| Title | Automated indicator-mineral analysis of the fine-sand heavy-mineral concentrate fraction of till: a promising exploration tool for porphyry copper mineralization |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Plouffe, A ;
Wilton, D H C; McNeil, R; Ferbey, T |
| 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. 203-223, https://doi.org/10.4095/327991
 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 | 92I/06; 92I/07; 92I/10; 92I/11; 93A/03; 93A/04; 93A/05; 93A/06; 93A/11; 93A/12; 93B/07; 93B/08; 93B/09; 93B/10 |
| Area | Likely; Quesnel River; Cariboo River; Horsefly Lake; Fraser River |
| Lat/Long WENS | -124.0000 -120.0000 53.0000 50.0000 |
| Lat/Long WENS | -122.5833 -121.2500 52.6667 52.1667 |
| Subjects | economic geology; mineralogy; 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; heavy mineral analyses; mineralogical analyses; scanning electron microscope analyses; detrital minerals; epidote; chalcopyrite; bedrock geology; lithology; igneous rocks;
intrusive rocks; granitic rocks; monzonites; granodiorites; diorites; monzo-granites; tonalites; metamorphic rocks; metavolcanic rocks; metasedimentary rocks; glacial deposits; tills; sands; 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; Highland Valley Deposit; Mount Polley
Intrusive Complex; Takomkane Batholith; Granite Mountain Batholith; Guichon Creek Batholith; Sheridan Creek Stock; ice-flow directions; Automation; Phanerozoic; Mesozoic; Jurassic; Triassic |
| Illustrations | location maps; geoscientific sketch maps; flow diagrams; 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 | Previous studies indicated that heavy mineralogy (specific gravity (SG) = 2.8-3.2 and >3.2) of the medium-sand fraction (0.25-0.50 mm) of till contains porphyry copper indicator minerals (PCIM) derived
from mineralization or alteration zones. To improve the PCIM method for mineral exploration, we analyzed the heavy mineralogy (>3.2 SG) of the fine-sand fraction (0.125-0.180 mm) of till using an automated method that combines scanning electron
microscopy (SEM) and mineral-liberation analysis (MLA). The MLA-SEM method identifies mineralogy based on grain composition determined by SEM-energy dispersive spectroscopy. The distributions of epidote and chalcopyrite in till at four porphyry
copper deposits in British Columbia show similarities between the fine-sand fraction analyzed by MLA-SEM and the medium-sand fraction analyzed by optical mineralogy: both show dispersal parallel to ice-flow movements. Analyzing the fine-sand,
heavy-mineral concentrate (HMC) fraction of till by MLA-SEM can be used in exploration for porphyry copper mineralization. We estimate 5 to 8 kg of bulk till is sufficient to prepare 0.3 g aliquots of fine-sand HMC for MLA-SEM; this is smaller than
the 9 to 15 kg required for optical mineral analysis of the medium-sand HMC fraction. Smaller field samples can lower costs for reconnaissance mineral exploration. |
| 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 | 327991 |
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