MEASUREMENT AND PALEOCLIMATIC SIGNIFICANCE OF SOIL BULK DENSITY FOR LOESS IN EXTREME ARID REGION

Soil bulk density of the loess-paleosol can not only reflect variations in strength of East Asian winter and summer monsoon, but also has important significance to study paleoclimate and reconstruct drying trend of Asian heartland. Now, most of researches on the soil bulk density concentrate their attention on Chinese Loess Plateau(CLP), while in the arid regions of Northwest China there are relatively fewer researches on the methods and paleoclimatic significance of the soil bulk density. Based on previous studies, an ideal method for measurement of the soil bulk density in arid region of Asian heartland is put forward in this paper, and we also find the soil bulk density value in negative correlation with variations in the grain sizes and magnetic susceptibility (MS), which is very different from that in Chinese Loess Plateau. Further analysis suggested that variations in the soil bulk density of extreme arid region loess was mainly controlled by the drought extent of source region, rather than monsoon intensity.