Structural features and activity in the east segment of Xiangshan northern margin active fault zone

Xiangshan northern margin active fault zone, mainly characterized by sinistral strike-slip faults with a little dip-slip component in the Holocene, is one of the important active faults of arc structural belt in the northeast margin of Tibetan Plateau. The fault zone consists of nine discontinuous secondary faults and is divided into eastern and western segment by the Yiwanquan discontinuity. Based on the field survey, the study on active intensity of the eastern segment of the fault zone since the Late Pleistocene has been conducted in different periods. The results show that the active intensity of the east segment since the Late Pleistocene is not strong because the average horizontal displacement rates are 1.44, 0.53 and 1.01 mm/a in early-middle stage of Late Pleistocene, late stage of Late Pleistocene, and Holocene, respectively. The sinistral strike-slips of the faults distribute inhomogeneously along the strike, and the location of the maximal slip (the center of the activation) displaced eastward, resulting in the Jiangou-Liugangjing secondary fault being the most active part up to now.