Determination of dynamic characteristics of fault is an important issue in the seismotectonic studies. Various methods have been proposed to achieve this through the analysis of the fault plane, either based on the orientation of the striations, in relation to the location of fault plane, or on the position of fractures associated with it.
In order to determine the dynamic characteristics of the Soltanieh fault in south and southwest Zanjan, the field description of the fault plane and its associated fractures were carried out. With frist step, by plotting the conjugated faults present within the area, the major paleo-stress axes were determined. The prevailing maximum stress direction within the area of study was then estimated by using the strike-slip fractures associated with the Soltanieh fault. Finally, considering the properties of the Soltanieh fault plane and the obtained trends of the major stresses, the variation limits of the slip axis of Soltanieh fault was calculated using the method described in Anglier (1988). The results of the study indicate a reverse mechanism of Soltanieh fault with a right-lateral strike-slip component. The maximum stress prevailed in the area at the time of faulting had its trends in the northeast-southwest direction (N40E approximately).