Distribution of Alkali and Alkaline Earth Elements in Bauxites-Laterites of Paduvari Plateau (South Kanara District, Karnataka State)

Abstract

Analysis of 34 bauxite-laterite and 11 precursor granitic gneiss samples, from Paduvari plateau, fer alkali and alkaline earth elements has revealed: (1) the strong depletion of laterites/bauxites in Ca, Na, K, Sr, Li and Rb, with a reduction in Ca by 124 times, Na and K by 55 times, Sr by 38 times, Li and Rb by 7½-8 times, (2) low mobility of Mg and Be to result in a depletion of only 2½ times, (3) the lack of significant or systematic variation in the content of these elements in the laterite-bauxite profile and (4) the retention of Na: K and Li : Rb ratios of the precursor gneiss in the laterite/ bauxite. The study substantiates the general observation that alkali and alkaline earth elements with their low ionic potential (except Be) are thoroughly leached during lateritization.