Reef evolution on a fault-controlled Miocene platform margin, western deep water area of South China Sea

In the South China Sea; there were favorable conditions for reef development. However, the reef structure was not precisely described due to the lack of high-quality seismic data. Geologic and geophysical analyses were used to study the reefs in the fault-controlled margin of the southern uplift of the western deep-water area in the South China Sea. The reefs showed hummocky or lenticular shape, and the internal reef crest and reef ditch were observed clearly. Vertically, the reef structure displayed aggradational and progradational characteristics. There were three types of reef identified according to their growth speed, including slow-growth, constant-growth and fast-growth ones. For the first type, reefs grew slowly and retrograded to continents. For the other two types, reefs grew fast and aggraded vertically. The spatial distribution and growth speed of reefs were controlled by sea level changes; space changes and ancient morphology.