Distribution Characteristics Of Trace Elements In The Sediments Of Shengjinhu Lake And Their Environmental Implications

It is important to reconstruct a reliable history of regional climate change whether the changes of the same proxies of core sediments from different locations in the lake are consistent.At present,most studies only use a single sedimentary core sediment in deep water area to invert regional climate and environmental changes,and there is a lack of research on the similarities and differences of core reconstruction results at different locations in the same area.This article take golden lake at different positions of two drill core deposits as the research object,and in combination with regional s estimation,based on the analysis of the various core sediment granularity,constant element oxide content,trace elements and other indicators of spatial variation,selection of the core sediments microelement proxies to rebuild the litres of golden lake since the pleistocene climate change,And compared with other trace element substitution index records in the region:（1）According to the particle size analysis of the two sediment column samples,silt is the main component of the two sediment column samples,followed by clay,and the content of sand is the lowest.The contents of clay and sand in the two sediment column samples decreased gradually from bottom to top,and the change trend was the same,while the silt content increased gradually from bottom to top.The contents of fine silt,medium silt and coarse silt decrease gradually from bottom to top.According to the analysis of sedimentary environment,the aeolian deposition was the dominant factor in the two sediment columns,followed by lacustrine deposition,which occurred at the bottom of the two sediment columns.Besides the above two sedimentary environments.Constant element oxide is mainly composed of two sediment column sample sample Na₂O、Mg O、Al₂O₃、Si O₂、K₂O、Ca O and Fe₂O₃7 species composition,respectively in zk03 and zk2801 column sample samples were 92.811%and91.711%of the total sediment（average）,the major elements of Si O₂ and Al₂O₃ the sum of the two elements respectively zk03 and constant elements in the sample zk2801 column samples were 81.134%and 79.136%of total,shows up golden lake sediment is given priority to with silicate and aluminum silicate.Compared with the sediments from several typical aeolian dust deposition areas,the weathering of the red soil in the Shengjinhu area and Xuancheng is the most similar and the most strongly influenced by weathering,and it is strong chemical weathering.According to the A-CN-K chemical weathering trend diagram of lake sediments in Shengjin Lake,the weathering materials in the study area are mainly derived from plagioclase minerals,and montmorillonite and illite minerals are mainly generated by weathering.（2）In the lake sediments from the Shenjinhu Lake area,the highest content of trace element is Zn in the two column samples,and the mean value of Zn in the column ZK03 and the column ZK2801 is 703.33×10-6μg/g and 542.03×10^-6μg/g,respectively.The lowest content of trace element was Co in the two samples,and the mean value of Co in the ZK03 and ZK2801 samples was 19.72×10^-6μg/g and 19.72×10^-6μg/g,respectively.The changes of the contents of V、Cr、Co、Ni、Cu and Ba have little difference.The differences of the contents of trace elements are related to the chemical properties of the elements themselves and the influence of the surrounding environment during the deposition process.Compared with the enrichment coefficients of trace elements in several typical aeolian sediment soils（Xiashu soil of Zhenjiang and laterite soil of Xuancheng）,the enrichment coefficients of trace elements of Cr,V and Ni in the two column samples from Shengjinhu area were greater than 1,indicating enrichment.However,the enrichment coefficients of Cr,V and Ni in Xiashu soil and Xuancheng red soil in Zhenjiang were less than 1,indicating a loss.The enrichment coefficients of Sr trace elements in these three areas are all less than 1,indicating obvious deficit.The enrichment coefficients of Co,Cu and Ba in the three regions are close to the average crustal abundance.（3）The REDOX,salinity change and climate change of the sediment cores at different locations of Shengjinhu Lake are similar.In the early Pleistocene,the sediment studies of Shengjinhu Lake showed weak oxidation and reduction state,and the salinity condition decreased,and the climate environment developed from dry and hot to warm and humid.In the middle of Pleistocene,oxidation,reduction and oxidation environment alternated,and the salinity was relatively low.The climatic environment alternated from warm and humid to hot and dry and then to warm and humid,indicating that the environmental change was in a relatively stable state.In the late Pleistocene,the lake was in an oxidized state with low salinity and a warm and humid climate.