TECTONIC SETTING AND COMPOSITION OF HIGH-POTASSIUM ULTRAMAFIC-MAFIC IGNEOUS COMPLEXES OF FOLDED AREAS (exemplified by the Altai-Sayan and other regions)
V.N. Dovgal', A.E. Izokh, G.V. Polyakov, and A.E. Teleshev
Institute of Geology, Siberian Branch of RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Magmatism, high-potassium, ultramafic-mafic, geodynamic conditions, Altai-Sayan Folded Area
Pages: 1053-1064
Abstract
Study was given to the character of location and geotectonic setting of ultramafic-mafic associations containing high- and ultrapotassium rocks of the Altai-Sayan Folded Area. It has been shown that the high-potassium ultramafic-mafic associations of high alkalinity are concentrated in long-lived sutures separating large diachronous blocks of the Earth's crust: at the junction of the Siberian craton with folded orogens of the protero-Sayans in the east, and in the zone of the Kuznetsk-Altai fault, in the west. The regular character of this distribution and intimate temporal relationship of high-potassium ultramafic-mafic complexes with postcollisional processes not only in folded but also in within-craton regions are illustrated by numerous examples from the rest of the world.
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