哈尔滨城市道路表土记录的痕量元素在不同粒级中的分布特征  

The distribution of trace elements in different grain-size fractions inferred from road surface soils in Harbin City, Heilongjiang Province

作　　者：谢远云[1] 孟杰[1] 郭令芬[1] 何葵[1] 

机构地区：[1]哈尔滨师范大学地理科学学院,黑龙江哈尔滨150025

出　　处：《中国地质》2013年第2期629-635,共7页Geology in China

基　　金：国家自然科学基金项目(41072259)资助

摘　　要：将城市道路表土样品进行粒度分级(全样、>63μm、63～30μm、30～11μm和<11μm),测定了各粒级组分的微量元素和稀土元素组成。结果显示,微量元素在不同粒级组分中的变化程度按照以下顺序依次递增:Sr<Rb<Ga<Y<V<Zn<Nb<Cr<Zr<Cu<Ni,Sr和Rb受粒度影响较小,Zr、Cu和Ni受粒度影响很大。绝大部分微量元素(V、Cr、Cu、Zn、Sr、Y、Zr、Nb)随粒度的变细含量趋于增加,而Rb则相反,Ni和Ga与粒度不存在明确的相关关系。Rb/Sr比值是一个基本不受粒度分选作用影响的化学风化指标,Zr/Rb、Cu/Zn、V/Cr和Ni/V比值受粒度的影响很大,Zr/Rb比值随粒度变细而明显增高。所有REE在不同粒级组分中的分布规律和波动幅度高度一致,趋向于在细颗粒物质中富集。δEu明显受粒度的影响,随粒度变细,Eu从正异常向负异常演化。δCe在不同粒级组分中的变化不大,显示受粒度的影响较小。The samples of urban road surface soils were collected from Harbin City of Heilongjiang Province and divided into different grain size fractions （bulk sample, 〉63μm, 63-30 μm, 30-11 μm and 〈11μm）. These samples were analyzed to obtain the composition of trace elements and rare earth elements （KEE）. The results indicate that the variation degree of trace elements in different size fractions increases in order of Sr〈Rb〈Ga〈Y〈 V〈Zn〈Nb〈Cr〈Zr〈Cu〈Ni, Sr and Rb are less affected by grain size, and Zr, Cu and Ni are severely affected by grain size. The volume of most trace elements such as V, Cr, Cu, Zn, St, Y, Zr and Nb tends to increase with decreasing grain size, while things are just opposite for Rb, and the relationship between Ni, Ga and grain size is unclear. Rb/Sr ratio is a chemical weathering index independent of grain-size sorting, Zr/Rb, Cu/Zn, V/Cr and Ni/V ratios are severely affected by grain size, Zr/Rb ratio obviously increases with decreasing grain size. It is shown that the distribution patterns and fluctuation ranges of all REE in different size fractions are highly consistent with each other, characterized by the enrichment of fine-grained material. The δEu value is obviously influenced by grain size, characterized by the variation of Eu from positive Eu anomalies to negative Eu anomalies with decreasing grain size. The variation of δCe in different size fractions was insignificant, indicating that δCe value was less influenced by grain size.

关 键 词：不同粒级组分 地球化学 微量元素 稀土元素 粒度效应 

分 类 号：P59[天文地球—地球化学] P512.1[天文地球—地质学]