Sedimentary characteristics and evolution of the braided delta deposits in the second member of the Dainan Formation in northern Gaoyou depression, Jiangsu

In the light of core examination, well logs, laboratory data and seismic data, the type, distribution and evolution of sedimentary facies are dealt with for the braided delta deposits in the second member of the Dainan Formation in northern Gaoyou depression, Jiangsu. The second member of the Dainan Formation is dominated by the braided delta facies, followed by the meandering and lake facies. The braided delta facies in the study area may be subdivided into the delta plain subfacies including the braided channel and overbank microfacies, delta front subfacies including the subaqueous distributary channel, subaqueous interdistributary bay, channel mouth bar, distal bar and sheet sands microfacies, and prodelta subfacies including the prodelta mud microfacies. The distribution and evolution of the sedimentary facies and genetic mechanism of the braided delta are examined in detail in this study.