A Rb/Sr record of catchment weathering response to Holocene climate change in Inner Mongolia

被引:173
作者
Jin, ZD [1 ]
Cao, JJ
Wu, JL
Wang, SM
机构
[1] Chinese Acad Sci, Inst Earth Environm, Xian 710054, Peoples R China
[2] Chinese Acad Sci, Nanjing Inst Geog & Limnol, Nanjing 210008, Peoples R China
[3] Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England
关键词
chemical weathering; lake sediment; elemental behaviour; Rb/Sr ratio; Holocene;
D O I
10.1002/esp.1243
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
Variation in the rubidium to strontium (Rb/Sr) ratio of the loess-palaeosol sequences has been proposed to reflect the degree of pedogenesis and weathering in the northwestern region of China. To characterize the Rb/Sr ratio of the dissolved loads of a single catchment, we analysed a 12(.)08 m sediment core from Daihai Lake in Inner Mongolia, north China. Dating control was provided by Pb-210, Cs-137 and AMS-C-14. Sequential extraction experiments were conducted to investigate the concentrations of Rb and Sr on various chemical fractions in the lake sediments. Down-core variation in the Rb/Sr ratios provides a record of Holocene weathering history. From 9 to 3(.)5 ka BP, accelerated chemical weathering was experienced throughout the Daihai catchment under mainly warm and humid conditions, and this reached a maximum at c. 5 ka in,. However, weathering was reduced between c. 8(.)25 and 7(.)90 ka BP, which may reflect the global 8(.)2 ka cooling event. After c. 2(.)5 ka BP, increased Rb/Sr ratios with higher frequency of fluctuations indicate reduced weathering within the Daihai catchment. The highest Rb/Sr ratios in the Little Ice Age lake sediments indicate the weakest phase of Holocene chemical weathering, resulting from a marked reduction in Sr flux into the basin. The Rb/Sr record also shows an enhancement of chemical weathering under today's climate, but its intensity is less than that of (he Medieval Warm Period. Increased Rb/Sr in lake sediment corresponding to reduced catchment weathering is in striking contrast to Rb/Sr decrease in the glacial loess layers in the loess-palaeosol sequence. Copyright (c) 2005 John Wiley & Sons, Ltd.
引用
收藏
页码:285 / 291
页数:7
相关论文
共 29 条
  • [11] Chen J., 1996, Acta Geol. Sin., V9, P290
  • [12] STRONTIUM ISOTOPES IN WEATHERING PROFILES, DEEP-SEA SEDIMENTS, AND SEDIMENTARY ROCKS
    DASCH, EJ
    [J]. GEOCHIMICA ET COSMOCHIMICA ACTA, 1969, 33 (12) : 1521 - &
  • [13] RIVER FLUXES OF DISSOLVED SILICA TO THE OCEAN WERE HIGHER DURING GLACIALS: Ge/Si IN DIATOMS, RIVERS, AND OCEANS
    Froelich, P. N.
    Blanc, V.
    Mortlock, R. A.
    Chillrud, S. N.
    Dunstan, W.
    Udomkit, A.
    Peng, T. -H.
    [J]. PALEOCEANOGRAPHY, 1992, 7 (06): : 739 - 767
  • [14] GLOBAL CHEMICAL EROSION DURING THE LAST GLACIAL MAXIMUM AND THE PRESENT - SENSITIVITY TO CHANGES IN LITHOLOGY AND HYDROLOGY
    GIBBS, MT
    KUMP, LR
    [J]. PALEOCEANOGRAPHY, 1994, 9 (04): : 529 - 543
  • [15] Chemical weathering since the little ice age recorded in lake sediments: A high-resolution proxy of past climate
    Jin, ZD
    Wang, SM
    Shen, J
    Zhang, EL
    Li, FC
    Ji, JF
    Lu, XW
    [J]. EARTH SURFACE PROCESSES AND LANDFORMS, 2001, 26 (07) : 775 - 782
  • [16] The Little Ice Age and Medieval warm period in the Sargasso Sea
    Keigwin, LD
    [J]. SCIENCE, 1996, 274 (5292) : 1504 - 1508
  • [17] SEQUENTIAL EXTRACTION OF SOILS FOR MULTIELEMENT ANALYSIS BY ICP-AES
    LI, XD
    COLES, BJ
    RAMSEY, MH
    THORNTON, I
    [J]. CHEMICAL GEOLOGY, 1995, 124 (1-2) : 109 - 123
  • [18] Enhanced chemical weathering of rocks during the last glacial maximum:: a sink for atmospheric CO2?
    Ludwig, W
    Amiotte-Suchet, P
    Probst, JL
    [J]. CHEMICAL GEOLOGY, 1999, 159 (1-4) : 147 - 161
  • [19] Glacial-interglacial variability of atmospheric CO2 due to changing continental silicate rock weathering: A model study
    Munhoven, G
    Francois, LM
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1996, 101 (D16) : 21423 - 21437
  • [20] Warm climate surprises
    Overpeck, JT
    [J]. SCIENCE, 1996, 271 (5257) : 1820 - 1821