SEDIMENTARY SEQUENCE AND EVOLUTION OF SUBMARINE CHANNEL-LOBE IN BAIYUN DEEPWATER AREA, NORTHERN SOUTH CHINA SEA

Submarine channels and lobes have been important exploration targets in recent years. There are many submarine channel-lobe systems in Baiyun deepwater areas of northern South China Sea. Researches on abyssal sedimentary processes in the modern continental slope contribute to disclosing the evolution and distribution of the deepwater sedimentation. Deepwater sequence stratigraphy has been documented in this paper. Seismic reflection features from the high quality 3-D seismic data, such as the migration of onlap and downlap, are used to characterise the deepwater sedimentary sequence. The sedimentary dynamics of submarine channel-lobe systems in different periods has been discussed. Submarine channel-lobe systems show significant progradation,aggradation and retrogradation. A sedimentary sequence model is proposed for this development sequence. Debris flow and slide dominating in channel-lobe systems were developed in the early stage of LST,and turbidity current in the late stage. Researches on modern deepwater deposit process and the study results within a chronological framework can help reservoir predicting in deepwater exploration.