Paleostress and stress phases separation analyses using fault slikenlines of the Dasht-e-Arjan graben, southwestern Iran

The NE oriented Dasht-e- Arjan graben is located about 65 Km west of Shiraz and is formed as a result of segmentations of the active Kare-e-Bas Fault. This extensional graben bounded by two boundary east-Arjan and west-Arjan Faults perpendicular to the Shahneshin and Salamati anticlines. Analysis of data from slickenlines was used to reconstruct the orientations effective stress using graphic method (fault-slip inversion technique). The position and trend of the local stresses are, σ1 is NNE, N23°E, 72º and σ3 is SE, S58°E, 26° and σ2, is SW S34°W, 10°, respectively. Based on the study of fault-slip data and slickenside lineation, using the multiple inverse methods, two phases of stress are extracted. An early tension stress field caused faulting with the SW trend in the area, while, the later stress phase is resulted in occurrence of young joint system in the area.