GEOSCAN, résultats de la recherche


TitreDrift prospecting applied to iron oxide copper gold exploration in the Great Bear Magmatic Zone, Northwest Territories, Canada
AuteurNormandeau, P X; McMartin, I; Paquette, J; Corriveau, L
SourceL'Association géologique du Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 34, 2011 p. 154; 1 CD-ROM
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100454
RéunionOttawa 2011 GAC-MAC-SEG-SGA Joint Annual Meeting; Ottawa; CA; mai 25-27, 2011
Documentpublication en série
Mediapapier; CD-ROM
ProvinceTerritoires du Nord-Ouest
Sujetsexploration de dépôts glaciaires; dépôts glaciaires; exploration; méthodes d'exploration; oxydes de fer; cuivre; or; minéralisation; Zone de Great Bear Magmatic ; Dépôt de Nico ; géologie économique; géologie des dépôts meubles/géomorphologie; Cénozoïque; Quaternaire
ProgrammeGisements polymétalliques - Zone magmatique du Grand lac de l'Ours (T.N-O.), GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
As 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.