中国不同类型土壤中稀土元素的形态分布特征

采用中子活化分析地中国不同地带土壤中的稀土元素含量分布模型及其赋存形态进行了系统的研究。结果表明，黄棕壤，褐土，淋溶黑钙土及白浆土中稀土元素的分布均为轻稀土富集，Ｅｕ亏损型，砖红壤，红壤为轻稀土富集，Ｃｅ亏损型。

Speciation of Rare Earth Elements in Different Types of Soils in China

Contents, distribution patterns and speciation of rare earth elements(REEs) in latesol(tropical zone), red earth(middle subtripical earth), yellow brown soil(Northern subtripical earth), cinnamon soil(warm temperature zone), leached chernozem(temperate zone) and albic bleached soil(temperate zone) in China were determined with instrumental neutron activation analysis(INAA). In all the six soils, REEs mainly exist in residual form, and with the increase of atomic number, intermediate REEs(IRRE) have lower proportions of residual form than light REEs(LREE) and heavy REEs(HREE). Among the six unstable forms, the water soluble form has the lowest proportion. The proportions of exchangeable form carbonate and specific adsorption form are lower. The proportions of Fe-Mn oxides form in different types of soils decrease gradually from the Southern region to the Northern region. Proportions of bound organic matters are higher and follow the order: Albic bleached soil>leached chernozem>red earth>latesol>yellow brown soil>cinnamon soil. The albic bleached soil has higher proportion of softly bound organic matter form. The leached chernozem has higher proportion in tightly bound organic matter form.