TUVA-MONGOLIA TERRANE (in the context of microcontinents in the Paleoasian ocean)
V.G. Belichenko, L.Z. Reznitsky, N.K. Geletii, and I.G. Barash
Institute of the Earth's Crust, Siberian Branch of the RAS, 128 ul. Lermontova, Irkutsk, 664033, Russia
Keywords: Microcontinent, basement, sedimentary cover, terrane, amalgamation, metamorphic complexes
Pages: 531-541
Abstract
The Tuva-Mongolia block has become commonly recognized and is often invoked in palinspastic reconstructions as a separate terrane. However, its position has been doubted recently despite abundant geological evidence providing new details of its origin and evolution.
We analyze the available geological data to reconsider the structure and outlines of the Tuva-Mongolia terrane and justify its existence as an independent tectonic unit in the Central Asian belt of Paleozoides. The terrane has a pre-Vendian accretionary basement overlain by Vendian-Cambrian carbonates. In Vendian-Cambrian time it was a microcontinent drifting in the Paleoasian ocean, and platform carbonate deposition within its limits was synchronous with the formation of ophiolites and island arcs in the surrounding oceanic space. Paleozoic plutonism and metamorphism record rather the Ordovician collision than the preorogenic tectonic history of the terrane.
|
