Late Cretaceous paleomagnetic results from northeast Asian continental margin: The Sikhote Alin Mountain Range, eastern Russia

Abstract

Welded tuffs in the Upper Cretaceous Kisin Group have been collected for paleomagnetic study from 24 sites in Sikhote Alin, eastern Russia. Normal paleomagnetic directions from 11 sites are regarded as primary directions, whereas reversed paleomagnetic directions from 13 sites are ascribed to secondary origin. The normal directions of the Kisin Group together with the characteristic directions of the Sijanov Group yield the Late Cretaceous characteristic direction of Sikhote Alin ( D = 355.0°, I = 59.8° with α 95 = 7.2°). A significant separation (15.4°±11.9°) of pole positions is observed between Sikhote Alin (85.9°N, 11.3°E with A 95 = 10.1°) and the North China Block. Sikhote Alin has been subjected to counterclockwise rotation through 20.5°±17.7° with respect to North China Block. The rotation occurred during 66–51 Ma, and is ascribed to sinistral motion along the central Sikhote Alin fault.