渤海湾西北缘及其邻近地区地壳结构与构造特征

Crustal structure and its features in the northwest margin of Bohai bay and adjacent areas

对塘沽—玉田地震测深剖面资料进行二维处理、计算和综合解释研究,获得了渤海湾西北缘及其邻近地区二维地壳速度结构和构造的基本特征、断层的空间展布特征,得知深浅部地质构造环境剖面具有层状结构特征,地壳厚度由南向北逐渐加厚,不同区域的地壳速度结构在纵向和横向上均具有明显的非均匀性.在渤海湾附近塘沽至宁河之间M界面有一斜坡带,地壳深度由塘沽的28km向北至宁河附近逐渐加深至31km.

DSS data of Tanggu-Yutian profile was processed, and the result obtained in this paper and the results of other five profiles, which cross this profile, were interpreted comprehensively in this paper. The purpose is to find out the basic features of 2-D velocity structures, spatial distribution of faults, geological structure of shallow and deep crust in the northwest margin of Bohai bay and adjacent area. The result shows that obvious layered structure appears along the profile, the crustal thickness increases gradually from south to north, and the crustal velocity structures in different region have obvious heterogeneity in the lateral and vertical directions. The Moho is a slope between Tanggu and Ninghe near Bohai bay. The crustal depth deepens gradually northward from 28 km in Tanggu to 31 km in Ninghe.