| Abstract |
West Coast of India hosts a string of hot sprigs along a narrow stretch nearly 300 km long parallel to the coast. Thermal water composition of these hot springs indicate that chloride content varies from 78 to 4800 ppm, sulphate from 85 to 225 ppm, sodium from 76 to 410 ppm, silica upto122 ppm and low boron and fluoride. Hg varies from 20 to 110 ppb in soil. Cl- SO4 -HCO3 ternary diagram suggests that most of the thermal water is mixed type while the thermal water from Sativali, Geneshpuri and Unhavre (Khed) show more affinity to geothermal water. Mixing of hot water with ground water is common in these hot springs. The Na-K-Mg plot indicates that the thermal water from Unhavre (Khed) and Sativali is more mature as compared to the hot water from the other springs. The stable isotope analysis suggests that the geothermal water is mostly of meteoric origin. Geochemical characters of these hot springs are not similar to each other and suggest that these hot springs may be independent occurrences. Though, silica geothermometer indicated reservoir temperature of 120?C in Tural and Na/K geothermometer indicated temperature of 180?C in Unhavre (Khed), the maximum temperature recorded in the borehole logging is 75.5?C at the depth of 170m, which is much less than the indicated reservoir temperature, hence, the actual reservoir temperature needs to be ascertained by deep drilling. |