Grain-size and chemical characteristics of the lacustrine deposits from the Xi Tuanpiao profile in Jinzhou, southern Liaoning province and their environmental significances

Lake deposits are ideal carriers for study of climate changes in history due to their high deposition rate, good continuity and high resolution. The southern part of Liaodong peninsula lies on the east coast of the Eurasian continent, and some typical Quaternary lacustrine deposits are well preserved there. In this paper, the lacustrine sediments from the western Jinzhou, southern Liaoning province were taken as the research carriers for reconstruction of environmental changes. Field investigation is carried out together with laboratory testing for particle size, chemical composition, ignition loss and electrical conductivity. The results show that the study area has suffered a climate change from cold and drought (30.81~15.64 kaBP) to cold and drought (15.64~10.36 kaBP) to warm and drought (10.36~5.77 kaBP) to warm and humid (5.77~0.90 kaBP) and to cool and drought (0.90 kaBP until now). Combined with the comparative study of geochemical indicators, it is preliminarily believed that the EM1 may indicate the fine particles carried into the lake by wind and flowing water, the EM2 represent a kind of weak fluvial sediments, and the EM3 a strong alluvium deposits.