Sequence Architecture And Depositional Evolution In Lufeng Depression, Pearl River Mouth Basin, South China Sea Part A: The Braided Delta Deposits Of Cenozoic Enping Formation

The seismic merging dataset, wireline logs, core photographs, thin sections, and other geological information were employed to investigate sequence architecture and reveal depositional evolution of Enping Formation in Lufeng Depression, Pearl River Mouth Basin. The results showed that one second-order sequence and four third-order sequences were identified based on the unconformities along basin margin/slope and correlative conformities in the basin centre. In addition, several associated sedimentary facies or microfacies (including braided channel deposits, subaqueous distributary channel deposits, beach-bar deposits, and so on) that were recognized within sequence stratigraphic framework and depositional evolution were revealed by well tie-seismic correlations with seismic attributes extracted from the stratal slicing in terms of sand sections/units in Enping Formation. It was characterized by progradational process from seismic attributes in general that the delta deposits gradually retrograded. Through comprehensive analysis, it can be concluded that episodic tectonic movements and subsequent uplift played an important role in controlling sequence architecture. Sediment supply and lacustrine level fluctuations derived from accommodation space changes exerted an essential effect on depositional evolution. This study provides new and robust insights into understanding the sequence architecture, depositional evolution, and hydrocarbon exploration in Enping Formation. In addition to the significance for academia, study of sequence architecture and depositional evolution are of great importance for hosting potential hydrocarbon reserves, because they are frequently related to important and potential reservoirs. Consequently, investigating sequence architecture and depositional evolution are significant economically as well.