Trace Element Concentrations in the Thermal Waters Along the West Coast of Maharashtra, India

Abstract

Extensive work has been carried out in the past on the major ion and isotope chemistry of the thermal waters along the west coast of Maharashtra. However trace element and rare earth element (REE) study was never attempted. This is for the first time such a project has been taken up with the aim of understanding the evolution and circulation pattern of these thermal springs. The concentration of trace elements viz., B, Ba, Br, Cs, F, Li, Rb, Si, Sr and REE’s in the thermal springs, ground-waters and surface waters have been determined. The thermal waters had temperatures ranging from 42 to 71 °C, pH from 7.7 to 8.8 and total dissolved solids between 337and 2534 ppm. Most of the thermal waters were Na-Ca-Cl type except one which is of Na-Ca-HCO3 type. The thermal waters contained low concentration of some elements such as less than 0.1 ppb of Ag and Cd, 1-3 ppb of Cr, Zn, Co, Cu, Pb and Ni, whereas elements like Li (25-177 ppb), B (47 – 374 ppb), Sr (16-5548 ppb), Rb (13-221 ppb), Cs (3-28 ppb) and Ba (3- 2077 ppb) were much higher in concentration. The chondrite normalized pattern for REE’s exhibits a positive Eu anomaly. In the light of the present study, it appears that there could be different sources of rocks playing there part in the evolution of these thermal springs in contrast to the earlier belief that all the springs are issuing through a similar geological set-up of the Deccan Flood Basalts.