Clay Mineral Composition, Genesis and Classification of Some Soils Developed from Basalts in Madhya Pradesh

The quantitative clay mineralogical make-up of four typical black soil profiles developed from the basalts in Madhya Pradesh was determined by combination of a number of techniques, viz., X-ray diffraction, D. T. A. and T. G. A. supplemented by chemical analysis, surface area determination and electron microscopy. The results show that the soil clays were essentially dominant in smectites with the presence of some amount of kaolinite and small quantities of illite and quartz. Electron micrographs corroborated the mineralogical composition as estimated by the other methods and revealed that the kaolinite present in the soils is in a very poor crystalline state. Based on the morphological features and laboratory investigations, a short discussion on the classification and genesis is also presented.