GEOCHRONOLOGIC AND PETROCHRONOLOGIC CONSTRAINTS ON THE PERMIAN-TRIASSIC NORTHERN SOURCE REGION OF THE SVERDRUP BASIN, CANADIAN ARCTIC ISLANDS

The tectonic history of the northern source region for clastic strata of Canada’s Sverdrup Basin remains poorly constrained. Geochronologic and Petrochronologic analysis of detrital zircon and rutile from Permian and Triassic strata of the Sverdrup Basin are used to constrain the tectonic evolution of the northern source terrane. The detrital zircon and rutile data provide insight on sediment pathways into the Sverdrup Basin and help refine paleogeographic models of the arctic during the Late Paleozoic and Early Mesozoic.

Approximately 1400 detrital zircon U-Pb ages from twelve samples, collected from Permian and Triassic strata, contribute to the growing detrital zircon dataset from the Sverdrup Basin and demonstrate considerable variability in provenance both spatially and temporally. While analyzing for detrital zircon U-Pb ages select samples were analyzed for Rare Earth Element and trace element abundances on the same sample volume (Petrochronology). This method was also applied to detrital rutile to determine the contribution of mid- to high-grade (>450°C) metamorphic sources available to the sediment budget of the Sverdrup Basin.

The data suggest significant variation in the northern source region for the northeastern Sverdrup Basin compared to the north-central and northwestern Sverdrup Basin during the Permian, Early Triassic and early-Late Triassic. The most notable difference is the lack of Permian and Triassic detrital zircon in the north-central and northwestern samples compared to an abundance of these ages in previously published data from Triassic samples of the northeastern Sverdrup margin. The data also indicate a considerable shift in provenance along the basins northeastern margin during the Late Triassic from primarily northerly-derived sources in the mid-Late Triassic to primarily southerly-derived sources in the latest Triassic.