Formation of Hengchun Accretionary Prism Turbidites and Implications for Deep-water Transport Processes in the Northern South China Sea  

作　　者：CUI Yuchi SHAO Lei YU Mengming HUANG Chiyue 

机构地区：[1]State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China [2]Earth Dynamics Research Group,The Institute for Geoscience Research(TIGeR),School of Earth and Planetary Sciences,Curtin University,GPO Box U1987,Australia

出　　处：《Acta Geologica Sinica(English Edition)》2021年第1期55-65,共11页地质学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant nos 42076066,92055203 and 41874076);the National Science and Technology Major Project of China(grant no.2016ZX05026004-002);the National Key Research and Development Program of China(grant no.2018YFE0202400)。

摘　　要：Located at the end of the northern Manila Trench,the Hengchun Peninsula is the latest exposed part of Taiwan Island,and preserves a complete sequence of accretionary deep-sea turbidite sandstones.Combined with extensive field observations,a’source-to-sink’approach was employed to systematically analyze the formation and evolutionary process of the accretionary prism turbidites on the Hengchun Peninsula.Lying at the base of the Hengchun turbidites are abundant mafic normal oceanic crust gravels with a certain degree of roundness.The gravels with U-Pb ages ranging from 25.4 to23.6 Ma are underlain by hundreds-of-meters thickness of younger deep-sea sandstone turbidites with interbedded gravels.This indicates that large amounts of terrigenous materials from both the’Kontum-Ying-Qiong’River of Indochina and the Pearl River of South China were transported into the deep-water areas of the northern South China Sea during the late Miocene and further eastward in the form of turbidity currents.The turbidity flow drastically eroded and snatched mafic materials from the normal South China Sea oceanic crust along the way,and subsequently unloaded large bodies of basic gravel-bearing sandstones to form turbidites near the northern Manila Trench.With the Philippine Sea Plate drifting clockwise to the northwest,these turbidite successions eventually migrated and,since the Middle Pleistocene,were exposed as an accretionary prism on the Hengchun Peninsula.

关 键 词：IODP boreholes source-to-sink analysis submarine canyon turbidite sandstones Hengchun Peninsula Taiwan 

分 类 号：P736.21[天文地球—海洋地质]