几种亚热带淋溶土基质和胶膜中1.4 nm过渡矿物组成的差异及其意义

以我国亚热带的黄褐土和黄棕壤的铁锰－粘粒混合胶膜为材料，分析了胶膜及其相应的淋溶土在粘土矿物类型和含量上的差别。研究结果表明：土壤和胶膜的粘土矿物均由1.4nm矿物、水云母、高岭石组成，土壤的1.4nm矿物为1.4nm过渡矿物和蛭石的混合相，而胶膜的1.4nm矿物全部由蛭石组成。由此认为，胶膜中的1.4nm过渡矿物主要来源于表层粘粒的淀积和裂隙周围基质土壤中粘土矿物的转化，胶膜的有机质含量、交换性盐基总量等性质明显不同于基质土壤，其微环境抑制了土壤中的蛭石向1.4nm过渡矿物的转化，并导致1.4nm过渡矿物向蛭石的转化。

THE DIFFERENCE AND SIGNIFICANCE OF 1.4 nm INTERGRADE MINERALS BETWEEN MATRIX AND CUTAN IN SEVERAL SUBTROPICAL ALFISOL

The types and amounts of the clay minerals in iron-manganese-argillans and matrix soils in subtropical zone soils of yellow cinnamon soil and yellow brown earth were studied. The results indicated that the clay minerals in cutans and matrix soils were both consisted of 1.4 nm minerals, hydromicas and kaolinites. In matrix soils,1.4 nm minerals were 1.4 nm intergrade minerals and vermiculites, but in cutans they only contained vermiculites. So we considered that the 1.4 nm intergrade minerals in cutans mainly came from the changes of clay minerals which illuviated from the topsoil and moved from the matrix soil around cracks. There were the differences of the contents of organic matter, exchanged bases and pH value between cutans and matrix soils, so the microregions restrained the transforms of vermiculites to 1.4 nm intergrade minerals and led to the changes of 1.4 nm intergrade minerals to vermiculites in the tested soils.