夏垫断裂东北段地震勘探资料研究

Analysis of the Northeast Segment of the Xiadian Fault Based on Seismic Exploration Data

摘要:

为查明夏垫断裂东北段的空间位置、性质及其活动性，由大厂八百户起向东北方向，经过三河齐心庄至北京马坊镇，以可控震源激发方式，完成高分辨率浅层地震勘探测线7条，长约22 km。各地震反射时间剖面波组特征变化明显，断裂特征清晰，获取了准确的断点定位及断裂发育特征，展现了自八百户经齐心庄至马坊镇延伸约20 km范围内夏垫断裂的空间展布及浅部构造特征。结果表明：研究区内夏垫断裂为倾向SE、视倾角约为69°的正断层，结合以往研究成果分析，夏垫断裂属于全新世活动断裂；同时揭示夏垫断裂东北段明显的分段性，齐心庄以北出现一倾向NW的分支断裂。

Abstract:

High-resolution seismic reflection surveys are an irreplaceable geophysical method for investigating active faults in thick overburden areas. To identify the spatial location, property, and activity of the northern section of the Xiadian fault, a shallow seismic exploration was carried out, and seven high-resolution shallow seismic exploration survey lines were laid out with a total length of approximately 22 km. To ensure that the detection results could reveal the geological structure characteristics of greater depth and higher resolution, the observation system used unilateral vibroseis excitation and obtained reliable original data. The fine data processing found that the characteristics of the seismic reflection time profile vary and the fault features are clear. The accurate location of breakpoints and fault development characteristics were obtained. Results show that the Xiadian fault is a normal fault with a SE tendency and a dip angle of approximately 69° and it is also a Holocene active fault. The spatial distribution and shallow structural characteristics of the Xiadian fault in the range of approximately 20km are shown, and the fracture trend of the Xiadian fault within the range of the interpretation survey line is approximately N40°E.