【摘 要】
：
The determined results in this paper, which were obtained by the multielement analysis of the 260 cm-deep core sediments under the water of Xihu Lake in the Gr
【机 构】
：
Institute of Geography, Academia Sinica, Beijing 100101, PRCrrrrrrrrn,Department of Geology
【出 处】
：
Science in China,Ser.B
论文部分内容阅读
The determined results in this paper, which were obtained by the multielement analysis of the 260 cm-deep core sediments under the water of Xihu Lake in the Great Wall Station area, are as follows: The Cenozoic volcanic rocks around Xihu Lake are the main source of sediments in the lake. The chemical differentiation in very fine particles is still detectable. From the variation of ratios of the Cs/Rb, Br/CI and La/Yb in the clay fraction with depth and from the variation or CaCO_3 contained in the sediments, cation replacing amount in the clay grains and the sediment grain sizes in time, it can be seen that since 3600 a. B. P., there has existed the climatic variation of warm-cold-warm, which embodies the advance and retreat history of the ice sheet in this area.
The determined results in this paper, which were obtained by the multielement analysis of the 260 cm-deep core sediments under the water of Xihu Lake in the Great Wall Station area, are as follows: The Cenozoic volcanic rocks around Xihu Lake are the main source of the sediments in the lake. The chemical differentiation in very fine particles is still detectable. From the variation of ratios of the Cs / Rb, Br / CI and La / Yb in the clay fraction with depth and from the variation or CaCO_3 contained in the sediments, cation replacement amount in the clay grains and the sediment grain sizes in time, it can be seen that since 3600 a. BP, there has existed the climatic variation of warm-cold-warm, which embodies the advance and retreat history of the the ice sheet in this area.
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