北黄海海域的重磁场特征及其地质意义

GRAVITY AND AEROMAGNETIC CHARACTERISTICS OF THE NORTH YELLOW SEA AND GEOLOGICAL INTERPRETATION

北黄海是我国近海勘探程度最低的海区,到目前为止只进行了地球物理调查工作,没有进行钻探。根据最新的重磁数据,详细地分析了北黄海海域的重磁场特征、构造特征、基底岩相构造和岩浆岩分布。通过重磁数据处理解释推测认为:两条NW向的次级隆起将海洋岛隆起与刘公岛隆起连接起来,同时将北黄海盆地分成3部分;研究区内断裂非常发育,即有切割较深的深大断裂,又有一般的基底断裂,还存在许多较小的断裂;基底为太古界—元古界变质岩;区内岩浆岩分布广泛,以燕山期中酸性侵入岩为主。

The North Yellow Sea is the lowest explored area of China Seas. It has only seen survey of physical geography and no drilling up to now. Based on the new gravity and aeromagnetic data, we have analyzed not only the gravity and aeromagnetic characteristics but also the floor lithofacies structures and the distribution of igneous rocks of the North Yellow Sea in detail. After processing gravity and aeromagnetic data, we infer that the Haiyang Island and Liugong Island uplifts are connected by two smaller uplifts in NW direction, and these two smaller uplifts divide the North Yellow Sea basin into three parts. There are many faults in the investigated area, including deeply incising faults, basement faults and some small ones. We infer that the floor of the area consists of metamorphic rocks that belong to the Archean and Proterozoic. There are rich igneous rocks in the investigated area, mostly intermediate-felsic rocks of Yanshanian period.