The Combined Effect of Tibetan Plateau Uplift and Glacial-Interglacial Cycles on the Quaternary Evolution of the East Asian Monsoon: Evidence from South China Sea Sediments  

作　　者：MENG Xianwei LIU Yanguang ZHANG Xiaodong ZHANG Jun 

机构地区：[1]First Institute of Oceanography,State Oceanic Administration [2]Ocean University of China

出　　处：《Acta Geologica Sinica(English Edition)》2014年第2期661-668,共8页地质学报（英文版）

基　　金：Funding for this research was provided by the National Natural Science Foundation of China (NSFC), grant number 40576034

摘　　要：The siliciclastic sediments of the uppermost section of 185 mcd （meters composite depth） from ODP Site 1146 on the northern continental slope of the South China Sea （SCS） were partitioned according to their sources using end-member modeling on grain-size data.The goal was to evaluate the evolution of the East Asian monsoon over the past 2 million years.The siliciclastic sediments were described as hybrids of four end-members,EM1,EM2,EM3,and EM4,with modal grain sizes of 8-22 μm,2-8 μm,31-125 μm,and 4-11 μm,respectively.EM1 and EM3 are interpreted as eolian dust and EM2 and EM4 as fluvial mud.The ratio of eolian dust to fluvial mud （（EM1＋EM3）/（EM2＋EM4）） is regarded as an indicator of the East Asian monsoon.The variation in this ratio not only shows periodical oscillations consistent with oxygen isotope stages,but also exhibits a phased increasing trend corresponding with the phased uplifts of the Tibetan Plateau,indicating that the evolution of the East Asian Monsoon was controlled not only by glacial-interglacial cycles,but also by the phased uplifts of the Tibetan Plateau during the Quaternary.The siliciclastic sediments of the uppermost section of 185 mcd （meters composite depth） from ODP Site 1146 on the northern continental slope of the South China Sea （SCS） were partitioned according to their sources using end-member modeling on grain-size data.The goal was to evaluate the evolution of the East Asian monsoon over the past 2 million years.The siliciclastic sediments were described as hybrids of four end-members,EM1,EM2,EM3,and EM4,with modal grain sizes of 8-22 μm,2-8 μm,31-125 μm,and 4-11 μm,respectively.EM1 and EM3 are interpreted as eolian dust and EM2 and EM4 as fluvial mud.The ratio of eolian dust to fluvial mud （（EM1＋EM3）/（EM2＋EM4）） is regarded as an indicator of the East Asian monsoon.The variation in this ratio not only shows periodical oscillations consistent with oxygen isotope stages,but also exhibits a phased increasing trend corresponding with the phased uplifts of the Tibetan Plateau,indicating that the evolution of the East Asian Monsoon was controlled not only by glacial-interglacial cycles,but also by the phased uplifts of the Tibetan Plateau during the Quaternary.

关 键 词：East Asian monsoon South China Sea Tibetan Plateau uplift glacial-interglacial cycle QUATERNARY 

分 类 号：P736.21[天文地球—海洋地质]