Depositional systems in the Shahejie Formation in the ramp zone of the Chengbei region, Bohai Gulf

The Paleogene Shahejie Formation strata occur in the fault terraces in the ramp facies zone of the Chengbei region Bohai Gulf, and are grouped, on the basis of geological structures, stratigraphy, sedimentary facies and provenance, into six third-order sequences.The correlation of the sequence stratigraphic isochronous framework and provenance analysis result in the establishment of the spatial distribution of clastic ramp-dominated depositional systems and delineament of three types of favourable reservoirs including braided delta, littoral and shallow lake beach and bar, and turbidite fan in the ramp zone.