Sand and clay mineralogy of soils of Garhwal Himalaya, Uttarakhand

Abstract

Fine sand and clay mineralogy of selected horizons of forest soils representing various landforms of Maldeota, Satengal and Dhanaulti areas of Raipur and Jaunpur ranges of Mussoorie forest division of Garhwal Himalaya were investigated. Light minerals constituted more than 80 percent of total fine sand fractions and consisted of quartz, feldspar and mica in order of their abundance. Heavy minerals occurred in minute amounts and constitute 20 percent of the minerals and were dominated by opaque minerals followed by biotite, chlorite, chloritized mica, zircon, garnet, hornblende, tourmaline, rutile etc. Quartz is the dominant mineral in Maldeota and Satengal sites followed by Dhanaulti while feldspar and mica are abundant in Dhanaulti followed by Maldeota and Satengal. Among the heavy minerals opaque minerals, biotite and calcite are present in appreciable quantity in all the three sites viz. Maldeoata, Satengal and Dhanaulti. The other heavy minerals are present in small quantities at all the three sites. The clay fractions from the soils of Maldeota are characterized by illite as the dominant clay mineral associated with kaolinite, chlorite, vermiculite and quartz. The clays from Satengal contained mixture of illite as dominant mineral followed by mica, mixed layer minerals, vermiculite, chlorite and quartz. The soil clays from Dhanaulti indicates the presence of illite, muscovite, kaolinite, mixed layer minerals, chlorite and small traces of vermiculite, calcite and quartz. Differences in mineralogical make up were mostly associated with nature and composition of parent material and degree of weathering. The study, therefore, suggests that soils of the study area contained low to moderate amount of weatherable minerals indicating their podzolic nature.