Analysis of stress regimes in Azerbaijan plateau, North West Iran

The Azerbaijan area is a region has been located in the northwestern part of Iran and has by deformation among large Caucasus, alborz and by distance from Zagros. In the recent decades¡ increasing the number of earthquakes and epicenter of this events¡ such as Ahar earthquake makes possible for accurate estimation of change tectonic regime by using the Win-Tensor inversion focal mechanism data. For this purpose¡ Focal mechanism data collected from various sources¡ including CMT and other resources .Then divided area to 5 subzone and by analyzing of focal mechanism and obtained changes in the stress field up to today. The results show that occurred 2 brittle stage in this region. First stage is compression¡ which related to Eocene by (NE-SW) direction that created a compressional structures with NW-SE direction¡ including North and South Bozgush¡ south Ahar and Gushedagh thrust belts. Second brittle stage occurred in Miocene by (NW-SE) direction cause developing of thrusts N-S directions that is active up to present. Due to this stress regimes¡ reduced that Azerbaijan plateau have counter-clock wise rotation due to movement strike slip faults and continuous compression between Arabia plate¡ south Caspian basin and Caucasus region.