地理学报(英文版)
地理學報(英文版)
지이학보(영문판)
JOURNAL OF GEOGRAPHICAL SCIENCES
2008年
3期
373-384
,共12页
陈磊%申洪源%贾玉连%吴敬禄%李徐生%魏灵%王朋岭
陳磊%申洪源%賈玉連%吳敬祿%李徐生%魏靈%王朋嶺
진뢰%신홍원%가옥련%오경록%리서생%위령%왕붕령
Inner Mongolia%Huangqihai Lake%Holocene%different grain size fractions%lake sediment%Rb/Sr ratio%climatic change
Based on the geochemical elements Rb and Sr in sediments with three different grain size fractions from profile H3 on the northern lacustrine bottomland 13 m above the Huangqihai Lake surface in 1986, the paper investigates the record of palaeolake stand state, sedimentary environmental evolution, and winter monsoon change. First, these samples are separated into three different grain size fractions, i.e., total sediments, 77-20 μm and <20 μm. Second, the chemical elements--Rb and Sr--of the grain size separation were tested and analyzed systematically in this paper. Then the elements compositions of these samples are measured using VP-320 mode fluorescence spectrum instrument, respectively. The magnetic susceptibility of these samples is measured using Kappabridge KLY-3 mode instrument made in Czech AGICO Company. The results showed the elements and the ratios varied regularly with the grain size. But the ratio of Rb/Sr in the sediments <20 μm correlates positively with the magnetic susceptibility of these samples. Therefore, the ratio of Rb/Sr in the fraction <20 μm from the lake sediments reflected the strengthening of the weathering in the deposition sites. It is a good indicator of the summer monsoon-induced weathering and pedogenesis fluctuations and can be used to reconstruct the conditions of the paleoclimate and paleoenvironment.