A Study on the Silt Fraction of the Soils of Outer Himalayas

Chemical composition and the proportion of primary minerals in the silt fractions were studied in the soils of Mussoorie Hills (U.P.), which have developed over different parent materials under varying climatic conditions and vegetation. The study reveals that the silt fraction of the soils developed over shales under oak contains a relatively lower proportion of heavy minerals and a higher proportion of light minerals as compared to those developed over limestone under conifers indicating thereby more podzolization and less illimerization in them. Alteration of kaolin into muscovite and accumulation of quartz muscovite and heavy minerals in the surface lowest and illuvial horizons respectively, of the former also indicate more podzolization and intense weathering in them as compared to latter which were rich in calcite, dolomite and other resistant minerals.