Abstract:
Study area (Shekarab Mountains) is located in Sistan suture zone. The aim of this research is to investigate the variation of stress pattern (direction of stress tensors and stress ellipsoids shape) in Neogene units, Paleogene units and older units. In this research characteristics of brittle structures (faults) were interpreted using Win-Tensor software. Structural analysis and analysis of Steps of applied Paleo stress in Shekarab Mountains indicate that in Cretaceous time stress regime operation tectonic was pressure with the direction of the main stress axes σ1=337/26, σ2=070/06, σ3=172/64 and stress ratio was 0.1 which caused the uplifting of peridotites and ophiolites in eastern part of study area. The second step of stress has been strike slip and transpressive with the direction of the main stress axes σ1=003/31, σ2=110/26, σ3=232/47 and stress ratio was 0.29, more exhumation of igneous units is related to in the eastern part of Shekarab Mountains in these regions units' stress regime has been displaced locally from strike slip to transpressive that is due to local changes of stress direction in this regions. The third step of stress regime of in Shekarab Mountains is strike slip with the direction of the main stress axes σ1=060/10, σ2=227/72, σ3=152/08 and stress ratio 0.5. Results of stress analysis indicate that major stress axis (σ1) in Cretaceous units had N337 trend, in Eocene units had N003 trend and in Quaternary units has N060 trend.