Essential features of seismotectonics of Central segment of the Alpine Belt

Structural zoning of Central segment of Alpine Belt, including Great and Lesser Caucasus, Kopet-Dagh, Elbours, Zagros, Central Iran upland,Turan-Skiphian and Arabian plates consists of foredeeps, external and internal fold systems, Central Iran Stable massif and surrounding ancient and young platforms. Deep faults separate these essential tectonic units. The main geodynamic moving force for the fold-fracture deformation of Central segment of Alpine Belt from GPS data is the interaction of the Arabian, Skihpian and Central Iranian lithosphere plates. The Arabian plate displacement to the northeast due to spreading the Red sea rift at the recent and modern stages, and also spreading of the Central Iran region subsiding and the recent volcanism cause the intensive compression stress in the Zagros fold system. Similarly the Kopet-Dagh and Caucasus fold zones are compressed between Turan-Skiphian and Central Iran platforms. This development type results the domination of compressive stress in outer zones of the fold region, being as a result of orogenic uplift and increasing of the axial zone. Stress field is characterized by horizontal orientation of the compression axis across the external and internal fold systems. In such field most active from geological and seismological points of view are reverse boundary faults, separating the above mentioned main tectonic zones, and shear diagonal faults, separating blocks of the earth’s crust inside fold zones and foredeeps.