根据重力资料定性与定量解释银川平原断裂体系

银川平原是活动断层发育的地区,活动断层与地震灾害联系密切,研究银川平原的断裂体系对城市发展具有重要意义。笔者对银川平原1∶20万布格重力资料进行二次处理,分析了该地区的布格重力异常特征,并利用重力异常边界识别方法划分了断裂体系;运用断裂参量图法、欧拉反褶积法、最优化反演以及2.5D人机交互反演等方法对研究区83503线剖面做定量反演,并利用地震资料进行约束。笔者利用现有的重力资料,探讨了根据重力资料解释平面断裂体系以及剖面断裂定量反演的方法,得出了银川断裂有北延趋势、黄河断裂部分段相对前人断裂划分结果向西偏移等新认识,为活动断层的研究提供了新的参考资料。

Qualitative and quantitative interpretation of fracture system in Yinchuan plain based on gravity data

The Yinchuan plain is a region of active faults which are closely related to earthquake disasters. The study of active faults in the Yinchuan plain is of great significance for the development of the city. In this paper, the gravity anomaly characteristics of the area are analyzed and the fracture system is divided by the method of gravity boundary recognition based on the re-processing of 1 ∶200 000 Bouguergravity anomaly data of the Yinchuan plain. The quantitative inversion of the 83503 line section of the study area is carried out by using the method of fracture parametric graph, the Euler homogeneous equation, the optimal inversion and the 2.5D inversion. The inversion results and the seismic interpretation are coincident. Using the existing gravity data, the authors probed into the method of interpreting the plane fracture system and the quantitative inversion of the section fracture and, as a result, some new understanding was obtained such as the north extension of the Yinchuan fault and westward migration of a part of Yellow River fault. The result provides a new reference for the research on active faults.