| 风化成壤对原始粉尘粒度组成的改造证据 |
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| 引用本文： | 孙有斌,周杰,鹿化煜,安芷生.风化成壤对原始粉尘粒度组成的改造证据[J].中国沙漠,2002,22(1):16-20. |
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| 作者姓名： | 孙有斌 周杰 鹿化煜 安芷生 |
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| 作者单位： | 1. 中国科学院 地球环境研究所, 陕西 西安 710075;2. 中国科学院 海洋研究所, 山东 青岛 266071 |
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| 基金项目： | 国家自然科学基金项目（49823001和49902009）成果 |
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| 摘 要： | 对现代粉尘、黄土、古土壤、红粘土全样和对应石英样的粒度分析结果表明,现代粉尘和对应石英样的粒度组成最为相似,而其它经历了风化成壤改造后的全样,粒度组成发生了不同程度的变化,其中以古土壤和红粘土样尤为显著。全样和石英样品的平均粒径比值变化,反映了原始粉尘经风化成壤改造而细化的程度,可能与夏季风强度关系密切。灵台剖面L6以来的黄土—古土壤序列的磁化率、全样和石英样平均粒径及其比值变化对比表明,在冰期-间冰期旋回时间尺度上,全样和石英样平均粒径记录的冬季风变化特征类似,但在千年时间尺度上,平均粒径比值和石英样的平均粒径变化则揭示出东亚季风具有更高频次的变率特征。
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| 关 键 词： | 原始粉尘 黄土古土壤 粒度组成 风化成壤 |
| 文章编号： | 1000-694(2002)01-0016-05 |
| 收稿时间： | 2000-09-22 |
| 修稿时间： | 2000年9月22日 |
Modification to the Grain Size Distribution of Original Eolian Dust by Weathering and Pedogenic Processes |
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| SUN You-bin,ZHOU Jie,LU Hua-yu,AN Zhi-sheng.Modification to the Grain Size Distribution of Original Eolian Dust by Weathering and Pedogenic Processes[J].Journal of Desert Research,2002,22(1):16-20. |
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| Authors: | SUN You-bin ZHOU Jie LU Hua-yu AN Zhi-sheng |
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| Institution: | 1. Institute of Earth Environment, Chinese Academy of Sciences, Xian 710075, China;2. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China |
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| Abstract: | The grain size has been regarded as an approximate measure for the strength of winter monsoon because both bulk loess and paleosols have been modified to various degrees by weathering and pedogenic processes. Eolian quartz is the main components of Chinese loess; owning to its stable physical and chemical characteristics, grain size of quartz can be considered as a more reliable proxy for the winter monsoon intensity. However, it is unknowable what the difference of grain size distribution between the quartz and bulk samples. Here we choose modern dust and loess-paleosol-red clay samples from Lingtai section. Quartz particle was isolated by chemical method and grain size has been measured for all the quartz and bulk samples. Through the primary study in this paper, the main conclusions were listed as following: Comparison of grain size distribution between bulk modern dust, loess, paleosol, red clay and isolated quartz samples indicated that the original eolian dusts had been modified to various degrees by weathering and pedogenic processes. The grain size distribution of quartz is closed to that of primary eolian dust and thus can be regarded as a more reliable index of winter monsoon strength. Mean values of quartz are general coarser than those of bulk loess-paleosol samples. The variation of mean value of quartz reflected the higher-frequency variability of winter monsoon than that of bulk samples on millennial time scale. The variations of mean ratio values of modern dust, loess, paleosol and red clay samples indicated that the stronger summer monsoon intensity and the greater modification to primary eolian dust, which was also proved by the well correlation between magnetic susceptibility and mean ratio variation of Lingtai loess-paleosol sequence. |
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| Keywords: | eolian dust isolated quartz grain size weathering and pedogenisis |
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