新生代早期南海北部水系演变

The evolutions of the fluvial systems in the northern South China Sea since the early Cenozoic

珠江在早渐新世仅是涉及华南沿海地区的小河;到晚渐新世,向西延伸到云贵高原前缘地带;到中新世,现代珠江流域格局初步形成。证据显示,南海北部还发育过一条源自南海西部隆起区的大型水系-昆莺琼古河,后淹没在南海之中,但在南海的沉积充填过程中扮演了重要角色。南海北部水系及沉积环境的重建,对于深刻认识南海新生代早期古地理特征以及该地区的油气勘探均具有重要意义。

The fluvial systems in the South China Sea have experienced prominent variations since the SCS was originally formed.During the early Oligocene,the drainage area of the Pearl River was constrained within the coastal South China.It gradually extended westward into the plateau margin of Yunnan-Guizhou during the late Oligocene.It is until Miocene that the modern Pearl River fluvial network has been well established.A source-to-sink analysis also indicates that a paleo-river“Kontum-Ying-Qiong”was originated from the western South China Sea paleo-ranges and played a significant role in the sedimentary infilling processes,but finally buried under the sediments with the following South China Sea seafloor spreading.The evolution reconstruction of the northern South China Sea fluvial systems and the sedimentary environment has provided considerable insights into the paleogeographic reconstruction of the South China Sea as well as the Eurasian southeastern margin since the early Cenozoic,as well as the petroleum exploration within the South China Sea sedimentary basins.