Displacement and timing of left-lateral faulting in the Kunlun Fault Zone,northern Tibet,inferred from geologic and geomorphic features
作者单位：State Key Laboratory of Lithospheric Evolution.Institute of Geology and GeophysicsChinese Academy of Sciences Active Fault Research Center.AIST.Tsukuba 305-8567Japan
会议名称：《中国科学院地质与地球物理研究所2007学术年会》
会议日期：2008年
学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学]
基 金：funded by the research project from President Foundation of Chinese Academy of Sciences
关 键 词：Left-lateral faulting Displaced basement rocks Pull-apart basin Pressure ridge Kunlun Fault Zone Northern Tibet
摘 要：The E-W to WNW-ESE striking Kunlun Fault Zone,extending about 1600 km,is one of the large strike-slip faults in the northern Tibet,*** a major strike-slip fault,it plays an important role on the extrusion of Tibet Plateau in accommodating northeastward shortening caused by the India-Asia ***,the time of initiation left-lateral faulting of the Kunlun Fault Zone is still largely debated,ranging from the Middle to Late Triassic(240-200 Ma) to early Quaternary(2 Ma).We document displaced basement rocks and geomorphic features along the Kunlun Fault Zone,based on tectono-geomorphic interpretation of satellite remote sensing images and field geologic and geomorphic *** results show that the largest cumulative offset of basement rocks is likely to be 100±20 ***,a series of pull-apart basins(Kusai,Xiugou and Tuosu lake basins) and pressure ridges(East Deshuiwai and Maji Snow Mountains),each 45-70 km long and～8-12 km wide,are developed along the Kunlun Fault Zone,which resulted from long-term tectono-geomorphic growth since the Late Miocene or Early *** evidence indicates that the Kunlun Fault Zone had a long-term slip rate of ca.10 mm/yr during the late *** slip rate is similar to that shown by present-day GPS measurements. Thus,we estimate that the Kunlun Fault Zone probably began left-lateral faulting at 10±2 Ma based on a total displacement of 100±20 km,and assuming a constant long-term slip rate of ca.10 mm/yr for several millions of *** this timing constraint on initiation of left-lateral faulting of the Kunlun Fault Zone is consistent with widespread tectonic deformation which occurred in the Tibetan Plateau.