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TitleThermochronological history of the northern Canadian Shield
AuthorKellett, D AORCID logo; Pehrsson, S; Skipton, D R; Regis, D; Camacho, A; Schneider, D A; Berman, RORCID logo
SourcePrecambrian Research vol. 342, 105703, 2020 p. 1-22,
Alt SeriesNatural Resources Canada, Contribution Series 20190602
Mediapaper; on-line; digital
File formatpdf; html; docx; shp; xml
ProvinceManitoba; Northwest Territories; Nunavut; Quebec; Saskatchewan; Newfoundland and Labrador; Ontario; British Columbia; Alberta
NTS13; 14; 15; 16; 22; 23; 24; 25; 26; 27; 31; 32; 33; 34; 35; 36; 37; 38; 41; 42; 43; 44; 45; 46; 47; 48; 52; 53; 54; 55; 56; 57; 58; 62; 63; 64; 65; 66; 67; 68; 72; 73; 74; 75; 76; 77; 78; 82; 83; 84; 85; 86; 87; 93; 94; 95; 96; 97
Lat/Long WENS-128.0000 -56.0000 74.0000 45.0000
Subjectsgeochronology; tectonics; geophysics; economic geology; Nature and Environment; Science and Technology; thermal history; radiometric dating; potassium argon dating; argon argon dating; crustal evolution; craton; sutures; tectonic history; orogenies; hornblende; muscovite; biotite; phlogopite; mineral deposits; mineral potential; unconformity-type deposit; uranium; geophysical interpretations; magnetic interpretations; Archean; Canadian Shield; Nuna Supercontinent; Churchill Province; Trans-Hudson Orogen; Thelon Tectonic Zone; Rae Craton; Reindeer Zone; Cape Smith Belt; Superior Craton; Paleoproterozoic; Mesoproterozoic; Precambrian; Proterozoic
Illustrationsgeoscientific sketch maps; plots; schematic representations; histograms; profiles
ProgramGEM2: Geo-mapping for Energy and Minerals GEM Synthesis
Released2020 03 14
AbstractThe northern Canadian Shield is comprised of multiple Archean cratons that were sutured by the late Paleoproterozoic to form the Canadian component of supercontinent Nuna. More than 2000 combined K-Ar and 40Ar/39Ar cooling ages from across the region reveal a stark contrast in upper and lower plate thermal responses to Nuna-forming events, with the Churchill Province in particular revealing near complete thermal reworking during the late Paleoproterozoic. We review the detailed cooling history for five regions that span the Churchill Province and Trans-Hudson orogen (THO): Thelon Tectonic Zone, South Rae, Reindeer Zone, South Hall Peninsula, and the Cape Smith Belt. The cooling patterns across Churchill Province are revealed in two >1500 km transects. At the plate scale, Churchill's cooling history is dominated by THO accretionary and collisional events, during which it formed the upper plate. Cooling ages generally young from west to east across both southern and central Churchill, and latest cooling in the THO is 50 myr older in southernmost Churchill (Reindeer Zone) compared to eastern Churchill (Hall Peninsula), indicating diachronous thermal equilibration across 2000 km strike length of the THO. Churchill exhibits relatively high post-terminal THO cooling rates of ~4 °C/myr, which support other geological evidence for widespread rapid exhumation of the THO upper plate following terminal collision, potentially in response to lithospheric delamination.
Summary(Plain Language Summary, not published)
This review paper provides a compilation of all published 40Ar/39Ar and K-Ar cooling ages for a large portion of the Canadian Shield, which represents the oldest rocks in Canada. These two dating methods capture the age of rocks not as they form, but as they cool from middle crustal conditions of >500 degrees Celsius to upper crust conditions of <300 degrees Celsius. These data are useful for understanding how rocks have behaved in response to continental collisions such as the collisions that took place in the late Paleoproterozoic in the Canadian Shield, between 2.0 and 1.7 billion years ago.

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