SEQUENCE STRATIGRAPHY OF LOWER TRIASSIC IN THE SOUTH YELLOW SEA BASIN

The South Yellow Sea Basin is the extension of the Lower Yangtze Block to the sea where the Mesozoic-Paleozoic marine strata are poorly studied. The lack of stratigraphic framework restricts the oil and gas exploration in the study area. Upon the correlation with the research results of the Lower Yangtze area, we establish the third-order sequence stratigraphic framework of the South Yellow Sea Basin by using the geological, drilling, logging, cores and other data available in the study area and the North Jiangsu Basin. The results show that the boundaries of third-order sequences are either lithologic contacts or unconformities. The Lower Triassic can be subdivided into three third-order sequences. Each third-order sequence consists of transgressive and highstand system tracts and the lowstand system tracts are missing. The framework may provide a reliable geological basis for further study of sedimentary facies and reservoir prediction.