The characteristic of the Younger Dryas Event in Bilut Lake, Inner Mongolia, China

To investigate the region which affected by Younger Dryas Event, we collect sediments of the lakes from Inner Mongolia of China. In general, sediments of lakes and sea are considered as a good material to study climate change because they could record continuously the information about the change of environment for long time. Inner Mongolia is located at the central part of the Asian continent, where its climate is controlled predominantly by the interaction between the East Asian monsoons and Westerly. At least 494 lakes have been recognized from the literature and aerial images that provide good materials for studying the climate changes occurred in this area. The Bilut Lake (43°25'12.0'' N, 113°46'32.5'' E) is located in the center of Inner Mongolia, and it is the farming-grazing transitional zone in northern China. It is considered as a sensitive response for the climate change, so we drilled and analyzed the lake sediments here. The retrieved core from this lake was 751 cm in length which covered the age ranging from 9.5 to 13 cal. ka, and the average sedimentation rate was estimated as 0.167cm/yr. The lacustrine sediments are composed of gray-green mud with interbedded silts in bottom, and black muds are distributed randomly in the core. The X-ray diffraction (XRD) analyses show that the mineral assemblages are mainly constituted with quartz, feldspar, illite, aragonite, dolomite and some saline minerals. The presence of aragonite may imply warm and dry climate in 10.2 to 10.7 cal. ka and 12.6 to 12.7 cal. ka. The presence of dolomite also suggests dry climate in 11 to 12 cal. ka. The investigation of mineralogical results will be combined with major element analyses and mineral-magnetism measurements further and discuss the characteristic of the YD event in the North China.