Paleoseismologic record of earthquakes along the Wuzunxiaoer section of the Altyn Tagh fault and its implication for cascade rupture behavior  

作　　者：Zhaode YUAN Jing LIU-ZENG You ZHOU Zhigang LI Heng WANG Wenqian YAO Longfei HAN 

机构地区：[1]State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China [2]Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China [3]School of Earth Sciences and Engineering,Sun Yat-Sen University,Guangzhou 510275,China

出　　处：《Science China Earth Sciences》2020年第1期93-107,共15页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China (Grant Nos. U1839203, 41761144065, 41802228);Central Public-Interest Scientific Institution Basal Research Fund (Grant No. IGCEA1814);State Key Laboratory of Earthquake Dynamics of China (Grant No. LED2017A01)

摘　　要：The Altyn Tagh fault is one of the few great active strike-slip faults in the world. The recurrence characteristics of paleoearthquakes on this fault are still poorly understood due to the lack of paleoseismic records recorded in high-resolution strata. We document a paleoseismic record in a pull-apart basin along the Wuzunxiaoer section of the central Altyn Tagh fault.The high-resolution strata recorded abundant seismic deformations and their sedimentary responses. Four earthquakes are identified based on event evidence in the form of open fissures, thickened strata, angular unconformities, and folds. The occurrence times of the four events were constrained using radiocarbon dating. Event W1 occurred at AD1220–1773, events W2 and W3 occurred between 407 and 215 BC, and event W4 occurred slightly earlier at 1608–1462 BC, indicating clustered recurrence characteristics. A comparison of the earthquake records along the Wuzunxiaoer section with other records along the Xorkoli section suggests that both sections ruptured during the most recent event.The Altyn Tagh fault is one of the few great active strike-slip faults in the world. The recurrence characteristics of paleoearthquakes on this fault are still poorly understood due to the lack of paleoseismic records recorded in high-resolution strata. We document a paleoseismic record in a pull-apart basin along the Wuzunxiaoer section of the central Altyn Tagh fault.The high-resolution strata recorded abundant seismic deformations and their sedimentary responses. Four earthquakes are identified based on event evidence in the form of open fissures, thickened strata, angular unconformities, and folds. The occurrence times of the four events were constrained using radiocarbon dating. Event W1 occurred at AD1220–1773, events W2 and W3 occurred between 407 and 215 BC, and event W4 occurred slightly earlier at 1608–1462 BC, indicating clustered recurrence characteristics. A comparison of the earthquake records along the Wuzunxiaoer section with other records along the Xorkoli section suggests that both sections ruptured during the most recent event.

关 键 词：TIBET Altyn Tagh fault Strike-slip fault PALEOEARTHQUAKE Coseismic offset 

分 类 号：P315[天文地球—地震学]