喀喇昆仑断裂南段晚第四纪分段活动特征与扎西岗地表破裂带研究  

Late Quaternary segmentation activity of the southern part of the Karakorum fault and a study of the Chaxikang surface rupture

作　　者：韩帅 吴中海[1,2,3] 王世锋 高扬[1,4] 张圣听 陆诗铭 张铭杲 HAN Shuai;WU Zhonghai;WANG Shifeng;GAO Yang;ZHANG Shengting;LU Shiming;ZHANG Minggao(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China;Research Center of Neotectonism and Crustal Stability,China Geological Survey,Beijing 100081,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;China Unitersity of Geoscience,Beijing 100083,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部活动构造与地质安全重点实验室,北京100081 [3]中国地质调查局新构造与地壳稳定性研究中心,北京100081 [4]北京大学地球与空间科学学院,北京100871 [5]中国地质大学,北京100083

出　　处：《地质学报》2025年第2期399-416,共18页Acta Geologica Sinica

基　　金：中国地质科学院地质力学研究所基本科研业务费项目(编号所科研56);中国地质调查项目(编号DD20221644)联合资助的成果。

摘　　要：青藏高原近20~30年间发生了一系列大地震,引起了国内外学者的广泛关注。这些大震往往发生在规模巨大的断裂带上。这些断裂带不仅晚第四纪活动强烈,而且具备孕育和发生强震的构造条件。喀喇昆仑断裂是青藏高原西部的一条规模巨大的右旋走滑断裂,其中龙木错断裂以南的部分是活动性更为明显的段落,并曾发生过1883年普兰M_(S)7.0大地震。查明断裂的分段活动特征和地表破裂,有助于理解断裂最新的变形行为并分析其发震习性。文中基于高分辨率遥感影像解译和野外地质调查,详细研究了喀喇昆仑断裂南段晚第四纪活动的分段性和扎西岗地表破裂带。结果表明,断裂带南段可分为拉达克—扎西岗段、昆莎—巴尔段和门士—公珠错段三个一级段落,分别表现为右旋走滑、右旋走滑拉分和右旋走滑兼马尾状正断。地震地表破裂带测得的最小水平位移为8~9 m,结合地表破裂约200 km的长度,推测此次地震震级可达~7.5级。喀喇昆仑断裂带在调节高原西部物质向东挤出的方式,由北西段的刚性块体运移方式,向东南段逐渐转化为较为分散的弧形正断和走滑变形。Numerous significant earthquakes have occurred in the Tibetan Plateau since the recent decades years,attracting considerable attention from scholars both domestically and internationally.These major earthquakes often occur along enormous fault zones,which not only exhibit intense activity in the late Quaternary period but also possess structural conditions necessary for the development and occurrence of strong earthquakes.The Karakorum fault stands out as a large-scale dextral strike-slip fault in the western part of the Tibetan Plateau.The part south of the Lungmu Co fault more pronounced activity and has experienced the Pulan M_(S)7.0 earthquake in 1883.Understanding the most recent deformation behavior of this fault and analyzing its seismogenic characteristics are crucial in identifying the segmented activity patterns and surface rupture features of the fault zone.Based on high resolution remote sensing image interpretation and field geological survey,the late Quaternary segmented activity of the southern section of the Karakorum fault and the Chaxikang surface rupture zone have been meticulously investigated.The findings reveal that the southern section of the fault zone can be further divided into three primary segments:Ladakh-Chaxikang,Kunsha-Bar and Menshi-Gongzhu Co segment.These segments are characterized by dextral strike-slip,dextral strike-slip normal faulting and dextral strike-slip with a horsetail normal fault,respectively.Measurements taken from the surface rupture zone indicate a minimum horizontal displacement of 8~9 m.Considering the approximately 200 km length of the surface rupture,it is estimated that the magnitude of the earthquake could be~7.5.The Karakorum fault zone,which controls the material extrusion in the western plateau,gradually transforms from a rigid block migration mode in the northwest section to a more dispersed arc-shaped normal fault and strike slip deformation in the southeast section.

关 键 词：喀喇昆仑断裂 断裂分段性 地表破裂 晚第四纪 构造活动 

分 类 号：P534.63[天文地球—第四纪地质学] P542[天文地球—古生物学与地层学]