Mineralogy of Sand and Clay Fractions from Acidic Soils of Jammu Region

Mineralogy of sand and clay fractions in selected horizons of six acidic soil profiles from Jammu region was studied. All soil profiles had almost similar primary and clay minerals indicating that soils of the present study are still experiencing the dominating influence of parent material. Quartz, feldspar and muscovite-mica were the main minerals in the light sand fraction and opaque type of minerals vis-a-vis zircon, tourmaline, augite, hornblende and biotite in the heavy fractions of sand. Feldspar comprised mostly of orthoclase and plagioclase; the latter was highly weathered. Higher concentration of muscovite-mica in soils of Shahdara was attributed to more micaceous nature of parent rocks from which these soils had originated. The X-ray diffraction analysis of clays indicated the occurrence of mica or illite as the dominant mineral followed by chlorite, smectite and mixed layer minerals. In some of the soils, illite seemed to be markedly degraded due to more broadening of 10 A at the base denoting its formation towards mixed layer minerals. Kaolinite was present in soil clays of Bani.