伊犁黄土物质来源研究及其对环境的指示意义

项目名称： 伊犁黄土物质来源研究及其对环境的指示意义

项目编号： No.41302149

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 陈秀玲

作者单位： 福建师范大学

项目金额： 26万元

中文摘要： 伊犁黄土是研究西风环流演变历史的理想载体，目前对于该区黄土的物质来源还存在许多疑问，是西风携带为主？还是由近地面风携带近源物质为主？尚缺乏来自地球化学的有力论证，并且没有来自"源区"的直接证据。不同的物质来源是影响气候代用指标理化性质的重要因素，系统追踪伊犁黄土的物源有助于正确解译气候代用指标的古环境意义，对进一步揭示西风气候演化与古大气环流历史具有重要的意义。本项研究根据研究区的主导风向，选取哈萨克斯坦的萨雷耶西克阿特劳沙漠、沙漠东南部天山山前洪积扇沉积和山麓黄土、伊犁地区山前洪积扇沉积以及伊犁黄土的表土样品，以63μm、20μm和4μm为界提取不同粒级组分，进行各相同组分的地球化学元素和Sr-Nd同位素组成特征对比分析，结合伊犁地区和沙漠东南部天山北麓典型黄土剖面的对应研究，探讨伊犁黄土的物质来源，为明确伊犁黄土气候代用指标的古环境意义和进一步探讨西风气候演化提供重要依据。

中文关键词： 伊犁盆地；黄土；稀土元素；物质来源；

英文摘要： Though the loess record of Ili Basin provides an ideal archive of westerlies evolution, the provenance of loess material still remains controversial. Which atomospheric cirulucation plays a more important role in the dust transportion? The dust transported by the westerlies or the silt-sized particles carried by near-surface wind? It still remains deliberated, asking for more geochemical discussion and direct evidence from source regions. The physicochemical properties of climate proxies are closely related to the provenances of loess material, therefore, source tracing of loess in Ili Basin systematically is beneficial to understand the implications of climate proxies, and play crucial insight into the evolution of the westerlies and the history of atmospheric circulation. In this study, various sediments from such as topsoil/desert sands of Sary-Ishikotrau Desert, alluvial fan of Tianshan to the southeast of the desert, loess in southeast Kazakhstan, alluvial fan and loess of Ili Basin will be selected as research objectives, and will be extracted into four grain-size fractions taking 63μm, 20μm and 2μm as boundaries. The provenance of Ili loess will be explored through the analysis of geochemical and Sr-Nd isotopic properties of each fraction, combined with corresponding research of loess sequence in southeas

英文关键词： the Ili Basin；loess；REE；provenance；