Back to Larry Lawver's homepage.

Under construction!

Tectonic evolution of the Arctic Region from Devonian to Cretaceous

by L.A. Lawver
in preparation, for Bering-Chukchi-Arctic volume, GSA Special Paper 189, edited by Elizabeth Miller and Art Grantz.

Abstract:
It is easy to think of the Arctic region as having always been at high latitudes and in roughly the same configuration as present. During Late Ordovician [450 Ma] the continental blocks that make up the Arctic were in fact dispersed over a broad area between 10°S and 30°N. Through time, the Arctic blocks coalesced then partially broke apart, perhaps caused by a mantle plume during the Devonian, coalesced again and then, in Early Cretaceous, through interaction with the Siberian Traps/Iceland hotspot and subduction along the Pacific margin, the Canada Basin opened. Northern Eurasia formed in nearly its present shape when three major pieces, Siberia, Kazahstan and Baltica came together in Late Paleozoic. In general, the continental blocks of the Arctic have migrated northward since Carboniferous. When the Arctic region reached far northern latitudes during the Jurassic, it broke up, with major subsea ridges, the Alpha and Mendeleev ridges, left as the track of the Siberian Traps/Iceland hotspot. By the time the North Atlantic and Nansen-Gakkel ridges initiated seafloor spreading [Early Tertiary], Alaska and Far Eastern Siberia had already crossed over the North Pole and had began to move southward while Greenland and western Eurasia continued their northward movement.

450 Ma	420 Ma	390 Ma	360 Ma
330 Ma	300 Ma	270 Ma	240 Ma
210 Ma	180 Ma	150 Ma	120 Ma
90 Ma	60 Ma	30 Ma	0 Ma