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Title40 Ar-39 Ar geochemical investigations in the central Hearne domain, western Churchill Province, Nunavut: a progress report; Radiogenic age and isotopic studies: Report 14
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AuthorSanderman, H A
SourceGeological Survey of Canada, Current Research (Online) no. 2001-F4, 2001, 19 pages, https://doi.org/10.4095/212670
Year2001
PublisherNatural Resources Canada
Documentserial
Lang.English
Mediapaper; on-line; digital; CD-ROM
RelatedThis publication is contained in Stern, R A; (2001). Radiogenic age and isotopic studies: Report 14, Geological Survey of Canada, Current Research (Online) no. 2001-F
RelatedThis publication is contained in Geological Survey of Canada; Geological Survey of Canada; (2001). Current Research 2001, winter release, Geological Survey of Canada, Current Research no. 2001
File formatpdf
ProvinceNunavut
NTS55E; 55F; 55K; 55L; 55M; 55N; 65H; 65I; 65P
AreaYathkyed Lake; Henik Lakes; Kaminak Lake; Rankin Inlet
Lat/Long WENS-98.0000 -92.0000 64.0000 61.0000
Subjectsgeochronology; radiometric dates; analytical methods; radiometric dating; zircon; electron probe analyses; argon argon dates; Archean; deformation; magmatism; petrography; Churchill Province; Hearne domain; thermal ionization mass spectrometry analysis
Illustrationsspectra; tables; sketch maps
LinksGSC Geochronology Laboratory home page
Image
Released2001 07 01
AbstractThe western Churchill Province of the northwest Canadian Shield was originally defined on the basis of wide- spread, Proterozoic K-Ar ages, but early mapping in conjunction with sparse, old K-Ar ages indicated that it con- tained preserved remnants of Archean supracrustal and granitoid rocks. A reconnaissance 40 Ar-39 Ar thermochronological investigation of a segment of crust lying along a north-northwest-trending transect from Kaminak Lake (central Hearne domain) in the south to Yathkyed Lake (northern Hearne domain) in the northwest, indicates that the Archean supracrustal belts preserve primary Archean igneous and metamorphic cooling ages for hornblende, but biotite ages were reset in the Proterozoic. The domain lying between the two supracrustal belts yielded Proterozoic ages for all dated minerals. The resetting of the 40 Ar-39 Ar systematics is attributed tolarge-scale thermal overprinting during Hudsonian deformation and magmatism at ca. 1830-1810 Ma and subse- quent slow cooling. Local evidence for ca. 1750 Maresetting of mica ages exists, but no unequivocal evidence for a ca. 1900 Ma tectonothermal event can be discerned in the 40 Ar-39 Ar thermochronological data.
GEOSCAN ID212670