中更新世晚期以来中条山北麓断层滑动速率研究  

STUDY ON THE SLIP RATE OF THE NORTH ZHONGTIAO SHAN FAULT SINCE THE LATE MIDDLE PLEISTOCENE

作　　者：张秀丽 熊建国 张培震 刘晴日[1,3] 姚勇 钟岳志 张会平 李有利[3] ZHANG Xiu-li;XIONG Jian-guo;ZHANG Pei-zhen;LIU Qing-ri;YAO Yong;ZHONG Yue-zhi;ZHANG Hui-ping;LI You-li(State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Guangdong Provincial Key Laboratory of Geodynamics and Geohazards,School of Earth Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China;Key Laboratory of Earth Surface Process of Ministry of Education,Peking University,Beijing 100871,China;State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029 [2]中山大学地球科学与工程学院,广东省地球动力作用与地质灾害重点实验室,广州510275 [3]北京大学城市与环境学院,地表过程分析与模拟教育部重点实验室,北京100871 [4]中国科学院地质与地球物理研究所,岩石圈演化国家重点实验室,北京100029

出　　处：《地震地质》2022年第6期1403-1420,共18页Seismology and Geology

基　　金：国家自然科学基金(41971002,41888101)资助。

摘　　要：约束断层在不同时间尺度上的滑动速率,有利于认识其活动性和区域构造特征。文中以山西地堑系南部中条山北麓断层为研究对象,利用无人机摄影测量技术获取小李村河断错地貌的高精度DEM,通过光释光和AMS^(14)C年代学约束河流阶地序列的废弃年代和地层的沉积时代,建立中更新世晚期以来小李村河地貌演化与中条山北麓断层活动的关系。结合断层上盘钻孔所揭露的沉积地层和光释光年龄,约束中条山北麓断层在中更新世晚期以来2个不同时段的垂直断距,获得的相应滑动速率为0.3~0.4mm/a,并简要讨论了晚新生代以来该断层滑动速率的变化。Slip rate is an important parameter for the quantitative study of active fault and can be used to reflect the mode and intensity of fault activity.However,the selection of geomorphic surface,the acquisition of displacements,and the limitation of chronologic methods result in challenges to constrain the slip rate.A series of boreholes and geochronology studies revealed a continuous sedimentary sequence of the Quaternary in the Yuncheng Basin in the southern Shanxi Graben System.Multiple late Quaternary river terraces have developed and been preserved in the northern piedmont of the Zhongtiao Shan.The activities of the north Zhongtiao Shan Fault resulted in the elevation difference between the strata in the Yuncheng Basin and the river terraces.In this study,we chose the geomorphic units of the Xiaolicun River and combined them with the results of boreholes in the Yuncheng Basin to constrain the slip rates of the north Zhongtiao Shan Fault since the Late Pleistocene.Based on field observation and remote sensing image interpretation,we established the distribution and sedimentary characteristics of four terraces and the latest alluvial fan of the Xiaolicun River.Two main faults(F1and F2)and a series of fractures or branch faults have been identified in these sedimentary strata.The high-resolution DEM of the faulted landform of the Xiaolicun River was obtained using UAV photogrammetry technology.Combined with a stratigraphic outcrop survey,the landform and sedimentary section across the fault were constructed.The abandonment ages of the terraces T4,T3,T2,and T1have been determined as(214.3±13.9)ka,(118.5±6.4)ka,(59.6±2.4)ka,and(10.9±0.5)ka by OSL dating,respectively.The chronological results of the AMS14C dating show that the alluvial fan north of F2was deposited at 35~1ka.Based on these results,this study established the relationship between the geomorphic evolution of the Xiaolicun River and the activities of the north Zhongtiao Shan Fault.Since the late Middle Pleistocene,F1had been active,accompanied by the a

关 键 词：滑动速率 河流阶地 中更新世 中条山北麓断层 山西地堑系 

分 类 号：P315.2[天文地球—地震学]