地震地质 ›› 2008, Vol. 30 ›› Issue (1): 250-263.

• 专题综述 • 上一篇    下一篇

银川隐伏断层钻孔联合剖面探测

雷启云1, 柴炽章1, 孟广魁1, 杜鹏1, 王银1, 谢晓峰1, 张学辉2   

  1. 1. 宁夏回族自治区地震局, 银川, 750001;
    2. 甘肃省金昌市地震局, 金昌, 737100
  • 收稿日期:2007-10-21 修回日期:2008-01-24 出版日期:2008-03-19 发布日期:2009-08-24
  • 作者简介:雷启云,男,1981年生,2005年毕业于兰州大学地质工程专业,获工学硕士学位,工程师,现主要从事活动构造研究工作,电话:0951-5068227,E-mail:leiqy624@163.com.
  • 基金资助:
    国家发展和改革委员会发改投资"城市活断层试验探测"项目(20041138)资助.

COMPOSITE DRILLING SECTION EXPLORATION OF YINCHUAN BURIED FAULT

LEI Qi-yun1, CHAI Chi-zhang1, MENG Guang-kui1, DU Peng1, WANG Yin1, XIE Xiao-feng1, ZHANG Xue-hui2   

  1. 1. Earthquake Administration of Ningxia Hui Autonomous Region, Yinchuan 750001, China;
    2. Earthquake Administration of Jinchang of Gansu Province, Jinchang 737100, China
  • Received:2007-10-21 Revised:2008-01-24 Online:2008-03-19 Published:2009-08-24

摘要: 为获取银川隐伏断层近地表断错、上断点埋深、最新活动时代及滑动速率等信息,在浅层地震勘探基础上,沿断层自北向南横跨主断层布施了新渠梢、满春和板桥3条钻孔联合剖面,确定了主断层在3条剖面上的准确位置,获得主断层上断点埋深分别为5.18~8.30m(新渠梢)、5.01~6.50m(满春)和10.0~13.59m(板桥)。结合测年数据分析:新渠梢剖面断层全新世活动,晚更新世末期以来滑动速率为0.14mm/a;满春剖面断层也是全新世活动,但晚更新世末期以来滑动速率为0.05mm/a;板桥剖面断层全新世不活动。综合地震勘探资料进一步分析认为,以银古路为界,目标区银川隐伏断层分南北2段:北段属全新世活动断层,且自北向南活动强度呈减弱趋势,南段属晚更新世末期活动断层;北段活动强度显著大于南段。

关键词: 银川隐伏断层, 活断层, 钻孔联合剖面, 上断点, 滑动速率

Abstract: This paper introduces the result of exploration of the Yinchuan buried fault using the composite drilling section method. As one of the main buried faults in Yinchuan plain,the Yinchuan buried fault has restricted seriously the development of Yinchuan City for a long time due to its indistinct location and unclear activity property. So the Yinchuan buried fault was taken as one of main tasks of active fault exploration in Yinchuan City. Most of shallow seismic explorations had been done before the drilling. However,due to the limited precision of shallow seismic exploration,the actual location of the Yinchuan buried fault can't be explored. For obtaining the information about the location and the depth of the upper break point, the active time and slip rate of the Yinchuan buried fault,three composite drilling sections,Xinqushao, Manchun and Banqiao,were laid out along the Yinchuan Fault based on the result of shallow seismic exploration. After comparing with the marker horizons disclosed by drilling,the position,scale and the depth of the upper break point of Yinchuan buried fault were found,and the buried active fault was located precisely. From the exploration result we get the apparent dip of the Yinchuan buried fault as 71 degrees at Xinqushao,71 dgrees at Manchun and 66 degrees at Banqiao,and the depth of the upper break points as 5.18~8.30m,5.01~6.50m and from 10.0~13.59m,respectively. Therefore,the latest active date of the Yinchuan buried fault is determined and the question whether the fault is active or not is answered by dating. The Yinchuan buried fault at Xinqushao and Manchun sections is manifested as a Holocene active fault, and at Banqiao,it is shown as a late Pleistocene active fault. The slip rate of the Yinchuan buried fault since late Pleistocene is 0.14mm/a at Xinqushao,0.05mm/a at Manchun and 0mm/a at Banqiao. Based on the result obtained from seismic exploration and the spatial positions of the three composite drilling sections,we draw the following conclusions:the Yinchuan buried fault can be divided into two segments with Yingu Road as the boundary; the northern segment was active in Holocene and the southern one was active in late Pleistocene; the activity of the northern segment is more recent than that of the southern one.

Key words: Yinchuan buried fault, active fault, composite drilling section, upper break point, slip rate

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