Geodynamics of Carpathian and Crimean fold belts formation

Carpathian arched fold-and-thrust belt has formed as a result of its occurrence at the beginning of its formation within the rigid limits of Precambrian geo-structural units: Czech massif, Volyno-Podolian and Moesian plates, Pannonian middle massif with a consequent collision of a number of plates and microplates: of East-European microplate with African plate, which moves from south-west through the intermediate Adriatic and Pannonian microplates, of West-European microplate, which moves from west-north-west, with Pannonian microplate and of Arabian plate, which moves from south-south-east through Anatolian and West-Black Sea microplates with microplate of Transilvanian and Pannonian depressions. Differences in mass of plates and microplates are not big, that is why their collision occurs according to the scheme of collision and low-angle subduction under Pannonian and Transilvanian depressions of somewhat heavier and cooler plates from northwest, north-east and south-east. Collision belts of these plates and microplates are limited by fold-and-thrust subduction zones. Collision and low-angle subduction caused heating of the mantle mass, forming of the mantle asthenolith and its uplift, which resulted in intense heat flow and crust thickness reduction under Pannonian and Transilvanian depressions. This explains the high position of Moho under these depressions. As a result of subduction of the European plate under the Pannonian and Transilvanian microplates during Late Cretaceous till present, about 150 linear kilometers of substrate have been assimilated, and the Cretaceous-Paleogene flysch has been displaced from its platform basement and intensively deformed into structures of north, north-east and south-east vergence.
   In front of the Crimean fold belt, on the north-east, the platformian part (Skythian microplate) is distinguished, further southwards – the system of depressions and somewhat uplifted structures of latitudinal extension and more southwards the mountains of Crimea and Caucasus formed during the Kimmeridgian and Alpine folding phases. Southwards from these mountains the Paleogene depression of Black Sea has formed, in which the West- and East- Black Sea parts are distinguished. Southern coast of the Black Sea is represented by the mountain massifs of the Pontian Mountains (Pontides) formed during the Alpine folding and with a convex part of the arc directed to south-east. System of Crimean and Caucasus Mountains, taking into consideration their both subairial and submarine occurrence, has an arched shape and with its convex part directed to south-east. It has formed as a result of collision of the Eurasian plate with the plates of the present-day East- and West-Black Sea depressions. The beginning of collision is referred to Triassic (Kimmeridgian folding). During Triassic, Jurassic and Cretaceous a system of depressions, Crimean and Caucasus Mountains, Black Sea depression has been formed. During Jurassic-Cretaceous-Paleogene the process of denudation of the Crimean Mountains took place. At the end of Cretaceous the tectonic movements of the Alpine orogeny recommenced, which is evidenced by the laccoliths in the internal ridge of the Crimean Mountains.
   During the Alpine folding cycle as a result of the movement of Arabian and Anatolian plates to south-west their movement has been transferred to the west of the Black Sea plate, which as a wedge along the Teisseyre-Tornquist line is pressed into the body of the Eurasian plate. This movement is observed till the Baltic Sea region. At the present epoch the movement of the Eurasian plate to south-west and its collision with the East-Black Sea plate continues. As a result was formed the Azov Sea depression, Indolo-Kuban depression continues to be formed, Sivash lagoon has been formed. The present-day Sea of Azov is an external part of the foredeep where the molasse deposits are formed. The present-day Black Sea is an intramontane depression.
   At the present epoch the movements along the Trans-European tectonic activation zone – the Teisseyre-Tornquist zone have activated. This is confirmed by a number of earthquakes, existence of “hot” points and GPS measurements.