德钦—中甸断裂北西段全新世地震活动证据  

The Holocene Activity Evidence of Paleo-earthquakes in the Northwestern Segment of the Deqin-Zhongdian Fault

作　　者：常玉巧[1] 李西 周青云[1] 白仙富[1] 冉华[1] 罗伟东[1] CHANG Yuqiao;LI Xi;ZHOU Qingyun;BAI Xianfu;RAN Hua;LUO Weidong(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China;School of Earth Science,Yunnan University,Kunming 650500,Yunnan,China)

机构地区：[1]云南省地震局,云南昆明650224 [2]云南大学地球科学学院,云南昆明650500

出　　处：《地震研究》2023年第2期261-270,共10页Journal of Seismological Research

基　　金：云南省地震局科技专项(2019ZX03);上海佘山地球物理国家野外科学观测研究站开放基金(SSOP202101)。

摘　　要：在高分辨率遥感解译基础上,沿德钦—中甸断裂开展野外地质地貌调查和断错地貌无人机测绘等工作,并在断裂北西段德钦县北的贡卡湖附近线性断层槽谷内开挖了一个大型探槽,探槽剖面揭露出多条断裂信息。结合多个14C样品年代学分析发现,断裂明确错断了全新世地层,且揭露出一次明确地震事件E1:(1140±30)—(1010±30)a BP,一次可能事件E2:(570±30)—(410±30)a BP。结果表明:德钦—中甸断裂北西段全新世以来有过活动,水平方向以右旋走滑为主,垂向上具有倾滑分量,总体表现为正走滑特征。Based on the high-resolution remote sensing interpretation and a detailed field geological and geomorphological survey,we excavate a trench in the linear fault trough beside the Gongka Lake to reveal the direct evidence of the Holocene activity and paleo-earthquake.The trench,which is perpendicular to the fault trace,obviously manifests positive dip-slip faults and shows that the Deqin-Zhongdian Fault has dislocated the Holocene stratum.Through paleoseismic analysis of the relationship between the fault and stratigraphic ages,cracks and colluvial,and the age of sedimentation determined by means of AMS-14C dating,two palaeo-seismic events are identified.They are respectively between(1140±30)-(1010±30)a BP and(570±30)-(410±30)a BP.The segment in the northwest of the Deqin-Zhongdian Fault was an active fault in Holocene and was characterized as positive dip-slip.

关 键 词：德钦—中甸断裂 贡卡湖探槽 地震事件 全新世活动 滇藏铁路 

分 类 号：P315.2[天文地球—地震学]