Features and genesis of active faults in the Anhui segment of the Tan-Lu fault zone

Our detailed filed investigation demonstrates the wide-spread presence of active faults in the Anhui segment of the Tan-Lu fault zone. They occur along the eastern and western boundary of the Jiashan Basin and the eastern boundaries of the Hefei Basin and Dabie orogenic belt. The active faults strike from NNE-SSW to NE-SW from north and south, and show similar dips to previous normal faults at the basin boundaries. Kinematics of the active faults dominated by reverse dextral displacement, but showing increased in reverse component with reduction in dip angles. Inversion of a series of measured fault-slip data indicates NEE-SWW compression for activity of the active faults, which is consistent with present stress field. Many phenomena suggest Middle Pleistocene for the most recent time of the activity in the Anhui segment of the Tan-Lu fault zone, which is consistent with the absence of strong earthquakes and weak earthquake concentration in the fault zone. We propose that the active faults originated from dir