ANDESITES OF THE PRE-JURASSIC BASEMENT OF THE WEST SIBERIAN PLATE
A.Ya. Medvedev, A.I. Al'mukhamedov, and N.P. Kirda*
Institute of Geochemistry, Siberian Branch of the RAS, 1a ul. Favorskogo, Irkutsk, 664033, Russia
* Institute of Petroleum Geology and Geophysics, Siberian Branch of the RAS,
3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Andesites, basalts, crystallization differentiation, West Siberian Plate
Pages: 975-981
Abstract
Detailed geochemical studies of buried andesites, supposedly of Permo-Triassic age, from the West Siberian Plate have revealed their specific features. The andesites differ drastically in petro- and geochemical compositions from similar rocks of active continental margins and island arcs and are very similar in geochemistry to continental latites. These data do not contradict the model of andesite formation through crystallization differentiation of subalkalic basaltic melt.
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