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TitleDrift prospecting applied to iron oxide copper gold exploration in the Great Bear Magmatic Zone, Northwest Territories, Canada
AuthorNormandeau, P X; McMartin, I; Paquette, J; Corriveau, L
SourceGeological Association of Canada-Mineralogical Association of Canada, Joint Annual Meeting, Abstracts Volume vol. 34, 2011 p. 154; 1 CD-ROM
LinksOnline - En ligne
Alt SeriesEarth Sciences Sector, Contribution Series 20100454
MeetingOttawa 2011 GAC-MAC-SEG-SGA Joint Annual Meeting; Ottawa; CA; May 25-27, 2011
Mediapaper; CD-ROM
File formatpdf
ProvinceNorthwest Territories
Subjectseconomic geology; surficial geology/geomorphology; drift prospecting; drift deposits; exploration; exploration methods; iron oxides; copper; gold; mineralization; Great Bear Magmatic Zone; NICO Deposit; Cenozoic; Quaternary
ProgramGEM: Geo-mapping for Energy and Minerals, Iron-oxide Copper-gold (IOCG) / Multiple Metals - Great Bear Lake (NWT)
AbstractAs part of Canada's Geomapping for Energy and Minerals (GEM) Program, an applied Quaternary research activity under the IOCG-Great Bear Project was undertaken in the Great Bear magmatic zone (GBMZ) to provide a practical guide to geochemical and indicator mineral exploration for iron oxide copper-gold (IOCG) deposits in glaciated terrain. Initial work completed in 2007 consisted of an orientation study around the NICO Co-Au-Bi deposit, interpreted as a magnetite-group IOCG deposit.
During subsequent field work in 2009 and 2010, detailed sampling was completed in the vicinity of the Sue-Dianne Cu-Ag-Au hematite-group IOCG deposit and near additional showings thought to be part of large polymetallic IOCG systems within an IOCG-porphyry-epithermal continuum across the GBMZ. Bedrock (n=111) and till (n=102) samples were collected up-ice, proximal to, and down-ice from mineralization, hydrothermally altered host rocks and least altered bedrocks. The physical properties and the minor and trace element composition of non-ferromagnetic indicator minerals and the till matrix geochemistry will be used to evaluate the degree of preservation of diagnostic IOCG deposit mineralization or alteration signatures in glacial sediments.
Preliminary results indicate the presence of chalcopyrite, apatite, pyrrhotite, andradite, Mn-epidote, bornite, allanite, ferroactinolite, fluorite and gold in various concentrations within the indicator mineral fraction (0.25-2 mm; SG>3.2). Surface bedrock samples collected at the Sue-Dianne deposit contain chalcopyrite, malachite, bornite, allanite, gold and hematite/magnetite. Till collected over or immediately down-ice of Sue-Dianne contains apatite and tourmaline grains, while gold, chalcopyrite, gahnite and Mn-epidote are present in lower concentrations. SEM examination revealed trace amounts of iron oxides as inclusions and/or fracture filling in gahnite, apatite, tourmaline and andradite grains (0.25-0.5 mm) from till samples collected down-ice of Sue-Dianne and other showings. Some chalcopyrite grains (0.25-1 mm) are found in association with specular hematite suggesting leads for the identification of IOCG signatures in indicator minerals. Future work includes further examination of selected grains, electron microprobe analysis and LA-ICP-MS analysis.