PALEOMAGNETISM OF THE PERMIAN-TRIASSIC TRAPS FROM THE KUZNETSK BASIN, SOUTHERN SIBERIA
A.Yu. Kazansky, D.V. Metelkin, V.Yu. Bragin, and L.V. Kungurtsev
Institute of Geology, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Trap formation, Permian-Triassic, paleomagnetism, intraplate displacement, Kuznetsk Basin
Pages: 1089-1102
Abstract
In this paper we generalize the data obtained for the Kuznetsk Basin traps studied over many years. A rich collection of samples from the Permian and Triassic igneous/sedimentary succession of the Kuznetsk Basin was analyzed. As a result, directions of characteristic remanent magnetization have been established ( Ds = 227.1, Is = -64.3, α95 = 2.8). Also, the paleomagnetic pole has been located accurately enough to be used in paleotectonic reconstructions. The Permian-Triassic age of the characteristic component of magnetization has been confirmed by fold and baked-contact tests. Comparative analysis of the magnetic zoning record in the sections of traps of the Kuznetsk Basin, northern Siberian Platform and West Siberian Plate shows that the processes of intraplate magmatism were mutually related in these areas about the time of the Permian-Triassic transition. Systematization of the obtained and available paleomagnetic data shows that the trap magmatism in the Kuznetsk Basin, as compared with the rest of Siberia, was an extremely short-term event. The entire section corresponds to the initial stage of the intraplate magmatic activity in the Siberian region, with their formation lasting no more than 1 Myr. The position of the calculated paleomagnetic pole (PLat = 60.0, PLong = 172.7, α95 = 4.0) and the orientation of the Permo-Triassic latitudes of the Kuznetsk Basin have a considerable angular deviation from those of the Siberian Platform (PLat = 49.0, PLong = 151.6, α95 = 5.0). The angular distance makes about 24
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