The Sr-Nd Isotopic Geochemical Study Of Dust In Typical Original Area Over The Tibetan Plateau

As the world's highest plateau-Tibetan plateau,in the summer and winter seasons,respectively,as the cold source and heat source at the center of the land,greatly strengthen the east Asia monsoon and the south Asian monsoon,make an important impact on atmospheric circulation.At the same time,due to the high altitude of the Tibetan plateau,the winter sky westerlies run also be impeded and divided into north and south branch,changed the trajectories of airflow.Due to the surface of the Tibetan plateau exist desertification regions,the fine grained detrital material is easy to be carried by the wind,into the west wind currents in the high altitude,in the northern hemisphere sky for long distance transmission,therefore,in theory,the source of Asia dust should have a provenance contribution from Tibet plateau.Based on the study of the Sr-Nd isotopic characteristics of the surface sand,loess and theweatheringmaterial,divid the plateau into 10 isotopic characteristics regions:the Ritu zone(?Nd:-9.06),Shiquanhe zone(?Nd:-7.6),Xiangquanhe zone(?Nd:-13.3),Cuoni zone(?Nd:-9.4),Zhongba zone(?Nd:-8.9),Xainza zone(?Nd;-15.1),Shigatsezone(?Nd:-7.6)?Shannan zone(?Nd:-9.5),Lhasazone(?Nd:-5.7)and Tanggula Mountainzone(?Nd:-9.38).The isotopic characteristics regions are not contiguous in space so divid them into different partitions.The samples all reflect the distribution characteristics of rare earth elements of the upper crustal material.Although the distinction between the mineral composition is similar,but the partition has the characteristics of the district.It is consistent with the Nd-Sr isotopic characteristic zoning from the mineral characteristics of the Tibetan plateau dust(including surface sand and surface weathering matter).Mineral characteristics reflect the dust characteristics of the Tibetan Plateau.The mineral is dominated by near-source weathering products.Some areas have extensive magma,hydrothermal activity,regional oxidation is not strong,chemical weathering is weak,and local evaporation is local.Due to the Sr-Nd isotopic characteristics of the Tibetan Plateau dust and the mineral characteristics,there maybe some material contributions from the Tibetan Plateau in the remotetransmission dust ofNorth Pacific and the Greenland ice core.Mainly from the the Yarlung Zangbo River valley and Tanggula Mountain isotopicregion.The characteristics of the other regions are similar to those of the remote transmission dust,the amount of the dust is limited due to the limited dust content in the area,and the contribution is limited.