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    南京老虎山黄土剖面中铷锶地球化学和磁化率与古气候变化的关系

    Rubidium and strontium geochemistry in the Laohushan loess section, Nanjing,and relation between magnetic susceptibility and paleoclimatic change

    • 摘要: 提要:宁镇地区的下蜀黄土记录了古气候变化的丰富信息。作为中国北方风尘堆积的南部边缘相,下蜀黄土在全球环境变化研究中占有重要的地位。本文以10cm间距系统分析了老虎山剖面的Rb、Sr含量和频率磁化率。结果显示,磁化率和Rb含量可以较好地指示东亚冬季风强度变化;Rb/Sr比可以作为下蜀黄土化学风化强度的替代性指标;剖面的Rb/Sr比由下至上升高是南京地区12万年以来化学风化作用增强的结果。

       

      Abstract: Abstract: The Xiashu loess in the Nanjing-Zhenjiang area records abundant information of the paleoclimatic change. The Xiashu loess, as a facies at the southern margin of eolian and dusty accumulations in northern China, occupies an important position in the study of the global environmental change. The authors systematically analyzed the Rb and Sr concentrations and magnetic susceptibility at the Laohushan section at 10 cm intervals. The results show that the Rb concentration and magnetic susceptibility may better indicate the variations in intensity of the East Asian monsoon and that the Rb/Sr ratio may server as a substitute proxy for chemical weathering of the Xiashu loess. The increase of the Rb/Sr ratio at the section from below upward is the result of intensification of chemical weathering over the last 120 ka.

       

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