The Characteristics Of Mesozoic Sediment And Basin Analyses In The Northeast Part Of South China Sea

The Northern continental margin of South China Sea located at the junction point of three plate--the Eurasian Plate, the Pacific plate and the Indian-Australian plate. There is enriched petroleum and gas, so it is a hotspot of petroleum exploration.The study area includes the continental shelf, slope, deep water area of the Northern continental margin of South China Sea, the central and eastern area of Guangdong. The total area is about 500,000 square kilometers.In this study, the author summarized a lot of geological data and literature about the Mesozoic strata of south China region and northern continental margin of South China sea, and investigated 5 Mesozoic outcrops in Fujian and Guangdong province, and interpreted 5,000 kilometers seismic , parts of gravity and magnetic data.Based on those works, the author drew the distribution map of Mesozoic strata in the Northern of South China Sea, and put forward the unit of the tectonic structures of Northern continental margin in it.By researching, the main achievements of this thesis are listed as following:1.The Mesozoic tectonic frame of the Northern South China Sea region is controlled by the basement fracture zone. On air scape, the tectonic frame of Northern continental margin is NE direction, and it is divided by NE fracture zone. The fracture zone of the NW direction leads the NE direction regional structure divide into small blocks. From north to south in the Northern South China Sea, the Mesozoic tectonic framework could be divided into five subsidence belt: the subsidence area of east & central Guangdong, the Pearl River Mouth-Penghu paleouplift belt, the Chaoshan-Gaoxiong depression belt, the Bijia trough and the Bijia deep-sea basin.2.During the Yanshan tectonic moved, The Northern continental margin of the South China Sea gradually converged to the Southeast margin of South China continent. It was mainly controlled by the Paleo-Pacific tectonic domain. The evolution of the tectonic could be divided into three stages: the intercontinental sea expand stage (Late Triassic epoch– Lias), the software collision between small continentals stage (middle-late Jurassic epoch), the NNW direction extrusion stage (Cretaceous). 3.the Chaoshan-Gaoxiong depression belt and Bijia trough is primary Mesozoic basin development zone in the Northern South China Sea. It is distributed in NE trending on the whole. The ChaoShan and GaoXiong basin are two Mesozoic continental margin depression basin, its'total area is about 5.7×10~4km~2. Because of its contain large and huge Mesozoic sedimentary stratum, those three basin have good oil and gas geological conditions, the Mesozoic formation is the potential exploration target.