汉中盆地内梁山南缘断裂的活动性分析——以汉江大堤位置为例  

Activity Analysis of the Liangshan Southern Margin Fault in Hanzhong Basin——A Case Study of Hanjiang River Levee

作　　者：李晓妮[1] 冯希杰[1] 任隽[1] 李高阳[1] 李苗[1] 

机构地区：[1]陕西省地震局,陕西西安710068

出　　处：《地震研究》2012年第3期341-346,共6页Journal of Seismological Research

基　　金：灾后恢复重建项目汉中市活断层探测(陕发改投资〔2009〕1154号)资助

摘　　要：为获取梁山南缘断裂在汉江大堤上断点的具体位置、近地表断错、上断点埋深、最新活动时代及滑动速率等信息,对其进行了浅层地震勘探和钻孔联合剖面探测。浅层地震解译结果显示断点两侧第四纪以来的12组反射波全被垂向错断,最大错距约370m,影响带宽度约400m,影响带内地层起伏强烈。钻探结果反映主断层晚更新世中期的最大错距约28m,晚期错距约11m,平均滑动速率为0.38～0.49mm/a,上断点埋深为5～13m,属于晚更新世晚期活动断层。Using the shallow seismic and composite drilling section exploration, we obtained actual position of the breakpoint, near-surface dislocation, buried depth of upper breakpoint, the latest active time and slip rate of Li- angshan Southern Margin Fault on the Hanjiang River Levee. Shallow seismic interpretation results show that 12 reflected wave groups are vertically leaped by Liangshan Southern Margin Fault since Quaternary peri- od. Maximum dislocation of bottom interface of the fault is about 370 m, and the width of the influence belt is a- bout 400 m. The strata undulate strongly in the influence belt. The drilling results reflect that the maximum dislo- cation of the main fault is 28.2 m in middle period of late Pleistocene, it is about 11 m on late period of late Pleistocene. The average slip rate of the main fault is about 0. 38 -0. 49 mm/a and the buried depth of its upper breakpoint is about 0. 38 -0. 49 mm/a. The Liangshan Southern Margin Fault is the active fault on late period of late Pleistocene.

关 键 词：梁山南缘断裂 浅层地震探测 钻探 活动速率 晚更新世 

分 类 号：P315.24[天文地球—地震学]