关键词: 隐伏断裂, 断裂活动性, 地震参数, 反射波法, 观测系统

Abstract: The spatial distribution,scale and property of the Pujiang-Xinjin-Deyang buried fault in Fenghuangshan area were investigated by the use of seismic reflection survey technique. The result shows that the fault cut off the late-pleistocene sediment in the process of eastward underthrusting,and has been significantly active since Quaternary. It has controlled to some extent the formation of the Fenghuangshan platform. Surface geological investigation and historical earthquake research have revealed that the Pujiang-Xinjin-Deyang buried fault were active during late Pleistocene. The activity of the south segment of the fault is obviously stronger than that of the north segment,indicating that the north segment of the fault is a zone of weak seismicity in the Chengdu Plain. At the same time,the layout of observational systems and the selection of seismic parameters for seismic reflection surveying of buried fault in densely populated suburban areas have been studied as well. It is found that the use of small group intervals,small offset,multiple channels,short array length,multiple coverage and high-frequency receivers,as well as the appropriate selection of seismic parameters are of great significance to the effective separation of reflected wave from disturbing wave,and also to the improvement of the resolving power of seismic prospecting technique.

Key words: buried fault, fault activity, seismic parameters, seismic reflection survey, observation system