腾格里沙漠南缘末次冰消期微量元素反映的古气候环境

腾格里沙漠南缘土门剖面52L~41FD层段由3层风成沙丘砂、2层湖相沉积、2层古土壤和5层砂黄土构成. 分析结果表明:微量元素含量的高低变化依次为Mn、P、Sr、Rb、Cr、V、Zn、Ni、Cu、Nb，各元素含量在砂黄土、古土壤和湖相沉积中表现为相对峰态，而在沙丘砂层段中则呈现为相对谷态；在垂直方向上，各微量元素含量随着各沉积相的多次更替，构成了10条峰谷交替的锯齿状形态的元素波动过程线. 结合研究区地理位置与微量元素特征，认为可用Zn（ppm）、P（ppm）为代表作为气候替代性指标，指示本区东亚冬夏季风变化. 据此划分出了8个冷暖波动事件:冷干事件，即C1(11 870~11 640 a BP)、C2(12 650~12 050 a BP)、C3(13 340~13 010 a BP)、C4(13 810~13 620 a BP)， 暖湿事件， 即W1(12050~11870 a BP)、W2(13010~12650 a BP)、W3(13620~13340 a BP)、W4(14850~13810 a BP). 本研究与格陵兰GRIP冰芯和中国南京葫芦洞H82石笋之间较高的同步性，这表明，腾格里沙漠南缘气候波动可能与格陵兰气候变化受相同的高纬动力驱动.

Trace-Elements Characteristics of Tumen Section in Southern Tengger Desert and its Paleoclimatic Implications for#br# the Last Deglacial

The Tumen sequence(52L~41FD) on the southern edge of the Tengger Desert is composed of three layers of dune sands, two layers of lacustrine facies, two layers of paleosoil and five layers of sand loess. The results of trace elements analysis show that the concentrations of 10 trace elements in the last Deglacial of Tumen profile vary as Mn, P, Sr, Rb, Cr, V, Zn, Ni, Cu, Nb. The content of each element shows crest in the layers of lacustrine facies, paleosoil and sand loess, but shows trough in the layers of dune sands. As the sedimentary facies are alternated in the vertical direction of the profile, the elemental content also forms an elemental fluctuation process line. Based on the analysis of trace elements in combination with the particular terrain, it is considered that the elements represented by Zn(ppm) and P(ppm) are used as the climatic substitutes to indicate the fluctuation of Asian monsoon climate. Eight cold and warm incidents could be distinguished in terms of the elements. The cold incidents are C1(11870~11640 a BP), C2(12650~12050 a BP), C3(13340~13010 a BP), C4(13810~13620 a BP) and the warm incidents are W1(12050~11870 a BP), W2(13010~12650 a BP), W3(13620~13340 a BP), W4(14850~13810 a BP). The last deglaciation climate fluctuation which was recorded by the last deglaciation segment of Tumen section is highly similar to the data collected from Greenland GRIP ice core and Nanjing hulu cave stalagmite. It shows that the last deglaciation Asian monsoon climate changes of this region may be closely related to the climate mechanism in Northern Hemisphere.