关键词: 浑善达克沙地, 粒度, 全新世, 气候变化

Abstract: The Hunshandake desert is located in the west of Inner Mongolia, China. This region is sensitive to climate change with annual temperature between 0.9~5.5 ℃ and annual precipitation between 240.3～422.6 mm. The samples were gotten at 5-cm intervals in the Xilinhaote section（43°52′36.6″N, 116°05′34.1″E）which is 2.8 m high and lies in the Hunshandake desert. In the laboratory the character of the grain-size composition and the changes of the grain-size parameters were analyzed. The relationships of the indicators of monsoon like Mz (mean particle diameter), Md (median size), D/SC (the ratio of the coarse sands to the sum of fine sands and clay), the coarse sands fraction(>63 μm), σ1 (standard deviation) and the clay fraction(<2 μm) with the monsoon variables were analyzed. The winter monsoon becomes strong when Mz, Md and the clay fraction become low, but D/SC and σ1 become high; on the contrary, the summer monsoon becomes strong when Mz, Md and the clay fraction become high, but D/SC and σ1 become low.According to the relationships, the climate changes since 10 ka BP could be divided into 4 stages: 10.7～9.6 cal ka BP, cold and arid; 9.6～6 cal ka BP, warm and humid; 6～3.4 cal ka BP, fluctuated between cold/arid and warm/humid; 3.4 cal ka BP to present, arid predominated. The climate changes in the Hunshandake desert are similar with other regions in China and in the world. It is mainly affected by the winter monsoon and the summer monsoon.

Key words: the Hunshandake Desert, grain-size, Holocene, climate change