中文摘要：

2008年汶川Ms8．0地震在龙门山中段的彭灌断裂带产生的地表破裂，是该地震产生的第二大地表破裂带。综合应用地质、钻井以及二维、三维地震数据，利用横贯前山带的多条人工地震反射剖面，对彭灌断裂带产生同震破裂的断层进行准确识别和解释。研究表明，龙门山中段的彭灌断裂带是一套由3条主要断层和次级广泛发育的断裂组合构成，浅层表现为叠瓦构造样式，断裂之间发育小型双重构造。汶川Ms8．0地震在彭灌断裂带产生的地表破裂是由该断裂带前缘③号主断层活动产生的。彭灌断裂整体看上陡下缓，为轴面多次转折形成断坪-断坡式组合样式。分析认为彭灌断裂初步形成于晚三叠世末期，晚侏罗世之后大规模逆冲推覆，新生代继续活动，是多期次继承性断层。根据浅表地质主要断裂构造以及同震地表破裂特征，龙门山中段彭灌断裂带沿走向可分为白鹿和汉旺两个次级构造段。对龙门山中段彭灌断裂带的浅、表构造特征进行研究，可为进一步认识前山带主要断裂构造带提供一定的依据和约束。

英文摘要：

The Ms 8.0 Wenchuan, China, earthquake ruptured two large thrust faults along the Longmen Mountains thrust belt. Between them, the co-seismic fault in Pengguan thrust belt created the second longest surface ruptures. In this paper, in order to distinguish the co-seismic fault in Pengguan thrust belt,the fine interpretation of seismic profiles in the central Longmen Mountains have been accomplished by take advantage of geology map,drilling data and 2D/3D seismic reflection profiles, Our studies found that the Pengguan thrust belt have three main faults and another branch faults. The main faults are developing imbricated structure in the shallow strata and among them are developing the duplex. The co-seismic fault which made the surface ruptures in the Pengguan thrust belt is the ③ fault,that is also the largest fault in the front of central Longmen Mountains. These faults are formed with flat and ramp and they are steep at the surface but the angle dip decreased with the depth increasing. Our studies indicated that these fault were generating in the Late Triassic period, developing in the Late Jurassic period and keeping on activity in the Cenozoic period. According to characteristics of geology, the main fault and the co-seismic surface ruptures,the front of central Longmen Mountains can be divided into two sub-segments, one is the Bailu area and the other is Hanwang area. The characteristics of shallow structures in the Pengguan thrust belt could provide some details and restriction for the research of faults in the front central Longmen Mountains.