四川盆地三台-盐亭地区上三叠统须家河组沉积体系分析

通过岩心及薄片观察，从岩石学、沉积构造、古生物标志及测井曲线特征等方面，对四川盆地三台-盐亭地区须家河组沉积体系进行了深入分析。结果表明：该区须家河组为一套三角洲、湖泊及有障壁海岸的多类型沉积体系复合体．其中三角洲沉积体系根据进入蓄水盆地中地表径流水体性质的不同可划分为辫状河三角洲和曲流河三角洲，并可进一步识别出三角洲平原、三角洲前缘及前三角洲3种亚相沉积；湖泊沉积体系发育滨湖和浅湖2种亚相沉积；有障壁海岸沉积体系发育潮坪亚相沉积。在此基础上，分别建立了辫状河三角洲及曲流河三角洲沉积相模式，并分析了该区须家河组地层在不同时期的沉积相与微相的展布特征及空间配置关系。

Sedimentary system of Upper Triassic Xujiahe Formation in Santai-Yanting area,Sichuan Basin

Based on the core and thin section observation, this paper analyzed the sedimentary system of Xujiahe Formation in Santai-Yanting area from the aspects of petrology, sedimentary structures, paleontology evidence and well logging. It is believed that the sedimentary system include delta, lake and barrier coast. Among them, delta sedimentary system can be divided into braided fiver delta and meandering river delta in accordance with the different properties of water runoff into the water basin, furthermore, both of the braided river delta and meandering river delta can be subdivided into three sub-facies, including delta plain, delta front and prodelta. Lake sedimentary system consists of two sub-facies, including lakeshore and shallow lake. Barrier coast sedimentary system mainly consists of tidal flat sub-facies. On this basis, the sedimentary facies models of braided river delta and meandering river delta were established respectively, and the distribution characteristics and space allocating relation of facies and sub-facies in different periods of Xujiahe Formation in the study area were analyzed.