龙门山山前彭州隐伏断裂高分辨率地震反射剖面  

High-resolution seismic reflection profile across Pengzhou buried fault in the frontal areas of Longmen Shan

作　　者：刘保金[1] 张先康[1] 酆少英[1] 赵成彬[1] 姬计法[1] 石金虎[1] 袁洪克[1] 

机构地区：[1]中国地震局地球物理勘探中心,郑州450002

出　　处：《地球物理学报》2009年第2期538-546,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40841020);地震行业科研专项(200808041);中国地震局汶川8.0级地震应急科学考察项目资助

摘　　要：彭州断裂是龙门山山前一条重要的隐伏断裂.为了调查彭州断裂的位置、性质及其活动性,5·12汶川M_S8.0。地震发生后,作者采用可控震源和高精度的地震反射勘探方法,对彭州隐伏断裂进行了高分辨率地震反射成像.本文利用获得的浅层地震剖面资料并结合石油地震反射剖面,给出了彭州断裂的空间展布特征以及断裂两侧的新生代地层厚度.结果表明,彭州断裂为一条走向NE、倾向NW、倾角约为58°-62°的逆断层,该断层向上错断了第四纪沉积层,具有明显的第四纪活动,向下大约在深度8-10 km左右收敛到向西缓倾的滑脱面之上.研究结果为评价断裂的活动性和灾后重建提供了地震学证据.Pengzhou fault is an important buried fault in the frontal areas of Longmen Shan. In order to investigate the location, characteristics and activities of Pengzhou fault, after the Wenchuan earthquake （Ms8. 0） of May 12,2008, a high-resolution shallow seismic reflection experiment using vibrator sources was carried out to obtain the imaging of Pengzhou buried fault. In this paper,based on the shallow seismic reflection data and in combination with the Petroleum seismic reflection section in same region, the geometry of Pengzhou buried fault and the thicknesses of Cenozoic strata in both sides of the fault was determined. The results show that Pengzhou fault is an active thrust fault running in NE and dipping in NW, and its dip angle is about 58°-62°. This fault extends upwards into Quaternary sediments, and it merges downwards into the west dipping detachment at depth about 8-10 km. The results also provide seismological evidence for estimating the fault activities and rebuilding the homeland after the disaster.

关 键 词：龙门山断裂带 汶川地震 成都平原 地震反射剂面 彭州隐伏断裂 

分 类 号：P315[天文地球—地震学]