张家口-宣化地区断裂构造与地震带分布

Distribution of Fault Structure and Seismic Belt in Xuanhua- Zhangjiakou Region

通过对张家口地区区域重力调查资料编图,系统探讨研究区内北西西向构造带、北北东构造带的地质构造背景及其与地震带分布的对应关系.认为区内地震活动受北西西向张家口-蓬莱构造带和北北东向山西断陷带的控制作用明显.新生代以来,在NEE-SWW向挤压,NNW-NNE向拉张应力作用下,NWW向张家口—蓬莱断裂带持续发育和活动.研究结果为深入研究该区地壳深部结构、地震活动等提供重要依据.

In this paper, the author tries to compile the regional gravity survey data in the Zhangjiakou-Xuanhua region, and investigate the formation of tectonic background of the north- west-west tectonic belt and the north-north-east tectonic belt in the research region and its cor- responding relationship with distribution of seismic belt systematically. It is considered that control effect of the Zhangjiakou-Penglai tectonic belt with the direction of North-West-West and the Shanxi fault depression belt with the direction of North-North-East on seismic activities in the research region is obvious. Since the Cenozoic, under the action of extrusion stress in the NEE-SWW direction and the tensile stress in the NNW-NNE direction, the Zhangjiakou- Penglai tectonic belt with the direction of NWW is developing and active continuously. The re- search results provide an important basis for further study of deep crustal structure and seismic activity in this region.