Reconstruction of the Eocene-Oligocene Paleostress field in the Horamak-Gharqharok region; Strike-slip faults system in eastern Iran (Zahedan fault)

The study area is exposed in the western margin of the Zahedan dextral strike-slip fault in eastern part of Sistan suture zone. This study investigates the situation of paleo-stress field based on heterogeneous fault slip data and slip-lines in Eocene-Oligocene limestone blocks. The results show the position of the three axes s 1 =45/53,  s 2 =207/35, s 3 =303/09. Based on the "right Dihedron" and "rotational optimization" methods, R¢= R (F)=0.43 , which represents the simultaneous compressional - shear stress component in eastern Sistan fold and thrust belt. Accompaniment of tensional structures such as boudinage, shear fractures and Normal faulting, indicate local Tensional stress whith  N340 direction. This results, show the occurrence of a progressive deformational phases and rotational displacement of the internal elements in this right-lateral strike-slip fault.  The local maximum tensional stress direction in this area, rotated clockwise direction, about 25° from Eocene  to recent time. The location of Ghargharook area near the fault-bent, along the Zahedan dextral strike-slip fault, can be caused  to clockwise rotation of  principal stress axis.