SEISMOLOGY AND GEOLOGY ›› 2016, Vol. 38 ›› Issue (1): 141-151.DOI: 10.3969/j.issn.0253-4967.2016.01.011

• Research Paper • Previous Articles     Next Articles

DISTRIBUTION OF YANGJIA VILLAGE-YAODIAN SECTION OF WEIHE FAULT AND THE CHARACTERISTICS OF ITS LATE QUATERNARY ACTIVITY

TIAN Qin-hu1, ZHOU Ben-gang2, LI Xiao-ni1, SHI Jin-hu3, WEI Qing-ke1, BIAN Ju-mei1   

  1. 1. Earthquake Administration of Shaanxi Province, Xi'an 710068, China;
    2. Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    3. Geophysical Exploration Center, China Earthquake Administration, Zhengzhou 450002, China
  • Received:2015-12-02 Online:2016-03-20 Published:2016-05-17

渭河断裂杨家村-窑店段展布及晚第四纪活动特征

田勤虎1, 周本刚2, 李晓妮1, 石金虎3, 魏青珂1, 卞菊梅1   

  1. 1. 陕西省地震局, 西安 710068;
    2. 中国地震局地质研究所, 北京 100029;
    3. 中国地震局地球物理勘探中心, 郑州 450002
  • 通讯作者: 周本刚,男,研究员,E-mail:zhoubg@ies.ac.cn
  • 作者简介:田勤虎,男,1982年生,2007年于长安大学获地图学与地理信息系统专业硕士学位,高级工程师,主要研究方向为活动构造、工程地震、地震应急,电话:029-88465343,E-mail:glorich@126.com。
  • 基金资助:

    中国地震局地质研究所基本科研业务专项(IGCEA1220);陕西省自然科学基础研究计划(2011JM5012);中国地震局地震科技星火计划项目(XH13023Y)与陕西省防震减灾"十一五"重点项目(SCZC2008)共同资助

Abstract:

The Yangjia Village-Yaodian segment of Weihe Fault, starting from Yangjia Village in the west, passing through Weijiaquan, Jinjiazhuang, Donger Village, Chenjiatai to Yaodian, occurs as a NE-striking fault dipping south with a total length of 33 kilometers. As a syn-depositional normal fault, it extends along the leading and trail edge of T1, T2 and T3 terrace at the northern bank of Weihe River. Results of remote sensing interpretation, shallow seismic exploration, exploratory trench, and drilling show that the Yangjia Village-Yaodian section of Weihe Fault manifests as fault scarps, overlapping with the NE-extending terrace scarp at the northern bank of Weihe River. Weihe Fault broke the T1 that can be distinguished on the shallow seismic profile and multiple profiles with broken signs from T1 to the ground, which is the same with the cracks through the Han Tomb at the top of the exploratory trench in Yangjia Village. It shows that the fault may still be active from the late Pleistocene to Holocene. Through composite drilling section and the analysis of exploratory trench, there is no significant difference in activity between the Yangjia Village-Jinjiazhuang and Donger Village-Yaodian section. This segment has experienced a large displacement event since (46.0±3.3)ka BP, approximately 11.0~16.5m, with a vertical slip rate of 0.34~0.45mm/a. The most recent activity occurred approximately around 2.0ka BP. The left-step en echelon fracture zone at Jingjiazhuang separates this section into two minor ones, Yangjia Village-Jinjiazhuang section and Donger Villag-Yaodian section. Yangjia Village-Yaodian section in Weihe Fault and Yaodian-Zhangjiawan section which was found out in the Xi'an active fault detection and seismic risk assessment project can be combined into the Yangjia Village-Zhangjiawan section.

Key words: Weihe Fault, distribution, shallow seismic exploration, trench, terrace scarp

摘要:

渭河断裂杨家村-窑店段西起杨家村,经魏家泉、金家庄、东耳村、陈家台,到达窑店,走向NE,倾向S,长约33km,为同生正断层,沿渭河北岸I级、Ⅱ级、Ⅲ级阶地前、后缘展布。遥感解译、浅层地震探测、探槽、钻孔联合剖面结果表明,渭河断裂杨家村-窑店段在咸阳附近的渭河北岸阶地表现为断层陡坎,与NE向阶地坎重合;断裂在晚更新世晚期至全新世可能仍有活动。渭河断裂杨家村-窑店段自(46.0±3.3)ka以来断距较大,在11.0~16.5m之间;垂直滑动速率在0.34~0.45mm/a之间;断裂最新活动时间约为2.0ka BP。金家庄左阶斜裂区将渭河断裂杨家村-窑店段划分为杨家村-金家庄段和东耳村-窑店段。

关键词: 渭河断裂, 浅层地震探测, 探槽, 阶地陡坎

CLC Number: