南黄海盆地二叠系至三叠系沉积体系特征及其沉积演化

南黄海是下扬子板块主体，经过多年的油气勘探，从浅层陆相至深层海相地层仍未取得油气突破，总体勘探和认识程度都较低。根据南黄海地震和钻井资料，充分结合下扬子陆区成果认识，将南黄海二叠系龙潭组、大隆组和三叠系青龙组划分为6大沉积体系：河流沉积体系、三角洲沉积体系、潮坪沉积体系、开阔台地沉积体系、局限台地沉积体系、陆棚沉积体系，并分析了各沉积体系特征。根据二叠系龙潭组、大隆组和三叠系青龙组地震反射特征，可将其划分为4大地震相类型，分析了各地震相的沉积意义。钻井沉积相和地震相相结合，分析了沉积体系的分布特征，龙潭组、大隆组和青龙组沉积体系具有水体西北深、东南浅的分布特征。龙潭组至青龙组沉积时期，经历了两次大规模海侵和两次大规模海退，形成了海平面的上升-下降的旋回式变化，岩性组合上构成了潮坪砂泥岩-潮坪煤层-潮坪砂泥岩-陆棚页岩-开阔台地碳酸盐岩-局限台地碳酸盐岩的沉积演化序列。

Sedimentary System Characteristics and Their Sedimentary Evolution from the Permian to Triassic in the Southern Yellow Sea Basin

Southern Yellow Sea is the main body of Lower Yangtze plate. From shallowly buried continental strata to deeply buried marine strata, a breakthrough in oil and gas exploration can not be still obtained through many years work，and the exploration and understanding level are low. Fully combining with the achievements and understanding in the continental area of Lower Yangze plate and being based on seismic and drilling data in the Southern Yellow Sea, the Longtan Formation, the Dalong Formation of Permian period and the Qinglong Formation of Triassic period are divided into six sedimentary systems in the Southern Yellow Sea, which are fluvial, delta, tidal flat, open platform, limited platform and shelf, whose features of each sedimentary system were analysed. On the basis of seismic reflection characteristics, four types of seismic facies were recognized and the sedimentologic meaning of each seismic facies was studied. Combining with wells sedimentary facies and seismic facies, the sedimentary systems distribution characteristics were sculptured. Longtan Formation, Dalong Formation and Qinglong Formation share the similar sedimentary environment characteristics that the northwestern area has a deeper water depth than the southeastern area. Study area experienced twice larger-scale transgression to regression cycles, which formed the base-level oscillating texture in stratigraphic records. With the base-level changes, typical sedimentary evolution sequence formed, which is that tidal clastic rocks and coal bed combination changes to shelf shale, and up to open and restricted carbonation flatform combination from the bottom up.