| 5 000 a来柴达木盆地东南缘风成沉积记录的冬季风演化 |
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| 引用本文： | 牛光明,强明瑞,宋磊,郎丽丽,王立强.5 000 a来柴达木盆地东南缘风成沉积记录的冬季风演化[J].中国沙漠,2010,30(5):1031-1039. |
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| 作者姓名： | 牛光明 强明瑞 宋磊 郎丽丽 王立强 |
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| 作者单位： | 兰州大学,西部环境教育部重点实验室,甘肃,兰州,730000 |
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| 基金项目： | 国家自然科学基金，教育部博士点基金 |
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| 摘 要： | 通过柴达木盆地东南缘下西台剖面风成沉积粒度组成、元素含量等指标的分析，重建了该区5 000 a来冬季风的演化历史。其可划分为4个阶段：5 300~4 300 a BP和2 900~930 a BP时期冬季风较弱；4 300~2 900 a BP和930 a BP以来冬季风较强。同时，该记录揭示了两次气候突变事件： 3 960~3 720 a BP，冬季风急剧减弱；而1 700~1 400 a BP冬季风增强。重建结果与其他记录具有很好的可比性。在千年尺度上，下西台剖面所记录的冬季风演化与格陵兰冰芯的粉尘记录存在一定的联系，意味着源区近地面风场的变化在全球粉尘循环过程中起着重要的作用。柴达木盆地可能为东亚粉尘远程输送的主要源区之一。
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| 关 键 词： | 粒度组成 元素含量 冬季风 柴达木盆地 |
| 收稿时间： | 2009-9-5 |
| 修稿时间： | 2009-11-18 |
Change of Eastern Asian Winter Monsoon Recorded by Aeolian Deposits over the Past 5 000 Years at the Southeastern Margin of Qaidam Basin |
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| NIU Guang-ming,QIANG Ming-rui,SONG Lei,LANG Li-li,WANG Li-qiang.Change of Eastern Asian Winter Monsoon Recorded by Aeolian Deposits over the Past 5 000 Years at the Southeastern Margin of Qaidam Basin[J].Journal of Desert Research,2010,30(5):1031-1039. |
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| Authors: | NIU Guang-ming QIANG Ming-rui SONG Lei LANG Li-li WANG Li-qiang |
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| Institution: | Key Laboratory of Western Chinas Environmental Systems (Ministry of Education), Lanzhou University, Lanzhou 730000, China |
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| Abstract: | Atmospheric dust plays an important role in the global climate change. The Qaidam Basin, as one of the Asian dust source areas, can provide a great deal of mineral dust for deflation. Wind strength in the source areas is crucial for dust particle uptake. Grain size and elemental composition of the aeolian deposits at the southeastern margin of the Qaidam Basin were investigated to reconstruct the change of winter monsoon over the last 5 000 years. The fractions of >40 μm and 140~250 μm and the ratio of SiO2 to TiO2 were used as indicators of winter monsoon. In light of five controlling ages, the change of winter monsoon can be divided into four stages. Winter monsoon was very weak in 5 300~4 300 a BP and 2 900~930 a BP; whereas in 4 300~2 900 a BP and 934 a BP it was rather stronger. Two abrupt winter monsoon changes were observed at 3 960~3 720 a BP and 1 700~1 400 a BP. The former event is characterized by sharp weakening and the latter became intensive. The reconstructed results are broadly in agreement with other records from the adjacent regions. However, the decreasing trend of winter monsoon during 2 900~930 a BP is most likely related to high temperature in East China at that time, which was inferred from historical documents. Theres a close relation between the winter monsoon evolution records from the Xiaxitai sections and dust record of the Greenland ice core. Near-surface wind regime in dust source areas may play an important role in global atmospheric dust circulation. In addition, Qaidam Basin may be one of the important dust source regions in eastern Asian dust long-range transportation. |
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| Keywords: | grain size elemental composition winter monsoon Qaidam Basin |
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