渤海海域第四系发育概况

DEVELOPMENT OF THE QUATERNARY SYSTEM IN THE BOHAI SEA AREA, CHINA

渤海位于渤海湾新生代裂陷盆地的东部。该区第四纪构造活动强烈 ,历史上发生过多次7级以上地震。然而 ,渤海地区第四系的研究远不能与渤海湾盆地的陆地部分相比 ,有关第四系厚度分布的情况至今仍未见报道。为此 ,文中在综合已有研究成果的基础上 ,还利用新近系—第四系、新近系馆陶组和明化镇组的厚度分布资料 ,通过GIS与图像处理相结合的方法 ,编制了第四系厚度分布图。渤海地区第四系一般厚 30 0～ 6 0 0m ,局部厚达 80 0～ 10 0 0m ;

The Bohai Sea is located in the east of the Bohai Bay Cenozoic rift basin, and has been characterized by intense tectonic activities since Quaternary time. Many major earthquakes of M≥7 had occurred in this area in history. Although a great number of detailed studies on the land part of the basin have been made, little has been done on the research of the Quaternary sediments in the Bohai Sea area. The isopach map of Quaternary system for this area has not been compiled so far. Basing on the previous studies, we used the data of the thickness of Neogene - Quaternary system, and the thickness of the Guantao and Minghuazhen Groups of Neogene to compile the isopach map of the Quaternary system with the help of GIS and image processing. This map shows that the Quaternary system is generally 300～600m thick, and locally 800～1000m thick in the studied area. The isopach in the western and eastern parts of the Bohai Sea exhibits NW- and NE-trending belt-like shape, respectively.