ABSTRACT

ABSTRACT: A study was carried out to understand the geochemical processes and its contribution to groundwater chemistry in a region comprising of hard rock and sedimentary formations, south India. Results of this study indicate that groundwater occurring near the Palar river has high concentrations of major ions except calcium due to the absence of river flow, where as lower concentrations of major ions were observed in the central part of the study area (Hard rock formations) due to the recharge of fresh water from a number of reservoirs. The groundwater chemistry in this area is controlled by both mineral dissolution and anthropogenic activities, especially agricultural activities. The relative contributions of mineral dissolution and anthropogenic contamination are estimated by reaction stoichiometric approach, and it was found that mineral dissolution is the dominant processes in both the formations. Thus, groundwater chemistry of this region is largely influenced by mineral dissolution and anthropogenic activities.