几种土壤及其铁锰结核中粘粒矿物组合的研究

以我国几种常见土壤及相应土壤铁锰结核为试验材料，应用Ｘ－射线衍射，研究了土壤和铁锰结核中层状硅酸盐和氧化铁的类型组合。结果表明：１）从南到北，从供试红壤到砂姜黑土，其层状硅酸盐矿物组合变化表现为由１：１型高岭为主变为以２：１型水云母为主，１．４ｎｍ矿物中由１．４ｎｍ过渡矿物转变为蛭石；从不含蒙脱石到含有一定量的蒙脱石。供试铁锰结核与相应土壤中的层状硅酸盐矿物组合及含量消长趋势在总体上基本一致。２）

STUDY ON THE COMPOSITION OF CLAY MINERALS IN SEVERAL SOILS AND IRON-MANGANESE NODULES

The compositions of phyllosilicate and iron oxides for several main types of soils and their corresponding iron manganese nodules were studied by the means of XRD. The results showed that:1)From south to north, from red soil to shajiang black soil, the compositions of phyllosilicate have changed. The predominant mineral altered from kaolinite to hydromica; 1.4 nm transitional mineral turned into vermiculite; and smectite appeared with latitude increasing. In comparison to soils, the changes of the types and relative contents of phyllosilicate in iron manganese nodules were indentical.2) From red soil to shajiang black soil, the content of goethite were increased as the content of hematite were decreased in soils, and the composition of iron oxides was from goethite hematite mixture to goethite. The changes of types and relative contents of iron oxides in iron manganese nodules were similar to corresponding soils, however, the ratios of G/(G+H) in nodules were higher than those in soils. From the compositions of phyllosilicate and iron oxides in soils and iron manganese nodules, it was suggested that iron manganese nodules of soils were in the isolated relatively close system.