地震地质 ›› 2022, Vol. 44 ›› Issue (4): 909-924.DOI: 10.3969/j.issn.0253-4967.2022.04.006

• 研究论文 • 上一篇    下一篇

夏垫西断裂的晚第四纪活动性

沈军1,2)(), 戴训也1,2),*(), 肖淳1,2), 焦轩凯1,2), 白其乐格尔1,2), 邓梅3), 刘泽众4), 夏方华5), 刘玉5), 刘明5)   

  1. 1)河北省地震动力学重点实验室, 三河 065201
    2)防灾科技学院, 三河 065201
    3)六盘水市水城区工业和信息化局, 六盘水 553000
    4)北京环安工程检测有限责任公司, 北京 100026
    5)华北地质勘查局综合普查大队, 三河 065201
  • 收稿日期:2021-05-06 修回日期:2021-07-16 出版日期:2022-08-20 发布日期:2022-09-23
  • 通讯作者: 戴训也
  • 作者简介:沈军, 男, 1966年生, 博士, 研究员, 1998年于中国地震局地质研究所获构造地质学专业博士学位, 主要从事地震地质和综合减灾研究, 电话: 13651172760, E-mail: shenjuneq@qq.com
  • 基金资助:
    国家自然科学基金(42172253);国家自然科学基金(41372216);中央高校基本科研业务专项(ZY20160211)

STUDY ON THE LATE QUATERNARY ACTIVITY OF THE WEST XIADIAN FAULT IN BEIJING PLAIN

SHEN Jun1,2)(), DAI Xun-ye1,2),*(), XIAO Chun1,2), JIAO Xuan-kai1,2), BAI Qilegeer1,2), DENG Mei3), LIU Ze-zhong4), XIA Fang-hua5), LIU Yu5), LIU Ming5)   

  1. 1) Key Laboratory of Seismic Dynamics of Hebei Province, Sanhe 065201, China
    2) Institute of Disaster Prevention, Sanhe 065201, China
    3) Industry and Information Technology Bureau of Shuicheng District of Liupanshui City, Liupanshui 553000, China
    4) Beijing Huan’an Engineering Inspection & Test Co. Ltd., Beijing 100026, China
    5) Exploration Unit of North China Geological Exploration Bureau, Sanhe 065201, China
  • Received:2021-05-06 Revised:2021-07-16 Online:2022-08-20 Published:2022-09-23
  • Contact: DAI Xun-ye

摘要:

夏垫断裂是1679年三河-平谷8级地震的发震断层, 在其西侧发现一条新的断裂, 称其为夏垫西断裂。文中采用6条浅层地震剖面确定了该断层在三河市内的位置; 采用联排钻孔探测方法并应用磁化率测井技术, 结合释光测年, 研究了该断裂的晚第四纪活动性。该断裂蜿蜒曲折, 总体走向NE, 倾向NW。在垂直剖面上表现为正断层性质, 它是燕郊半地堑型断陷东南缘的主控断裂。该断裂与夏垫断裂倾向相反, 与夏垫断裂之间夹一地垒, 地垒最窄处<1km。由10个钻孔的岩心柱状图和测井曲线及8个有效的测年数据组成的钻孔联合剖面显示, 该隐伏断裂的上断点埋深约为12m, 错断了晚更新世晚期地层, 错断的最新地层的测年结果为(36.52±5.39)ka。晚更新世以来的垂直滑动速率约为0.075mm/a, 晚更新世晚期以来的滑动速率约为0.03mm/a。该断裂在平面上可能与夏垫断裂组成雁列构造, 二者在深部存在密切的联系, 同属于一条切过整个地壳的深大断裂。

关键词: 北京平原, 夏垫西断裂, 晚第四纪活动性, 联排钻孔探测, 浅层地震勘探

Abstract:

Beijing plain is a strong earthquake tectonic area in China, where the Sanhe-Pinggu earthquake with M8 occurred in 1679.The seismogenic fault of this earthquake is the Xiadian Fault. An about 10km-long earthquake surface fault is developed, striking northeast. Deep seismic exploration reveals that this surface fault is a direct exposure of a deep fault cutting through the whole crust, and it is concealed in the Quaternary layers to both ends. Previous studies have not yet revealed how the deep fault with M8 earthquake extended to the southwest and northeast. In the study of Xiadian Fault, it is found that there is another fault with similar strike and opposite dip in the west of Xiadian Fault, which is called the West Xiadian Fault in this paper. In this study, six shallow seismic profiles data are used to determine the location of this fault in Sanhe city, and the late Quaternary activity of the fault is studied by using the method of combined drilling, magnetic susceptibility logging and luminescence dating.

The results of shallow seismic exploration profiles show that the fault is zigzag with a general strike of NE and dip NW. In vertical profile, it is generally of normal fault. It shows the flower structure in one profile, which indicates that the fault may have a certain strike-slip property. On two long seismic reflection profiles, it can be seen that the northwest side of the fault is a half graben structure. This half graben-like depression, which has not been introduced by predecessors, is called Yanjiao fault depression in this paper. The maximum Quaternary thickness of the graben is 300m. The West Xiadian Fault is the main controlling fault in the southern margin of the sag.

The Xiadian Fault, which is opposite to the West Xiadian Fault in dips, controls the Dachang depression, which is a large-scale depression with a Quaternary thickness of more than 600m. The West Xiadian Fault is opposite to the Xiadian Fault, and there is a horst between the West Xiadian Fault and the Xiadian Fault. The width of the horst varies greatly, and the narrowest part is less than 1km. The West Xiadian Fault may form an echelon structure with Xiadian Fault in plane, and they are closely related in depth.

According to the core histogram and logging curves of ten boreholes and eight effective dating data, the buried depth of the upper breakpoint of the concealed fault is about 12m, which dislocates the late Pleistocene strata. The effective dating result of this set of strata is(36.52±5.39)ka. There is no evidence of Holocene activity of the fault, but it is certain that the fault is an active fault in the late Pleistocene in Sanhe region. The vertical slip rate is about 0.075mm/a since late Pleistocene, and about 0.03mm/a since the late period of late Pleistocene. These slip rates are less than those of the Xiadian Fault in the same period. According to our study, the vertical slip rate of Xiadian Fault since late Pleistocene is about 0.25mm/a.

Although the latest active age, the total movement amplitude since Quaternary and the sliding rate since late Pleistocene of West Xiadian Fault are less than those of Xiadian Fault, its movement characteristics is very similar to that of Xiadian Fault, and the two faults are close to each other in space, and closely related in deep structure. It can be inferred that the fault is probably a part of the seismogenic structure of the 1679 Sanhe-Pinggu M8 earthquake. In a broad sense, the Xiadian fault zone is likely to extend to the southwest along the West Xiadian Fault.

Key words: Beijing plain, West Xiadian Fault, late Quaternary activity, row drilling exploration, shallow seismic exploration

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