Paleomagnetism of Upper Jurassic basalts from Transbaikalia: new data on the time of closure of the Mongol-Okhotsk Ocean and Mesozoic intraplate tectonics of Central Asia
D.V. Metelkin a, b , I.V. Gordienko c , V.S. Klimuk c
a Institute of Geology and Mineralogy, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
b Novosibirsk State University, 2 ul. Pirogova, Novosibirsk, 630090, Russia
c Geological Institute, Siberian Branch of the RAS, 8 ul. Sakh'yanovoi, Ulan Ude, 670047, Russia
Keywords: Paleomagnetism; bimodal magmatism; Mongol-Okhotsk Ocean; intraplate strike-slip motions; Transbaikalia
Pages: 825-834
Subsection: PETROLOGY, GEOCHEMISTRY AND MINERALOGY
Abstract
The Upper Jurassic basalts (150-160 Ma) described as the Ichetui Formation over the territory of the Tugnui, Margintui, and Maly Khamar-Daban volcanic structures have been studied paleomagnetically. It is shown that natural remanent magnetization still contains a component which may reflect the geomagnetic field direction at the beginning of the Late Jurassic. This is supported by reversal and conglomerate tests. Calculation of mean paleopole gives: Plat = 63.6
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