Paleomagnetic and plate-tectonic constraints on the evolution of the Alaskan-eastern Siberian Arctic

Abstract

Abstract The tectonic development of the Arctic Basin is constrained by several independent sets of data. These include paleomagnetic Apparent Polar Wander Paths for the North American and Eurasian Plates, paleomagnetic data from Arctic Alaska, and magnetic isochrons in the Arctic, Atlantic, and Pacific Oceans. In this chapter we use each set of data to constrain plate-tectonic models describing the development of the Amerasia Basin, northern Alaska, and the northeast USSR. First, we use Apparent Polar Wander Paths for the Eurasian and North American Plates to show the existence of a gap between these two plates in the Arctic Basin region before the formation of oceanic crust in the North Atlantic and Arctic oceans (the Late Carboniferous to Early Cretaceous, about 310 to 120 Ma). We then review and present new paleomagnetic data from the North Slope of Alaska to constrain the timing and geometry of the opening of the Canada Basin. The new data shows that counterclockwise rotation of -70° has occurred since Barremian time, providing strong evidence supporting a rotational opening of the Canada Basin. Next, we review plate-tectonic models describing rifting in the Arctic and North Atlantic Basins and correlate tectonic events in the Arctic Basin with these motions. We correlate periods of strong convergence between the continental plates from ~70 to ~56 Ma (Maastrichtian to Paleocene) with compressional deformation between the Chukotsk Peninsula and northern Alaska and movement along the Denali Fault. transform motion between these plates from ~56 through 50 to 38 Ma (lower to upper Eocene)