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TitleTill composition near Cu-porphyry deposits in British Columbia: highlights for mineral exploration
DownloadDownload (whole publication)
AuthorPlouffe, A; Ferbey, T
SourceTGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation; by Rogers, N (ed.); Geological Survey of Canada, Open File 7843, 2015 p. 15-37, (Open Access)
LinksCanadian Database of Geochemical Surveys, downloadable files
LinksBanque de données de levés géochimiques du Canada, fichiers téléchargeables
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
RelatedThis publication is contained in Rogers, N; (2015). TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation, Geological Survey of Canada, Open File 7843
File formatpdf
ProvinceBritish Columbia
NTS92I; 92P; 93A; 93B
AreaWilliams Lake; Woodjam; Gibraltar; Highland Valley
Lat/Long WENS-124.0000 -120.0000 53.0000 50.0000
Subjectseconomic geology; surficial geology/geomorphology; porphyry deposits; porphyry copper; mineral exploration; glacial deposits; tills; till analyses; till geochemistry; drift prospecting; drift deposits; ice flow; ice movement directions; dispersal patterns; mineralization; indicator elements; tungsten; molybdenum; tin; bismuth; molybdenite; copper; gold; Gibraltar Mine; Highland Valley Mine; Mesozoic; Jurassic; Triassic
Illustrationslocation maps; photomicrographs; flow charts; cross-sections
ProgramTargeted Geoscience Initiative (TGI-4), Intrusion/Porphyry Ore Systems
Released2015 06 11
AbstractTill orientation surveys were completed in the region of four Cu porphyry deposits in British Columbia with the objective of defining geochemical and mineralogical indicators of porphyry mineralisation buried by glacial sediments. We demonstrate that even if those deposits contain low to medium metal grades (e.g., 0.2 to 0.4 % Cu compared to an average crustal abundance of 0.0075 % Cu), they are reflected in the till composition with elevated concentrations of ore metals (Cu, Au, Mo) and pathfinder elements (Hg, Pb, Zn, Ag), and large grain counts of ore minerals (chalcopyrite, gold grains) and alteration minerals (e.g., epidote, andradite garnet, apatite) which are in contrast with surrounding regions devoid of mineralisation. These zones with elevated metal or mineral content in till define glacial dispersal trains that extend several kilometres down-ice from the bedrock mineralised sources. In this study, the shape of the dispersal trains is principally controlled by: 1) the ice-flow directions; and 2) the areal extent of the mineralisation exposed to glacial erosion which can comprise a cluster of sub-economic mineralised zones in the periphery of the main economic deposits. Using those porphyry indicators and existing till composition data sets from a region underlain by Late Triassic to Early Jurassic intrusions within the Quesnel terrane, we postulate that potential for Cu-Au porphyry style mineralisation exists within the Spout Lake pluton to the west of the Takomkane batholith and at the northern end of the Thuya batholith.