Ophiolites of Western Tyva as fragments of a late Vendian Island arc of the Paleoasian ocean.

The article offers information on the geochemical and geochronological data ophiolite rocks in western Tyva in the Khemchiksko-Systygkhemskaya accretion zone. It states that the ophiolite fragments within the western part of the zone comprise essentially harzburgitic Ak-Dovurakskii, ultrabasic-basic Kopsekskii, Akkhemskii and Kodeiskii, as well as some other small massifs. It mentions that diabase and gabbro-diabase of the Shatskii massif compose complexes of the 'dyke-in-dyke' type with different orientations.