腾格里沙漠南缘末次冰盛期以来沙漠演化与气候变化

位于现代季风区边缘的沙漠黄土边界带,具有高度的不稳定性,末次冰盛期以来历经多次北进南退移动和暖湿、冷干变化。依据对腾格里沙漠南缘白岩沟剖面的黄土古土壤风成砂序列的年代测定,建立了腾格里沙漠南缘末次冰盛期以来沙漠演化的时间序列,并结合剖面各地层的粒度分析、色度分析和CaCO3分析结果,认为末次冰盛期该区主要经历了两次沙漠强烈扩张、两次退缩以及一次小幅度扩张的阶段。而全球变化所导致的东亚冬、夏季风变化是沙漠正、逆过程演变的主要驱动因子。

Desert Evolution and Climate Change of Southern Margin of Tengger Desert since Last Glacial Maximum

Located at the margin of the East Asian monsoon region,the desert-loess transitional zone is characterized by high instability.Since the Last Glacial Maximum,this area has experienced dramatic environment change.In detail,the boundary of loess-desert moved southward during warm/humid period and northward in cold/dry period.To investigate the Tengger desert evolvement,here we report the data of grain size,color reflectance,and CaCO_3 content of the loess-paleosol-eolian sand profile in Baiyangou located at the southern margin of the Tengger desert.Two times of widely expansion and retreat with one small scale expansion of the Tengger desert have been detected since Last Glacial Maximum.We proposed that the fluctuation of the East Asian monsoon controlled by the global change,is the driving force of the expansion and retreat of the Tengger desert.