SEISMOLOGY AND GEOLOGY ›› 2019, Vol. 41 ›› Issue (2): 266-280.DOI: 10.3969/j.issn.0253-4967.2019.02.002

• Research Paper • Previous Articles     Next Articles


HU Zong-kai1, YANG Xiao-ping1, YANG Hai-bo1, LI Jun2, WU Guo-dong1,2, HUANG Wei-liang3   

  1. 1. Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    2. Earthquake Agency of the Xinjiang Uygur Autonomous Region, Urumqi 830011, China;
    3. Chang'an University, Xi'an 050011, China
  • Received:2018-06-29 Revised:2018-11-13 Online:2019-04-20 Published:2019-05-21


胡宗凯1, 杨晓平1, 杨海波1, 李军2, 吴国栋1,2, 黄伟亮3   

  1. 1. 中国地震局地质研究所, 活动构造与火山重点实验室, 北京 100029;
    2. 新疆维吾尔族自治区地震局, 乌鲁木齐 830011;
    3. 长安大学, 西安 050011
  • 通讯作者: 杨晓平,男,研究员,
  • 作者简介:胡宗凯,男,1993年生,2016年于合肥工业大学获地质学专业学士学位,中国地震局地质研究所活动构造与地震地质专业在读硕士研究生,。
  • 基金资助:

Abstract: The Bolokonu-Aqikekuduke fault zone(Bo-A Fault)is the plate convergence boundary between the middle and the northern Tianshan. Bo-A Fault is an inherited right-lateral strike-slip active fault and obliquely cuts the Tianshan Mountains to the northwest. Accurately constrained fault activity and slip rate is crucial for understanding the tectonic deformation mechanism, strain rate distribution and regional seismic hazard. Based on the interpretation of satellite remote sensing images and topographic surveys, this paper divides the alluvial fans in the southeast of Jinghe River into four phases, Fan1, Fan2, Fan3 and Fan4 by geomorphological elevation, water density, depth of cut, etc. This paper interprets gullies and terrace scarps by high-resolution LiDAR topographic data. Right-laterally offset gullies, fault scarps and terrace scarps are distributed in Fan1, Fan2b and Fan3. We have identified a total of 30 right-laterally offset gullies and terrace scarps. Minimum right-lateral displacement is about 6m and the maximum right-lateral displacements are(414±10)m, (91±5)m and(39±1)m on Fan2b, Fan3a and Fan3b. The landform scarp dividing Fan2b and Fan3a is offset right-laterally by (212±11)m. Combining the work done by the predecessors in the northern foothills of the Tianshan Mountains with Guliya ice core climate curve, this paper concludes that the undercut age of alluvial fan are 56~64ka, 35~41ka, 10~14ka in the Tianshan Mountains. The slip rate of Bo-A Fault since the formation of the Fan2b, Fan3a and Fan3b of the alluvial-proluvial fan is 3.3~3.7mm/a, 2.2~2.6mm/a and 2.7~3.9mm/a. The right-lateral strike-slip rate since the late Pleistocene is obtained to be 3.1±0.3mm/a based on high-resolution LiDAR topographic data and Monte Carlo analysis.

Key words: Bo-A Fault, alluvial fans, gully displacement, glaciations-interglacial slip rate, Tianshan

摘要: 博罗可努-阿齐克库都克断裂(博-阿断裂)是中天山与北天山的板块会聚边界,它NW向斜切天山山脉,是一条继承性的右旋走滑活动断层。研究其活动性质、限定其滑动速率有助于理解天山地区晚第四纪构造变形模式、应变速率分配情况及评估区域地震危险性。文中通过卫星遥感影像解译及野外考察,基于地貌面高程、水系密度和切割深度等,将精河东南的冲洪积扇分为4期,由老到新分别命名为Fan1、Fan2、Fan3和Fan4。利用无人机航拍获取断裂附近的高精度影像,并对冲洪积扇上发育的冲沟、阶地陡坎等进行构造地貌解译,发现Fan1、Fan2和Fan3 3期冲洪积扇上发育右旋位错冲沟及断层陡坎。其中,Fan2b、Fan3a和Fan3b上的冲沟最小右旋位错约6m,最大位错分别为(414±10)m、(91±5)m和(39±1)m;Fan2b与Fan3a分界的地貌陡坎被右旋位错(212±11)m。结合前人在天山北麓得到的阶地或冲洪积扇的堆积年龄,并与古里雅冰芯气候曲线进行对比,推测Fan2b、Fan3a和Fan3b 3期冲洪积扇的下切年龄分别为56~64ka、35~41ka和10~14ka。博-阿断裂自冲洪积扇Fan2b、Fan3a和Fan3b形成以来的滑动速率分别为3.3~3.7mm/a、2.2~2.6mm/a和2.7~3.9mm/a,利用蒙特卡洛模拟方法拟合得到晚更新世以来其平均右旋走滑速率为(3.1±0.3)mm/a。

关键词: 博-阿断裂, 冲洪积扇, 冲沟位移, 冰期-间冰期滑动速率, 天山

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