Boron isotope geochemistry of sediments from the Zigetang Co saline lake in Tibetan Plateau

摘要：

　　The origin of boron in boron-rich salt lakes in the Tibetan Plateau is highly controversial.In this study,we carried out a detailed study on boron geochemistry and isotope composition of lake sediments collected in the Zigetang Co which located in central Tibet.The evaporite phase of the sediments show high boron concentrations of 172.3μg/g to 418.6μg/g and δ11B value of -8.2‰ to -3.3‰,which suggest a non-marine origin of the saline lake.The boron isotopic fractionation factor(α)between evaporite and brackish water(i.e.αevaporite-brackish)increase systematically as depth increases,from 0.9893 at the bottom of the drill core to 0.9942 at the top,the linear variation between the αevaporite-brackish value and the depth reflects the boron isotopic fractionation associated with progressive crystallization.The positive correlation between δ11B vs.B and δ11B vs.depth in the evaporite phase reflects the pH and boron speciation in the solution control on the adsorption of boron,and B(OH)3 species incorporated preferentially into Mg(OH)2 precipitation at high pH.

关键词： Boron isotopes Zigetang Co Equilibrium isotopic fractionation Boron concentration

作者: Xiaodan Wang Congqiang Liu Zhiqi Zhao Shijie Li Gangjian Wei

作者单位: State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Scie State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Scie State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of

会议类型: 国际会议

会议名称: The 11th International Symposium on Geochemistry of the Earths Surface(GES-11)(第十一届地球表层地球化学国际研讨会)

会议地点: 贵阳

会议语种:英文

页码: 1-4

在线出版日期: 2017-06-11（万方平台首次上网日期，不代表论文的发表时间）