SEISMOLOGY AND GEOLOGY ›› 2020, Vol. 42 ›› Issue (5): 1058-1071.DOI: 10.3969/j.issn.0253-4967.2020.05.003

• Research paper • Previous Articles     Next Articles

LATE QUATERNARY ACTIVITY CHARACTERISTICS OF THE TANGBAL-TASDUN FAULT ZONE IN THE EASTERN TIENSHAN AREA

HUANG Shuai-tang1), HU Wei-hua1), YANG Pan-xin2), LI Shuai1), Yiliyaer1)   

  1. 1)Earthquake Agency of Xinjiang Uygur Autonomous Region, Urumqi 830011, China;
    2)Institute of Earthquake Forecasting, CEA, Beijing 100036, China
  • Received:2020-02-08 Revised:2020-04-20 Online:2020-10-20 Published:2021-01-06

东天山唐巴勒-塔斯墩断裂带晚第四纪活动特征

黄帅堂1), 胡伟华1),*, 杨攀新2), 李帅1), 伊力亚尔1)   

  1. 1)新疆维吾尔自治区地震局, 乌鲁木齐 830011;
    2)中国地震局地震预测研究所, 北京 100036
  • 通讯作者: *胡伟华, 男, 1970年生, 副研究员, 主要从事活动构造研究, E-mail: 893912979@qq.com。
  • 作者简介:黄帅堂, 男, 1990年生, 2016年于中国地震局地震预测研究所获构造地质学专业硕士学位, 工程师, 目前研究方向为活动构造与构造地貌, 电话: 0991-3853817, E-mail: shuaith@126.com。
  • 基金资助:
    新疆地震局科技创新团队计划(XJDZCXTD2020-2)、中国地震局地震预测研究所基本科研业务专项重点项目(援疆项目)(2016IES0103)、 中国地震局地震工程与工程振动重点实验室重点专项(2020EEEVL0203)、 地震应急青年课题(CEAEDEM201916)和新疆地震局基金(201910)共同资助

Abstract: There were several strong earthquakes of MS≥7.0 occurring in the eastern Tianshan in the history, which is an important part of Tianshan earthquake zone. The Tangbal-Tasdun Fault is a left-lateral strike-slip fault zone of Late Pleistocene in the northwest of Barkol Basin. The study of the characteristics of its late Quaternary activities is one of the important basic work to understand the risk of strong earthquakes in Barkol area. Due to the low level of research in the eastern Tianshan region, there is a lot of controversy over the historical earthquakes. But there is no doubt that this area has the ability of generating earthquakes of magnitude greater than 7.0. Current GPS monitoring data on both sides and inside of Tianshan Mountains shows an about 20mm/a northward movement of the Pamir and Tarim plates, but a 4mm/a crustal movement rate of eastern Tianshan. This indicates that the tectonic activity of the western section of Tianshan Mountains is obviously stronger than that of the eastern section. However, according to the historical earthquake records of eastern Tianshan, there are at least two earthquakes of magnitude 7 or above happening in Barkol region. This indicates that the tectonic activity in the Barcol area is intense and the area has the condition for generating strong earthquakes.
In this paper, the methods of high resolution satellite image interpretation, field observation and analysis, micro-geographic survey and trenching are used. The geometric distribution characteristics of the Tangbal-Tasdun Fault are determined, which reveals the movement and activity of the fault zone. The activity parameters of the fault since late Pleistocene are preliminarily obtained. The results show that the fault is left-handed strike-slip with thrust motion. A surface rupture zone with a length of about 50km is developed in the east of Jijitaizi Village. The fault offset the T2 terrace with a vertical displacement of about 0.9m and a horizontal displacement between 9m and 11m. The vertical displacement of T3 terrace is about 1.6m, and the horizontal displacement is between 13m and 20m. To the west of Hongjingzi Town and Tashbastawu Village, the fault is distributed in a straight line on satellite images. The fault offset the latest geomorphic surface, with the minimum vertical displacement of about 0.1m, the maximum vertical displacement of 2m, and the horizontal displacement of 1.8~4.3m. The horizontal displacement of the fault is larger than the vertical displacement of the same period. The excavation of a trench near Kutaizi village shows that the fault has obvious characteristics of strike-slip movement. According to the phenomena of water spraying and sand emitting along the fault and the relation of cut and cover between the fault and strata, two ancient seismic events are revealed in the trench. The most recent event ruptured the ground surface. According to the empirical formula for magnitude estimation, M=7.13+0.68lgD, it is calculated and inferred that this fault section is qualified for the occurrence of M7.3~7.4 earthquake.

Key words: Tangbal-Tasdun Fault(TTF), activity characteristics, ancient earthquake, quantitative parameter, rupture zone

摘要: 有历史记载以来, 东天山地区发生过多次7级左右强震, 是天山地震带的重要组成部分。 唐巴勒-塔斯墩断裂是东天山巴里坤盆地NW侧一条晚更新世活动的左旋走滑断裂带, 研究其晚第四纪活动特征是认识巴里坤地区强震危险性的重要基础工作之一。 文中采用高分辨率卫星影像解译、 野外地质地貌考察、 微地貌测量及古地震探槽研究相结合的方法, 厘定了唐巴勒-塔斯墩断裂的几何展布特征, 揭示了断裂的运动性质与活动性, 初步获得了断裂晚更新世以来的活动参数。 结果表明, 断裂为左旋走滑兼具逆冲的运动性质; 在芨芨台子村以东断裂发育有地表破裂带, 长约50km; 芨芨台子村附近断层断错地貌的线性较好, 断错T2阶地的垂直位移量约为0.9m, 水平位移量为9~11m, T3阶地的垂直位移量约为1.6m, 水平位移量为13~20m; 在红井子镇及塔什巴斯他乌村以西, 断裂在卫星影像上呈直线状展布, 断层断错了最新地貌面, 其中最小垂直位移量约为0.1m, 最大垂直位移量约为2m, 水平位移量为1.8~4.3m, 断裂的水平位移大于同期的垂直滑动位移。 在芨芨台子村附近开挖的探槽表明, 断层具有明显的走滑活动特征, 根据断层、 喷砂冒水现象及地层的切盖关系, 探槽共揭示出2次古地震事件, 最新一次事件断错地表。

关键词: 唐巴勒-塔斯墩断裂, 活动特征, 古地震, 定量参数, 破裂带

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