Investigations on Rare Earth Elements in Sediments from South Vellar Estuary along Bay of Bengal and Palk Strait, Tamil Nadu, India

Abstract

The rare earth elements (REEs) in the sediments of the South Vellar estuary on the eastern coast of India were measured using thermal ionization mass spectrometry (TIMS). Lanthanides (La-Lu) and a number of other elements (Cr, Ni, Zn, Pb, Ag, Co, Cd, and V) were studied in bed sediment samples. The estuary’s total REE content (REE) ranges from 73.30 to 360.50 g/g. Continental weathering has a substantial impact on the distribution of REEs. Using factor analysis on the elemental data, two important groups of elements were identified: (a) LREEs, HREEs, Pb, Ag, and Cd, revealing an association with river detritals; and (b) Co, Ni, Zn, Cr, and V, indicating complex estuary processes. Because of the silicate weathering of crustal materials and the resultant increase in LREEs in detritals, LREEs are more enriched than HREEs. We get to the conclusion that 30% of HREE flux and 70% of LREE flux to the Bay of Bengal are provided by the estuarine system.