HIGH-PRESSURE COMPLEXES OF CENTRAL ASIAN FOLD BELT: GEOLOGIC SETTING, GEOCHEMISTRY, AND GEODYNAMIC IMPLICATIONS
N.I. Volkova a and E.V. Sklyarov b
a Institute of Geology and Mineralogy, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk 630090, Russia
b Institute of the Earth's Crust, Siberian Branch of the RAS, 128 ul. Lermontova, Irkutsk 664033, Russia
Keywords: Blueschist, geochemistry, subduction, accretion, geochronology, Central Asian Fold Belt
Pages: 625-628
Subsection: MATURE STAGE OF EVOLUTION OF THE PALEOASIAN OCEAN AND ITS CLOSURE (THE PALEOZOIC-EARLY MESOZOIC)
Abstract
Blueschists are constituents of subduction-accretion complexes, where they occur either as separate tectonic slabs, slices, and lenses, or as exotic blocks in a melange. Often associated with ophiolites, blueschists are commonly metamorphosed members of ophiolite sections. Along with ophiolite, a typical component of high-pressure belts is alkaline ocean-island basalt comprehensively studied in the Uimon zone of Gorny Altai and Chara zone of Eastern Kazakhstan. This suggests active plume magmatism in the Early Paleozoic evolution of the Paleoasian Ocean. As inferred from sutures with high-pressure rocks, different parts of Paleoasian Ocean were closing successively.
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