大柴旦断裂中段晚第四纪活动特征  

Late Quaternary activity characteristics of the middle segment of Dachaidan fault

作　　者：庞炜[1] 何文贵[2] 吴赵 张波[2] PANG Wei;HE Wengui;WU Zhao;ZHANG Bo(The Second Monitoring and Application Center,CEA,Xi'an 710054,Shaanxi,China;Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China;Beijing Earthquake Prevention Technology Development Co.,Ltd.,Beijing 100029,China)

机构地区：[1]中国地震局第二监测中心,陕西西安710054 [2]中国地震局兰州地震研究所,甘肃兰州730000 [3]北京震防科技发展有限公司,北京100029

出　　处：《地震工程学报》2023年第2期465-473,共9页China Earthquake Engineering Journal

基　　金：国家自然科学基金(41802229);中国地震局星火科技项目(XH20080Y)。

摘　　要：通过航卫片遥感数据解译、野外地质地貌调查,并结合差分GPS等测量手段,获取大柴旦断裂晚第四纪以来的地质地貌特征。结果显示:大柴旦断裂总长约135 km,整体上显示为一反“S”形,根据断裂走向的变化、地貌特征、活动强弱等,大致以温泉沟、塔塔棱河为分界点,可将大柴旦断裂分为三段。晚第四纪以来,该断裂北段和南段逆冲性质较为明显。本次工作集中在断裂中段,该段以右旋逆冲活动为主,逆冲量和右旋量在不同地貌面上是不同的,显示出明显的多期次活动特征。野外天然古地震剖面揭示出1次古地震事件,发生在(2402.5±57.5)a.B.P之后,表明该断裂在全新世活动强烈,与该区域近年来频繁的强震活动相吻合。The geological and geomorphological characteristics of the Dachaidan fault since the Late Quaternary were obtained through the interpretation of remote sensing data,field investigation,and differential GPS survey.The results show that the Dachaidan fault,with a total length of about 135 km,shows an inverse“S”shape.According to the change of fault strike,geomorphic characteristics,and fault activity,the fault is roughly divided into three sections,with Wenquangou and Tataleng Rivers as dividing points.The nature of reverse thrust has been obvious in the northern and southern segments of the Dachaidan fault since the Late Quaternary,and the middle section is dominated by dextral thrust activities.The reversed and strike-slip displacements are different on different geomorphic surfaces,showing obvious multi-stage activity characteristics.The paleoseismic profile in the field revealed a paleoseismic event,which occurred after(2402.5±57.5)a.B.P.,indicating that the fault was strongly active in the Holocene,consistent with the frequent strong seismic activities in the region in recent years.

关 键 词：大柴旦断裂 晚第四纪活动 右旋 断错地貌测量 测年 

分 类 号：P315.2[天文地球—地震学]