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TitreTwo Neoarchean supercontinents revisited: the case for a Rae family of cratons
AuteurPehrsson, S J; Berman, R G; Eglington, B; Rainbird, R H
SourcePrecambrian Research vol. 232, 2013 p. 27-43, https://doi.org/10.1016/j.precamres.2013.02.005
Année2013
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120012
ÉditeurElsevier
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.precamres.2013.02.005
Mediapapier; en ligne; numérique
Formatspdf
ProvinceColombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long OENS-180.0000 180.0000 90.0000 -90.0000
Sujetsmilieux tectoniques; évolution tectonique; cadre tectonique; interprétations tectoniques; orogénies; Province de Churchill ; Géochronologie; tectonique; Précambrien; Protérozoïque
Illustrationsgeological sketch maps; location maps; stratigraphic cross-sections; graphs; diagram
ProgrammeUranium, GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
A variety of early Paleoproterozoic supercontinents or supercratons have been proposed, including Kenor-land, Superia and Vaalbara. Improved geologic knowledge of the Churchill Province, Canadian shield,suggests that the classical Kenorland configuration, with linked Rae and Hearne cratons, is invalid andrepresents a younger ca. 1.9 Ga Nuna configuration. We review the early Paleoproterozoic tectonic historyof the Rae craton and propose that the ca. 2.55-2.50 Ga MacQuoid and 2.50-2.28 Ga Arrowsmith orogensrepresent critical piercing points for supercontinent reconstruction. Utilizing the StratDB and DateViewdatabases, we have identified nearly two dozen regions worldwide that show effects of these orogenicevents, including the Rae, Gawler-Mawson, peninsular India, West Africa, Amazonia, North China, andSask crustal blocks. We propose that these cratonic blocks form a distinct Rae family lineage. Utilizingnew time-space plots for the Rae family and components of the Superia and Vaalbara supercratons, wedemonstrate that the Rae family lacks the distinctive early Paleoproterozoic depositional and glaciogenicrecord characteristic of Superia and Vaalbara, but has an important contemporaneous record of juvenilecrust formation and contractional orogenesis. We propose the collective history of the Rae family is best reconciled if it represents the now dispersed blocks of a third earliest Paleoproterozoic supercraton thatwe term Nunavutia. In this model the magmatic and tectonometamorphic record of these cratons includes an early 2.55-2.45 Ga period of interior collisional orogenesis in which the supercraton amalgamated,and a later phase of long-lived peripheral orogenesis (2.45-2.28 Ga) prior to its partial break-up at ca.2.05 Ga. Forming within an otherwise globally quiescent period, the history of the Rae family is important for assessment of constrasting models of early Paleoproterozoic geodynamic activity.
GEOSCAN ID291364