GEOSCAN Search Results: Fastlink


TitleGeology and geochemistry of mafic and ultramafic bodies in the Shebandowan mine area, Wawa-Abitibi terrane: implications for Ni-Cu-(PGE) and Cr-(PGE) mineralization, Ontario and Quebec
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorKuster, K; Lesher, C M; Houlé, M G
SourceGeological Survey of Canada, Scientific Presentation 130, 2022, 25 pages, Open Access logo Open Access
PublisherNatural Resources Canada
MeetingHarquail School of Earth Sciences Graduate Symposium; April 2021
Mediadigital; on-line
File formatpdf
Lat/Long WENS -78.3603 -78.0331 48.6331 48.5381
Subjectseconomic geology; geochemistry; tectonics; regional geology; structural geology; mineralogy; Science and Technology; Nature and Environment; mineral exploration; mineral potential; mineral deposits; nickel; copper; chromium; sulphide deposits; ore mineral genesis; mineralization; ore controls; bedrock geology; lithology; mafic rocks; ultramafic rocks; igneous rocks; volcanic rocks; lava flows; basalts; komatiites; intrusive rocks; metamorphic rocks; serpentinites; schists; structural features; lineations; faults; tectonic setting; tectonic history; magmatism; volcanism; intrusions; sills; metamorphism; alteration; aluminum geochemistry; magnesium geochemistry; mantle; models; fluid dynamics; lithogeochemistry; host rocks; sulphides; oxides; Archean; Shebandowan Mine; Wawa-Abitibi Terrane; Shebandowan Greenstone Belt; Superior Province; Shebandowan Assemblage; Kashabowie Assemblage; Burchell Assemblage; Greenwater Assemblage; Crayfish Creek Fault; platinum group elements; Precambrian; Proterozoic
Illustrationsgeoscientific sketch maps; stratigraphic columns; sections; photographs; plots; photomicrographs; ternary diagrams; tables
ProgramTargeted Geoscience Initiative (TGI-6) Ore systems
Released2022 02 23
AbstractThe Shebandowan Ni-Cu-(PGE) deposit occurs in the Shebandowan greenstone belt in the Wawa-Abitibi terrane. This deposit is one of a few economic Ni-Cu-(PGE) deposits in the Superior Province and one of a very few deposits worldwide that contains both Ni-Cu-(PGE) and Cr-(PGE) mineralization. The mafic-ultramafic successions in the area comprise abundant flows and sills of tholeiitic basalt and lesser Al-undepleted komatiite (MgO >18 wt%, Al2O3/TiO2 = 15-25), the latter indicating separation from mantle sources at shallow levels. Siliceous high-Mg basalts (MgO 8-12 wt%, SiO2 > 53 wt%, TiO2 < 1.2 wt%, La/Sm[MN] < 1-2) are relatively abundant in the area and likely represent crustally contaminated komatiites. Ultramafic bodies in the Shebandowan mine area comprise at least three or four komatiitic sills (A-B, C, D) and at least two komatiitic flows (E, F), all of which are altered to serpentinites or talc-carbonate schists with relict igneous chromite and rare relict igneous orthopyroxene-clinopyroxene. Unit A-B contains pentlandite-pyrrhotite-chalcopyrite-pyrite-magnetite mineralization, occurring as massive sulfides, sulfide breccias, or stringers, and subeconomic chromite mineralization in contorted massive bands varying from a few millimetres up to 10 metres thick. The localization of massive and semi-massive Ni-Cu-(PGE) ores along the margins of Unit A and the paucity of disseminated and net-textured ores suggest tectonic mobilization. Chromite is typically zoned with Cr-Mg-Al-rich (chromite) cores and Fe-rich (ferrichromite/magnetite) rims due to alteration and/or metamorphism, but rarely contains amoeboid magnetite cores. The thickness of chromite in Unit B is too great to have crystallized in cotectic proportion from the komatiitic magma and a model involving dynamic upgrading of magnetite xenoliths derived from interflow oxide facies iron formations is being tested.
Summary(Plain Language Summary, not published)
Under the Targeted Geoscience Initiative (TGI) Program of the Geological Survey of Canada (GSC), this study aims to better understand how nickel (Ni), copper (Cu) and platinum-group elements (PGE) mineralization form in the Canadian Shield. This specific contribution summarize preliminary results from a geological and geochemical compilation around the Shebandowan Ni-Cu-(PGE) mine in the Thunder Bay area in northwestern Ontario. This deposit is one of numerous economic Ni-Cu-(PGE) deposits in the Superior Province but is only one of very few deposits that contains both Ni-Cu-(PGE) and Cr-(PGE) mineralization.

Date modified: