GEOSCAN Search Results: Fastlink


TitleThe IOCG - porphyry - epithermal continuum in the Great Bear Magmatic Zone, Northwest Territories, Canada
AuthorMumin, A H; Somarin, A K; Jones, B; Corriveau, L; Ootes, L; Camier, J
SourceExploring for iron oxide copper-gold deposits: Canada and global analogues; by Corriveau, L (ed.); Mumin, H (ed.); Geological Association of Canada, Short Course Notes no. 20, 2010 p. 59-78
LinksOnline - En ligne
Alt SeriesEarth Sciences Sector, Contribution Series 20090314
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthwest Territories
NTS85N; 86C; 86D; 86E; 86F; 86K; 86L
AreaGreat Bear Lake; Lac la Martre; Hottah Lake
Lat/Long WENS-119.0000 -116.0000 67.0000 63.0000
Subjectseconomic geology; mineral deposits; mineral occurrences; iron oxides; copper; gold; mineralization; alteration; hydrothermal alteration; hydrothermal deposits; Great Bear magmatic zone
Illustrationslocation maps; photographs; cross-sections; tables
ProgramGEM: Geo-mapping for Energy and Minerals, Iron-oxide Copper-gold (IOCG) / Multiple Metals - Great Bear Lake (NWT)
ProgramTargeted Geoscience Initiative (TGI-3), 2005-2010
ProgramSecure Canadian Energy Supply
AbstractGiant magmatic-driven hydrothermal systems are associated with episodic construction of 1.88 - 1.84 Ga continental stratovolcano complexes along the Great Bear Magmatic Zone (GBMZ). Seemingly disparate styles of mineralization are spatially and genetically linked to these hydrothermal systems, and form a ternary continuum of IOCG, porphyry Cu (+/- Au) and epithermal-type deposits with many variants. Hydrothermal alteration follows similar characteristics throughout the GBMZ, but this is not obvious due to the extensive spatial footprint of the systems and cryptic nature of some of the alteration. High temperature core zones are albite or magnetite dominant. Proximal magnetite is commonly transitional to hematite and/or K-feldspar, and K-feldspar is transitional to phyllic and finally distal propyllitic alteration. Hydrothermal carbonate and quartz occupy structural zones and/or form replacements distal to hydrothermal centres and/or occur as late stage retrograde alteration. Tourmaline is common, fluorite occurs locally, and skarn assemblages develop in some carbonate-rich rocks. Recognition of the spatial and genetic association between regional variations of hydrothermal alteration, coupled with appreciation of the genetic association between seemingly disparate styles of mineralization, is a powerful and encouraging exploration guide.