Palaeoenvironmental Record Based On The Minerals From Selin Co Sediments Since Last Glacial In The Central Tibetan Plateau

The mineral indicators in lake sediments are the records of the information of source,climate,sedimentary and structural.It can provide qualitative and quantitative basis for paleoenvironmental evolution,such as detrital minerals and carbonate minerals can indicate past environmental changes.The records of lake sediments since since last glacial have the advantages of better preservation,high time resolution and suitable for high precision measurement.It is a good carrier for the study of paleoenvironmental evolution.Selin Co is one of the most valuable places to study the evolution of paleoenvironment,which is located in the central Tibetan Plateau and is sensitive to climate.This paper uses XRD to conduct analysis of the sample from the noutheastern second terrace in Selin Co,and the paleoenvironment has been reconstructed since the last glacial.We got the results in below:(1)There were Silicate minerals-Quartz,Potassium feldspar,Sodium feldspar,Clay minerals-Chlorite,Illite,Kaolinite,Carbonate minerals-Calcite,Aragonite,Dolomite in the main minerals from sediments.(2)Palaeoenvironmental evolution in Selin Co since last glacial was 18.5 ~ 15.4 cal ka B.P.-cold and dry,low lake;15.4 ~ 11.1 cal ka B.P.-cool and dry,low lake;11.1 ~ 6.2 cal ka B.P.-warm and humid,high lake;6.2 ~ 4.4 cal ka B.P.-cool and dry,low lake;4.4 ~ 3.4 cal ka B.P.-cold and dry,low lake;3.4 ~ 2.4 cal ka B.P.-warm and humid,lake rised;2.4 ~ 1.2 cal ka B.P.-cold and dry,low lake and fast retreated.(3)Palaeoenvironmental evolution in Selin Co since last glacial was affected by solar radiation intensity in the Tibetan Plateau,when the solar radiation was strong the lake was high and when the solar radiation was weak the lake was low.Its evolution was basically the same as that of the isotope record of Guriya ice core.