Decisive Controls in the Formation of the East Coast Bauxite Deposits of India

The formation of lateritic bauxite deposits is, by and large, governed by the cumulative effect of several controls. Salient amongst them are: (i) favourable source rock, (ii) effective porosity, (iii) high rainfall, (iv) good drainage, (v) tropical climate, (vi) low to moderate topographic relief, (vi i) prolonged stability, and (viii) presence of vegetation. Despite a general consensus on these causative factors to promote bauxitisation, the decisive controls, still remain to be discerned. A synthesis attempted from this angle in respect of the East Coast Bauxite (EeB) deposits of India has brought to focus the effective permeability of the source rock and a congenial geomorphic base, preferably unidirectional, of low to moderate slope angles (3° to 15°) as the decisive controls in their formation. These, in turn, are dependent on the structural history of the terrain.