Abstract

                                Characterisation of clay minerats was attempted by fusion analysis with Ne,CO and determination of CEC of the clay separates. Sixteen clay samples were chosen, four representing each soll group. The date revealed two extremes: the black soils were highly siliceous and laterite soil clay highly sesquioxidic. The soils could be arranged in a sequence, black, alluvial, red and laterite in the increasing order of kaolinite and decreas ing order of montmorillonite. 1:1 clay minerals were dominant in alluvial soils with admixture of 2:1 clay minerals and kaolinite was found to be dominant in the red soil clays. The laterite soils were mainly kaolinitic. CEC and silica-sesquioxide ratio bore s alose relationship between themselves and either of those could be used as a reliable Indicator of clay minerals.

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