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TitreDetrital zircon geochronology of the western Ellesmerian clastic wedge, northwestern Canada: Insights on Arctic tectonics and the evolution of the northern Cordilleran miogeocline
AuteurBeranek, L P; Mortensen, J K; Lane, L S; Allen, T L; Fraser, T A; Hadlari, T; Zantvoort, W G
SourceGeological Society of America Bulletin vol. 122, no. 11/12, 2010 p. 1899-1911,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090354
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceTerritoires du Nord-Ouest; Yukon; Nunavut
SNRC39; 48; 49; 57; 58; 59; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 96; 97; 98; 99; 106; 107; 116; 117; 120; 340; 560
Lat/Long OENS-142.0000 -56.0000 84.0000 64.0000
Sujetsdatations radiométriques; datation radiométrique; zircon; datations au zircon; tectonique de plaques; antécédents tectoniques; stades tectoniques; évolution tectonique; interprétations tectoniques; cadre tectonique; Formation d'Imperial ; Formation de Tuttle ; géochronologie; tectonique; Paléozoïque; Mississippien; Dévonien; Silurien; Mississippien
Illustrationslocation maps; plots
ProgrammeBassins sédimentaires du Yukon, GEM : La géocartographie de l'énergie et des minéraux
Diffusé2010 08 11
Résumé(disponible en anglais seulement)
Detrital zircon provenance investigations of mid-Paleozoic sandstone from the western Ellesmerian clastic wedge and Cordilleran miogeocline in northern Yukon and Northwest Territories, northwestern Canada, provide critical new data on the source of foreland basin sedimentation attributed to terrane accretion and plate convergence along the ancestral Arctic margin of North America. Late Devonian and early Mississippian clastic wedge strata yield "exotic" ca. 360 - 390, 430 - 460, 530 - 680, and 1500 - 1600 Ma detrital zircon populations that are consistent with source rocks that originated near the Caledonian and Timanian orogenic belts. Specifically, the Pearya and Arctic Alaska - Chukotka terranes, the landmass of Crockerland, and Caledonian rocks in eastern Greenland are the inferred sources for exotic detrital zircons in clastic wedge strata. Progressive recycling of Ellesmerian foreland basin sediments into the continental margin environment along northwestern Laurentia is indicated by the presence of ca. 360 - 430 Ma and 1500 - 1600 Ma detrital zircons in post-tectonic, middle to late Mississippian miogeoclinal strata in Yukon. Provenance data from these Mississippian samples record a dramatic shift in the source of the Cordilleran miogeocline, since Caledonian and Baltican (Timanide) detrital zircon signatures are not recognized in pre - Late Devonian sedimentary rocks in western Canada. Devonian strata of the Alexander terrane and Yreka subterrane (eastern Klamath terrane) have Caledonian and Baltican detrital zircon age signatures similar to Ellesmerian clastic wedge sandstones, implying that several Cordilleran terranes originated in the paleo-Arctic realm. Speculative correlations suggest that the Arctic Alaska - Chukotka terrane was located to the west of Crockerland and the Canadian Arctic Islands in pre-Cretaceous time, prior to opening of the Amerasian basin. Rifting models for the western Arctic Ocean featuring counter clockwise rotation of the Arctic Alaska - Chukotka terrane away from the Canadian Arctic Islands may need re-evaluation.