摘要
The Songliao Basin evolved into the late down-warping stage, and shallow-water deltas had extensively developed in the third Member of Nenjiang Formation, Upper Cretaceous. Based on abundant data of dense wells, sedimentary facies maps and sandbodies structures of subaqueous distributary channel in each sand-units were analyzed in detail, and a series of changes accompanied with basin flattening and shallowing gradually were summed up as follows: 1) deltas farther extended; 2) subaqueous distributary channels more stabilized; 3) single channel farther elongated; 4) channels less bifurcated and converged; 5)crevasse splay occurred more frequently; and 6) subaqueous interdistributary bays distributed more extensively.