Nature, characterization and resource potential of littoral placer deposits of Goa, central west coast of India

Abstract

This paper presents an overview of the littoral heavy mineral placers from selected beaches of Goa, central west coast of India. The placer minerals are detailed in terms of their spatial and temporal distributions, mineral assemblage, microscopic characters, mineral chemistry, elemental ratios, hydraulic fractionation and depositional environments. The mineral assemblage is represented by opaque (ilmenite, magnetite) and transparent minerals (garnet, hornblende, tourmaline, epidote, zircon, augite, hypersthene, titanite, olivine, kyanite, sillimanite staurolite and rutile. The presence of fresh and altered minerals along with ultra-stable minerals are suggestive of their mixed contribution from rivers and paleo-sediments in near shore/shelf through combined actions of waves and littoral currents during various stages of sea-level fluctuations during Holocene. Erosional and depositional signatures of sea-level fluctuations during Holocene are well preserved along the shore. Heavy mineral assemblage with variable ratios and factor analysis suggests their derivation from metamorphic rocks (primarily metagreywackes) and igneous (basaltic dykes) rocks present in the study area. The potential inferred reserves of strategic minerals are ilmenite 81,480 t and magnetite 1,23,491 t.