阿尔金断裂东段的河流阶地累积位错  

CUMULATIVE DISLOCATIONS OF RIVER TERRACES IN THE EASTERN SEGMENT OF THE ALTYN TAGH FAULT

作　　者：李路瑶 丁锐 姜大伟 张世民 LI Lu-yao;DING Rui;JIANG Da-wei;ZHANG Shi-min(National Institute of Natural Hazards,MEMC,Beijing 100085,China)

机构地区：[1]应急管理部国家自然灾害防治研究院,北京100085

出　　处：《地震地质》2024年第3期547-569,共23页Seismology and Geology

基　　金：中央级公益性科研院所基本科研业务专项(ZDJ2020-12);国家自然科学基金地震科学联合基金项目(U2039201)共同资助。

摘　　要：阿尔金断裂带是青藏高原北缘的大型左旋走滑断裂,其东段与NW走向的祁连山逆冲断裂带斜接。文中基于无人机摄影测量技术(SfM)获得的高分辨率影像数据,对阿尔金断裂带东段长约127km的段落开展了详细解译,并对其中9个典型河流阶地位错点进行测量与统计。沿阿尔金断裂带向E,晚第四纪左旋累积位移总体呈衰减趋势,且以断裂带东侧NW走向斜接逆冲断裂或逆冲走滑断裂为界,其累积位错量在同一断裂段内大致相当,但相邻断裂段之间表现为阶梯状递减,指示了斜接断裂的构造转换关系及可能的地震破裂分段作用,为阿尔金断裂带活动性分段研究与潜在发震能力评价提供了依据。The Altyn Tagh fault zone is a sizeable sinistral strike-slip fault on the northern margin of the Qinghai-Tibet Plateau,and its eastern section is obliquely connected with the northwest Qilian Mountain thrust fault zone.The left-lateral strike-slip action of the Altyn Tagh fault zone and the Qilian Mountain thrust belt constitute a structural transformation relationship.The activity behavior of this fault,especially the amount of sinistral dislocations,segmentation,and slip rate,has always been a hot topic of discussion among scholars.At present,based on geological methods and geodetic research,the slip rates of different sections of the Altyn Tagh Fault have been obtained,with a time scale ranging from tens of thousands of years to decades.The research results generally support the gradual attenuation of the slip rate of the Altyn Tagh fault zone from about 93°E to the east,indicating that its left-lateral attenuation is absorbed by a series of NW-trending thrust faults on its eastern side,and this trend has changed little for decades.The above work provides a framework for us to study the structural transformation relationship between the Altyn Tagh fault zone and the Qilian Mountains thrust belt in time and space.However,due to the limitations of previous observation points,especially the different methods of fault geomorphology measurement and dating used by various authors,there are significant differences in the obtained fault slip rates.Currently,it is not possible to analyze the segmented characteristics of the slip rate in the east section of the Altyn Tagh fault zone further and its spatial relationship with the Qilian Mountain thrust structural zone based on this.In recent years,the application of UAV aerial survey technology has allowed image data to be obtained at the centimeter to millimeter level,making the study of tectonic geomorphology more refined.Researchers can obtain the cumulative displacement or co-seismic displacement of several seismic cycles through micro-faulted landforms and reconstr

关 键 词：阿尔金断裂带 高分辨率地形数据 累积位移 断错地貌构造转换 

分 类 号：P315.2[天文地球—地震学]