土壤粗粒氧化铁矿物及其在发生分类上的意义

应用传统的地质重砂矿物测量法,穆斯堡尔谱以及光学显微镜技术,鉴别福建南亚、中亚热带的赤红壤、红壤和黄壤诊断层的粗粒氧化铁矿物。结果表明,黄壤电磁性矿物以针铁矿为主,铝硅酸盐矿物结构中含有较多的Fe~(2+);而红壤和赤红壤则以赤铁矿和针铁矿为主。黄壤中残留的原生矿物种类远较红壤和赤红壤复杂多样。由此认为,土壤粗粒矿物的组成特性,尤其是粗粒氧化铁矿物,与粘粒矿物一样反映了相应的土壤发生环境和过程,可作为自然土壤发生分类的一项参考依据。

Iron Oxide Minerals in Soil Coarse Fraction and Its Improtance on Pedogenic Classification

The iron oxide minerals in soil coarse fraction of lateritic red,red and yellow soils from Fujian south-subtropical and middle-subtropical zones were studied with microscopy,M(?)ssbauer spectroscopy and the traditional geological measurement of heavy placer mineral.The results showed that goethite was the main iron oxide in the magnetic frac- tion of yellow soil,but hematite and goethite were in red and lateritic red soils.However, the magnetic coarse fraction of yellow soil contained mord comparative amount of silicate-Fe~(++).According to the results obtained,the compositions of soil coarse fraction, especially iron oxide minerals like clay mineral reflected their respective soil environments and genesis of soil,and may be used as a referential index for soil classification.