Development of Carbonate Platform and Its Response to Cenozoic Tectonic in Reed Bank Area,the South China Sea

Fang Penggao; Ding Weiwei; Fang Yinxia; Zhao Zhongxian

doi:10.3799/dqkx.2015.182

Abstract：In order to research the role of carbonate platform in the evolution of basin,the development of the carbonate plat-form and its correlation with the Cenozoic tectonic subsidence characteristics in the Reed Bank area in the southern South China Sea are explored in this study.The rate and amount of tectonic subsidence,and the tectonics are analyzed on the basis of two multi-channel seismic profiles across the Reed Bank area in NW-SE direction.Detailed seismic interpretations prove the occur-rence of a wide distributed carbonate platform developed between the Late Oligocene to Early Miocene,which was submerged after the Middle Miocene.Reconstruction of the tectonic subsidence history shows that the tectonic subsidence was controlled by the tectonic activities in different periods,and could be divided into 5 episodes:the slow subsidence episode (Paleocene to Early Oligocene,rifting stage),the uplift and erosion episode (Late Oligocene to Early Miocene,drifting stage),the accelera-ting subsidence episode(the latest Early Miocene,post-drift stage 1 ),the intensive subsidence episode(Miocene,post-drift stage 2),and the steady subsidence episode (Late Miocene to present,post-rift stage 3).The development stage of the carbon-ate platform was consistent with the drifting stage of the South China Sea,during which the tectonic subsidence analysis sug-gests an uplift and erosion characteristics.This stable shallow water environment was favorable to the development of carbon-ates.During the drifting stage,large-scale mantle under the oceanic basin and the lateral temperature gradients under the conti-nental margin might have triggered a secondary mantle convection under the rifted Reed Bank basin,resulting in the uplift and erosion activities in this stage,and the wide-development of carbonate platform.