b s2-2a s2-2b s3-3a s3-3b s4-4a s4-4b s5-5a s5-5b s6-6aLocation core rim core rim core rim core rim core rim core(wt.%)CaO 26.02 26.61 27.00 26.65 26.11 26.84 26.70 26.84 26.47 26.83 26.80SiO2 29.58 30.04 29.95 29.99 29.47 29.73 29.66 30.09 29.39 29.98 29.78TiO2 35.02 35.84 37.30 36.46 35.38 36.27 36.62 36.74 35.59 36.08 35.75ZrO2 0.30 0.20 0.12 - 0.31 - 0.08 - 0.23 0.09 0.14SnO2 0.10 - 0.14 - - - - - - - -Al2O3 1.03 0.93 0.93 0.94 0.95 0.89 0.87 1.00 1.05 1.06 1.08V2O3 0.12 0.13 0.16 0.18 0.15 0.17 0.23 0.19 0.09 0.18 0.10Cr2O3 - 0.09 - - - - - - 0.04 - -Fe2O3 1.72 1.61 1.38 1.48 1.65 1.57 1.81 1.57 1.83 1.81 1.88MgO 0.03 - - 0.04 - - - - 0.03 - 0.03MnO 0.15 0.13 0.18 0.14 0.15 0.17 0.19 0.15 0.20 0.17 0.17Nb2O5 0.50 0.26 0.10 0.25 0.50 0.25 0.22 0.16 0.33 - 0.17Y2O3 0.79 0.45 0.20 0.34 0.67 0.39 0.12 0.31 0.27 0.23 0.52Ce2O3 0.54 0.26 - 0.41 0.64 0.45 0.42 0.36 0.39 0.31 0.39Nd2O3 0.50 - - - 0.41 - - - - - -Na2O 0.04 0.03 0.03 - - - 0.05 0.05 0.04 - 0.04K2O - - 0.02 - - - - 0.05 0.02 - 0.04F 0.26 0.29 - - - 0.29 - 0.51 0.31 0.37 -H2O 0.42 0.46 0.60 0.61 0.51 0.36 0.74 0.42 0.52 0.53 0.53F=O -0.33 -0.12 -0.08 -0.05 0.00 -0.12 0.00 -0.21 -0.13 -0.16 -0.05Total 98.19 99.23 99.94 99.53 98.76 99.23 99.83 100.23 98.91 99.77 99.79(a.p.f.u.)Ca site 0.943 0.954 0.950 0.955 0.947 0.964 0.952 0.951 0.956 0.957 0.961Si site 1.001 1.005 0.998 0.989 0.998 0.997 0.987 0.995 0.990 0.998 0.996Ti site 0.891 0.902 0.912 0.926 0.901 0.915 0.917 0.914 0.902 0.903 0.900Zr 0.005 0.003 0.001 - 0.005 - 0.001 - 0.004 0.001 0.002Sn 0.001 - 0.001 - - - - - - - -Al 0.041 0.036 0.037 0.036 0.038 0.035 0.034 0.039 0.042 0.041 0.042V 0.003 0.004 0.005 0.004 0.004 0.005 0.006 0.005 0.002 0.005 0.003Cr - 0.002 - - - - - - 0.001 - -Fe 0.044 0.040 0.037 0.034 0.042 0.040 0.045 0.039 0.046 0.045 0.047Mg 0.002 - - 0.000 - - - - 0.001 - 0.002Mn 0.004 0.004 0.004 0.005 0.004 0.005 0.005 0.004 0.006 0.005 0.005Nb 0.008 0.004 0.004 0.001 0.008 0.004 0.003 0.002 0.005 - 0.003Y 0.014 0.008 0.006 0.003 0.012 0.007 0.002 0.005 0.005 0.004 0.009Ce 0.007 0.003 - 0.001 0.008 0.005 0.005 0.004 0.005 0.004 0.005Nd 0.006 - - - 0.005 - - - - - -Na 0.003 0.002 0.000 - - - 0.003 0.003 0.003 - 0.003K - - 0.000 - - - - 0.002 0.001 - 0.002F- 0.028 0.031 - - - 0.031 - 0.053 0.033 0.039 -OH- 0.095 0.103 0.134 0.133 0.115 0.080 0.163 0.093 0.116 0.118 0.117"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsTable B1.6. Electron microprobe analysis of titanite from Mount Milligan2 20 Thin section: CMT-13Spot No. S1-1a S1-1b S3-1a S3-1b S5-1a S5-1b S9-1a S9-1bLocation core rim core rim core rim core rim(wt.%)CaO 27.73 26.56 28.48 27.95 27.75 27.90 28.23 27.72SiO2 30.12 31.79 30.58 30.42 30.34 30.68 30.63 30.84TiO2 35.43 36.36 36.74 36.25 36.98 37.18 36.71 36.93ZrO2 - - - - - 0.15 - -SnO2 - - - - - - - -Al2O3 1.39 1.83 1.82 1.85 1.11 1.41 1.46 1.04V2O3 0.18 0.15 0.25 0.29 0.21 0.13 0.41 0.36Cr2O3 0.09 - - - - - - -Fe2O3 3.04 1.92 1.84 2.16 2.10 1.43 1.97 1.93MgO 0.03 - - - - - 0.15 0.44MnO - - 0.05 - - - - -Nb2O5 - - - - - - - -Y2O3 0.33 0.24 - - 0.22 - - -Ce2O3 0.40 - - - 0.34 - - -Nd2O3 - 0.28 - - - - - -Na2O - 0.23 - - - - - -K2O 0.04 0.35 0.02 0.02 0.07 0.21 - -F - 0.38 0.28 - 0.27 0.31 - 0.28H2O 0.75 1.09 0.60 0.84 0.49 0.51 0.86 0.96F=O -0.04 -0.16 -0.12 -0.06 -0.12 -0.13 0.00 -0.12Total 100.16 101.47 101.02 100.31 100.26 100.30 100.77 100.83(a.p.f.u.)Ca site 0.970 0.902 0.981 0.967 0.968 0.968 0.973 0.951Si site 0.983 1.008 0.984 0.983 0.988 0.994 0.985 0.988Ti site 0.870 0.867 0.889 0.881 0.906 0.906 0.888 0.890Zr - - - - - 0.002 - -Sn - - - - - - - -Al 0.053 0.068 0.069 0.070 0.042 0.054 0.055 0.039V 0.005 0.004 0.006 0.007 0.005 0.003 0.010 0.009Cr 0.002 - - - - - - -Fe 0.083 0.051 0.049 0.058 0.057 0.039 0.053 0.052Mg 0.002 - - - - - 0.007 0.021Mn - - 0.001 - - - - -Nb - - - - - - - -Y 0.006 0.004 - - 0.004 - - -Ce 0.005 - - - 0.004 - - -Nd - 0.003 - - - - - -Na - 0.014 - - - - - -K 0.002 0.014 0.001 0.001 0.003 0.009 - -F- - 0.038 0.028 - 0.028 0.032 - 0.029OH- 0.163 0.230 0.129 0.180 0.107 0.110 0.184 0.205"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsTable B1.7. Electron microprobe analysis of titanite from Copper Mountain2 21 Table B1.8. Electron microprobe analysis of titanite from Copper MountainThin section: CM12P223-352mSpot No. S11-1a S11-1b S1-1a S1-1b S2-1a S2-1b S2-2a S2-2b S4-1a S4-1b S4-2a S4-2b S5-1a S5-1b S6-1a S6-1b S6-2a S6-2b S8-1a S8-1c S9-1a S9-1bLocation core rim core rim core rim core rim core rim core rim core rim core rim rim core core rim core rim(wt.%)CaO 28.08 27.99 28.11 28.07 28.07 28.18 27.52 28.50 27.35 27.74 28.01 28.07 28.31 28.49 28.49 28.09 27.90 28.31 27.44 27.19 27.40 28.33SiO2 30.60 30.67 30.31 30.47 29.87 30.31 29.90 30.54 30.36 29.45 30.27 30.05 30.40 30.64 30.42 29.98 30.37 30.74 29.86 31.51 29.95 30.58TiO2 34.34 34.48 37.93 36.14 36.63 36.43 38.17 34.40 35.06 35.57 35.18 35.16 36.25 34.25 34.92 36.82 33.56 35.86 38.01 36.23 35.07 34.45ZrO2 - - - - 0.97 0.13 - - - - - - 0.76 - - - - - - - 0.28 -SnO2 0.08 - - - - - - - 0.13 - - 0.11 - - - - - - - - - -Al2O3 2.45 1.75 0.75 1.80 1.12 1.73 0.77 2.76 1.87 1.42 2.06 1.98 1.41 2.52 2.09 1.15 2.45 1.64 0.79 1.96 1.22 2.05V2O3 0.49 1.58 0.85 0.48 0.44 0.66 0.21 0.79 1.74 1.20 0.27 0.31 0.24 0.49 0.78 1.24 1.68 0.99 0.37 0.66 0.61 0.65Cr2O3 - - - - - - 0.05 0.03 0.06 0.07 - - - - - 0.04 - - - - 0.06 0.04Fe2O3 2.35 1.12 1.58 2.16 1.60 1.33 1.23 1.23 1.52 1.50 2.08 2.22 1.68 1.78 1.69 1.09 1.38 1.50 1.38 1.37 2.32 2.06MgO - - - - - 0.03 - 0.03 0.57 - 0.03 - 0.03 0.03 - - - - - - 0.03 -MnO - - - - - - 0.06 - 0.06 - - 0.06 - 0.08 - - - - 0.07 - 0.10 -Nb2O5 - - - - - - - - - - - - - - 0.13 - - - - - 0.20 -Y2O3 - 0.09 - - - - 0.18 - - - - - - - - - 0.08 - 0.22 - 0.10 -Ce2O3 - - 0.28 - - - 0.37 - - - - - - - - - - - 0.40 - 0.53 -Nd2O3 - - - - - - - - - - - - - - - - - - 0.33 - - -Na2O - - - - - - - - - - - - - - - - - - - 0.27 - -K2O - - 0.02 - - - - - - - - - - 0.03 0.03 - - - - 0.03 - 0.02F 1.51 0.87 0.75 1.03 0.82 1.05 0.45 1.00 0.96 0.82 0.57 0.47 0.53 1.32 0.96 0.76 0.82 0.93 0.62 1.02 1.01 0.78H2O 0.31 0.32 0.24 0.42 0.19 0.24 0.27 0.32 1.14 0.31 0.57 0.59 0.34 0.14 0.25 0.25 0.58 0.30 0.23 0.71 0.27 0.40F=O -0.64 -0.37 -0.32 -0.43 -0.35 -0.44 -0.19 -0.42 -0.41 -0.34 -0.24 -0.20 -0.27 -0.16 -0.40 -0.23 -0.35 -0.39 -0.26 -0.43 -0.43 -0.33Total 100.09 98.82 101.02 100.48 99.63 99.96 99.33 99.41 100.61 98.13 99.13 99.12 97.33 96.73 99.68 97.14 98.65 100.20 99.68 100.81 99.19 99.31(a.p.f.u.)Ca site 0.974 0.985 0.974 0.971 0.987 0.981 0.970 0.994 0.936 0.987 0.981 0.985 0.989 0.995 0.996 0.987 0.980 0.983 0.965 0.928 0.969 0.992Si site 0.990 1.007 0.980 0.983 0.980 0.984 0.983 0.995 0.970 0.978 0.989 0.985 0.991 0.999 0.992 0.983 0.996 0.996 0.980 1.003 0.988 0.999Ti site 0.836 0.852 0.923 0.877 0.904 0.890 0.944 0.843 0.843 0.888 0.865 0.866 0.889 0.840 0.857 0.908 0.828 0.874 0.938 0.868 0.871 0.847Zr - - - - 0.016 0.002 - - - - - - 0.012 - - - - - - - 0.005 -Sn 0.001 - - - - - - - 0.002 - - 0.001 - - - - - - - - - -Al 0.093 0.068 0.029 0.068 0.043 0.066 0.030 0.106 0.070 0.056 0.079 0.077 0.054 0.097 0.080 0.044 0.095 0.063 0.030 0.073 0.048 0.079V 0.013 0.042 0.022 0.012 0.011 0.017 0.005 0.021 0.044 0.032 0.007 0.008 0.006 0.013 0.020 0.032 0.044 0.026 0.010 0.017 0.016 0.017Cr - - - - - - 0.001 0.001 0.001 0.002 - - - - - 0.001 - - - - 0.002 0.001Fe 0.064 0.031 0.043 0.058 0.044 0.036 0.034 0.034 0.041 0.042 0.057 0.061 0.046 0.048 0.046 0.030 0.038 0.041 0.038 0.036 0.064 0.056Mg - - - - - 0.001 - 0.001 0.027 - 0.001 - 0.001 0.001 - - - - - - 0.001 -Mn - - - - - - 0.002 - 0.002 - - 0.002 - 0.002 - - - - 0.002 - 0.003 -Nb - - - - - - - - - - - - - - 0.002 - - - - - 0.003 -Y - 0.002 - - - - 0.003 - - - - - - - - - 0.001 - 0.004 - 0.002 -Ce - - 0.003 - - - 0.004 - - - - - - - - - - - 0.005 - 0.006 -Nd - - - - - - - - - - - - - - - - - - 0.004 - - -Na - - - - - - - - - - - - - - - - - - - 0.016 - -K - - 0.001 - - - - - - - - - - 0.001 0.001 - - - - 0.001 - 0.001F- 0.154 0.091 0.077 0.105 0.085 0.108 0.047 0.103 0.097 0.086 0.059 0.049 0.055 0.136 0.099 0.079 0.085 0.095 0.065 0.103 0.105 0.081OH- 0.067 0.070 0.052 0.091 0.041 0.053 0.058 0.070 0.244 0.069 0.125 0.129 0.073 0.030 0.055 0.054 0.126 0.065 0.050 0.152 0.059 0.088"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 22 Table B1.9. Electron microprobe analysis of titanite from Copper MountaiThin section: CMAB015-13.4mSpot No. s1-1a s1-1b s2-1a s2-1b s3-1a s3-1b s4-1a s4-1b s5-1a s5-1b s6-1a s6-1bLocation core rim core rim core rim core rim core rim core rim(wt.%)CaO 27.53 27.97 26.23 26.44 27.61 27.69 27.66 27.96 28.00 27.58 27.61 27.51SiO2 29.89 30.30 28.88 29.31 29.86 30.02 30.40 30.22 30.05 30.06 30.11 29.94TiO2 37.23 36.71 35.67 36.56 37.33 36.55 37.40 37.58 37.59 37.62 36.60 37.28ZrO2 0.25 - 0.15 - 0.88 0.10 - - - 0.33 0.09 0.15SnO2 - - - - - - - - - - - -Al2O3 0.30 0.40 0.34 0.46 0.25 0.31 0.37 0.31 0.45 0.27 0.35 0.28V2O3 0.29 0.33 0.21 0.30 0.12 0.30 0.18 0.35 0.26 0.15 0.25 0.21Cr2O3 0.04 - 0.43 0.29 0.04 - - - - - 0.03 -Fe2O3 2.32 2.21 2.06 1.59 1.41 1.44 2.01 1.59 1.42 1.54 1.97 1.57MgO 0.03 0.03 0.02 - - - 0.06 - 0.03 - - -MnO 0.10 - - 0.14 0.10 0.14 0.09 0.09 0.09 0.11 0.08 0.10Nb2O5 0.23 - - 0.20 0.17 - - 0.19 - 0.17 0.27 0.10Y2O3 - - - 0.10 - - - - - - - -Ce2O3 - - - - - - - - 0.21 0.23 - -Nd2O3 - - - - - - - - - - - -Na2O 0.05 0.08 0.07 0.07 0.04 0.06 0.05 0.06 0.03 0.04 0.06 0.07K2O - 0.05 0.02 0.15 - 0.11 0.03 0.02 0.02 0.10 0.04 0.05F 0.41 0.44 - 0.53 - 0.40 - 0.32 0.40 0.38 0.53 0.35H2O 0.41 0.17 0.58 0.43 0.33 0.05 0.44 0.19 0.07 0.21 0.13 0.22F=O -0.17 -0.18 -0.09 -0.22 0.00 -0.17 -0.09 -0.14 -0.17 -0.16 -0.33 -0.15Total 101.52 101.20 97.22 98.23 99.94 98.74 101.46 100.72 100.45 100.37 98.19 99.54(a.p.f.u.)Ca site 0.973 0.993 0.963 0.956 0.985 0.999 0.974 0.990 0.995 0.979 0.986 0.984Si site 0.986 1.003 0.990 0.989 0.995 1.011 0.999 0.998 0.996 0.997 1.004 1.000Ti site 0.924 0.915 0.920 0.928 0.935 0.926 0.924 0.934 0.938 0.938 0.918 0.936Zr 0.004 - 0.003 - 0.014 0.002 - - - 0.005 0.001 0.002Sn - - - - - - - - - - - -Al 0.012 0.016 0.014 0.018 0.010 0.012 0.014 0.012 0.017 0.011 0.014 0.011V 0.008 0.009 0.006 0.008 0.003 0.008 0.005 0.009 0.007 0.004 0.007 0.006Cr 0.001 - 0.012 0.008 0.001 - - - - - 0.001 -Fe 0.058 0.055 0.053 0.040 0.035 0.036 0.050 0.039 0.035 0.038 0.049 0.039Mg 0.001 0.002 0.001 - - - 0.003 - 0.001 - - -Mn 0.003 - - 0.004 0.003 0.004 0.002 0.003 0.002 0.003 0.002 0.003Nb 0.003 - - 0.003 0.003 - - 0.003 - 0.002 0.004 0.002Y - - - 0.002 - - - - - - - -Ce - - - - - - - - 0.003 0.003 - -Nd - - - - - - - - - - - -Na 0.003 0.005 0.004 0.004 0.002 0.004 0.003 0.004 0.002 0.003 0.004 0.004K - 0.002 0.001 0.007 - 0.005 0.001 0.001 0.001 0.004 0.002 0.002F- 0.043 0.046 - 0.056 - 0.042 - 0.034 0.042 0.039 0.055 0.037OH- 0.090 0.038 0.133 0.097 0.073 0.012 0.095 0.042 0.014 0.045 0.030 0.049"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 23 Table B2.1. Electron microprobe analysis of titanite HMC in bedrocks from Mount Polley SELFRAG samples: P-3 and P-6Spot No. P3-0-1c P3-0-1r P3-1-1c P3-1-1r P3-3-1c P3-5-1c P3-5-1r P3-7-1r P6-1c P6-1r P6-2c P6-2r P6-3c P6-3r P6-4c P6-4r P6-5c P6-5r P6-6c P6-6r P6-7c P6-7rLocation core rim core rim core core rim rim core rim core rim core rim core rim core rim core rim core rim(wt.%)CaO 26.75 26.99 26.67 26.72 26.63 26.42 26.30 26.83 27.43 27.77 27.43 27.41 27.46 27.10 27.76 27.48 27.44 27.63 27.40 27.08 27.48 27.29SiO2 29.26 29.56 29.61 29.72 29.88 29.62 29.76 29.66 29.88 30.37 29.90 30.32 29.87 30.05 29.83 29.67 30.07 29.74 29.79 30.16 29.88 30.05TiO2 35.77 34.88 35.30 34.53 37.28 35.13 34.97 36.78 37.53 36.38 35.86 35.75 36.39 36.19 36.86 36.67 36.49 36.59 36.59 36.77 36.39 37.01ZrO2 0.92 1.02 1.54 0.52 0.35 0.85 1.00 0.46 - 0.12 - - 0.19 0.15 0.21 0.25 0.20 0.31 0.27 0.37 0.34 0.32SnO2 - 0.08 - 0.09 0.14 - - 0.10 - - - - - - 0.08 0.09 - - - - - -Al2O3 0.57 0.68 0.79 0.86 0.84 0.85 0.77 0.82 0.91 0.98 1.02 1.04 1.04 1.09 0.89 0.99 1.07 1.04 0.94 1.05 1.01 1.01V2O3 0.31 0.22 0.26 0.31 0.14 0.12 0.13 0.29 0.20 0.26 0.29 0.24 0.18 0.20 0.25 0.20 0.23 0.14 0.18 0.28 0.26 0.24Cr2O3 - - 0.06 - - - - - - - - 0.10 0.10 - - - - - - - - -Fe2O3 1.95 2.06 2.21 2.70 1.22 2.34 2.15 1.79 1.53 1.74 1.95 2.04 1.64 1.61 1.34 1.79 1.77 1.48 1.60 1.60 1.61 1.61MgO - - - 0.04 - - - - - 0.03 0.03 0.04 - 0.05 - - - - - 0.02 - 0.03MnO - 0.09 - 0.08 - - 0.09 0.08 0.11 0.11 0.09 0.13 0.13 0.14 0.11 0.10 0.16 0.17 0.07 0.14 0.18 0.13Nb2O5 - - - - - - - - - - - 0.12 - 0.09 - - - - - 0.11 - -Y2O3 0.22 0.12 0.19 0.51 0.47 0.35 0.25 0.34 0.28 0.09 0.27 0.19 0.37 0.38 0.26 0.24 0.38 0.30 0.28 0.34 0.28 0.42Ce2O3 0.23 - 0.27 0.23 0.23 0.26 - 0.30 0.30 0.36 - - - 0.39 0.33 0.25 0.23 0.59 0.42 0.29 0.36 0.33Nd2O3 - - - - 0.27 0.27 - - - 0.28 0.40 0.39 0.38 - 0.31 - 0.42 0.35 - 0.33 - -Na2O - - - 0.03 - - - - 0.04 0.04 - - - - 0.03 - - - 0.03 0.05 - 0.04K2O - - - - - - - - - - - - - - - - 0.03 - - - - -F 0.56 0.71 0.69 0.94 0.43 0.65 0.60 0.64 0.58 0.63 0.71 0.41 - 0.36 0.59 0.67 0.46 0.56 0.71 0.61 0.48 0.61H2O 0.28 0.24 0.43 0.29 0.41 0.43 0.54 0.39 0.29 0.21 0.19 0.51 0.42 0.44 0.05 0.21 0.36 0.09 0.13 0.42 0.33 0.33F=O -0.23 -0.30 -0.29 -0.40 -0.18 -0.27 -0.16 -0.27 -0.25 -0.27 -0.30 -0.23 -0.27 -0.16 -0.33 -0.28 -0.20 -0.24 -0.30 -0.26 -0.20 -0.26Total 97.12 96.77 98.27 97.65 98.28 97.33 96.73 98.60 99.15 99.38 98.32 97.14 97.33 96.73 98.19 98.91 99.42 99.05 98.38 99.55 98.71 99.57(a.p.f.u.)Ca site 0.953 0.960 0.948 0.972 0.946 0.949 0.948 0.953 0.968 0.978 0.967 0.979 0.978 0.968 0.976 0.962 0.988 0.975 0.968 0.983 0.976 0.951Si site 0.987 0.997 0.989 0.997 0.991 0.993 1.001 0.983 0.988 0.999 0.984 0.999 0.995 1.000 0.991 0.996 0.990 0.983 0.990 0.988 0.991 0.989Ti site 0.885 0.871 0.941 0.922 0.930 0.886 0.885 0.917 0.909 0.887 0.929 0.900 0.898 0.887 0.908 0.902 0.921 0.914 0.904 0.914 0.915 0.907Zr 0.025 0.009 0.000 0.001 0.006 0.014 0.016 0.007 - 0.017 - - 0.000 0.000 0.003 0.002 0.003 0.004 0.003 0.005 0.004 0.006Sn - 0.001 - 0.002 0.002 - - 0.001 - - - - - - 0.000 0.000 - - - - - -Al 0.031 0.034 0.030 0.039 0.033 0.034 0.031 0.032 0.023 0.027 0.035 0.038 0.040 0.041 0.041 0.042 0.035 0.039 0.041 0.041 0.037 0.041V 0.007 0.008 0.003 0.005 0.004 0.003 0.004 0.008 0.008 0.006 0.005 0.007 0.008 0.006 0.005 0.005 0.007 0.005 0.006 0.004 0.005 0.007Cr - - 0.001 - - - - - - - - 0.000 0.000 - - - - - - - - -Fe 0.062 0.076 0.033 0.031 0.034 0.066 0.061 0.050 0.055 0.058 0.042 0.048 0.054 0.056 0.045 0.045 0.037 0.050 0.049 0.041 0.045 0.044Mg - - - 0.001 - - - - - 0.000 0.000 0.001 - 0.002 - - - - - 0.001 - 0.001Mn - 0.002 - 0.002 - - 0.003 0.002 0.001 0.003 0.003 0.003 0.003 0.004 0.004 0.004 0.003 0.003 0.005 0.005 0.002 0.004Nb - - - - - - - - - - - 0.001 - 0.002 - - - - - 0.001 - -Y 0.003 0.009 0.009 0.000 0.008 0.006 0.004 0.006 0.004 0.002 0.005 0.002 0.005 0.003 0.007 0.007 0.005 0.004 0.007 0.005 0.005 0.006Ce 0.003 - 0.004 0.000 0.003 0.003 - 0.004 0.003 0.001 - - - 0.000 0.002 0.005 0.004 0.003 0.003 0.007 0.005 0.004Nd - - - - 0.003 0.003 - - - 0.000 0.001 0.003 0.005 - 0.004 - 0.004 0.003 - 0.004 - -Na - - - 0.001 - - - - 0.000 0.000 - - - - 0.001 - - - 0.000 0.000 - 0.003K - - - - - - - - - - - - - - - - 0.000 - - - - -F- 0.073 0.100 0.034 0.062 0.045 0.069 0.063 0.067 0.059 0.076 0.061 0.066 - 0.043 0.018 0.038 0.062 0.071 0.048 0.059 0.075 0.063OH- 0.096 0.064 0.089 0.069 0.090 0.096 0.122 0.086 0.064 0.055 0.063 0.047 0.042 0.111 0.093 0.097 0.011 0.047 0.079 0.020 0.030 0.092"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsP-3 P-62 24 Table B2.2. Electron microprobe analysis of titanite HMC in bedrocks from Copper MountainSELFRAG samples: CMT-13, CM12P221-65.5m and CMT-7 Spot No. C13-1cC13-1rC65-10cC65-10C65-1cC65-1rC65-2cC65-2rC65-3cC65-3rC65-4cC65-4rC65-5cC65-5rC65-6cC65-6rC65-7cC65-7rC65-8cC65-8rC65-9cC65-9r C7-1c C7-2c C7-2r C7-3c C7-5c C7-5rLocation core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core core rim core core rim(wt.%)CaO 27.80 28.08 27.99 27.87 27.66 27.53 27.51 27.72 27.58 27.86 27.86 27.75 27.81 27.47 27.59 27.77 27.61 27.67 27.84 27.73 27.35 27.52 28.64 28.17 27.92 28.02 27.31 27.01SiO2 30.03 29.65 29.96 29.86 30.03 30.36 29.55 30.51 29.78 29.66 30.10 29.89 29.79 29.77 29.67 30.37 30.11 29.99 29.99 30.30 29.89 29.95 30.46 29.84 30.14 29.82 29.83 30.19TiO2 36.85 37.69 36.98 36.84 37.07 36.83 36.81 37.55 36.42 36.90 36.76 36.74 36.32 36.77 36.43 36.18 36.05 36.36 36.59 36.05 34.84 36.14 36.16 37.11 35.98 37.03 34.04 33.95ZrO2 0.10 0.29 0.33 0.44 0.25 0.81 0.48 - 0.16 0.35 0.61 0.61 0.25 0.21 0.37 0.33 0.89 0.89 - - - 0.19 - - 0.11 0.09 - 0.15SnO2 - - - - - - - - - - - - - - 0.13 0.09 - - - - - - - - - - - -Al2O3 0.67 0.52 0.88 0.87 0.71 0.75 0.76 0.74 0.91 0.75 0.71 0.76 0.75 0.72 0.78 0.91 0.78 0.77 0.87 0.88 1.12 1.20 1.23 0.75 0.83 0.71 1.34 1.37V2O3 0.58 0.37 0.42 0.40 0.25 0.30 0.41 0.58 0.44 0.63 0.30 0.52 0.48 0.22 0.40 0.37 0.32 0.44 0.63 0.65 0.38 0.28 1.46 0.50 0.91 0.52 0.58 0.58Cr2O3 - 0.03 - - - - 0.05 0.07 - - - 0.09 0.03 - - - - - - - 0.04 - - - - 0.08 - -Fe2O3 1.31 1.13 1.54 1.48 1.36 1.40 1.29 1.26 1.59 1.22 1.11 1.20 1.30 1.26 1.59 1.73 1.34 1.28 1.58 1.70 1.98 1.95 0.63 1.32 1.51 1.72 2.55 2.39MgO - - - 0.04 - 0.05 0.02 - 0.03 0.04 0.06 0.03 0.05 0.04 - 0.04 - - 0.05 0.06 0.03 0.03 - - 0.04 - - 0.04MnO - - 0.11 0.13 0.13 0.14 0.10 0.07 0.12 0.12 0.07 0.12 0.07 0.12 0.10 0.13 0.18 0.17 0.05 0.06 0.14 0.14 - - 0.07 - 0.06 0.07Nb2O5 - - - 0.10 0.16 0.18 - - - - 0.10 - - - - - 0.13 0.11 - - 0.12 - - - - - 0.14 0.12Y2O3 0.11 0.15 - 0.09 0.14 0.24 0.13 0.09 - - 0.15 0.08 0.17 0.22 0.11 - 0.10 - - - 0.32 0.28 - - - - 0.30 0.18Ce2O3 0.27 0.23 0.23 0.27 0.25 0.40 - - - - 0.23 - 0.22 0.30 0.23 - 0.26 0.21 0.22 0.30 0.33 0.20 - - - - 0.46 0.63Nd2O3 - - 0.32 - - 0.26 - - - - - - - 0.38 - - - - 0.37 0.38 - - - - - - 0.27 -Na2O - - - - - - - 0.04 - - - - - 0.05 - - - - - 0.07 0.05 0.04 - - - - 0.04 0.04K2O - - - - - 0.03 - - - - - - - - - 0.02 - - 0.02 - - 0.03 - - - 0.03 - 0.02F 0.41 0.46 0.35 0.41 0.45 0.50 0.51 - 0.56 0.63 0.49 0.59 0.36 0.50 0.29 0.45 0.61 0.33 0.72 0.67 0.69 0.58 0.73 0.45 0.65 0.40 1.20 1.13H2O 0.17 -0.04 0.27 0.31 0.28 0.24 0.22 0.56 0.31 0.17 0.08 0.22 0.13 0.08 0.38 0.33 0.18 0.33 0.15 0.19 0.19 0.40 0.01 0.05 0.18 0.18 -0.01 0.20F=O -0.17 -0.19 -0.15 -0.17 -0.33 -0.19 -0.21 -0.06 -0.24 -0.26 -0.21 -0.25 -0.15 -0.21 -0.19 -0.12 -0.26 -0.14 -0.31 -0.28 -0.29 -0.25 -0.33 -0.19 -0.27 -0.17 -0.50 -0.48Total 98.45 98.66 99.50 99.16 98.19 98.73 97.97 99.56 98.10 98.28 98.81 98.63 98.02 98.09 99.12 98.20 98.56 98.65 99.17 99.07 97.72 99.05 98.19 99.89 100.01 100.89 100.53 100.38(a.p.f.u.)Ca site 0.990 1.002 0.988 0.985 0.967 0.981 0.984 0.969 0.982 0.992 0.991 0.985 0.997 0.985 0.985 0.979 0.983 0.983 0.985 0.981 0.982 0.971 0.982 1.004 0.992 0.994 0.982 0.967Si site 0.998 0.987 0.987 0.985 0.995 0.994 0.986 0.996 0.990 0.986 0.999 0.990 0.997 0.996 0.989 1.000 1.000 0.995 0.990 1.001 1.002 0.986 0.999 0.993 1.000 0.988 1.002 1.008Ti site 0.921 0.944 0.916 0.914 0.908 0.923 0.924 0.922 0.910 0.923 0.918 0.916 0.914 0.925 0.913 0.896 0.901 0.907 0.909 0.896 0.878 0.896 0.896 0.929 0.898 0.922 0.860 0.853Zr 0.002 0.005 0.005 0.007 0.013 0.004 0.008 - 0.003 0.006 0.010 0.010 0.004 0.003 0.006 0.005 0.014 0.014 - - - 0.003 - - 0.002 0.001 - 0.003Sn - - - - - - - - - - - - - - 0.002 0.001 - - - - - - - - - - - -Al 0.026 0.020 0.034 0.034 0.029 0.028 0.030 0.029 0.036 0.030 0.028 0.030 0.030 0.028 0.031 0.035 0.031 0.030 0.034 0.034 0.044 0.047 0.042 0.030 0.033 0.028 0.053 0.054V 0.015 0.010 0.011 0.011 0.008 0.007 0.011 0.015 0.012 0.017 0.008 0.014 0.013 0.006 0.011 0.010 0.009 0.012 0.017 0.017 0.010 0.007 0.013 0.013 0.024 0.014 0.016 0.016Cr - 0.001 - - - - 0.001 0.002 - - - 0.002 0.001 - - - - - - - 0.001 - - - - 0.002 - -Fe 0.037 0.032 0.042 0.041 0.038 0.038 0.036 0.034 0.044 0.034 0.031 0.033 0.036 0.035 0.044 0.048 0.037 0.035 0.044 0.047 0.055 0.054 0.045 0.033 0.038 0.043 0.064 0.060Mg - - - 0.002 - 0.001 0.001 - 0.001 0.002 0.003 0.001 0.003 0.002 - 0.002 - - 0.003 0.003 0.002 0.001 - - 0.002 - - 0.002Mn - - 0.003 0.003 0.004 0.004 0.003 0.002 0.003 0.003 0.002 0.003 0.002 0.003 0.003 0.004 0.005 0.005 0.001 0.002 0.004 0.004 - - 0.002 - 0.002 0.002Nb - - - 0.001 0.003 0.002 - - - - 0.001 - - - - - 0.002 0.002 - - 0.002 - - - - - 0.002 0.002Y 0.002 0.003 0.001 0.002 0.004 0.003 0.002 0.002 - - 0.003 0.001 0.003 0.004 0.002 - 0.002 - - - 0.006 0.005 - - - - 0.005 0.003Ce 0.003 0.003 0.003 0.003 0.005 0.003 - - - - 0.003 - 0.003 0.004 0.003 - 0.003 0.003 0.003 0.004 0.004 0.002 - - - - 0.006 0.008Nd - - 0.004 - - 0.000 - - - - - - - 0.005 - - - - 0.004 0.004 - - - - - - 0.003 -Na - - - - - - - 0.002 - - - - - 0.004 - - - - - 0.004 0.003 0.002 - - - - 0.002 0.003K - - - - - 0.000 - - - - - - - - - 0.001 - - 0.001 - - 0.001 - - - 0.001 - 0.001F- 0.043 0.048 0.037 0.043 0.052 0.047 0.054 0.014 0.059 0.066 0.052 0.062 0.038 0.053 0.031 0.047 0.064 0.035 0.076 0.070 0.073 0.061 0.101 0.047 0.068 0.042 0.127 0.120OH- 0.037 ##### 0.059 0.068 0.060 0.053 0.050 0.122 0.070 0.038 0.018 0.048 0.029 0.017 0.074 0.084 0.041 0.072 0.034 0.043 0.043 0.088 0.000 0.010 0.041 0.040 -0.002 0.045"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsCM12P221-65.5mCMT-13 CMT-7 2 25 Table B3.1 Electron microprobe analysis of titanite HMC in till from Mount MilliganTill samples: MT12 and MT13Spot No. MT12-1c MT12-1r MT12-2c MT12-2r MT12-8c MT12-8r MT12-9c MT12-9r MT13-1c MT13-6c MT13-6rLocation core rim core rim core rim core rim core core rim(wt.%)CaO 27.25 27.38 27.77 27.71 27.82 28.01 27.69 27.88 27.56 27.83 27.60SiO2 30.03 29.82 30.02 29.73 30.02 29.95 30.07 30.22 29.86 29.96 29.79TiO2 36.14 37.05 36.85 37.01 37.55 37.40 36.72 37.04 36.81 36.84 37.86ZrO2 - - 0.11 - - 0.10 0.09 - - 0.11 -SnO2 - - - - - - - 0.10 - - -Al2O3 0.96 0.91 0.74 0.80 0.82 1.00 0.88 0.88 0.91 0.81 0.87V2O3 0.09 0.16 0.11 0.14 0.21 0.09 0.17 0.12 0.07 0.08 0.16Cr2O3 - - 0.07 0.05 - 0.09 0.03 - 0.03 0.05 -Fe2O3 1.80 1.64 1.24 1.36 1.33 1.46 1.70 1.51 1.69 1.18 1.02MgO - - - - - 0.02 - - 0.03 - -MnO 0.19 0.22 0.14 0.19 0.13 0.15 0.21 0.18 0.22 0.17 0.14Nb2O5 0.11 0.29 0.10 - - - 0.16 0.14 0.10 0.18 -Y2O3 0.25 0.19 - 0.10 0.11 - 0.19 - - 0.14 -Ce2O3 0.58 0.39 - - 0.21 - 0.22 - 0.36 - -Nd2O3 - 0.49 0.31 - - - - - - - -Na2O - - - - - - - - - - -K2O - - - - - - - - - - -F 0.26 0.30 0.33 0.26 0.42 0.52 0.36 0.45 0.35 - 0.45H2O 0.42 0.39 0.17 0.30 0.27 0.26 0.36 0.34 0.41 0.34 0.41F=O -0.11 -0.13 -0.14 -0.11 -0.18 -0.22 -0.15 -0.19 -0.15 -0.10 -0.19Total 98.44 99.33 98.16 97.99 98.93 99.24 99.08 98.88 98.25 98.40 98.49(a.p.f.u.)Ca site 0.970 0.968 0.992 0.989 0.983 0.987 0.979 0.983 0.977 0.987 0.973Si site 0.998 0.984 1.000 0.991 0.990 0.985 0.992 0.995 0.988 0.992 0.980Ti site 0.903 0.919 0.924 0.928 0.931 0.925 0.911 0.917 0.916 0.917 0.937Zr - - 0.002 - - 0.002 0.001 - - 0.002 -Sn - - - - - - - 0.001 - - -Al 0.038 0.035 0.029 0.031 0.032 0.039 0.034 0.034 0.036 0.031 0.034V 0.002 0.004 0.003 0.004 0.005 0.002 0.004 0.003 0.002 0.002 0.004Cr - - 0.002 0.001 - 0.002 0.001 - 0.001 0.001 -Fe 0.050 0.045 0.034 0.038 0.037 0.040 0.047 0.042 0.047 0.047 0.040Mg - - - - - 0.001 - - 0.001 - -Mn 0.005 0.006 0.004 0.005 0.004 0.004 0.006 0.005 0.006 0.005 0.004Nb 0.002 0.004 0.002 - - - 0.002 0.002 0.001 0.003 -Y 0.004 0.003 - 0.002 0.002 - 0.003 - - 0.002 -Ce 0.007 0.005 - - 0.003 - 0.003 - 0.004 - -Nd - 0.006 0.004 - - - - - - - -Na - - - - - - - - - - -K - - - - - - - - - - -F- 0.027 0.032 0.035 0.028 0.044 0.054 0.038 0.047 0.037 - 0.046OH- 0.092 0.085 0.039 0.066 0.059 0.058 0.079 0.074 0.091 0.075 0.089"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atomsMT12 MT132 26 Table B3.2 Electron microprobe analysis of titanite HMC in till from Mount MilliganTill sample: MT15Spot No. 1c 1r 2c 2r 3c 3r 4c 4r 5c 6c 6r 7c 7r 8c 8r 9c 11c 11r 12c 12r 13c 13r 14c 14r 15c 15rLocation core rim core rim core rim core rim core core rim core rim core rim core core rim core rim core rim core rim core rim(wt.%)CaO 27.31 28.03 27.22 27.24 27.66 27.19 26.85 27.16 25.96 27.70 28.05 26.40 26.95 27.10 27.17 27.41 27.74 27.38 27.66 27.97 27.06 27.45 27.53 28.05 27.81 27.77SiO2 29.52 29.62 29.68 29.95 30.00 29.78 29.37 29.86 29.41 29.82 30.56 29.49 29.81 29.69 29.50 29.64 29.93 30.18 29.84 29.97 29.74 30.12 29.90 30.51 29.82 30.09TiO2 36.08 36.29 36.00 35.61 37.82 35.24 35.14 35.39 36.25 36.80 36.03 35.82 35.17 36.46 35.85 36.30 36.80 36.57 36.98 36.44 35.92 37.33 35.99 36.52 36.14 36.37ZrO2 0.19 - - 0.10 - 0.16 0.10 - - - - 0.09 - - 0.20 - - - 0.10 - - - - - - -SnO2 - - - 0.11 - - - - - - - - - - - - - - - - - - - - - -Al2O3 1.25 0.97 1.14 1.27 1.01 1.27 1.05 1.28 1.15 0.91 1.18 1.26 1.31 1.03 1.12 0.85 1.04 1.17 0.95 1.03 1.30 0.90 1.16 1.20 1.18 1.17V2O3 0.13 0.43 0.15 0.19 0.18 0.11 0.08 0.13 0.15 0.08 0.21 0.07 0.14 0.18 0.15 0.08 0.07 0.08 0.11 0.18 0.07 - - 0.15 0.08 0.13Cr2O3 - - 0.07 0.04 0.07 - - 0.03 - 0.06 0.04 - - - - - - - - - - - - - - -Fe2O3 1.67 1.45 1.82 1.97 1.39 1.84 1.62 1.95 2.06 1.25 1.90 1.96 2.02 1.50 1.61 1.53 1.79 1.90 1.55 1.64 1.96 1.26 1.79 1.85 1.93 1.93MgO - - - 0.05 0.03 0.03 0.04 0.02 0.04 - 0.03 - 0.03 - 0.02 0.03 0.03 - - - 0.03 0.03 - 0.05 - -MnO 0.11 - 0.13 0.14 0.16 0.16 0.15 0.20 0.20 0.12 0.20 0.10 0.15 0.07 0.13 0.17 0.11 0.23 0.11 0.13 0.15 0.12 0.17 0.13 0.11 0.14Nb2O5 0.11 - 0.28 0.12 0.11 0.17 0.43 0.11 0.39 - 0.13 0.32 0.11 - 0.13 0.48 0.23 0.20 - - - 0.11 - - - -Y2O3 - - 0.13 0.36 - 0.28 0.30 0.23 0.79 - - 0.48 0.41 0.22 0.22 0.13 0.20 0.09 - - 0.31 0.13 0.11 - - -Ce2O3 0.35 - 0.42 0.54 - 0.23 0.66 0.40 1.04 - - 0.52 0.48 0.33 0.45 0.35 0.32 0.26 - - 0.23 0.22 0.30 - - -Nd2O3 0.25 - - 0.41 - 0.38 0.58 - 0.76 - - 0.49 0.49 0.43 - - 0.27 - - - 0.39 - - - - -Na2O - - - 0.04 - - 0.04 - - - - - - - - 0.03 - - - - - - - - - -K2O - - - - - - - - - - - - - - - 0.02 0.02 - - - - - - - - 0.03F 0.61 0.71 0.77 0.60 0.86 0.81 0.40 0.51 0.52 0.43 0.72 0.69 0.64 0.65 0.71 0.28 0.69 0.71 0.31 - 0.44 0.42 0.61 0.79 0.73 0.89H2O 0.27 0.03 0.25 0.31 0.29 0.19 0.15 0.43 0.49 0.20 0.32 0.38 0.30 0.19 0.16 0.29 0.15 0.45 0.42 0.41 0.47 0.34 0.28 0.30 0.20 0.23F=O -0.26 -0.30 -0.32 -0.25 -0.36 -0.34 -0.17 -0.22 -0.22 -0.18 -0.30 -0.29 -0.27 -0.27 -0.30 -0.12 -0.29 -0.30 -0.13 -0.08 -0.19 -0.18 -0.26 -0.33 -0.31 -0.37Total 97.89 97.53 98.21 99.04 99.62 97.77 96.99 97.93 99.31 97.65 99.37 98.03 98.04 97.81 97.59 97.77 99.40 99.39 98.19 98.22 98.18 98.55 98.04 99.65 98.26 98.78(a.p.f.u.)Ca site 0.977 1.006 0.970 0.966 0.967 0.975 0.977 0.969 0.922 0.991 0.984 0.944 0.965 0.971 0.977 0.983 0.980 0.960 0.982 0.994 0.964 0.971 0.981 0.981 0.989 0.980Si site 0.986 0.992 0.988 0.992 0.979 0.996 0.997 0.995 0.975 0.996 1.000 0.985 0.996 0.993 0.990 0.992 0.987 0.988 0.989 0.994 0.988 0.995 0.995 0.995 0.990 0.991Ti site 0.906 0.914 0.901 0.887 0.929 0.887 0.898 0.887 0.904 0.925 0.887 0.899 0.884 0.917 0.905 0.914 0.913 0.900 0.922 0.909 0.898 0.927 0.901 0.896 0.902 0.901Zr 0.003 - - 0.002 - 0.003 0.002 - - - - 0.002 - - 0.003 - - - 0.002 - - - - - - -Sn - - - 0.001 - - - - - - - - - - - - - - - - - - - - - -Al 0.049 0.038 0.045 0.050 0.039 0.050 0.042 0.050 0.045 0.036 0.046 0.049 0.051 0.041 0.044 0.034 0.040 0.045 0.037 0.040 0.051 0.035 0.045 0.046 0.046 0.045V 0.003 0.012 0.004 0.005 0.005 0.003 0.002 0.003 0.004 0.002 0.005 0.002 0.004 0.005 0.004 0.002 0.002 0.002 0.003 0.005 0.002 - - 0.004 0.002 0.003Cr - - 0.002 0.001 0.002 - - 0.001 - 0.001 0.001 - - - - - - - - - - - - - - -Fe 0.047 0.041 0.051 0.055 0.038 0.051 0.046 0.054 0.057 0.035 0.052 0.055 0.056 0.042 0.045 0.043 0.049 0.052 0.043 0.045 0.054 0.035 0.050 0.051 0.054 0.053Mg - - - 0.002 0.001 0.002 0.002 0.001 0.002 - 0.001 - 0.002 - 0.001 0.001 0.002 - - - 0.001 0.001 - 0.002 - -Mn 0.003 - 0.004 0.004 0.005 0.005 0.004 0.006 0.006 0.003 0.006 0.003 0.004 0.002 0.004 0.005 0.003 0.006 0.003 0.004 0.004 0.003 0.005 0.004 0.003 0.004Nb 0.002 - 0.004 0.002 0.002 0.003 0.007 0.002 0.006 - 0.002 0.005 0.002 - 0.002 0.007 0.003 0.003 - - - 0.002 - - - -Y - - 0.002 0.006 - 0.005 0.005 0.004 0.014 - - 0.009 0.007 0.004 0.004 0.002 0.004 0.002 - - 0.006 0.002 0.002 - - -Ce 0.004 - 0.005 0.006 - 0.003 0.008 0.005 0.013 - - 0.006 0.006 0.004 0.005 0.004 0.004 0.003 - - 0.003 0.003 0.004 - - -Nd 0.003 - - 0.005 - 0.004 0.007 - 0.009 - - 0.006 0.006 0.005 - - 0.003 - - - 0.005 - - - - -Na - - - 0.003 - - 0.003 - - - - - - - - 0.002 - - - - - - - - - -K - - - - - - - - - - - - - - - 0.001 0.001 - - - - - - - - 0.001F- 0.064 0.075 0.081 0.063 0.089 0.086 0.043 0.054 0.054 0.045 0.075 0.073 0.068 0.068 0.075 0.030 0.072 0.073 0.032 - 0.046 0.044 0.065 0.082 0.077 0.092OH- 0.060 0.007 0.055 0.068 0.063 0.042 0.034 0.096 0.108 0.043 0.070 0.084 0.067 0.042 0.035 0.065 0.032 0.099 0.092 0.090 0.104 0.074 0.061 0.065 0.045 0.051"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 27 Table B3.3 Electron microprobe analysis of titanite HMC in till from Mount MilliganTill sample: MT16Spot No. 1c 1r 4c 4r 6c 6r 7c 7r 9c 9r 10c 10r 11c 11r 13r 14c 14r 15c 15rLocation core rim core rim core rim core rim core rim core rim core rim rim core rim core rim(wt.%)CaO 26.97 27.07 26.82 26.84 26.74 27.62 26.78 27.88 27.18 27.86 27.63 27.69 26.40 27.96 27.29 26.46 27.55 27.37 27.33SiO2 29.32 29.92 29.21 29.58 29.34 30.16 29.75 29.82 29.97 30.28 30.02 29.95 29.31 29.67 29.70 29.55 30.39 29.51 30.07TiO2 35.72 35.69 35.42 35.35 35.86 37.54 36.43 38.29 35.63 35.50 35.98 35.93 35.19 36.82 36.54 35.16 36.40 35.64 36.70ZrO2 0.10 0.15 - 0.14 - - - - - - 0.21 - 0.14 - 0.17 0.16 - 0.11 -SnO2 - - - - - - - - - - - - - - - - - - -Al2O3 1.32 1.34 1.17 1.39 1.07 0.91 0.88 0.69 1.44 1.30 1.26 1.26 1.04 1.04 0.92 1.27 0.97 1.17 0.91V2O3 0.14 0.12 0.10 - 0.13 0.08 0.15 0.16 0.16 0.16 0.12 0.18 0.10 0.07 0.15 0.16 0.11 0.13 -Cr2O3 - - 0.05 - 0.03 - 0.06 - 0.03 0.04 - - - 0.06 - - 0.04 - -Fe2O3 1.86 1.75 1.63 2.25 1.34 1.27 1.36 1.09 2.12 1.81 1.96 1.99 1.77 1.55 1.48 2.38 1.70 1.88 1.46MgO 0.05 - 0.03 0.05 - 0.02 - 0.02 - - - 0.03 0.04 - - 0.07 - 0.05 -MnO 0.14 0.23 0.19 0.09 0.13 0.12 0.11 0.12 0.15 0.14 0.12 0.15 0.17 0.18 0.12 0.11 0.08 0.13 0.18Nb2O5 0.21 0.13 0.41 0.36 0.32 - 0.39 - 0.17 - 0.14 - 0.60 0.10 0.36 0.59 0.26 0.57 0.24Y2O3 0.38 0.32 0.30 0.42 0.44 0.15 0.47 0.09 0.12 - 0.11 - 0.43 - 0.26 0.44 - 0.14 0.17Ce2O3 0.43 0.37 0.71 0.47 0.60 - 0.79 - 0.38 - 0.29 - 0.68 - 0.45 0.74 0.41 0.29 0.30Nd2O3 0.56 - 0.34 - 0.32 - 0.34 - 0.32 - 0.29 - 0.72 0.32 0.25 0.81 - - 0.40Na2O - - - - - - 0.03 - 0.03 - - 0.03 - - - - - - -K2O - - - - - - - - - - 0.02 - - - - - - 0.03 -F 0.38 0.70 0.52 0.56 0.27 0.70 0.30 0.43 1.02 0.99 0.78 0.78 0.48 0.63 0.67 0.61 0.88 0.55 0.51H2O 0.39 0.37 0.22 0.47 0.28 0.18 0.26 0.20 0.30 0.11 0.23 0.28 0.27 0.10 0.09 0.44 0.14 0.29 0.24F=O -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.13 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.23 -0.28 -0.23 -0.23 -0.23 -0.23Total 97.14 97.14 97.14 97.14 97.14 97.14 98.15 97.14 97.14 97.14 97.14 97.14 97.14 97.14 98.35 97.14 97.14 97.14 97.14(a.p.f.u.)Ca site 0.967 0.962 0.971 0.956 0.969 0.974 0.960 0.985 0.960 0.989 0.977 0.981 0.957 0.995 0.975 0.942 0.973 0.980 0.971Si site 0.981 0.993 0.988 0.984 0.993 0.993 0.995 0.983 0.988 1.003 0.991 0.990 0.991 0.986 0.991 0.982 1.002 0.986 0.997Ti site 0.899 0.891 0.901 0.884 0.912 0.930 0.917 0.950 0.884 0.885 0.893 0.894 0.895 0.920 0.917 0.879 0.903 0.896 0.916Zr 0.002 0.002 - 0.002 - - - - - - 0.003 - 0.002 - 0.003 0.003 - 0.002 -Sn - - - - - - - - - - - - - - - - - - -Al 0.052 0.052 0.047 0.055 0.043 0.035 0.035 0.027 0.056 0.051 0.049 0.049 0.042 0.041 0.036 0.050 0.038 0.046 0.036V 0.004 0.003 0.003 - 0.003 0.002 0.004 0.004 0.004 0.004 0.003 0.005 0.003 0.002 0.004 0.004 0.003 0.003 -Cr - - 0.001 - 0.001 - 0.002 - 0.001 0.001 - - - 0.001 - - 0.001 - -Fe 0.052 0.049 0.046 0.063 0.038 0.035 0.038 0.030 0.059 0.050 0.054 0.055 0.050 0.043 0.041 0.066 0.047 0.052 0.040Mg 0.002 - 0.002 0.002 - 0.001 - 0.001 - - - 0.001 0.002 - - 0.004 - 0.003 -Mn 0.004 0.007 0.005 0.003 0.004 0.003 0.003 0.003 0.004 0.004 0.003 0.004 0.005 0.005 0.003 0.003 0.002 0.004 0.005Nb 0.003 0.002 0.006 0.005 0.005 - 0.006 - 0.003 - 0.002 - 0.009 0.001 0.005 0.009 0.004 0.009 0.004Y 0.007 0.006 0.005 0.007 0.008 0.003 0.008 0.002 0.002 - 0.002 - 0.008 - 0.005 0.008 - 0.003 0.003Ce 0.005 0.005 0.009 0.006 0.007 - 0.010 - 0.005 - 0.003 - 0.008 - 0.006 0.009 0.005 0.004 0.004Nd 0.007 - 0.004 - 0.004 - 0.004 - 0.004 - 0.003 - 0.009 0.004 0.003 0.010 - - 0.005Na - - - - - - 0.002 - 0.002 - - 0.002 - - - - - - -K - - - - - - - - - - 0.001 - - - - - - 0.001 -F- 0.040 0.073 0.056 0.059 0.029 0.073 0.032 0.045 0.106 0.103 0.082 0.082 0.051 0.066 0.071 0.064 0.092 0.058 0.053OH- 0.086 0.083 0.049 0.105 0.063 0.039 0.058 0.044 0.066 0.024 0.050 0.062 0.060 0.022 0.021 0.096 0.030 0.065 0.054"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 28 Table B3.4 Electron microprobe analysis of titanite HMC in till from Mount MilliganTill sample: S1303-14.9mSpot No. 1c 1r 2c 2r 3c 3r 4c 4r 5c 5r 6c 6r 8c 8r 9c 9r 10c 10r 11c 11r 12c 12r 13c 13r 14c 14r 15c 15rLocation core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim core rim(wt.%)CaO 26.88 27.94 26.12 27.21 27.34 27.67 27.74 27.63 26.56 27.63 27.48 27.01 26.54 27.47 27.74 27.63 27.54 27.62 26.05 27.77 26.15 27.46 26.90 26.89 27.07 27.73 27.23 27.68SiO2 29.70 30.58 29.10 29.48 29.69 30.36 29.88 29.91 29.63 30.31 29.96 29.60 29.44 29.91 29.42 29.81 29.86 30.02 29.17 29.87 29.09 29.82 29.59 29.13 29.65 29.77 29.41 30.05TiO2 35.98 37.16 35.25 36.85 35.80 36.45 36.41 36.71 35.05 36.96 36.60 36.24 35.18 36.10 36.78 36.88 36.29 36.54 33.99 36.76 34.73 37.11 34.67 36.51 35.42 37.24 35.25 36.30ZrO2 - - - - - - - - 0.12 0.10 - - 0.09 - - - - - - - - 0.10 - - - - - -SnO2 0.11 - - - - 0.09 - - - - - - - - - 0.10 - - - - - - - - - - - -Al2O3 1.19 1.07 1.07 0.89 1.08 1.00 1.02 0.94 1.20 0.99 1.15 1.02 1.24 1.31 0.82 0.77 1.02 1.11 1.46 1.01 1.01 0.90 1.23 1.00 1.30 0.87 1.13 1.11V2O3 0.10 0.09 0.08 - 0.19 0.06 0.24 - 0.16 0.16 0.10 - 0.16 0.15 - - 0.14 0.12 0.11 0.12 0.17 0.08 0.11 0.15 0.09 0.14 0.12 0.13Cr2O3 - - - - 0.05 - 0.06 - 0.05 - - - 0.06 - - - 0.04 - - - - - - 0.03 - - - -Fe2O3 1.67 1.37 1.88 1.44 1.48 1.60 1.57 1.44 2.12 1.65 1.89 1.82 1.81 1.87 1.35 1.29 1.76 1.59 2.19 1.26 2.25 1.56 2.04 1.59 2.18 1.25 1.89 1.89MgO 0.03 - 0.03 - - - 0.04 - 0.06 0.03 0.04 0.03 0.03 0.03 0.02 0.02 0.03 - 0.03 0.03 0.07 0.04 - - - 0.03 0.06 0.02MnO 0.09 0.16 0.13 0.18 0.08 0.11 0.15 0.10 0.09 0.06 0.17 0.11 0.16 0.16 0.11 0.15 0.16 0.08 0.23 0.17 0.08 0.17 0.17 0.14 0.15 0.12 0.13 0.17Nb2O5 0.21 - 0.34 0.16 - 0.17 - 0.11 0.31 0.11 0.16 0.26 0.29 0.11 - - - - 0.29 0.11 1.21 - 0.27 0.57 0.40 0.10 0.35 0.11Y2O3 0.42 - 0.74 0.26 0.09 0.08 - - 0.62 - 0.12 0.32 0.47 0.26 - - - - 0.83 - 0.22 0.12 0.42 0.30 0.27 0.11 0.15 -Ce2O3 0.41 - 0.86 0.36 0.38 - - 0.24 0.78 0.41 0.27 0.57 0.54 0.45 - - - - 0.92 0.23 1.17 0.30 0.54 0.85 0.58 0.30 0.37 0.34Nd2O3 0.46 - 0.78 - - - - - 0.54 0.35 - 0.27 0.52 - - 0.30 - - 1.09 - 0.73 0.32 0.44 0.30 - - - -Na2O - - 0.04 0.04 - - - - 0.05 - - - - 0.03 0.03 0.05 - - - - 0.06 - - - - - - 0.03K2O - - - - - - - - - - - - - - - - - - - 0.03 - - - - - - - -F - 0.81 0.28 0.31 0.36 0.29 - - 0.64 0.54 0.57 0.36 0.59 0.81 0.30 0.54 0.60 0.61 0.65 0.54 0.68 0.86 0.48 - 0.34 0.42 0.46 0.72H2O 0.05 -0.11 -0.18 -0.04 -0.09 0.01 0.06 -0.04 -0.26 -0.11 -0.03 -0.09 -0.14 -0.22 -0.16 -0.24 -0.10 -0.10 -0.34 -0.15 -0.34 -0.27 -0.24 -0.03 -0.06 -0.15 -0.19 -0.21F=O -0.07 -0.34 -0.12 -0.13 -0.15 -0.12 -0.10 -0.09 -0.27 -0.23 -0.24 -0.15 -0.25 -0.34 -0.13 -0.23 -0.25 -0.26 -0.27 -0.23 -0.29 -0.36 -0.20 -0.06 -0.14 -0.18 -0.19 -0.30Total 95.81 97.41 94.54 95.69 94.93 96.39 95.93 95.93 95.34 97.33 96.49 95.72 94.97 96.25 95.19 96.03 95.45 96.04 94.21 96.37 94.83 96.76 94.41 96.04 95.34 96.69 94.54 96.38(a.p.f.u.)Ca site 0.984 0.997 0.978 0.996 1.007 1.001 1.008 1.007 0.982 0.994 0.994 0.991 0.982 0.998 1.020 1.008 1.005 1.002 0.981 1.008 0.978 0.995 1.002 0.988 0.996 1.005 1.011 1.005Si site 1.015 1.019 1.016 1.007 1.021 1.025 1.014 1.017 1.023 1.017 1.011 1.013 1.017 1.015 1.010 1.016 1.018 1.017 1.025 1.012 1.016 1.008 1.029 0.999 1.018 1.007 1.019 1.018Ti site 0.925 0.931 0.926 0.947 0.926 0.925 0.929 0.939 0.910 0.933 0.930 0.933 0.914 0.921 0.950 0.945 0.930 0.931 0.898 0.937 0.912 0.944 0.907 0.941 0.915 0.948 0.919 0.925Zr - - - - - - - - 0.002 0.002 - - 0.002 - - - - - - - - 0.002 - - - - - -Sn 0.002 - - - - 0.001 - - - - - - - - - 0.001 - - - - - - - - - - - -Al 0.048 0.042 0.044 0.036 0.044 0.040 0.041 0.038 0.049 0.039 0.046 0.041 0.051 0.052 0.033 0.031 0.041 0.044 0.061 0.040 0.042 0.036 0.051 0.040 0.053 0.035 0.046 0.044V 0.003 0.002 0.002 - 0.005 0.002 0.006 - 0.004 0.004 0.003 - 0.004 0.004 - - 0.004 0.003 0.003 0.003 0.005 0.002 0.003 0.004 0.002 0.004 0.003 0.004Cr - - - - 0.001 - 0.002 - 0.001 - - - 0.002 - - - 0.001 - - - - - - 0.001 - - - -Fe 0.047 0.037 0.054 0.040 0.042 0.044 0.043 0.040 0.059 0.045 0.052 0.051 0.051 0.052 0.038 0.036 0.049 0.044 0.062 0.035 0.064 0.043 0.057 0.045 0.061 0.035 0.053 0.052Mg 0.002 - 0.001 - - - 0.002 - 0.003 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 - 0.002 0.001 0.004 0.002 - - - 0.001 0.003 0.001Mn 0.003 0.005 0.004 0.005 0.002 0.003 0.004 0.003 0.003 0.002 0.005 0.003 0.005 0.004 0.003 0.004 0.005 0.002 0.007 0.005 0.002 0.005 0.005 0.004 0.004 0.003 0.004 0.005Nb 0.003 - 0.005 0.002 - 0.003 - 0.002 0.005 0.002 0.002 0.004 0.005 0.002 - - - - 0.005 0.002 0.019 - 0.004 0.009 0.006 0.002 0.005 0.002Y 0.008 - 0.014 0.005 0.002 0.001 - - 0.011 - 0.002 0.006 0.009 0.005 - - - - 0.015 - 0.004 0.002 0.008 0.006 0.005 0.002 0.003 -Ce 0.005 - 0.011 0.005 0.005 - - 0.003 0.010 0.005 0.003 0.007 0.007 0.006 - - - - 0.012 0.003 0.015 0.004 0.007 0.011 0.007 0.004 0.005 0.004Nd 0.006 - 0.010 - - - - - 0.007 0.004 - 0.003 0.006 - - 0.004 - - 0.014 - 0.009 0.004 0.005 0.004 - - - -Na - - 0.003 0.002 - - - - 0.004 - - - - 0.002 0.002 0.003 - - - - 0.004 - - - - - - 0.002K - - - - - - - - - - - - - - - - - - - 0.001 - - - - - - - -F- - 0.086 0.031 0.033 0.040 0.031 - - 0.070 0.057 0.061 0.039 0.065 0.087 0.033 0.058 0.064 0.065 0.072 0.058 0.075 0.092 0.052 - 0.037 0.045 0.050 0.077OH- 0.012 -0.024 -0.041 -0.010 -0.021 0.002 0.014 -0.009 -0.061 -0.026 -0.007 -0.021 -0.032 -0.050 -0.036 -0.055 -0.022 -0.023 -0.080 -0.033 -0.080 -0.061 -0.056 -0.006 -0.014 -0.033 -0.044 -0.048"-" represents value below detection limits.Structural formula calculated on the basis of O = 5 atoms2 29 Appendix C Laser ablation ICP-MS Analytical Data Tables C1. LA-ICP-MS analyses in thick sections Tables C2. LA-ICP-MS analyses in SELFRAG concentrates Table C3. LA-ICP-MS analyses in till concentrates 2 30 Table C1.1 LA-ICP-MS analyses of titanite from Mount Polley (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE∑ MREE∑ HREEs4t1a core 993 38 1900 1403 377 51 25 57 20 660 1925 275 1294 315 79 306 49 329 68 204 31 196 25 5756 4154 1078 524s4t1b rim 989 1 2252 1521 390 57 30 58 19 718 2163 330 1629 436 101 420 65 427 86 245 35 208 25 6887 4840 1449 598s1t1a core 999 1 1959 1506 434 53 29 61 18 660 1997 290 1380 331 85 317 51 349 72 212 31 187 22 5983 4327 1133 524s1t1b rim 1042 1 2116 1546 366 59 27 57 19 687 2059 306 1491 377 91 368 58 394 79 226 33 198 24 6390 4543 1287 561s5t1a core 1110 - 1910 1254 328 44 22 56 20 679 1938 283 1342 359 86 354 53 349 70 201 28 166 21 5929 4242 1201 486s5t1b rim 2730 3 1320 6200 291 210 17 130 143 498 1470 191 858 226 71 208 33 226 46 141 21 157 25 4171 3017 763 390s3t1a core 1065 1 2038 1491 416 57 32 58 19 756 2216 325 1589 394 95 382 59 385 77 215 31 190 23 6736 4886 1315 535s3t1b rim 1500 17 1500 1970 386 80 22 136 53 815 2220 280 1285 277 74 268 42 270 55 159 25 161 21 5951 4600 931 421s2t1a core 1027 - 2369 1479 424 55 34 59 19 729 2183 335 1675 436 108 435 69 455 91 253 36 215 26 7045 4922 1503 621s2t1b rim 1017 1 2152 1366 356 52 31 49 17 599 1883 303 1596 437 110 429 66 433 85 232 31 185 22 6410 4381 1475 554s4t1a core 1613 2 2451 1584 465 60 39 68 18 940 2848 424 2098 507 112 471 74 477 94 259 36 205 24 8569 6310 1641 618s4t1b rim 1218 3 1450 950 267 36 22 36 13 550 1610 234 1170 288 61 279 44 288 55 157 21 126 14 4898 3564 960 374s2t1a core 1759 9 2207 1567 373 56 31 53 19 823 2504 377 1817 451 103 427 67 426 83 235 32 183 21 7549 5521 1473 555s2t1b rim 1470 25 870 790 180 28 11 30 11 344 1050 164 740 186 42 165 26 169 33 91 14 85 9 3118 2298 588 232s1t1 core 1950 119 1690 2430 384 69 27 97 49 759 2210 317 1410 331 75 310 48 317 64 181 27 158 20 6226 4696 1081 450s1t2 core 1572 1 2336 1437 374 54 30 54 16 866 2661 408 1933 466 109 441 70 447 89 248 34 194 22 7987 5868 1533 586s3t1a core 2105 2 1832 1457 337 55 25 42 15 709 2129 339 1622 405 95 373 57 366 69 191 26 151 17 6550 4799 1296 455s3t1b rim 1980 4 2100 2620 451 80 32 61 32 844 2533 386 1730 418 90 378 60 400 80 218 31 180 20 7369 5493 1346 530s3t2 core 2188 148 1397 2480 264 107 8 110 107 544 1450 212 1002 273 86 279 44 299 58 166 24 144 15 4597 3208 982 407s4t2 core 1464 186 436 1770 109 32 4 49 96 612 1052 121 475 96 63 87 13 80 16 46 6 33 3 2704 2260 339 105s1t2 core 1142 50 104 543 33 10 2 7 36 147 232 23 83 15 30 14 3 18 4 12 2 12 1 595 485 79 30s2t2 core 2120 1320 703 1900 780 33 15 103 287 799 2090 250 930 181 61 151 21 156 28 65 10 53 5 4799 4069 570 160s2t1 core 1740 176 652 2238 233 63 11 51 224 819 1740 199 746 150 67 130 18 122 24 69 10 72 8 4175 3504 487 184"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuPTB045P-6WB04109-269mThick Section2 31 Table C1.2 LA-ICP-MS analysis of titanite from Mount Milligan (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEs1t1a core 1002 - 141 1613 433 40 28 90 8 208 467 57 235 41 27 34 4 26 5 15 2 16 3 1140 967 91 42s1t1b rim 2160 2 142 1270 1200 25 26 221 43 281 496 48 144 22 23 22 4 26 5 14 3 18 3 1108 969 75 42s4t1a core 1330 27 122 920 635 23 27 124 77 231 420 46 163 27 21 25 4 19 4 13 2 13 2 990 860 69 34s4t1b rim 3440 53 142 43 425 2 49 12 3 91 235 34 152 38 18 39 4 29 5 13 2 12 1 672 512 90 33s2t1a core 1003 1 469 990 1163 30 29 148 86 453 1387 183 723 126 68 100 15 92 19 56 9 58 10 3298 2746 275 151s2t1b rim 1308 1 794 316 1440 8 18 310 226 819 2470 343 1420 252 112 193 26 163 33 101 15 107 17 6069 5052 493 272s5t1a core 1451 1 181 105 485 2 4 9 - 110 230 32 157 38 20 38 6 34 6 19 3 15 2 708 529 97 45s5t1b rim 1702 - 264 319 910 7 14 9 1 80 295 51 261 67 22 61 9 54 10 26 3 19 2 960 687 146 60s3t1a core 1175 9 2188 204 1614 8 17 171 32 510 2105 372 1891 498 130 436 70 468 92 278 44 295 37 7225 4878 1104 746s3t1b rim 1504 - 877 2250 2370 64 60 345 172 748 2050 275 1166 229 94 193 28 181 35 105 16 105 15 5238 4239 495 275s2t1a core 4110 1 1179 2147 74 62 4 35 69 6 39 11 102 69 22 135 27 201 42 118 16 102 13 902 158 384 291s2t1b rim 3230 1 745 906 80 44 4 18 20 29 85 14 96 47 19 87 16 122 26 77 11 65 9 702 224 244 187s1t2 core 1950 46 448 303 124 14 4 33 31 177 473 64 294 67 30 79 12 84 17 51 7 43 6 1405 1008 205 125s3t1a core 5060 21 380 167 80 5 1 9 54 22 76 11 51 20 10 25 7 63 17 35 6 42 6 390 160 105 105s3t1b rim 4890 35 158 143 79 5 2 4 18 25 63 8 35 14 5 12 5 35 7 24 3 17 1 253 131 57 51"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to Lu06948-63.4m111015_238mThick section2 32 Table C1.3 LA-ICP-MS analysis of titanite from Copper Mountain (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEs4t2 core 3280 6 247 89 86 6 6 2 17 32 159 29 163 52 12 49 7 48 9 25 3 22 2 612 383 168 61s5t1a core 839 2 864 270 138 5 6 16 38 103 413 73 423 148 22 173 25 159 32 90 13 79 11 1764 1012 526 225s5t1b rim 709 1 936 72 114 3 6 3 7 73 371 79 495 183 24 201 30 187 36 99 12 72 9 1870 1018 625 227s1t2 core 1810 4 1220 191 253 8 14 174 192 247 1010 171 890 262 41 253 36 224 44 126 18 113 14 3449 2318 816 315s2t2 core 795 - 93 50 21 1 - 12 25 47 165 25 122 30 13 22 3 21 3 10 2 11 1 475 359 89 27s3t2 core 188 5 55 3 6 - - 10 4 84 164 19 91 18 7 14 1 10 2 6 - 4 - 419 358 50 11s1t2 core 3394 - 429 1624 167 81 13 30 11 78 436 80 411 85 49 73 11 72 15 44 7 44 4 1409 1006 290 113s3t1 core 3860 1 578 8130 830 218 48 150 40 398 1190 153 660 139 41 119 17 113 20 62 9 58 7 2987 2401 429 157s3t2 core 4190 3 525 2530 494 72 19 273 41 600 1480 174 751 161 44 120 16 106 19 55 8 56 7 3596 3005 446 145s4t2 core 3150 4 395 4020 338 110 18 75 41 176 670 98 442 96 35 76 12 73 13 40 6 35 4 1776 1386 292 98s2t2 core 2770 - 453 1273 170 50 14 31 9 133 476 74 361 86 29 81 12 81 15 47 7 43 5 1448 1043 288 116s5t1a core 1910 38 139 1490 169 43 32 7 54 7 19 3 17 9 21 15 3 22 5 19 3 22 3 166 45 69 51s5t1b rim 8980 160 730 910 270 30 38 74 224 330 800 123 630 193 76 185 26 138 26 71 10 60 8 2676 1883 618 175s5t2a core 7930 6 444 264 129 21 9 18 38 59 191 31 158 52 66 66 11 75 17 51 7 49 6 838 439 270 130s5t2b rim 9610 2 453 171 110 13 9 11 35 29 97 16 93 38 86 58 10 79 17 52 7 46 6 633 235 271 127s3t1a core 2132 - 127 920 122 40 4 4 87 1 5 1 10 7 20 13 3 21 5 17 3 19 2 129 18 64 46s3t1b rim 2049 3 87 1330 121 46 5 3 80 3 8 - 8 6 13 10 2 15 3 12 2 12 1 95 19 45 31s2t2a core 4825 - 721 172 25 13 2 12 15 152 580 103 572 168 66 163 24 144 26 72 10 66 8 2155 1407 564 184s2t2b rim 4235 1 514 403 93 25 7 17 74 147 540 87 422 109 54 104 16 93 20 53 8 54 7 1713 1196 376 141s2t1a core 4510 - 1076 393 212 40 13 174 40 488 1599 248 1176 283 89 259 36 214 40 107 15 99 12 4664 3511 881 272s2t1b rim 2030 - 102 176 27 11 2 6 12 26 82 14 79 25 10 23 4 22 4 12 2 12 1 315 201 84 31s2t3a core 5520 - 278 473 111 30 9 12 49 43 122 18 94 29 33 40 7 48 11 34 5 37 5 525 277 157 91s2t3b rim 4690 - 369 291 151 17 6 18 61 58 141 20 101 34 44 49 8 62 14 43 7 47 6 635 321 198 116s4t1a core 8520 - 443 74 75 8 6 4 26 13 41 8 44 24 64 44 9 75 17 49 7 45 5 445 105 217 124s4t1b rim 7890 - 368 462 139 34 11 20 49 30 96 17 91 40 89 58 10 66 14 39 6 37 5 596 234 262 100s1t1a core #### 5 547 94 97 8 5 7 34 21 60 10 60 32 78 55 12 90 20 64 9 58 7 575 151 266 158s1t1b rim 3280 1 317 1940 243 118 14 10 141 9 35 8 60 35 44 55 9 58 12 36 5 37 5 406 111 201 94"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuCMT-13CM14-15CM12P223-352mThick section2 33 Table C2.1 LA-ICP-MS analysis of titanite HMC of bedrocks from Mount Polley (ppm)Spot No. Location V Cu Y Nb Ta La Ce Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEP3-1a core 1659 18 1739 142 5 511 1494 1016 269 80 279 45 305 62 180 26 163 18 4447 3021 977 449P3-1b rim 1864 18 1599 142 8 586 1720 1250 320 96 304 46 289 56 150 21 119 12 4969 3556 1055 358P3-2a core 1386 - 2436 321 19 844 2497 1575 383 112 390 63 426 89 259 38 235 25 6935 4916 1374 645P3-2b rim 968 3 2520 207 12 778 2334 1540 404 112 410 66 451 93 273 41 268 35 6805 4652 1444 709P3-3a core 1879 1 2823 291 15 1046 2807 1953 505 134 483 75 496 98 272 38 218 22 8145 5806 1692 647P3-3b rim 1787 60 2254 168 7 639 1925 1312 344 102 347 56 385 80 233 34 211 24 5693 3876 1235 582P3-5a core 853 17 2852 271 11 860 2516 1550 407 117 427 70 485 101 297 45 291 37 7204 4926 1507 771P3-5b rim 1009 31 2305 191 11 794 2407 1515 373 115 368 59 397 83 246 37 240 30 6662 4716 1310 636P3-7a core 1129 10 2377 251 16 825 2338 1450 359 109 371 58 402 83 246 36 231 29 6538 4613 1299 625P3-7b rim 839 6 2466 266 16 838 2509 1537 376 116 392 63 426 88 260 39 257 34 6935 4884 1372 678P3-9a core 1360 94 1597 265 16 753 1717 1044 265 69 261 42 287 59 169 25 157 18 4867 3514 925 429P6-1a core 1214 - 2890 287 33 695 2358 2121 595 133 582 92 592 111 298 39 214 24 7855 5174 1994 686P6-2a core 1960 2 1910 535 34 898 2505 1653 388 93 359 56 361 70 195 27 155 18 6777 5056 1257 464P6-3a core 1644 - 2740 484 42 946 2854 2062 516 114 499 79 518 101 282 38 219 25 8252 5862 1725 665P6-4a core 1834 1 2314 501 40 910 2626 1753 417 95 395 63 413 83 235 33 191 22 7234 5289 1382 564P6-4b rim 2121 - 2238 518 43 892 2583 1771 422 99 398 62 405 81 228 31 180 21 7173 5246 1387 540P6-5a core 1584 - 2914 528 46 1029 3089 2207 547 121 556 84 547 108 300 42 233 27 8889 6325 1855 709P6-6a core 1909 1 2501 492 43 1045 2975 2018 484 106 476 72 468 91 259 35 201 23 8252 6038 1606 609P6-7a core 1923 5 2365 504 37 993 2773 1725 393 85 390 60 406 83 241 34 203 24 7410 5491 1334 585"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuP-3P-6Rock Sample2 34 Table C2.2 LA-ICP-MS analysis of titanite HMC of bedrocks from Copper Mountain (ppm)Spot No. Location V Cu Y Nb Ta La Ce Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREECMT-13 C13a core 3610 47 750 132 3 553 1565 816 180 50 154 22 140 28 79 11 73 11 3682 2934 547 201C65_10a core 2891 1 872 214 10 623 1757 1055 234 57 190 26 158 30 87 13 83 11 4323 3434 664 225C65_10b rim 2692 3 583 328 30 689 1910 1001 194 61 143 18 107 21 62 10 67 10 4291 3600 523 168C65_1a core 2379 - 517 757 16 929 2428 1198 206 72 142 17 96 19 55 9 59 9 5238 4555 532 151C65_2a core 3140 2 805 426 28 906 2367 1265 256 74 196 25 148 29 84 13 85 12 5458 4538 698 222C65_3a core 3317 - 664 295 11 796 2067 1104 213 66 162 21 122 24 70 11 73 11 4739 3967 584 189C65_4a core 3845 - 409 126 3 754 1855 822 139 46 103 13 75 15 43 7 45 7 3923 3431 376 117C65_4b rim 3620 - 449 114 4 655 1725 785 146 45 110 14 87 16 49 8 47 8 3695 3165 403 128C65_6a core 2873 1 862 486 21 805 2196 1219 251 68 197 26 152 29 85 13 88 13 5143 4220 694 229C65_7a core 2429 8 774 647 46 1113 2828 1402 261 79 191 24 138 26 77 12 81 12 6245 5343 694 209C65_8a core 4765 1 488 171 2 1081 2593 1137 175 61 126 16 89 17 51 8 57 9 5419 4811 466 142C7_1a core 5650 8 488 112 3 326 947 487 112 51 109 15 90 18 49 7 43 6 2258 1760 376 122C7_2a core 5290 62 671 495 18 435 985 528 127 39 117 19 126 26 81 13 93 13 2601 1948 427 226C7_3a core 4095 47 340 110 5 477 1106 447 83 44 73 10 64 13 38 6 41 6 2408 2030 275 104C7_5a core 4713 5 1130 343 21 812 2150 1004 215 64 183 28 180 37 114 19 132 18 4955 3966 669 320"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuCM12P221-65mCMT-7Rock Sample2 35 Table C3.1 LA-ICP-MS analysis of titanite HMC in till from Mount Milligan (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEMT12_1a core 730 3 2147 479 1238 42 159 158 39 1097 3533 499 2005 377 88 318 49 329 71 231 39 280 39 8954 7134 1160 660MT12_1b rim 727 - 1312 461 1334 35 115 244 64 1052 2980 372 1367 217 73 180 28 183 41 135 25 190 30 6871 5771 681 420MT12_2a core 611 - 585 1588 473 99 24 243 138 590 1169 133 561 123 24 112 17 109 22 62 9 65 10 3004 2452 385 168MT12_2b rim 559 1 612 1006 632 36 14 368 315 765 1488 167 682 141 27 128 19 118 23 64 9 68 11 3709 3102 432 175MT12_8a core 737 2 814 517 590 30 20 425 130 678 1727 215 928 195 63 178 26 162 32 89 13 86 13 4405 3548 624 233MT12_8b rim 747 1 796 520 541 30 18 388 127 639 1632 204 877 186 59 168 24 158 31 86 13 88 13 4177 3351 595 230MT12_9a core 680 2 669 537 525 33 40 165 46 1069 2695 280 872 112 36 86 13 85 20 71 13 111 18 5480 4916 332 232MT12_9b rim 639 4 417 467 541 31 28 189 59 1033 1978 159 480 78 22 67 10 62 13 43 8 75 14 4043 3650 239 154MT13_1a core 724 1 870 517 712 48 43 317 251 1410 2696 272 989 181 41 151 23 145 30 92 15 119 19 6184 5367 541 276MT13_1b rim 732 - 403 509 402 32 20 226 72 688 1236 110 393 85 25 75 11 76 15 44 7 56 10 2830 2427 272 132MT13_1c rim 720 12 1120 311 653 29 45 219 100 1050 2381 278 1132 238 52 206 31 204 40 117 18 126 19 5892 4841 731 320MT13_6a core 962 1 486 976 300 52 10 656 215 812 1640 173 651 115 44 97 13 87 18 51 8 57 9 3775 3276 356 143MT13_6b rim 957 2 498 743 223 41 9 602 198 782 1598 171 672 121 45 105 14 91 18 53 8 57 9 3744 3223 376 145MT13_6c rim 1004 3 399 746 275 40 8 530 168 821 1634 167 610 104 37 85 12 73 14 41 7 45 7 3657 3232 311 115"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuMT-12MT-13Till Sample2 36 Table C3.2 LA-ICP-MS analysis of titanite HMC in till from Mount Milligan (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEMT15_1a core 846 1 862 1180 997 90 18 504 106 727 1687 202 844 182 42 159 24 155 31 89 14 95 14 4266 3460 563 242MT15_1b rim 714 - 516 1595 379 149 12 349 93 415 842 102 457 110 23 102 15 102 20 57 9 60 9 2321 1815 352 154MT15_2a core 841 1 2330 772 2825 67 147 623 98 1866 5016 640 2546 490 100 420 63 404 82 244 37 246 31 12184 10068 1477 640MT15_2b rim 829 - 486 600 382 46 8 317 81 601 1171 124 472 95 25 87 13 86 17 51 8 56 9 2816 2368 306 142MT15_3a core 825 11 719 528 617 42 15 379 150 684 1490 172 700 141 34 131 20 132 25 77 12 82 13 3711 3046 458 208MT15_3b rim 781 - 2260 926 1557 65 103 291 60 1104 3394 496 2270 509 91 460 67 434 84 244 36 224 30 9442 7264 1561 617MT15_4a core 809 - 4489 1259 2355 104 378 329 54 1489 5058 825 3991 1009 137 907 141 890 170 472 64 370 42 15564 11363 3084 1117MT15_4b rim 810 23 3520 869 1676 54 178 242 50 1196 4150 654 3160 799 114 716 108 682 130 360 48 295 35 12447 9160 2419 868MT15_5a core 741 - 6561 687 2804 48 312 301 50 2173 8300 1420 7030 1773 145 1479 226 1378 253 669 85 496 53 25480 18923 5002 1556MT15_6a core 719 1 584 649 663 51 15 714 143 745 1390 150 593 121 31 108 17 107 22 62 9 69 10 3433 2877 384 172MT15_6b rim 751 4 440 609 470 37 10 611 139 649 1124 120 481 96 25 89 13 85 16 47 7 49 8 2806 2373 307 126MT15_7a core 837 - 5040 956 2215 63 316 280 45 1587 5576 935 4634 1187 178 1061 161 1005 190 543 71 404 46 17578 12732 3592 1254MT15_7b rim 839 - 4949 1026 1874 72 272 256 47 1473 5210 862 4340 1110 168 1013 153 968 184 530 70 405 47 16532 11885 3411 1235MT15_8a core 889 - 4691 1192 2070 104 393 287 54 1472 5060 837 4102 1046 153 935 146 938 177 517 68 392 44 15887 11471 3218 1198MT15_8b rim 884 - 1920 568 835 56 255 361 509 1080 2580 372 1730 454 74 422 66 409 77 216 29 171 21 7700 5762 1425 513MT15_9a core 784 69 893 1085 3380 81 264 808 161 1822 3390 310 1036 181 44 163 23 154 31 97 16 121 19 7406 6558 565 283MT15_9b rim 755 47 673 694 1040 52 67 481 137 1151 2065 194 696 132 37 116 18 119 23 72 12 86 14 4735 4106 422 207MT15_11a core 617 - 1173 643 1548 47 120 380 77 1541 3665 389 1331 226 49 187 28 180 38 123 20 156 24 7956 6926 670 361MT15_11b rim 585 1 710 658 1274 56 65 601 115 1188 2103 211 814 161 45 137 20 128 26 73 11 79 12 5009 4316 491 201MT15_12a core 842 1 301 825 253 43 10 131 146 269 528 66 284 64 15 57 9 57 11 33 5 37 6 1443 1147 203 92MT15_12b rim 885 - 375 565 225 28 10 287 86 241 507 68 316 80 14 73 11 75 14 40 7 43 6 1496 1133 253 110MT15_13a core 884 - 2336 992 1123 60 65 273 62 1091 3320 485 2241 503 90 463 68 434 86 246 35 225 29 9317 7137 1558 622MT15_13b rim 854 - 1187 544 585 41 12 321 77 808 2059 263 1130 240 55 229 33 212 42 126 18 127 18 5362 4260 770 332MT15_14a core 755 1 404 427 317 42 11 354 345 913 1340 127 465 87 25 72 10 69 14 42 7 50 9 3230 2845 264 121MT15_14b rim 698 - 2365 621 1557 43 136 321 66 1817 5400 699 2687 477 71 384 57 377 78 252 39 262 36 12637 10603 1366 668MT15_15a core 744 1 531 466 488 29 18 509 212 685 1213 131 510 107 28 93 14 94 19 58 9 64 10 3033 2539 335 160MT15_15b rim 669 4 679 839 719 57 36 650 237 838 1492 165 645 137 31 119 18 119 25 75 11 80 13 3769 3140 425 205"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuMT15Till Sample2 37 Table C3.3 LA-ICP-MS analysis of titanite HMC in till from Mount Milligan (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREEMT16_1a core 978 1 3748 1024 1488 52 166 170 36 1140 4318 752 3850 1043 170 894 134 832 151 379 52 287 32 14035 10060 3074 901MT16_1b rim 874 - 1923 723 1355 42 101 218 45 1119 3530 499 2159 452 91 373 54 344 68 192 30 193 25 9129 7307 1314 507MT16_2a core 696 3 1074 830 2819 81 124 727 117 1567 3422 349 1226 230 56 184 28 187 38 110 18 131 20 7566 6564 685 317MT16_2b rim 674 3 928 735 2437 75 108 727 126 1459 3057 305 1050 201 52 163 24 159 32 95 16 115 17 6746 5871 600 275MT16_4a core 808 1 2658 820 2306 58 132 369 67 1495 4638 668 2974 658 109 555 82 515 97 273 39 244 30 12376 9775 1918 683MT16_4b rim 818 6 2120 674 1460 46 76 368 227 1154 3430 489 2180 501 83 427 64 404 78 220 32 197 25 9283 7253 1479 552MT16_5a core 641 - 2663 840 3599 70 334 434 74 2064 6260 808 3065 566 86 443 69 442 90 284 46 300 40 14562 12197 1606 759MT16_5b rim 633 10 1609 608 2292 45 180 386 79 1805 4893 554 1915 316 60 247 38 250 52 171 28 201 28 10557 9167 910 480MT16_6a core 930 - 668 368 140 26 7 611 403 884 1681 194 791 168 39 146 22 134 26 73 10 71 11 4248 3550 508 190MT16_6b rim 948 - 608 369 104 26 5 622 391 848 1561 178 715 151 37 130 20 121 23 65 10 68 10 3937 3302 459 176MT16_7a core 858 2 2683 527 2678 49 204 536 85 1841 5732 842 3829 856 126 671 98 565 103 274 37 218 26 15217 12244 2316 658MT16_7b rim 869 4 2038 747 1560 74 114 578 112 1166 3610 527 2407 551 94 473 70 407 79 211 29 172 21 9816 7710 1594 511MT16_8a core 776 5 2677 1166 1915 78 200 320 61 1232 3966 590 2703 623 108 547 82 512 102 281 41 244 31 11062 8491 1872 699MT16_8b rim 851 - 1861 768 967 50 55 285 65 982 2971 414 1788 399 79 346 53 332 67 190 29 193 26 7869 6155 1209 506MT16_9a core 839 - 2072 919 1109 57 63 203 44 1117 3373 461 1996 448 82 390 57 378 76 213 33 209 27 8859 6947 1355 558MT16_9b rim 765 - 1220 611 968 47 28 286 60 989 2554 317 1276 268 64 233 34 221 44 127 20 136 19 6301 5136 820 346MT16_10a core 763 5 675 633 1467 48 87 654 121 1303 2614 262 921 166 52 132 18 120 24 68 11 78 12 5781 5100 488 193MT16_10b rim 761 - 581 510 679 32 39 375 93 845 1808 188 681 127 41 108 16 104 21 59 10 69 11 4087 3522 395 170MT16_11a core 889 - 3303 1139 2840 80 272 359 64 1584 5080 752 3390 787 117 679 99 635 123 337 50 303 36 13970 10806 2317 848MT16_11b rim 829 1 3576 1405 3280 107 316 399 65 1599 5150 758 3450 808 121 717 105 678 131 360 53 319 38 14287 10957 2429 901MT16_12a core 955 - 7860 1107 4785 83 522 742 138 3542 #### 1852 8290 1909 198 1575 247 1549 292 797 111 616 67 33214 25854 5478 1882MT16_12b core 889 - 6733 836 4312 72 583 577 94 3369 #### 1784 8020 1830 178 1461 223 1370 252 672 91 504 54 31537 24903 5061 1573MT16_13a core 970 - 2918 585 1768 55 207 710 155 1990 6000 785 3242 654 82 552 82 516 104 301 46 299 38 14691 12017 1886 788MT16_13b rim 907 1 3983 606 2013 81 258 544 118 1979 6570 927 3993 875 96 733 111 703 137 405 60 377 46 17010 13468 2517 1025MT16_14a core 1003 8 4206 782 3359 59 332 350 73 2012 8160 1294 5954 1354 104 1020 149 883 159 427 59 344 39 21956 17420 3510 1026MT16_14b core 902 2 3398 748 5010 67 638 488 69 2330 8650 1267 5400 1110 102 809 116 676 126 355 49 302 34 21326 17647 2813 867MT16_15a core 690 - 1000 1109 2034 64 111 577 113 1153 2514 276 1037 210 69 181 27 180 36 109 17 115 17 5940 4980 667 293MT16_15b rim 699 2 936 790 1870 50 147 510 93 1276 2880 310 1131 211 79 172 26 167 32 102 15 109 15 6526 5597 655 274"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuMT16Till Sample2 38 Table C3.4 LA-ICP-MS analysis of titanite HMC in till from Mount Milligan (ppm)Spot No. Location V Cu Y Zr Nb Hf Ta Th U La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu ∑ REE ∑ LREE ∑ MREE ∑ HREES103_1a core 981 - 4291 957 1156 48 134 177 36 1065 4083 712 3780 1055 180 974 147 929 166 452 59 335 37 13975 9640 3286 1049S103_1b rim 969 - 4363 949 1100 47 130 172 36 1089 4159 727 3812 1068 182 982 151 942 168 455 59 330 37 14160 9787 3324 1049S103_2a core 648 - 2500 545 1991 57 140 360 259 2062 5200 670 2780 573 67 484 74 468 90 273 40 252 32 13065 10712 1666 687S103_2b rim 736 - 3930 627 1700 42 175 290 63 1951 6573 946 3987 822 94 675 105 674 132 406 61 378 46 16849 13457 2369 1023S103_3a core 1098 - 970 457 505 22 17 519 158 692 1802 244 1069 238 54 210 31 190 36 101 14 84 11 4776 3807 724 245S103_3b rim 1108 - 959 465 500 23 16 522 149 698 1800 241 1059 232 55 208 31 186 35 100 14 86 11 4754 3797 711 246S103_4a core 942 2 338 304 356 11 13 196 252 422 799 93 365 79 21 65 10 63 12 38 6 42 6 2020 1679 238 103S103_4b rim 808 - 722 727 1050 18 35 1138 1000 711 1293 158 674 153 33 139 21 141 27 80 12 86 13 3541 2836 487 218S103_5a core 998 1 1836 866 1849 53 149 333 60 1395 4092 535 2167 416 85 352 53 330 65 195 29 186 23 9923 8189 1236 498S103_5b rim 960 3 1091 635 1422 58 96 326 173 1183 2936 347 1349 248 59 213 30 192 38 113 17 117 16 6860 5815 743 302S103_6a core 691 - 1586 640 2470 52 203 403 75 1990 5290 599 2131 345 63 279 40 257 52 157 27 190 27 11445 10010 983 452S103_6b rim 638 1 2290 546 2842 42 248 397 68 2184 6567 804 3032 527 79 418 59 380 77 229 37 253 33 14679 12587 1462 630S103_8a core 804 - 3512 1125 1926 80 213 287 56 1335 4665 713 3371 793 119 714 104 666 129 352 52 316 37 13366 10084 2396 886S103_8b rim 836 3 2670 894 1497 55 115 244 58 1103 3684 548 2509 577 93 516 75 486 94 263 41 262 31 10279 7843 1746 690S103_9a core 582 1 721 569 931 40 37 451 92 1032 1904 197 770 172 41 152 22 139 27 73 11 79 11 4630 3903 526 201S103_9b rim 693 52 643 569 1049 35 42 442 129 981 1735 173 680 151 35 136 20 127 24 66 10 73 11 4220 3569 468 184S103_10a core 824 - 526 182 632 9 25 164 274 684 1391 151 577 112 53 99 14 96 19 56 9 64 9 3332 2803 374 156S103_10b rim 728 - 248 310 467 23 33 138 219 346 584 60 233 48 25 43 6 43 9 25 4 30 5 1461 1223 165 72S103_11a core 915 - 6673 651 1834 45 171 217 38 1711 6960 1196 6127 1609 232 1485 226 1368 254 661 86 482 51 22447 15994 4920 1534S103_11b rim 705 2 934 629 1095 44 92 326 59 1291 3129 337 1214 211 47 179 26 160 32 94 15 110 16 6860 5971 622 267S103_12a core 857 13 2169 915 7330 84 628 426 89 1901 6990 987 4180 813 70 606 79 429 77 216 31 190 22 16591 14058 1997 536S103_12b rim 632 - 1293 577 1355 34 101 240 44 1333 3509 425 1678 321 62 271 39 233 46 132 20 135 18 8223 6945 926 351S103_13a core 906 5 3244 556 1664 36 136 186 43 1742 6027 889 3962 845 118 726 106 612 120 332 46 284 35 15843 12620 2407 816S103_13b rim 910 - 3740 706 2430 50 211 300 49 2380 7960 1142 5070 1035 141 877 124 720 138 383 52 322 39 20384 16552 2897 934S103_14a core 807 - 2231 534 1696 47 138 563 185 1809 5197 674 2762 546 88 447 68 405 80 234 34 225 29 12599 10442 1554 603S103_14b rim 806 - 2284 536 1662 46 169 621 177 1924 5461 701 2790 528 92 428 65 396 79 232 34 236 31 12997 10876 1509 612S103_15a core 682 2 1093 550 1501 36 109 270 65 1440 3583 386 1310 214 43 177 27 169 35 114 19 145 21 7683 6719 630 334S103_15b rim 680 - 577 494 713 34 31 380 100 947 1685 167 616 120 35 106 16 99 20 62 10 74 12 3967 3414 376 177"-" represents value below detection limits.∑ REE total REE content∑ LREE light REE from La to Nd∑ MREE medium REE from Sm to Dy∑ HREE heavy REE from Ho to LuS1303-14.9mTill Sample2 39 Appendix D Heavy mineral concentrates (HMC) Quantitative Data Table D1. Titanite & PIMs HMC from bedrocks Table D2. Titanite HMC from till sediments Tables D3. PIMs HMC from till sediments 2 40 Table D1.1 Titanite and PIMs HMC in SELFRAG (300 g) bedrocksEstimate grain % in the 0.1 - 0.25 mm ; S.G. > 3.2 fractionDescriptionRock Sample Deposit Mag. Non Aug Ep Aug Ep Chr Gt Py Ttn Ccp Ap Ttn Py Ccp Ap Py Ccp ZrP-2 Mt. Polley 15.3 0.1 70% 0 0 0 0 0 0 0 0 0 0 50% 0 50% 5% 0 0 subhedral colorless ApP-3 Mt. Polley 38.3 3.3 90% 0 90% 0 0 0 0 0 0 90% 0 0 0 90% 0 0 0 abundant magnetite, augite and subhedral colorless ApP-4 Mt. Polley 32.1 4.8 0 30% 90% 50% 20% 40% 0 0 5% 0 0 0 0 10% 10% 0 0 abundant magnetite, augite and subhedral colorless Ap; dark brown GtP-10 Mt. Polley 18.7 0.4 25% 0 0 5% 0 0 10% 0 0 10% 0 50% 5% 5% 30% 5% 1% trace of rose ZrSD0981_92.3m Mt. Polley 16 3.2 10% 5% 0 0 0 0 0 0 0 0 0 0 0 0 50% 0 0 abundant Ccp + Py; abundant magnetiteSD0981_109.5m Mt. Polley 58.8 0.2 50% 0 0 30% 0 0 0 0 0 0 0 0 0 0 0 0 0 abundant magnetite; abundant Ccp + Py; 06938_92.6m Mt. Milligan 1 1.0 0 0 0 0 10% 0 80% 5% 30% 5% 0 70% 0 0 90% 0 0 Mag intergrowth with Ccp; traces of rombohedral blond Ttn06957_217.7m Mt. Milligan 1.5 4.1 15% 40% 30% 90% 30% 0 90% 0 80% 30% 0 90% 0 0 0 0 0 Mag intergrowth with Ccp11015_238m Mt. Milligan 7.8 34.2 40% 10% 0 0 0 0 90% 0 70% 0 0 90% 0 0 90% 0 0 abundant Py; Mag intergrowth with Ccp11015_286m Mt. Milligan 1.2 1.6 0 0 0 0 0 0 0 0 0 0 2% 90% 0 0 90% 0 1% abundant Py; rombohedral blond TtnCMT-6 Copper Mt. 0.5 4.6 0 15% 60% 10% 30% 0 90% 10% 90% 0 0 10% 0 10% 0 0 0 abundant augite; abundant Ccp + Py; rombohedral blond TtnCMT-7 Copper Mt. 24.6 1.3 0 0 30% 0 0 0 30% 30% 0 90% 2% 30% 10% 70% 30% 10% 0 abundant magnetite and subhedral colorless Ap; traces of rombohedral blond TtnCMT-11 Copper Mt. 27 0.5 0 25% 5% 0 2% 0 0 0 2% 30% 0 2% 0 30% 10% 2% 0 abundant magnetite and subhedral colorless ApCMT-13 Copper Mt. 0.0 0.2 0 0 0 10% 0 0 10% 0 90% 0 0 30% 10% 0 0 0 0 abundant Ccp + PyCM12AB12_92m Copper Mt. 25.9 1.5 15% 0 0 0 0 0 0 0 0 0 0 90% 30% 0 90% 30% 0 abundant magnetite; abundant Ccp + Py; CM12P223_505m Copper Mt. 22.7 1.5 40% 40% 90% 0 0 0 0 0 0 0 0 50% 0 50% 50% 0 0 abundant magnetite, augite and subhedral colorless ApDist. = distance from mine in metersE.M. = electromagnetic fraction in amperes (A)Mag. = magnetic fractionNon = non magnetic fractionS.G. = specific gravity / densityE.M.=0.6-0.8 A E.M.=0.8-1.0 A E.M.> 1.0 AS.G. >3.2 Au rshp.=gold reshaped; Au mod. = gold mod.; Au prist. = gold pristine; Ap = apatite; Apy = arsenopyrite; Bn = bornite; Chr= chromite; Ccp= chalcopyrite; Cin = cinnabar; Di = diopside; Ep= epidote; Gt= garnet; Jar = jarosite; Mal = malachite; Py= pyrite; Rt= rutile; Ttn= titanite; Tur= tourmaline; Zr = zirconE.M.=0.6-0.8 A2 41 Table D2.1 Titanite HMC in till sediments Grain count in fraction 0.1 - 0.25 mm ; S.G. > 3.2Deposit Till Sample Dist.(m) Location Depth Grain length (µm) width (µm) Habit Colour Inclusions CavitiesMT12-1 640 320 subhedral blond aug + ccp -MT12-2 410 370 anhedral blond aug + ccp -MT12-6 500 300 subhedral colourless n/a -MT12-8 640 420 anhedral blond py -MT12-9 420 290 subhedral blond n/a -MT13-1 750 590 anhedral blond ep + py -MT13-6 500 470 subhedral honey brown n/a -MT15-1 470 290 subhedral colourless n/a -MT15-2 830 435 anhedral blond py -MT15-3 580 515 subhedral blond ep + py -MT15-4 715 580 subhedral blond n/a -MT15-5 620 420 anhedral honey brown ep + py yesMT15-6 400 380 anhedral colourless ep + py -MT15-7 500 370 subhedral blond ep + py -MT15-8 670 460 anhedral blond aug + ep + py -MT15-9 490 290 subhedral honey brown rt + cal -MT15-11 750 540 subhedral blond ep + py -MT15-12 610 500 subhedral blond py -MT15-13 520 420 anhedral colourless ep + py -MT15-14 1000 490 subhedral honey brown py -MT15-15 870 740 anhedral colourless ep + py -MT16-1 530 370 anhedral blond py -MT16-2 560 305 subhedral blond ep -MT16-3 515 340 subhedral colourless rt + cal -MT16-4 600 540 anhedral blond ep -MT16-5 560 360 subhedral honey brown n/a -MT16-6 440 410 anhedral blond ep + py -MT16-7 460 420 subhedral blond n/a -MT16-8 580 385 anhedral blond ep + py -MT16-9 730 640 subhedral colourless n/a -MT16-10 570 265 subhedral colourless ep + py -MT16-11 410 350 subhedral colourless ep + py -MT16-12 600 330 subhedral honey brown ep + py -MT16-13 580 420 subhedral colourless ep + py -MT16-14 440 410 subhedral honey brown ep + py -MT16-15 950 450 subhedral blond ep + py -S103-1 520 400 anhedral blond py -S103-2 600 480 anhedral honey brown py -S103-3 600 520 anhedral honey brown ep + ccp -S103-4 790 435 anhedral honey brown ep + ccp -S103-5 590 500 subhedral honey brown ep + ccp -S103-6 700 500 anhedral honey brown ep + ccp -S103-8 810 525 anhedral honey brown ep + ccp -S103-9 650 420 subhedral honey brown py -S103-10 670 445 anhedral honey brown ep + ccp -S103-11 600 450 subhedral honey brown ep + ccp -S103-12 520 400 subhedral honey brown py yesS103-13 550 450 subhedral honey brown py -S103-14 550 520 subhedral blond py -S103-15 650 450 subhedral blond ep + ccp -PT1 100 overlying basal PT1-T1 440 440 subhedral colourless n/a -PT2 300 overlying basal PT2-T1 370 330 subhedral colourless ep + py -PT4 1100 down ice surficial PT4-T1 470 370 subhedral colourless n/a -PT5 7000 up ice surficial PT5-T1 470 370 subhedral colourless ep + py -Dist. = distance from mine in metersE.M. = electromagnetic fraction in amperes (A)Mag. = magnetic fractionNon = non magnetic fractionS.G. = specific gravity / density"- "= represents absence of cavitiesoverlying basal700200 overlying surficial100 overlying surficialoverlying basal100 overlying basalAu rshp.=gold reshaped; Au mod. = gold mod.; Au prist. = gold pristine; Ap = apatite; Apy = arsenopyrite; Bn = bornite; Chr= chromite; Ccp= chalcopyrite; Cin = cinnabar; Di = diopside; Ep= epidote; Gt= garnet; Jar = jarosite; Mal = malachite; Py= pyrite; Rt= rutile; Ttn= titanite; Tur= tourmaline; Zr = zirconMount MilliganMount MilliganMount MilliganMount MilliganMount MilliganMount PolleyMT12MT13MT15MT16S1303_14.9m1002 42 Table D3.1 PIMs HMC in till sediments from Mount Milligan Grain count in fraction 0.25 - 0.5 mm; S.G. >3.2; E.M. > 1.0 ASample UTM E UTM N Elev. Dist. Depth Interpretation Location Py Ccp Bn Gt Ep Di Chr Ttn Zr Jar Au rshp. Au mod. Au prist. Apy CinM-T1 434573 6108325 1105 500 surficial down ice SS Zone 200,000 40 - 50 - - 11 - - - 29 33 6 100 -M-T2 434634 6108429 1117 200 surficial down ice SS Zone 250,000 100 - 50 - - 6 - - - 64 105 55 100 -M-T3 434991 6108516 1098 900 surficial down ice SS Zone 200 1 - 40 1 50 19 - 1 - 4 - 2 - -M-T4 434929 6109039 1074 700 surficial overlying 66 Zone 800 - - - - - 3 - - 20,000 14 2 14 - -M-T5 434581 6109572 1126 200 surficial overlying MBX Zone 12 - - 150 1 - 30 - 1 - 17 - 13 - 2M-T6 433405 6109005 1106 800 surficial overlying Heidi Lake 1 - - 1000 3 - 40 - 4 - 9 - 2 - -M-T7 432267 6108771 1086 1800 surficial up ice Heidi Lake 20 - - 1000 2 40 70 - - 1 2 - - - 1S1302-35m 434416 6109768 1098 70 basal overlying MBX Zone 150 5 40 - - - 2 - - - - - 129 - -S1303-14m 434527 6109696 1095 100 basal overlying MBX Zone - - - 120 1 1 4 25 - 15 - 5 4 - -MT-12 434581 6109784 1105 200 surficial overlying mine site 400,000 60 200 40 4 - 1 6 - 200 119 285 375 - -MT-13 434433 6109827 1112 100 surficial overlying mine site 200,000 1 200 40 - 1 1 4 1 8000 116 230 290 - -MT-14 434342 6109786 1104 100 basal overlying MBX Zone 100,000 6 100 8 - - - 2 - 10,000 60 162 261 - -MT-15 434282 6109721 1110 100 basal overlying MBX Zone 30 - - 200 4 - 2 632 50 15 13 2 2 - -MT-16 434978 6109139 1090 700 basal overlying MBX Zone 100,000 10 60 40 1 - 6 131 6 100 84 70 28 - -MT-17 436287 6107492 1087 2400 basal down ice south of the mine 8 7 - 40 2 - 3 2 - 20 49 30 26 - -MT-18 435359 6106090 1104 2700 basal up ice south of the mine 500 2 - 13 - - 3 2 - - 6 1 - 10 -MT-19 435056 6107281 1127 1500 surficial down ice south of the mine 3000 2 - 40 - 1 3 1 2 - 9 11 2 - 2MT-20 444876 6106677 1045 11000 surficial up ice south of the mine 1 1 - 100 2 - 11 - 3 20 6 - - - 3MT-21 432367 6093387 1174 15000 surficial up ice Rainbow Rd. - 1 - 1000 2 - 30 - - 15 28 2 - - 5MT-22 434557 6108329 1125 500 basal overlying east of SS Zone 200,000 100 - 30 1 - 1 5 - - 27 1 6 - -MT-23 434687 6108220 1122 700 basal overlying east of SS Zone 70,000 3 9 40 - - 9 2 - - 3 - - - -Dist. = distance from mine in metersElev. = elevation in meters above sea levelE.M. = electromagnetic fraction in amperes ( A )S.G. = specific gravity / density"-" = represents absence of grainsAu rshp.=gold reshaped; Au mod. = gold mod.; Au prist. = gold pristine; Apy = arsenopyrite; Bn = bornite; Chr= chromite; Ccp= chalcopyrite; Cin = cinnabar; Di = diopside; Ep= epidote; Gt= garnet; Jar = jarosite; Mal = malachite; Py= pyrite; Rt= rutile; Ttn= titanite; Tur= tourmaline; Zr = zirconS G =2.8-3.2E.M. < 1.0 AE.M. < 0.8 AS G =2.8-3.22 43 Table D3.2 PIMs HMC in till sediments from Mount PolleyGrain count in fraction 0.25 - 0.5 mm; S.G. >3.2; E.M. > 1.0 ASample UTM E UTM N Elev. Dist. Interpretation Location Py Ccp Gt Chr Ep Di Ttn Rt Zr Mal Tur Au prist. Au mod. Au rshp.P-T1 592852 5825498 904 100 overlying North Zone 5 1 2 150 1 40 1 22 3 - 15 - - 1P-T2 592985 5825273 922 300 overlying North Zone 5 - 6 100 - 16 - 20 - - 15 - - 2P-T3 592985 5825042 929 400 overlying North Zone 100 49 150 14 - 4 - 6 - 4 5 - - -P-T4 590682 5823800 920 1100 down ice Springer Pit 5 1 20,000 6 1 4 - - - - - 9 - 73P-T5 596803 5818334 930 7000 up ice south of mine 3 - - 60 - 50 - 7 - - 40 - - 17Dist. = distance from mine in metersElev. = elevation in meters above sea levelE.M. = electromagnetic fraction in amperes ( Å )S.G. = specific gravity / density"-" = represents absence of grainsAu rshp.=gold reshaped; Au mod. = gold mod.; Au prist. = gold pristine; Apy = arsenopyrite; Bn = bornite; Chr= chromite; Ccp= chalcopyrite; Cin = cinnabar; Di = diopside; Ep= epidote; Gt= garnet; Jar = jarosite; Mal = malachite; Py= pyrite; Rt= rutile; Ttn= titanite; Tur= tourmaline; Zr = zirconE.M. < 1.0 AE.M. < 0.8 AS.G. =2.8-S.G. =2.8-2 44 Appendix E Till matrix Geochemical Data Tables E1. Till matrix geochemistry at Mount Milligan Tables E2. Till matrix geochemistry at Mount Polley 2 45 Table E1.1 Till matrix geochemistry (Mount Milligan) ICP-MS and INAA analyses in the < 0.074 mm fractionCu (ppm)Mo (ppm) Au (ppb) As (ppm) Sb (ppm) Fe % V (ppm) Zn (ppm) Pb (ppm)Sample UTM E UTM N Elev. Dist. (m) Interpretation Depth Location ICP-MS ICP-MS INAA INAA INAA INAA ICP-MS ICP-MS ICP-MSM-T1 434573 6108325 1105 500 down ice surficial SS Zone 279.9 4.7 52.0 21 3.4 5.4 91 45.4 12.6M-T2 434634 6108429 1117 200 down ice surficial SS Zone 285.3 3.6 96.0 30 4.2 5.5 79 40.1 13.6M-T3 434991 6108516 1098 900 down ice surficial SS Zone 218.9 1.6 44.0 26 3.5 5.8 104 88.8 38.8M-T4 434929 6109039 1074 700 overlying surficial 66 Zone 495.8 21.5 170.0 10 3.9 11.0 273 60.8 14.8M-T5 434581 6109572 1126 200 overlying surficial MBX Zone 316.4 1.5 42.0 13 2.6 4.3 86 55.0 13.4M-T6 433405 6109005 1106 800 overlying surficial Heidi Lake 145.2 0.9 12.0 11 1.5 3.8 88 50.2 11.4M-T7 432267 6108771 1086 1800 up ice surficial Heidi Lake 173.1 0.7 12.0 10 1.4 5.3 125 57.7 19.0MT-12 434581 6109784 1105 200 overlying surficial mine site 711.8 6.3 - 32 13.5 6.8 106 158.3 30.6MT-13 434433 6109827 1112 100 overlying surficial mine site 493.1 3.9 - 49 10.5 7.3 99 67.1 17.8MT-14 434342 6109786 1104 100 overlying basal MBX Zone 403.6 4.9 - 33 7.2 6.3 101 62.0 17.0MT-15 434282 6109721 1110 100 overlying basal MBX Zone 143.7 1.2 - 14 2.7 6.4 116 54.5 6.6MT-16 434978 6109139 1090 700 overlying basal MBX Zone 583.9 3.5 - 16 4.0 6.0 118 56.7 6.8MT-17 436287 6107492 1087 2400 down ice basal south of the mine 242.5 1.5 - 22 3.4 5.8 109 59.3 10.4MT-18 435359 6106090 1104 2700 up ice basal south of the mine 123.7 0.8 - 12 2.8 5.7 119 72.2 7.5MT-19 435056 6107281 1127 1500 down ice surficial south of the mine 135.1 0.9 - 17 3.4 5.6 115 84.2 8.9MT-20 444876 6106677 1045 11000 up ice surficial southwest of the mine 98.2 0.8 - 11 1.8 5.3 101 73.8 8.0MT-21 432367 6093387 1174 15000 up ice surficial Rainbow Rd. 83.5 0.6 - 10 1.6 4.6 95 67.6 6.7MT-22 434557 6108329 1125 500 overlying basal east of SS Zone 299.6 5.4 - 24 3.7 6.1 98 42.2 7.3MT-23 434687 6108220 1122 700 overlying basal east of SS Zone 214.0 2.5 - 24 3.5 5.3 89 40.4 7.5Dist. = distance from mine in metersDetection limits: Cu < 0.01ppm; Mo < 0.01ppm; Au < 2ppb; As < 0.5ppm; Sb <0.1ppm; Fe < 0.2%; V < 2ppm; Zn < 0.1ppm; Pb < 0.01ppmBackground values based on GSC-BCGS 2008: Cu < 45ppm; Mo < 1ppm; Au < 5.5ppb; As < 10ppm; Sb < 1.2ppm; Fe < 4.6%; V < 71ppm; Zn < 75ppm; Pb < 9.2ppm"-" = represents values below detection limits2 46 Table E1.2 Till matrix geochemistry (Mount Milligan)ICP-MS and INAA analyses in the < 0.25 mm fractionCu (ppm)Mo (ppm) Au (ppb) As (ppm) Sb (ppm) Fe % V (ppm) Zn (ppm) Pb (ppm)Sample UTM E UTM N Elev. Dist. (m) Interpretation Depth Location ICP-MS ICP-MS INAA INAA INAA INAA ICP-MS ICP-MS ICP-MSM-T1 434573 6108325 1105 500 down ice surficial SS Zone 246.5 4.0 61.0 22 3.5 5.7 83 39.6 9.2M-T2 434634 6108429 1117 200 down ice surficial SS Zone 263.0 3.6 68.0 30 3.9 5.1 76 44.7 11.7M-T3 434991 6108516 1098 900 down ice surficial SS Zone 160.0 1.4 35.0 22 3.1 5.6 93 83.0 21.5M-T4 434929 6109039 1074 700 overlying surficial 66 Zone 482.7 21.8 160.0 11 4.6 12.0 261 54.0 7.8M-T5 434581 6109572 1126 200 overlying surficial MBX Zone 291.9 1.4 40.0 12 2.7 4.5 84 56.0 9.3M-T6 433405 6109005 1106 800 overlying surficial Heidi Lake 120.9 1.0 17.0 12 1.7 4.6 99 43.9 6.7M-T7 432267 6108771 1086 1800 up ice surficial Heidi Lake 96.0 0.6 8.0 8 1.4 5.1 115 43.1 5.3MT-12 434581 6109784 1105 200 overlying surficial mine site 556.6 4.6 - 35 11.1 7.2 97 138.3 25.2MT-13 434433 6109827 1112 100 overlying surficial mine site 377.8 2.9 - 41 8.5 6.1 78 64.6 14.3MT-14 434342 6109786 1104 100 overlying basal MBX Zone 374.5 5.2 - 33 6.9 6.5 104 66.3 14.4MT-15 434282 6109721 1110 100 overlying basal MBX Zone 109.5 0.9 - 11 2.4 6.7 153 44.3 5.9MT-16 434978 6109139 1090 700 overlying basal MBX Zone 455.9 3.0 - 15 3.6 6.3 116 49.1 5.9MT-17 436287 6107492 1087 2400 down ice basal south of the mine 181.4 1.3 - 16 2.9 5.1 94 48.1 7.0MT-18 435359 6106090 1104 2700 up ice basal south of the mine 98.3 0.7 - 9 2.6 5.7 115 67.1 5.8MT-19 435056 6107281 1127 1500 down ice surficial south of the mine 110.5 0.8 - 15 3.2 5.5 103 72.1 7.6MT-20 444876 6106677 1045 11000 up ice surficial southwest of the mine 84.9 0.7 - 10 1.8 4.7 97 64.6 6.8MT-21 432367 6093387 1174 15000 up ice surficial Rainbow Rd. 75.7 0.7 - 9 1.5 4.5 98 62.2 5.9MT-22 434557 6108329 1125 500 overlying basal east of SS Zone 268.1 4.6 - 25 3.4 6.0 90 39.4 6.7MT-23 434687 6108220 1122 700 overlying basal east of SS Zone 194.6 2.2 - 25 3.2 5.3 86 42.5 6.7Dist. = distance from mine in metersDetection limits: Cu < 0.01ppm; Mo < 0.01ppm; Au < 2ppb; As < 0.5ppm; Sb <0.1ppm; Fe < 0.2%; V < 2ppm; Zn < 0.1ppm; Pb < 0.01ppmBackground values based on GSC-BCGS 2008: Cu < 45ppm; Mo < 1ppm; Au < 5.5ppb; As < 10ppm; Sb < 1.2ppm; Fe < 4.6%; V < 71ppm; Zn < 75ppm; Pb < 9.2ppm"-" = represents values below detection limits2 47 Table E2.1 Till matrix geochemistry (Mount Polley) ICP-MS and INAA analyses in the < 0.074 mm fractionCu (ppm)Mo (ppm) Au (ppb) As (ppm) Sb (ppm) Fe % V (ppm) Zn (ppm) Pb (ppm)Sample UTM E UTM N Elev. Dist. (m) Interpretation Depth Location ICP-MS ICP-MS INAA INAA INAA INAA ICP-MS ICP-MS ICP-MSPT-1 592852 5825498 904 100 overlying basal Wight Pit 108.4 0.8 6.0 15 1.0 4.0 67 58.9 17.5PT-2 592985 5825273 922 300 overlying basal Wight Pit 188.9 1.8 210.0 21 1.3 5.5 88 61.9 26.3PT-3 592985 5825042 929 400 overlying surficial Wight Pit 376.2 2.8 26.0 20 1.0 5.1 129 91.2 25.2PT-4 590682 5823800 920 2000 up ice surficial Surroundings 802.1 4.0 96.0 25 1.7 6.3 148 102.8 28.9PT-5 596803 5818334 930 4000 up ice surficial Surroundings 37.6 0.5 9.0 7 0.7 3.8 44 56.6 7.5Dist. = distance from mine in metersDetection limits: Cu < 0.01ppm; Mo < 0.01ppm; Au < 2ppb; As < 0.5ppm; Sb <0.1ppm; Fe < 0.2%; V < 2ppm; Zn < 0.1ppm; Pb < 0.01ppmBackground values based on GSC-BCGS 2008: Cu < 45ppm; Mo < 1ppm; Au < 5.5ppb; As < 10ppm; Sb < 1.2ppm; Fe < 4.6%; V < 71ppm; Zn < 75ppm; Pb < 9.2ppm"-" = represents values below detection limitsTable E2.1 Till matrix geochemistry (Mount Polley) ICP-MS and INAA analyses in the < 0.25 mm fractionCu (ppm)Mo (ppm) Au (ppb) As (ppm) Sb (ppm) Fe % V (ppm) Zn (ppm) Pb (ppm)Sample UTM E UTM N Elev. Dist. (m) Interpretation Depth Location ICP-MS ICP-MS INAA INAA INAA INAA ICP-MS ICP-MS ICP-MSPT-1 592852 5825498 904 100 overlying basal Wight Pit 93.7 0.7 - 14 1.1 4.4 84 61.4 10.6PT-2 592985 5825273 922 300 overlying basal Wight Pit 97.3 0.9 8.0 13 1.1 6.4 102 47.9 10.1PT-3 592985 5825042 929 400 overlying surficial Wight Pit 367.4 2.8 15.0 20 0.9 5.0 149 94.6 16.4PT-4 590682 5823800 920 2000 up ice surficial Surroundings 704.9 4.3 68.0 22 1.7 6.3 149 90.0 18.3PT-5 596803 5818334 930 4000 up ice surficial Surroundings 25.2 0.4 - 5 0.7 3.2 37 39.2 5.2Dist. = distance from mine in metersDetection limits: Cu < 0.01ppm; Mo < 0.01ppm; Au < 2ppb; As < 0.5ppm; Sb <0.1ppm; Fe < 0.2%; V < 2ppm; Zn < 0.1ppm; Pb < 0.01ppmBackground values based on GSC-BCGS 2008: Cu < 45ppm; Mo < 1ppm; Au < 5.5ppb; As < 10ppm; Sb < 1.2ppm; Fe < 4.6%; V < 71ppm; Zn < 75ppm; Pb < 9.2ppm"-" = represents values below detection limits
Thesis/Dissertation
eng
Geological Sciences
Vancouver : University of British Columbia Library
Attribution-NoDerivs 2.5 Canada
Graduate
Titanite as an indicator mineral for alkalic Cu-Au porphyry deposits in south central British Columbia
Text