地理科学 ›› 2012, Vol. 32 ›› Issue (11): 1397-1403.doi: 10.13249/j.cnki.sgs.2012.011.1397

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地球化学组成在不同粒级中的分布特征——以哈尔滨城市道路表土为例

谢远云1(), 孟杰1, 郭令芬1, 何葵1, 康春国2   

  1. 1. 哈尔滨师范大学地理科学学院, 黑龙江 哈尔滨 150080
    2. 哈尔滨学院地理系, 黑龙江 哈尔滨 150086
  • 收稿日期:2012-02-18 修回日期:2012-04-18 出版日期:2012-11-20 发布日期:2012-11-20
  • 作者简介:

    作者简介:谢远云(1971-),男,江西省瑞金市人,教授,主要从事第四纪地质研究。E-mail:xyy0451@163.com

  • 基金资助:
    国家自然科学基金项目(41072259)、黑龙江省自然科学基金项目(G201027)资助

The Distribution of Geochemical Composition in Different Grain-size Fractions: A Case Study of Road Surface Soils in Harbin City

Yuan-yun XIE1(), Jie MENG1, Lin-feng GUO1, Kui HE1, Chun-guo KANG2   

  1. 1. College of Geographical Science, Harbin Normal University, Harbin, Heilongjiang 150086, China
    2. Geography Department, Harbin Institute, Harbin, Heilongjiang 150086, China
  • Received:2012-02-18 Revised:2012-04-18 Online:2012-11-20 Published:2012-11-20

摘要:

将哈尔滨城市道路表土样品进行粒度分级,测定各粒级组分的常量元素、碳酸盐含量和碳酸盐碳同位素组成。结果显示,常量元素在不同粒级中的变化程度依次为:Al<Na<Si<K<Ca、Mg<Fe<Mn<P<Ti;Fe、Mg、Ca、Mn、Ti和P随粒度变细含量逐渐增加,而Si、Na和K元素则相反,Al元素与粒度的关系不清晰。化学风化指标按照以下的顺序受粒级的影响依次增大:CIA、(Al+Fe+Ti+Mn)/(Mg+Ca+K+Na)<(CaO+K2O+Na2O)/Al2O3<Fe2O3/MgO<K2O/Al2O3<(CaO+MgO+Na2O)/TiO2。碳酸盐含量在各粒级组分中变化幅度较大,且随着粒度的变细,碳酸盐含量逐渐增加。碳酸盐δ13C值在各粒级组分中的变化幅度较小,与粒级的关系较为复杂。

关键词: 不同粒级组分, 地球化学组成, 常量元素, 碳酸盐, 碳酸盐碳同位素, 化学风化

Abstract:

In the article,the samples of road surface soils in Harbin city are divided into different grain size fractions (bulk sample, >63 μm, 30-11 μm and <11 μm ) to measure major elements and carbonate and carbon isotope composition of different grain size fractions respectively. The results show that the variation degree of major elements in different grain size fractions is in sequence of Al<Na<Si<K<Ca, Mg<Fe<Mn<P<Ti, and the variation of Al element is relatively stable. The volume of Fe, Mg, Ca, Mn, Ti and P elements gradually raise with decreasing grain size, while the volume of Si, Na and K is exactly the opposite.The relationship between Al element and grain size is unclear, and Al element is enriched in >63 μm fraction, while the minimum in 63-30 μm fraction. The influence of grain size to chemical weathering index is in sequence of CIA, (Al+Fe+Ti+Mn)/(Mg+Ca+K+Na)<(CaO+K2O+Na2O)/Al2O3<Fe2O3/MgO<K2O/Al2O3<(CaO+MgO+Na2O)/TiO2. The ratio of CIA and (Al+Fe+Ti+Mn)/(Mg+Ca+K+Na) is the best index reflecting the chemical weathering degree, and next is the ratio of (CaO+K2O+Na2O)/Al2O3, Fe2O3/MgO and K2O/Al2O3, and the influence of grain size to (CaO+MgO+Na2O)/TiO2 ratio is larger, resulting in that (CaO+MgO+Na2O)/TiO2 ratio is not a good index indicating chemical weathering degree of sediments. The variation range of carbonate volume in different grain size fractions is larger, and carbonate volume gradually raise with decreasing grain size, showing carbonate volumes are not a good indicator distinguishing dust source region. The variation range of carbon isotope composition in different grain size fractions is less, showing carbonate carbon isotope compositions is a better tracing index indicating eolian dust provenance than carbonate contents, and the relationship between carbon isotope composition and grain size is relatively complicated, but most of samples are shown as “N shape” flexural variation modes, namely, rises, then descends and again rises, with decreasing grain size.

Key words: different size fractions, geochemical composition, major elements, carbonate, carbonate carbon isotopic, chemical weathering

中图分类号: 

  • P534.63