SEISMOLOGY AND GEOLOGY ›› 2017, Vol. 39 ›› Issue (1): 117-129.DOI: 10.3969/j.issn.0253-4967.2017.01.009

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THE CENOZOIC TECTONICS AND SEISMIC ACTIVITY OF XINZHENG-TAIKANG FAULT IN THE SOUTHERN EDGE OF TAIKANG AREA

WANG Zhi-shuo1, WANG Ming-liang1, ZHAO Xian-gang1, WAN Na1, MA Xing-quan1, YU Hao-yu2   

  1. 1. Earthquake Administration of Henan Province, Zhengzhou 450016, China;
    2. College of Geophysics and Information Engineering, China University of Petroleum, Beijing 102249, China
  • Received:2015-10-21 Revised:2016-10-26 Online:2017-02-20 Published:2017-04-26

太康隆起南缘新郑-太康断裂的新生代活动形迹与地震活动

王志铄1, 王明亮1, 赵显刚1, 万娜1, 马兴全1, 于浩雨2   

  1. 1. 河南省地震局, 郑州 450016;
    2. 中国石油大学(北京)地球物理与信息工程学院, 北京 102249
  • 作者简介:王志铄,男,1967年生,2015年在中国地震局地球物理研究所获得博士学位,副研究员,主要从事地震预报及地球物理理论、方法和应用研究,电话:0371-68109105,13700846975,E-mail:wgchui@126.com
  • 基金资助:

    我国地震重点监视防御区活动断层地震危险性评价:许昌-太康断层活动构造探测与河南省地震构造编图项目共同资助

Abstract:

On the basis of dividing and comparison of the Neogene strata and their bottoms revealed by 7 drill holes in Taikang area, we completed 101 seismic profiles with a total length of 4991km. Seismic data were compared and interpreted. The results indicate that Xinzheng-Taikang Fault, as a blind fault extending from Xinzheng to Taikang, which was considered as an EW striking fault from Xuchang to Taikang before, is the boundary of Taikang uplift and Zhoukou depression, controlling the sedimentation since Neogene Period. So we named the fault the Xinzheng-Taikang Fault, which is composed of two branches, mainly, the east and west branches. The west branch strikes northwest, dipping northeast with steep angles, and the fault plane extending more than 140km in length. As revealed on the seismic profiles, the eastern segment of the west branch is normal fault, while the west segment of the branch shows characteristics of strike-slip fault. The east branch trends NW-NEE, dipping SW-SSE with the length of about 50km. Two branches form a minus flower structure, indicating the strike slip-extension tectonic background. The bottom of Neogene strata is offset about 120m by the east branch, 20m by the west branch, and the bottom of Quaternary is probably offset too. Meanwhile, latest studies suggest that the composite strip of the two branches of Xinzheng-Taikang Fault, which is a tectonic transfer zone, is the subduction zone between the two strike-slip faults. The tectonic stress tends to be released by the east-west branch fault, and the zone should be the seismogenic structure for the recent seismicity in Taikang area. In 2010, the latest earthquake ofMS4.7 occurred in this area, causing 12 people wounded. The seismogenic structure was considered to be the Xinzheng-Taikang Fault. So locating the fault exactly is of great importance to disaster prevention.

Key words: active fault, Xinzheng-Taikang Fault, Taikang uplift, Xuchang-Taikang Fault, physical seismic

摘要:

在对比分析太康地区7个钻孔的新近纪地层及其底界基础上,对101条共4991km长的浅层地震剖面进行了追踪解释,结果显示:沿太康隆起南缘新郑市-太康县一带发育1条新生代活动的区域性隐伏断裂,控制着太康隆起与周口凹陷的分界,可称为新郑-太康断裂。该断裂由东、西2支组成。西支断裂总体走向NW,断面NE倾,长度超过140km;东支断裂走向NW-NEE,断面倾向SW-SSE,长约50km。2条支断裂均断错了新近系的底界,局部向上延伸至第四系。断裂东、西2支的叠合地带可能为应力累积区,现代地震主要发生在这一部位。

关键词: 活动断裂, 新郑-太康断裂, 太康隆起, 许昌-太康断裂, 地震

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