Contribution from coastal laterites to the nearshore placers of central west coast of India

Abstract

The heavy mineral placers with variable concentrations of ilmenite and magnetite occur in the surface and in the sub-surface sediments of many bays along central west coast of India. These sediments are associated with pebbles of laterite and basalts. The pebbles show genetic relation with the coastal laterites and Deccan trap basalts indicating their derivation from them before the last Holocene transgression. The petrography, mineralogical and geochemical analyses suggest that the minerals in the bay sediments may have been contributEd. by these laterites and basalts. The process of lateritisation is a probable reason for variation in the concentration of ilmenite and magnetite in the nearshore sediments along central west coast of India.