【摘要】 胜利油田渤南洼陷下第三系沙河街组中发现丰富的湖泊辫状河三角洲前缘及前三角洲沉积物，其特征显著，明显有别于其它类型的三角洲。辫状河三角洲前缘的主体是由含砾砂岩及中、粗粒砂岩组成的水下分流河道砂坝，三角洲中交错层理丰富，其中尤以水道砂坝侧向迁移加积而形成的侧积交错层异常发育为标志。更多还原

【Abstract】 Plenty of braided river delta front deposits and prodelta deposits were discovered in Lower Tertiary Shahejie Formation in Bonan Sag, Shengli Oilfields. They differ greatly from other types of delta deposits. The main body of the delta front consists of subaqueous distributary channel sandbars composed of pebbled sandstone and midium-coarse sandstone. Cross-bedding developed well in the delta, especially lateral accretion cross-bedding formed by lateral displacement and accretion of river channel sandbars.更多还原