Paleostress and kinematic analyses by using fault slickenline of the Qaemyeh, south western Iran

Abstract The Qaemyeh area is located in 100 km west of the Shiraz city and 40 km north of Kazerun city. The Qaemyeh fault was formed by segmentation of the Kamarij fault as part of the active Kazerun strike-slip fault. This fault is part of the Zagros Foreland Folded Belt. The study area includes the normal component of dextral strike-slip fault cut the Gurpi, Pabdeh and Sarvak formations, and the other right- lateral strike- slip fault cut Asmari formation. The fault is low angle Riedel shear fractures that follow the pattern of the Kazerun fault. Analysis of the slicken lines of the fault plane were preformed in order to reconstruct the orientations effective stress by using fault-slip graphical inversion method. The  calculated plunges and trends of the principal stresses  of the normal fault are σ1 76º, S71°W,σ2 06º, S60°E and σ3 is70º, N31°E, 70º and  for the strike- slip fault, σ1 are  NE, N31°E, 07º ,σ2 is SE, S84°W, 70º, and σ3 S60°E, 06º respectively. Based on the study of fault-slip data and slickenside lineation, using the multiple inverse methods, two phases of stress are recognized. An early tension stress field caused faulting in the area, while the later stress phase is resulted by occurrence of young fracture system in the area. The tectonic regime of prevailing in the region by ratio R= (σ2-σ3)/(σ1-σ3) is extension. The stress field around faults is related of the Kazerun fault activities.