Geochemistry Study Of Marine Surface Sediment In South China Sea And Arctic Sea Area

For make a marine sediment research to surface sediments in the South China Sea and Arctic sea area, adopting basic theory and method of geochemistry and modem analytic technique to give a whole and systemic research for the study area.Analysing the geochemistry of contaminated elements in the study area, and then judge the environment quality condition.After those study ,obtaining some conclusion as follows:(1)The trace elements contents of surface sediment in shelf area are higher than those in deep sea area's in South China Sea,and they are close to the Chinese Mainland sediments'.There is lower trace element concentration in middle sample stations than closing to continent's in Chukchi Sea.Because of deep water in Bering Sea, there is a complex distribution of trace elements.Correlation coefficient show that the sediments compositon is very near,which consist with its low temperature environment and feeble chemicial weathering.(2)REE enrich in north of sloping continental area, middle east of Indo-China Peninsula and northwest of Kalimantan Island in South China Sea,low content in southwest of Sunda sloping continental area, southeast of island reef area, Xisha and Pratas Islands .REE tracing results show they are mainly terrigenous.EREE distribution of the surface sediments in Chukchi Sea, high-values are mainly located in the southwest area adjacent to the west and north of Point Barrow area, a significant low in the area of Central. DREE distribution of surface sediments in Bering Sea, the central REE values area higher than that two sides'. REE tracing results show that the Bering Sea and Chukchi Sea surface sediments primarily from neighboring mainland . Contrasting with China loess, the average crust results show that the Arctic region is in a dry and cold climate of physical weathering to the Lord's environment.(3)Heavy metal enrich in the deep sea areas of surface sediments in South China Sea ,mainly because of deep basin area smaller sample size, the higher clay content, reflecting the "granularity rate control", and showing that volcanic material addition in deep basin area is not the main reason for heavy metal accumulation. Background value test results show that the majority of the content of contaminated elements are within the scope of the background. Environmental quality evaluation results show that shallow areas closing to the mainland were subject to different degrees of unnatural sources of influence.Background values calculated results in Arctic show that the heavy metal background values in Chukchi Sea are close to Bering Sea's.Evaluation results show that heavy metals of surface sediments in Arctic Chukchi Sea and the Bering Sea have not been artificially contaminated, remain within the scope of natural change.(4)Basically, the PGE enrich in the shallow water areas, some concentration in the deep basin area well, particularly for the most obvious Au, in addition to the deep basin area smaller sample size, higher clay content, PGE of the mantle material certainly affect the composition. deep-sea sediments for geologic evaluation results show that pollution mainly distributed in the shallow water near the mainland. Eastern China crust for enrichment factor values calculated results show that the platinum group elements are extremely high with EF values for non-continental crust sources and marine sediment characteristics.(5)Surface sediments in the South China Sea inherited the lead isotope of Yangtze block.Its lead isotope composition within the scope of the Red River and Mekong River K-feldspar lead isotopes . Aerosols Pb isotope values of Hong Kong and Taiwan affect north-west and north shallow water area.Pb isotope values of Chukchi Sea and the Bering Sea are within the scope of northern Pacific's, and closing to lead isotope average of Lena River's in eastern Siberia flowing into the Laptev Sea,and north Pacific especially impact on the Bering Sea.(6)Lower (?)Nd is in shallow water areas of surface sediments in South China Sea,and high-value areas are relative to volcanic activity areas. Higher (?)Nd values in lack of volcanic activity regions may be volcanic ash from the settlement. The dual mixed results show that surface sediments are mainly terrigenous, which (alumina components) accounted for 83%, (component-rock) mantle components accounted for 17 %.Land-based component high-value areas mainly distributed in the shallow shelf areas, high-value component of mantle-derived mainly distributed in deep sea basin of West Palawan Island, the theoretical distribution of pyroclastic sediments consist with the actual distribution of volcanic ash.