||The arid central Asia is sensitive to global climate change. Bosten Lake, the largest inland freshwater lake in China, is strongly influenced by westerly and can document the model and process of the climatic variations of westerlies dominant area during the Holocene. Based on the age model constructed with 210Pb, 137Cs, AMS C-14 and OSL dating results, multiproxy analysis of core sediments and surface sediments, including pollen analysis, carbonates content, grain size, magnetic susceptibility, has been applied to reconstruct the regional climate variability since late glacial. The primary conclusions are as follows:
1. A modern process within the Bosten Lake was investigated to understand the environmental significance of the proxies. Pollen analysis of the surface sediments suggested that the main difference of the pollen assemblages within the Bosten Lake was caused by the plants on the shore, and the pollen assemblage from the center of the lake could generally represent the regional vegetation scenery. On the other hand, it is also notable to consider the river induced influence on depositional process of the pollen grains. The pollen A/C index can generally reflect the arid state of the area. Like other lakes, the pollen concentration is correlated to the water depth, having a higher concentration in the lake center than that of the shallow water area. The growth of Pediastrum algae is strongly correlated with water depth and its concentration increase rapidly when water depth exceeds around 10 meters. Because Pediastrum algae is a kind of freshwater algae, its concentration variations can generally reflect both water salinity and lake depth. The spatial distribution of other proxies of the surface sediments also showed evident patterns. Grain size is much bigger in lake surrounding area than that from the center, and it can reflect the water dynamics and regional rainfall for the core sediments from the depocenter. Caclium carbonate content distribution shows a zonal pattern, and it is low in the river mouth area and southern part of the lake. Magnetic susceptibility varies reversely to that of calcium carbonate content, which might be related to terrestrial debris input brought by river.
2. Five groups of cores were retrieved from Bosten Lake, and the stratigraphy was comparable, which indicated that the lake sediments accumulated on a thick layer of sand. An age model of BST04H core was constructed by using ...