OPHIOLITES IN THE COLLISIONAL STRUCTURE OF THE SOUTHERN URALS

Abstract

Ophiolites are widespread in the southern Urals as large allochthonous sheets and discrete blocks in tectonic melange and mixtites. They are spatially associated with volcanic sequences varying in age from Ordovician to Upper Devonian and residing in basins with oceanic crust. Hence, at least some ophiolites can be regarded as direct constituents of Paleozoic oceanic crust formed at spreading centers. Geological mapping and structural studies provided insights into the morphology of ophiolitic massifs, their tectonic setting in Uralides, and relationships with diverse units of volcanic and volcanosedimentary rocks. The obtained results allows us to outline the main stages of Paleouralian ocean closure as a result of accretion and collision during tectonic juxtaposition of the East European continent, island arc, and East Uralian microcontinent.