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TitreLate Paleozoic to Triassic arc magmatism north of the Sverdrup Basin in the Canadian Arctic: evidence from detrital zircon U-Pb geochronology
AuteurAlonso-Torres, D; Beauchamp, B; Guest, B; Hadlari, T; Matthews, W
SourceLithosphere vol. 10, no. 3, 2018 p. 426-445, https://doi.org/10.1130/L683.1
Année2018
Séries alt.Ressources naturelles Canada, Contribution externe 20170373
ÉditeurGeological Society of America
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1130/L683.1
Mediapapier; en ligne; numérique
Formatspdf; html
ProvinceNunavut; Territoires du Nord-Ouest
SNRC29; 39; 49; 59; 69; 79; 89; 120; 340; 560
Lat/Long OENS-120.0000 -60.0000 85.0000 76.0000
Sujetsantécédents tectoniques; magmatisme; arcs magmatiques; subduction; volcanisme; marges plaques; décrochement horizontal; evolution du bassin; antecedents de sedimentation; roches clastiques; origine; paléogéographie; datation radiométrique; datation au uranium-plomb; datations au zircon; géologie du substratum rocheux; lithologie; roches sédimentaires; carbonates; chailles; mudstones; conglomérats; grès; schistes; évaporites; puits; Bassin de Sverdrup ; Orogenèse Appalachienne; Orogenèse Caledonienne; Orogenèse de Taconic ; Laurentie; Puit Brock C-50 ; Puit Isachsen J-37 ; Orogène Ellesmerien; Bassin Franklinien; tectonique; géochronologie; Phanérozoïque; Mésozoïque; Trias; Paléozoïque; Permien; Carbonifère; Pennsylvanien; Dévonien; Silurien; Précambrien; Protérozoïque
Illustrationslocation maps; geoscientific sketch maps; stratigraphic columns; tables; photographs; plots; histograms; schematic models; schematic cross-sections
ProgrammeTerrane Pearya, Ellesmere nord de l'ouest de l'Arctique, GEM2 : La géocartographie de l'énergie et des minéraux
Diffusé2018 03 23
Résumé(disponible en anglais seulement)
Paleozoic and Mesozoic tectonic reconstructions of the Arctic regions have been a subject of debate in recent years. The Permian emergence of a landmass north of the Sverdrup Basin in the Canadian Arctic led to the shedding of northerly derived detritus, an event that followed volcanism and basin inversion pulses that began in the late Pennsylvanian. However, the mechanisms for these events and the Paleozoic to Mesozoic paleogeography of this region remain controversial.
New detrital zircon U-Pb geochronology results from Permian to Lower Triassic strata from northern Axel Heiberg and Ellesmere islands constrain the magmatic events within this northern landmass and its implications for the tectonic regime of the Sverdrup Basin and adjacent domains. Permian to lowermost Triassic strata along the northern margin of the Sverdrup Basin contain zircons derived from Silurian to Devonian rocks (420-350 Ma), Timanian-aged basement (700-500 Ma), and a Permian syndepositional source (300-250 Ma). Coeval strata in the southern margin are dominated by zircons formed during the Taconic, Scandian, and post-Scandian phases of the Appalachian and Caledonian orogenies, respectively (480-400 Ma).
The detrital zircon signatures of the analyzed strata on the northern margin of the Sverdrup Basin record continuous magmatism within the northern landmass from latest Carboniferous (ca. 300 Ma) to at least earliest Triassic (ca. 250 Ma) time. These results are indicative of ongoing subduction and development of a magmatic arc off the northern margin of Laurentia, with the Sverdrup Basin potentially located in the backarc region of a proto-Pacific convergent margin involving parts of Arctic Alaska, Chukotka, and the Chukchi Shelf. The hypothesized onset of subduction in latest Carboniferous time and closure of this backarc basin in the latest Permian to earliest Triassic provides an explanation for the shift in stress regimes in the Sverdrup Basin that led to basin inversion and volcanism episodes. Therefore, the data presented here supports a backarc to retroarc setting for the Sverdrup Basin and the possibility of a convergent margin regime for the northern edge of Laurentia during the late Paleozoic to Triassic, contrasting with the generally accepted rift and passive margin settings.
Résumé(Résumé en langage clair et simple, non publié)
Cet article présente des données qui sont interprétées pour proposer des modèles fondamentaux changeants pour l'origine du bassin de Sverdrup. Les modèles plus anciens expliquent le réglage du bassin comme une extension passive, alors que ce document suggère qu'il s'agissait d'un arrière-arc, à peu près le même que le sud-est de la Chine continentale adjacent à la mer du Japon.
GEOSCAN ID306965