| Title | Detrital epidote chemistry: detecting the alteration footprint of porphyry copper mineralization in the
Quesnel terrane of the Canadian Cordillera, British Columbia |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Plouffe, A ;
Acosta-Góngora, P; Kjarsgaard, I M; Petts, D; Ferbey, T;
Venance, K E |
| Source | Targeted Geoscience Initiative 5: contributions to the understanding and exploration of porphyry deposits; by Plouffe, A (ed.); Schetselaar, E (ed.); Geological Survey of Canada, Bulletin 616, 2021 p. 137-157, https://doi.org/10.4095/327988
 Open Access |
| Image |  |
| Year | 2021 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Targeted Geoscience
Initiative 5: contributions to the understanding and exploration of porphyry deposits |
| File format | pdf; xlsx (Microsoft® Excel®) |
| Province | British Columbia |
| NTS | 93A/03; 93A/04; 93A/05; 93A/06; 93A/11; 93A/12; 93B/01; 93B/02; 93B/07; 93B/08; 93B/09; 93B/10 |
| Area | Likely; Quesnel River; Cariboo River; Horsefly Lake; Fraser River |
| Lat/Long WENS | -122.5833 -121.2500 52.6667 52.1667 |
| Lat/Long WENS | -122.5833 -121.2500 52.6667 52.1667 |
| Subjects | economic geology; geochemistry; surficial geology/geomorphology; Science and Technology; Nature and Environment; Lower Jurassic; Upper Triassic; mineral deposits; porphyry deposits; porphyry copper;
mineral exploration; exploration methods; mineralization; alteration; propylitization; hydrothermal alteration; detrital minerals; epidote; provenance; geochemical analyses; bedrock geology; lithology; igneous rocks; intrusive rocks; granitic rocks;
metamorphic rocks; metavolcanic rocks; metasedimentary rocks; glacial deposits; tills; till geochemistry; element distribution; statistical analyses; glacial history; ice flow; glacial erosion; sediment dispersal; mineral occurrences; Canadian
Cordillera; Quesnel Terrane; Nicola Group; Gibraltar Deposit; Mount Polley Deposit; Woodjam Deposit; Mount Polley Intrusive Complex; Takomkane Batholith; Granite Mountain Batholith; Methodology; ice-flow directions; Phanerozoic; Mesozoic; Jurassic;
Triassic |
| Illustrations | schematic representations; schematic cross-sections; location maps; geoscientific sketch maps; tables; photomicrographs; plots |
| Program | Targeted Geoscience Initiative (TGI-5) Intrusion/Porphyry ore systems - porphyry processes - mineral markers |
| Released | 2021 09 01; 2022 11 17 |
| Abstract | Epidote from detrital sediments derived from propylitic alteration associated with porphyry copper mineralization could be used as a vector for mineral exploration in drift-covered areas; however,
differentiating porphyry-related epidote from other sources is crucial. We analyzed the composition of epidote from granitoids associated with porphyry copper mineralization, Nicola Group rocks and grains from till at three sites (Gibraltar, Mount
Polley, and Woodjam) within British Columbia's Quesnel terrane, where two main sources of epidote in till are propylitic-altered rocks associated with porphyry mineralization and metamorphosed Nicola Group mafic volcanic and sedimentary rocks.
Although principal component analysis was insufficient to distinguish between intrusive- and metamorphic-related epidote, patterns in the abundance of sets of elements indicate provenance. Epidote from granitoids typically has less Hf+Th (<6 ppm) and
Sc+Cr+Y (<100 ppm) compared to epidote from Nicola Group rocks; abundances of As and Sb (>>4 ppm As and >>0.6 ppm Sb) in epidote derived from hydrothermal alteration zones associated with porphyry copper mineralization exceed levels measured in
metamorphic epidote; and elevated Cu (approximately >30 ppm) in epidote can indicate copper mineralization. These trends in the chemical composition of till-derived epidote can be used in mineral exploration to detect buried hydrothermal alteration
associated with porphyry copper mineralization. |
| Summary | (Plain Language Summary, not published)
This Bulletin published by the Geological Survey of Canada contains ten articles summarizing the results of five-year research projects conducted on
porphyry deposits in Canada as part of the Targeted Geoscience Initiative (TGI). Porphyry deposits are ore bodies, including past-producing and active mines, associated with intrusive rocks such as granite. They are significant producers of a variety
of metals, including copper, molybdenum, tin and tungsten. Nine out of ten papers describe projects conducted in the Canadian Cordillera where most Canadian porphyry deposits occur and a paper on similar, but older deposits in the Appalachians of
Atlantic Canada. The main objective of these TGI research projects was to better define the geological conditions where porphyry deposits form and test techniques to detect buried porphyry deposits in support of mineral exploration. |
| GEOSCAN ID | 327988 |
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