SEISMOLOGY AND GEOLOGY ›› 2008, Vol. 30 ›› Issue (3): 644-657.

• Research Paper • Previous Articles     Next Articles


YANG Xiao-ping1, FENG Xi-jie2, GE Tian-yong3, SONG Fang-min1, SHI Ya-qin2, LIU Yu-fa3   

  1. 1. National Center for Active Fault Studies, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    2. Earthquake Administration of Shaanxi Province, Xi'an 710068, China;
    3. Earthquake Administration of Sichuan Province, Chengdu 610041, China
  • Received:2008-07-16 Revised:2008-08-02 Online:2008-09-18 Published:2009-11-27


杨晓平1, 冯希杰2, 戈天勇3, 宋方敏1, 师亚芹2, 刘玉法3   

  1. 1. 中国地震局地质研究所, 国家地震活动断层研究中心, 北京, 100029;
    2. 陕西省地震局, 西安, 710068;
    3. 四川省地震局, 成都, 610041
  • 作者简介:杨晓平,男,1963年生,1995年在中国地震局地质研究所获得博士学位,研究员,主要从事中新生代构造、活动构造和工程地震等方面的研究,电话:010-62009144,
  • 基金资助:



The Longmenshan Fault zone is an important thrust belt on the eastern margin of the Qinghai-Tibet Plateau,consisting of the back-range,the central and the front-range faults,which differ from each other in size and activity.The rupture zone of the Wenchuan earthquake of 12 May 2008 occurred over a length of~270km along the Yingxiu-Beichuan Fault(a segment of the Central Fault)and a length of~70km along the Guanxian-Anxian Fault(a segment of the Front-Range Fault).The northern end of the fracture zone is at the Nanba region in Central Fault.In this work,we make a detailed field investigation on the northeast segment of the Longmenshan Fault zone.Qingchuan Fault is the northeast segment of the Longmenshan Back-range Fault,and the Chaba-Lin'ansi Fault is the northeast segment of the Longmenshan Central Fault.Along the above two faults,we make geological and geomorphologic mapping of Tuguanpu,Da'an and Hujiaba regions,where the Qingchuan Fault runs through the Tuguanpu and Da'an area,and Chaba-Lin'ansi Fault runs through the Hujiaba area.Based on the field investigation,there are five terraces in the northeast Longmenshan area along the major rivers.The height above the river of T1 terrace is about 3~5m,and the formation time is Holocene.The heights of T2 and T3 terraces are 10m and 30~35m above the river,and the deposition time of alluvium and diluvium is Late Pleistocence.The remnant of T4 terrace's sediment covers on some hills,with the height above the river of about 60~70m.In the remnant,granite cobble and sandstone cobbles have been air slaked,these gravels have the shapes only.T5 terrace's height is about 90m,the sediment on it has been eroded.Qingchuan Fault and Chaba-Lin'ansi Fault were strongly active faults in the times before T3 and after T4 formed.Some fault grooves were formed on T4 or T5 terrace,they have 30~180m in width,and 8~20m in depth.The vertical displacement of T4 terrace's gravels is 10~15m.Fault groove didn't form on T3 terrace,or the terrace height on a fault wall is consistent with other fault wall.At some places,T3 terrace's gravels overlie the fault zone.

Key words: Longmenshan Fault zone, river’s terrace, fault groove, fault activity, Quaternary



关键词: 龙门山断裂带, 河流阶地, 断层槽地, 断层活动, 第四纪

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