Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (3): 373-384.doi: 10.1007/s11442-008-0373-1

• Climate and Environmental Change • Previous Articles    

Environmental change inferred from Rb and Sr of lacustrine sediments in Huangqihai Lake, Inner Mongolia

CHEN Lei1, SHEN Hongyuan1, JIA Yulian2, WU Jinglu3, LI Xusheng4, WEI Ling4, WANG Pengling5   

  1. 1. Environment and Tourism College, Linyi Normal University, Linyi 276005, Shandong, China|
    2. School of Geography and Environment, Jiangxi Normal University, Nanchang 330027, China|
    3. Nanjing Institute of Geography and Limnology, CAS, Nanjing 210008, China|
    4. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China|
    5. Institute of Tibetan Plateau Research, CAS, Beijing 100029, China
  • Received:2008-03-03 Revised:2008-05-21 Online:2008-09-25 Published:2008-09-25
  • Supported by:

    National Natural Science Foundation of China, No.40401006

Abstract:

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 paleoen-vironment.

Key words: Inner Mongolia, Huangqihai Lake, Holocene, different grain size fractions, lake sediment, Rb/Sr ratio, climatic change