Post-rifting magmatism and the drowned reefs in the Xisha Archipelago domain

摘要: Fourteen isolated drowned reefs have been identified around the Xisha Uplift by multibeam and seismic data. The drowning processes of these can be divided into three different stages, which correspond to accelerated tectonic subsidence periods. is result combined action sea level fluctuations, rate had remain above 0.2 mm yr−1 for a long time. Three abrupt events that occurred in late Miocene, Pliocene early Quaternary were closely related thermal after stages post-rifting magmatism. magmatism middle Miocene following resulted northwestern uplift (Zone A). During Pliocene, massive magmatic intrusions volcanic eruptions Uplift. Then, subsequent started process northeastern western regions B C). Quaternary, large-scale also new rapid subsidence, caused southern southeastern drown D E).