末次冰消期以来青海湖风成沉积高密度光释光年代学与环境演变

末次冰消期以来全球环境发生重大变革，青海湖地区的风成沉积主要是该阶段的产物，记录了西风环流、亚洲季风环流以及区域环境演变的重要信息。然而，由于缺乏高分辨率年代学框架和系统的环境指标分析，导致该区古土壤、砂质古土壤成壤年代及其气候意义，亚轨道尺度环境演变特征无法得到进一步理解。这也使得丰富的湖相沉积和湖面变化研究成果无法得到有效验证。本项目拟对青海湖地区5个典型末次冰消期以来的风成沉积剖面进行高密度光释光年代学研究，结合粒度、孢粉、磁化率、CIA，δ13C等环境指标，建立以成壤-沉积事件为代表的古气候事件序列。另外单独选取3个厚度超过1米,底界年龄小于2000年的黄土剖面，进行系统的年代学研究和环境指标分析，重建2000年以来的环境演变信息和气候环境事件。最终，通过对比、印证、集成以上剖面信息，获取末次冰消期以来青海湖风成沉积记录的高分辨率亚轨道尺度环境演变特征，并探讨其驱动机制。

Since the last deglaciation, enormous changes occurred on the global surface, the wide distributed aeolian sediments in Lake Qinghai area mainly began to deposited just from this time.As an excellent enviromental recorder, the aeolian sediment records the westerly, Asian moonsoon circulation and the region environmental information. Because of the lack of high resolution chronology study and systematic environmental proxy data,the ages of the palesols ,the environmental indication of the paleosol and sandy paleosol, and the environmental characteristic on suborbital scale are not clear. This also leads to that lake sediment and lake level research resulsts can not be effectively verified by the aeolian research because fo the limitation of chronology.In this work, closely sapced OSL (optical stimulate luminescening) dating method will be adopted to construct high resolution chronology frameworks. Combined with the environmental proxy data analysis (grainsize, magnetic susceptibility, pollen assemblages, chemical index of alteration,organic carbon isotope and so on), based on the events of soil formation and aeolian sediment deposition, the paleocliamtic event sequences will be constructed. the soil formation and aeolian depostion. Considering the young aeolian sediment stratum of the last 2000 years is near to the surface and easy to disturb, 3 high accumulated loess sections, bottom age younger than 2000 years, will be systematicly OSL dated and environmental index analyzed. Finally, through comparing, confirming and synthesizing the environmental records of the 8 sections above, it will be reconstructed that the high resolution environmental change chacteristic on suborbital scale recorded in the aeolian sediment in Lake Qinghai area, since the last deglaciation, and the driving mechanism will be discussed.