关键词: 浅层地震勘探, 黄庄-高丽营隐伏断裂, 北京市立水桥

Abstract: This paper introduces the results of shallow seismic exploration on five traverse lines across the Huangzhuang Gaoliying buried fault in the vicinity of Lishuiqiao,Beijing area. The section of the Huangzhuang Gaoliying fault in the vicinity of Lishuiqiao can be distinguished distinctly on the spot map,but the other sections of the fault along river valley are undistinguishable. The shallow seismic exploration and geological information reveal that the velocity model of the shallow part around the Lishuiqiao area is characterized by 4-layer structure. The layers 1 and 2 are located at a depth range of 0～150m beneath the surface,and they can be assigned to Tertiary or Quaternary deposits,having a velocity of 800m/s to 2000m/s. The layers 3 and 4 are identified at a depth range of 130m to 300m,which are bedrock consisting of mudstone and sandstone,having a velocity of larger than 2000m/s or 2500m/s. At shallow depth,the Huangzhuang-Gaoliying Fault in Lishuiqiao area is composed of two sub-parallel faults about 1300m apart from each other. The two faults are N23°E-striking,dipping southeast at an angle of 22° for the western fault and 87° for the eastern one. At a depth of 634m the two faults converge into one fault,appearing as a branching fault. The buried depth of the highest point of the hanging wall of the fault is 101m,while that of the footwall is 109 m. The throw of the fault is about 8m. It is concluded,therefore,that the fault is a normal fault with strike-slip component,dissecting the T₂ and T₃ stratigraphic interfaces.

Key words: shallow seismic exploration, Huangzhuang-Gaoliying buried fault, Lishuiqiao area, Beijing