【摘要】 南海东北部与西北部海域均分布有中生代地层,地震勘探揭示南海北部中生界东、西之间在地震相及沉积充填结构上存在明显差异,东部中生界为双层结构,而西部为单层结构。东部中生代地层由海相及海陆过渡相侏罗系与陆相白垩系组成,而西部则由陆相白垩系构成,缺失侏罗系。从海水入侵方向看,南海北部中生界与特提斯域无关,可能更受太平洋域的影响。侏罗纪古太平洋边缘海盆在南海北部主要分布在珠江口盆地东部及台西南盆地,从早侏罗世到晚侏罗世海盆范围逐渐缩小;白垩纪南海北部整体抬升,除台西南盆地东部接受海相沉积外,白垩纪南海北部以小型断陷盆地为特征,在断陷盆地内接受陆相河湖相沉积。南海北部在中生代时期位于特提斯构造域与太平洋构造域的交接部位,东部中生界双层结构、西部单层结构的沉积模式进一步明确濒太平洋构造域的对南海北部中生界的控制作用,同时东部将是中生代油气勘探的有利区域。更多还原

【Abstract】 The results of seismic exploration and drilling indicate that Mesozoic exists in the northern South China Sea(SCS).The sedimentary models of Mesozoic and the facieses of seismic are different from west to east across the northern SCS.According to the seismic profiles,the Mesozoic sedimentary distribution in the northeast part of the SCS has double-layer structure,but the Mesozoic distribution in the northwest part of the SCS has monolayer structure.In the northeast part of the SCS,Mesozoic strata are com-posed of Jurassic marine sediments and Cretaceous continental sediments;in contrast,in the northwest part of the SCS,Mesozoic strata are only composed of Cretaceous continental sediments.According to the direction of seawater-intrusion,the sedimentary en-vironment of Mesozoic was correlated to paleo-Pacific other than Tethys.During Jurassic,paleo-Pacific covered the east of the Pearl River Mouth Basin and Taixinan Basin.From early to late Jurassic,the area of marine basin became less.During Cretaceous,the northern part of the SCS uplifted as a whole,except the east of the Taixinan Basin.During this period,small faulted basins were developed and accommodated continental sediments.The northern South China Sea located in the junction area of Tethys tectonic domain and the Pacific tectonic domain during Mesozoic;the sedimentary model clears further the control effect of Pacific Ocean structural domain to South China Sea.The northeast part of South China Sea would be beneficial areas for oil and gas exploration.更多还原