地震地质 ›› 2007, Vol. 29 ›› Issue (2): 330-335.

• 研究论文 • 上一篇    下一篇

临潼-长安断裂带晚第四纪以来的活动性

戴王强, 韩恒悦, 冯希杰, 师亚芹, 李晓妮   

  1. 陕西省地震局,西安 710068
  • 收稿日期:2006-09-06 修回日期:2006-11-11 出版日期:2007-06-09 发布日期:2009-08-27
  • 作者简介:戴王强,男,1978年出生,2003年毕业于兰州地震研究所构造地质专业,获硕士学位,工程师,主要从事地震地质等研究工作,电话:029-88465333,E-mail:daiwq@sina.com.
  • 基金资助:

    国家发展与改革委员会发改投资"城市活断层试验探测"项目(20041138);陕西省地震局基金项目(200501)共同资助

ACTIVITY OF THE LINTONG-CHANG'AN FAULT ZONE SINCE THE LATE QUATERNARY

DAI Wang-qiang, HAN Heng-yue, FENG Xi-jie, SHI Ya-qin, LI Xiao-ni   

  1. Earthquake Administration of Shanxi Province, Xi'an 710068, China
  • Received:2006-09-06 Revised:2006-11-11 Online:2007-06-09 Published:2009-08-27

摘要:

对临潼-长安断裂带进行了详细的野外调查,以期掌握其最新活动年代和第四纪以来的活动特征。该断裂总体走向NE,以张性垂直运动为主,断面明显错断了黄土中的第1层古土壤S1,说明其晚更新世以来仍在活动,并且北段和中段的活动性比南段强,但是错距大多<2m,滑动速率较小,考虑到临潼-长安断裂带由多条次级断层组成,其整体活动性应该比我们计算得到的局部断层滑动速率大得多。断层错距自上而下成递增趋势,并且根据不同地层年代计算出的滑动速率基本一致,因此该断裂带自中更新世晚期以来极可能以垂向蠕滑活动为主。

关键词: 活断层, 临潼-长安断裂, 第四纪, 活动性

Abstract:

The Lintong-Chang'an Fault zone locates in the middle part of Cenozoic Weihe depression.It is the boundary fault controlling the Lishan diamond block and Xi'an sag.The landforms are obviously different between the sides of the fault,and the geomorphic forms are stepped fault scraps and loess scraps.In the paper,by field geological survey to the Zhongdi Village,Wangjiabian Village and Qiaogou profiles on the Lintong-Chang'an Fault,and in combination with the dating data of regional loess and paleosol profile(An Zhi-sheng and Sun Jian-zhong),the fault is studied in order to explore the times of its latest activity and the characteristic of its late Quaternary movement.The fault strikes NE as a whole and is characterized with tensile vertical movement.The fault obviously offset the first paleosol layer S1 in loess stratum,indicating that it is still active since late Pleistocene epoch.But most fault displacements are less than 2m,the slip rate is low,and the activity level is higher in the northern and central segments than that in the southern segment of the fault.Regarding that the Lintong-Chang'an Fault consists of several secondary faults,its whole activity should be much higher than the local slip rate of the fault we have derived.The fault displacements show an increasing trend with depth and the slip rates calculated using the dating data of different strata are almost the same.So perhaps,the fault is mainly dominated by vertical creep-slip since the late of middle Pleistocene epoch.

Key words: active fault, Lintong-Chang’an fault, Quaternary, activity

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