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

摘要： 利用高精度的浅层地震勘探手段,探测出北京市立水桥附近的黄庄-高丽营隐伏断裂,并进行了地质解释。结果表明北京市立水桥附近区域的浅部速度模型为4层结构。第1层至第2层的介质深度从0～150m,P波速度从800～2000m/s,介质为第四纪或古-新近纪覆盖层;第3层至第4层的介质深度为130～300m,P波速度在2000～2500m/s以上,推测为泥岩、砂岩类的基岩区。黄庄-高丽营隐伏活断裂其浅部由东西2条近似平行、相距1300m、走向N23°E、倾向SE的断裂所组成,西断裂F₂倾角22°,东断裂F₁倾角67°,在634m深度归结成单条断层,构成分叉状结构;断层上盘埋深101m,下盘埋深109m,断距为8m,为断错T₂,T₃地层界面、带走滑分量的正断层型。

关键词: 浅层地震勘探, 黄庄-高丽营隐伏断裂, 北京市立水桥