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TitleProgress report: Precambrian geology, Angikuni Lake area, District of Keewatin, Northwest Territories
DownloadFree download (whole publication) (pdf 114493 KB)
AuthorAspler, L B; Chiarenzelli, J R; Powis, K B; Cousens, B L
SourceCanadian Shield/Bouclier canadien; by Geological Survey of Canada; Geological Survey of Canada, Current Research no. 1998-C, 1998 p. 55-66,
PublisherNatural Resources Canada
RelatedThis publication is contained in Geological Survey of Canada; Geological Survey of Canada; (1998). Canadian shield, Geological Survey of Canada, Current Research no. 1998-C
NTS65J/04; 65J/05
AreaAngikuni Lake
Lat/Long WENS-100.0000 -99.5000 62.5000 62.0000
Subjectsstructural geology; igneous and metamorphic petrology; geochemistry; lithology; depositional environment; volcanic rocks; igneous rocks; structural interpretations; structural features; bedrock geology; structural trends; shear zones; greenschist facies; amphibolite facies; metamorphism; foliation; Archean; gossans; analyses; trace element analyses; geochemical analyses; Dubawnt Supergroup; Snowbird tectonic zone; Baker Lake Basin; Precambrian
Illustrationssketch maps; photographs; analyses
ProgramWestern Churchill NATMAP Project
Released1998 03 01
AbstractNear Angikuni Lake, greenschist-grade remnants of ca. 2.68 Ga mafic to felsic volcanic, siliciclastic, and carbonate sequences were deposited in shallow water on transitional, if not continental, crust. Initial isotopic and geochemical data indicate that the volcanics are mantle-derived tholeiites, consistent with back-arc basin deposition. Amphibolite-grade granitic to gabbroic gneiss complexes formed during ca. 2.61 Ga plutonism and structural disruption of the supracrustal rocks, and are not basement. To the east, a northeast-trending, near-vertical, strike-lineated, dextral, mylonitic shear zone juxtaposes greenschist supracrustal rocks against amphibolite gneisses. It may be kinematically linked to a northwest-trending, shallowly north-dipping, dip-lineated, north-side-down shear zone to the southwest. Both shear zones and synkinematic tholeiitic plutonic rocks represent a distributed Snowbird tectonic zone, likely formed in an intracontinental setting late in the evolution of the Ennadai-Rankin greenstone belt. Paleoproterozoic Dubawnt Supergroup outliers outcrop across the area and define two northeast-trending sub-basins.