SEISMOLOGY AND GEOLOGY ›› 2013, Vol. 35 ›› Issue (1): 64-74.DOI: 10.3969/j.issn.0253-4967.2013.01.005

• Research Paper • Previous Articles     Next Articles

QUATERNARY FAULTS OF THE QIANLIYAN UPLIFT IN THE NORTHERN SOUTH YELLOW SEA

SHEN Zhong-yan, ZHOU Jian-ping, GAO Jin-yao, WU Zhao-cai, YANG Chun-guo, TAO Chun-hui, YANG Yong, ZHANG Tao   

  1. Key Laboratory of Submarine Geosciences of State Oceanic Administration, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China
  • Received:2012-02-07 Revised:2012-07-23 Online:2013-03-30 Published:2013-04-09

南黄海北部千里岩隆起带的第四纪活动断裂

沈中延, 周建平, 高金耀, 吴招才, 杨春国, 陶春辉, 杨勇, 张涛   

  1. 国家海洋局第二海洋研究所, 国家海洋局海底科学重点实验室, 杭州 310012
  • 基金资助:

    我国近海海洋地球物理调查研究项目(908ZCI06)资助。

Abstract:

By far,there have been only a few neotectonic studies of the Qianliyan Uplift. In recent years,we have gathered multi-channel seismic data covering the whole uplift. After interpretation,we recognized three major Quaternary faults/fault zones. They are the South Boundary Fault Zone(SBFZ),F3,and F2 from south to north,respectively. These faults are almost parallel each other and trend northeastward.The SBFZ on most sections has been active at least since the middle Pleistocene; some segments of SBFZ are active since the Early Pleistocene.The latest activity of F2 is in the Early Pleistocene while that of the F3 is in the Middle-Early Pleistocene.The deformation intensity of SBFZ varies along strike and is well correlated with the curvature of the fault trace, that is,big curvature correlates with big deformation intensity. This correlation implies a NW maximum principal stress that may be caused by the relative convergence of the Philippine Sea Plate and the Euro-Asia Plate.The map of earthquake epicenters (≥MS 3.0) shows that there are several earthquakes distributed roughly along the SBFZ.Considering the relative intense deformation of SBFZ,we propose that great attention should be paid to the seismic risk of SBFZ.

Key words: active faults, Quaternary, Qianliyan Uplift, Jiashan-Xiangshui Fault, South Yellow Sea

摘要:

前人对南黄海北部千里岩隆起带的活动断裂研究开展较少,文中利用908专项地球物理调查获得的覆盖整个千里岩隆起带的多道地震数据,在钻井及其他地震资料进行层位标定的基础上,对研究区的第四纪断裂活动性进行了研究。研究表明,千里岩隆起带主要的第四纪活动断裂(带)有3条,从南至北依次为千里岩南缘断裂带、千里岩隆起带3号断裂和2号断裂。这几条断裂(带)基本平行,均为NE走向; 在剖面上断裂都较为平直。千里岩隆起带南缘断裂带最新活动时间在大部分剖面上至少为中更新世,部分区段为早更新世; 千里岩隆起带2号断裂最新活动时间为早更新世; 千里岩隆起带3号断裂最新活动时间为中-晚更新世。千里岩隆起带南缘断裂变形强弱走向上有变化,变形强弱和断裂平面轨迹的曲率呈现很好的对应关系,曲率大的地方变形强,曲率小的地方变形弱,暗示主压应力为NW向,可能源于菲律宾板块和欧亚板块的NW向汇聚作用。沿着千里岩隆起带南缘断裂带有一些3级以上地震分布,考虑千里岩隆起带南缘断裂带第四纪的变形较强,因此认为这条断裂带发生大地震的可能性比较大。

关键词: 活动断裂, 第四纪, 千里岩隆起带, 嘉山-响水断裂, 南黄海

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