The Research of the Activity of the Piedmont Fault on the Tangshankou Segment of the Yuguang Basin Southern Marginal Fault  

作　　者：Wang Lin Tian Qinjian Li Dewen Zhang Xiaoliang 

机构地区：[1]Institute of Earthquake Science,China Earthquake Administration,Beijing 100036,China [2]Institute of Crustal Dynamics,China Earthquake Administration,Beijing 100085,China [3]China Earthquake Disaster Prevention Center,Beijing 100029,China

出　　处：《Earthquake Research in China》2017年第4期527-537,共11页中国地震研究（英文版）

基　　金：funded by the Special Fund for Basic Scientific Research of Institute of Earthquake Science,China Earthquake Administration(2015 IES010202);the Seismic Risk Assessment Project for Active Faults in Key Region of Earthquake Monitoring and Prevention in China(201210916)

摘　　要：The Yuguang basin is a half-graben basin in the basin-range tectonic zone in northwest Beijing,located at the northern end of the Shanxi graben system,and the Yuguang basin southern marginal fault( YBSMF) controls the formation of this basin. A linear fault escarpment has formed in the proluvial fan on the piedmont fault zone of the Tangshankou segment of YBSMF. A trench across this escarpment reveals three paleo-earthquake events on two active faults. One fault ruptured at about 9 ka for the first time,and then faulted again at about 7. 3 ka,causing the formation and synchronous activity of another fault.Finally,they faulted for the third time,but we cannot determine the faulting time due to the lack of relevant surface deposition. The accumulative vertical displacement of these three events is about 8. 1 m. We estimate that the average recurrence period of the piedmont fault is about 1. 7 ka,and the average slip rate of the piedmont fault is about1. 6 mm/a. We also estimate the reference magnitude of each event according to the empirical formula.The Yuguang basin is a half-graben basin in the basin-range tectonic zone in northwest Beijing,located at the northern end of the Shanxi graben system,and the Yuguang basin southern marginal fault( YBSMF) controls the formation of this basin. A linear fault escarpment has formed in the proluvial fan on the piedmont fault zone of the Tangshankou segment of YBSMF. A trench across this escarpment reveals three paleo-earthquake events on two active faults. One fault ruptured at about 9 ka for the first time,and then faulted again at about 7. 3 ka,causing the formation and synchronous activity of another fault.Finally,they faulted for the third time,but we cannot determine the faulting time due to the lack of relevant surface deposition. The accumulative vertical displacement of these three events is about 8. 1 m. We estimate that the average recurrence period of the piedmont fault is about 1. 7 ka,and the average slip rate of the piedmont fault is about1. 6 mm/a. We also estimate the reference magnitude of each event according to the empirical formula.

关 键 词：Yuguang BASIN south MARGINAL FAULT PIEDMONT FAULT zone FAULT ESCARPMENT Trench PALEOEARTHQUAKE event FAULT slip rate 

分 类 号：P315.2[天文地球—地震学] P542.3[天文地球—固体地球物理学]