The Pearl River Deep-water Fan Systems and Significant Geological Events

Abstract

Recent studies have discovered the Pearl River Deep-water Fan System,located in the deep water slope area of Baiyun Say in the Pearl River Mouth Basin of the South China Sea.With the rich sediments supplied by the Pearl River,under the paleo-geography sedimentary background of Baiyun Sag continuously subsiding,with sedimentary sequences related to relative transgressive sea level change,contrary to regressive eustasy,the Pearl River Deep-water Fan System has specific evolution characteristics,which left the sedimentary record controlled by peripherical significant geological events.The sharp change of deposition rate and lithologic geochemical characteristics about 23.8Ma sequence boundary demonstratesd that sediment source had changed,perhaps related to the uplift of Tibet plateau and spreading of the South China Sea,which led the paleo-Pearl River drainage to expand to western China plateau,maybe much broader than present.Consequently,IODP proposal to drill in the Pearl River Deep-water fan to study the response to the internal mechanism of the Pearl river deep-water fan sedimentation,Baiyun sag subsidence,evolution of the Pearl river drainage,transgressive relative sea level change,as well as the research will reveal the relationship and mechanism among the expansion of the south China sea,the deposition of marginal sea,the relative sea level change,and the uplift of chinese western plateau.