Heavy mineral contents and provenance of Late Quaternary sediments of southern Kerala, Southwest India

Abstract

Present paper deals with provenance and depositional history of the Late Quaternary sediments including heavy mineral placers in the coastal lands of Kollam district, SW India. Kollam coast is endowed with estuaries, old coastal plains with ridge-runnel systems and barrier beaches. Mineralogical analysis reveals that sediments in the estuarine basins that are seen entrenched over the Neogene sedimentary deposits were derived from dual sources. Heavy mineral residues of the upper estuarine zones are generally garnet bearing and are of alluvial origin. At the same time, sediments in the lower estuary are garnet-free and are derived from the nearby littoral zones during the tidal processes. Heavy mineralogical data together with statistical analysis discloses that the garnet and pyribole-free heavy mineral suite in the beaches and nearby coastal plains of the Kollam coast are primarily derived from denudation of the Neogene sedimentary deposits in the coastal lands. They are evolved during the rising phases of the sea level in the Late Quaternary period.