Heavy mineral distribution in the surficial sediments from the eastern continental margin of India and their implications on palaeoenvironment

Abstract

Heavy mineral distribution from the surficial sediments of the Eastern Continental Margin of India, between Machilipatnam and Gopalpur shows that their concentration ranges from 0.4 to 13.9%. Heavy minerals such as opaques, (ilmenite, magnetite and titanite), garnet, sillimanite, hornblende, hypersthene, tourmaline, zircon, monazite, biotite, kyanite and staurolite are present in variable proportions. Hydraulic fractionation (size, shape, density) and selective chemical decompositiom of unstable minerals are attributed to for variations within the heavy minerals. Reworking of heavy minerals during the Holocene transgression resulted in concentration of heavy minerals with high density, more stability and equant morphology along the submerged shorelines. These heavy minerals are believed to have been derived from two different provenances.