【摘要】 通过在四川石棉城区内利用地震反射法探测其隐伏断裂的实例,阐述了在地形变化大、人口密集、环境干扰强的条件下浅层地震勘探方法的实施.本次勘探针对场地条件使用了小能量激发和小偏移距、小道间距、短排列接收、高覆盖次数的观测系统,获得的高信噪比时间剖面清晰地揭示了石棉城区内覆盖层的厚度和隐伏断裂的展布情况.探测结果表明:石棉城区内普遍存在一个明显且连续的反射界面,结合区域地质资料推测该界面是埋深约为15—60m深浅不等的早更新世底界与上新世晚期顶界的第四系分界面.4条地震反射时间剖面均揭示了安宁河断裂带北段所属的石棉断裂东支在石棉城区内为全新世隐伏活动断裂.更多还原

【Abstract】 A scheme is described for seismic prospecting implemented under complicated conditions such as dramatic changes in topography,dense population and strong ambient noise.This is illustrated by detecting buried faults located in Shimian using seismic reflection method,in which spread geometry with small energy excitation,small receiver interval,short arrangement and high fold number was selected in accordance with the real site conditions.The seismic time section with higher SNR obtained in this case clearly reveals overburden thickness and distribution of buried faults in Shimian.The results show that there is a clear and continuous reflection interface in each profile.Combined with regional geological data it is speculated that the interface is a Quaternary interface with depth of about 15 to 60meters,ranging from the end of the Early Pleistocene to the Late Pliocene.Four seismic time profiles revealed that the northern section of Anninghe fault zone is exposed in Shimian with the formof buried faults,and as for the specific nature of the fault,the direction and depth,more reasonable explanation needs to be given combined with regional geological data.更多还原