LATE HOLOCENE PALEO-ENVIRONMENT RECONSTRUCTION WITH PALEOSOL FROM KEKDALA PROFILE IN YILI OF XINJIANG

For the purpose to study the characteristics of the Holocene paleo-aeolian sand and paleosol in the Kekdala profile, Yili of Xinjiang, we made a thorough analysis of magnetic susceptibility, TOC, clay fraction, and CaCO₃ of the sediments. The results show that the paleosol is resulted from the further weathering of loess deposits, as a kind of light gray desert soil formed under the weak clayization and calcification conditions in a desert-steppe environment. The paleo-aeolian sand and paleosol sequence suggest that the Yili valley of Xinjiang has suffered many times of climate fluctuations since 3.71 kaBP. There are 6 layers of paleosol developed in different degrees during this period, with 3 layers formed in the early stage which are more developed than the 3 layers formed in the late stage. The paleoclimate inferred from paleosol could be divided into two stages taking the 2 kaBP as the boundary, and the climate was dry in the early period but wet in the late period. Since 0.5 kaBP, however, the climate has become warm-dry and the aeolian sand was strongly activated.