Climate instability in the Yili region, Xinjiang during the last glaciation

The climate is influenced by westerlies year in year out and the aeolian lo ess is widespread in the Yili region, the Xinjiang Uygur Autonomous Region. Through the study of the loess section with a thickness of 21.5 m, much us eful information about climatic change in this region during the last glaci ation was gotten. Grain size analysis of loess samples in the section showe d that the climatic change in the Yili region was of instability during the last glaciation and similar to those of the North Atlantic Ocean and Green land. In correspondence with the Heinrich events. the percentage of the siz e fraction of loess with grain size less than 10 mu m decreased in cold sta dials in the Yili region. This result suggests that the westerly wind be st rengthened during the cold periods. Compared with the stadials, the content of the loess with grain size less than 10 um was increased in interstadial s, which indicated that the strength of the westerly wind was weakened, It is obvious that the climate was instable not only in the North Atlantic Oce an and polar regions. but also in other areas of Northern Hemisphere during the last glaciation.