琼东南盆地渐新统煤系(扇)辫状河三角洲特征

（扇）辫状河三角洲的沉积模式和类型研究有待丰富.在沉积学、层序地层学理论指导下，精细刻画了琼东南盆地渐新统煤系（扇）辫状河三角洲的发育与分布特征，建立了渐新统层序地层格架，识别出6个三级层序，分别与崖城组和陵水组的3个段对应；根据同沉积地貌、断层活动性等特征，划分了断崖型、断坡型、断沟型、横向背斜型与断弯型5种（扇）辫状河三角洲类型（可进一步细化为外部物源、内部物源两个亚类），分析了渐新统不同沉积期（扇）辫状河三角洲的发育特征与分布规律，归纳了低位、海侵和高位体系域中（扇）辫状河三角洲的发育特征，阐明了层序地层格架下不同体系域内（扇）辫状河三角洲的发育位置、规模和纵向叠加的差异和规律. 

Characteristics of (Fan) Braided River Delta in Oligocene Coal Measures of Qiongdongnan Basin

More studies are needed in the analyse of sedimentary patterns and types of (fan) braided river deltas. In order to understand the development features and distribution of (fan) braided river delta of Oligocene coal measures in Qiongdongnan Basin, sedimentology and sequence stratigraphy have been studied on the basis of related theories and methods. Through the systematic analysis, the characteristics of the coal measures (fan) braided river delta of the Oligocene were described in detail, the basin wide sequence stratigraphic framework of the Oligocene was established, and 6 third-order sequences were identified, respectively corresponding to the 3 sections of Yacheng Formation and Lingshui Formation. According to the characters of the synsedimentary landform, fault activity, etc, five types of (fan) braided river delta (bluff, cut slope, groove type, horizontal type anticline and fault bend) were divided in Oligocene, and two sub-types of internal source and external source were further identified. It is concluded that the sequence stratigraphic framework show differences and regularity in the location, scale, and longitudinal superposition of (fan) braided river delta in different system tracts.