Significance of heavy mineral suite in riverine and estuarine sediments in the southwest coast of India - A case study

Abstract

Heavy mineral studies were carried out in various size grades of sand fractions of Muvattupuzha river and Central Vembanad estuary. Heavy mineral contents are higher in the upstream reaches of the river compared to the downstream reaches. In the estuary, the total heavy mineral contents are comparatively less. The heavy mineral assemblage consists of opaques, amphiboles, pyroxenes, garnet, zircon and biotite as the major minerals and monazite, rutile and sillimanite as the minor minerals. A comparative evaluation of the morphological and optical characteristics of heavy minerals between the two environments reveals that a substantial quantity of the river sands are derived from the Precambrian crystallines, whereas a greater part of the estuarine sands are polycyclic and derived presumably from the beach ridges that bound the Vembanad estuary at many places.