PALEOMAGNETISM OF EARLY CRETACEOUS VOLCANIC ROCKS FROM TRANSBAIKALIA: ARGUMENT FOR MESOZOIC STRIKE-SLIP MOTIONS IN CENTRAL ASIAN STRUCTURE
D.V. Metelkin, I.V. Gordienko*, and Xixi Zhao**
Institute of Geology, Siberian Branch of RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
* Geological Institute, Siberian Branch of RAS, 6a ul. Sakh'yanovoi, Ulan Ude, 670047, Russia
** University of California, Santa Cruz, USA
Keywords: Early Cretaceous paleomagnetic pole, Transbaikalia, magmatism, within-plate strike-slip motions
Pages: 1349-1363
Abstract
New paleomagnetic data have been obtained from Early Cretaceous volcanosedimentary sections of the Chikoi-Khilok, Borgoi, and Uda depressions of Transbaikalia. A paleomagnetic pole has been positioned to satisfy the modern criteria of reliability so that it can be used in paleotectonic reconstructions. The Early Cretaceous age of the recognized directions of natural remanent magnetization receives support from reversal, fold, and conglomerate paleomagnetic tests as well as from the coincidence of magnetozones of normal and reversed polarity with the magnetochronological scale. The obtained paleomagnetic data evidence that there are strike-slip deformations of sinistral kinematics in the south of the Siberian Platform, which are responsible for the regime of intracontinental extension and formation of graben structures filled with products of intraplate magmatism.
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