Hydrogeologic, hydrogeochemical and isotopic studies of mineral and thermal waters from Aguas de Lindoia and Lindoia, SP

The underground circulation of the so-called mineral waters of Aguas de Lindoia and Lindoia is conditioned by fractures of Complex Amparo crystalline rocks. The geologic studies and its evolutionary history are so important for understanding the origin, circulation and mineralization of these explored waters. The chemical analysis of the waters both from springs and wells pointed to low mineralization with about 100 mg/l TDS. The bi carbonated calcic and calcic-magnesian content was interpreted as coming from alteration processes of silicate minerals. The isotopes δ 18 O and δ 2 H concentrations indicate the meteoric origin, different recharge zones and evaporation phenomena in the springs and wells waters on the study area. The Radon-222 radioactivity used to classification of mineral waters in this legislation is dubious because it is unstable (3,82 days) and may be dangerous to human. (author)