山西公海湖泊沉积物记录的大气粉尘现代过程

发布时间：2018-02-13 19:43

本文关键词： 湖泊沉积物粉尘现代过程粒度粗粉砂组分　出处：《中国沙漠》2017年02期 　论文类型：期刊论文

【摘要】：湖泊粉尘记录是研究区域大气粉尘演化历史的重要载体,而现代过程研究是定量提取湖泊沉积物中粉尘信号的重要基础。对山西公海湖泊沉积岩芯样品及周边不同类型的表土样品开展了粒度分析,并对岩芯样品进行粒度组分的定量分离。结果表明:全新世湖泊岩芯样品以黏粒(2μm)、细粉砂(2~19μm)和粗粉砂(19~78μm)为主,粗粉砂组分的粒度特征与湖泊沉积物中的石英颗粒、黄土样品中的粗粒组分及现代大气降尘的粒度特征相似,石英颗粒的表面微形态也具有典型风成特征。因此,公海湖泊沉积物中粒径19~78μm的粗粉砂组分可用来代表大气粉尘的变化,这与湖泊沉积物中粗粉砂组分是大气尘暴降尘主要组分的认识一致。另外,公海湖泊冰面粉尘样品的平均粒径还具有从西北向东南递减的趋势,表现出与冬季风方向一致的特征,进一步表明公海湖泊沉积物中粗粉砂组分可以代表东亚冬季风强度的变化。因此,公海湖泊岩芯中的粗粉砂组分可用来重建全新世大气粉尘变化以及可能的东亚冬季风强度演化历史。
[Abstract]:Lacustrine dust record is an important carrier to study the evolution history of atmospheric dust in the region. Modern process research is an important basis for quantitatively extracting dust signals from lake sediments. Grain size analysis is carried out on core samples of lake sediments in the high seas of Shanxi Province and different types of surface soil samples around them. The results showed that the core samples of Holocene were mainly composed of 2 渭 m of clay, 219 渭 m of fine silt and 1978 渭 m of coarse silt. The composition of coarse particles in loess samples and the particle size characteristics of modern atmospheric dust fall are similar, and the surface micromorphology of quartz particles also has typical wind characteristics. The coarse silt fraction of 1978 渭 m in the sediments of high seas lakes can be used to represent the variation of atmospheric dust, which is consistent with the understanding that the coarse silt component in lake sediments is the main component of dust control in atmospheric dust storm. The average particle size of the high seas lake ice dust samples also decreased from northwest to southeast, showing the same characteristics as winter monsoon. It is further indicated that the coarse silt composition in the sediments of the high seas lakes can represent the variation of the intensity of the East Asian winter monsoon. The coarse silt components in the high seas lake core can be used to reconstruct the Holocene atmospheric dust variation and possibly the history of the East Asian winter monsoon intensity evolution.
【作者单位】：兰州大学资源环境学院/西部环境教育部重点实验室;
【基金】：国家自然科学基金项目(41372180) 国家基础科学人才培养基金项目(J1310036)
【分类号】：P512.2;P425.55

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