Preliminary geochemical characterization of the thermal waters of Caronte SPA springs (Calabria, South Italy)

Abstract

Literature data with new geological, hydrogeological and geochemical investigations have been used to model the thermal spring waters of Caronte. Waters come from a deep hydrogeological circuit, which is chiefly hosted in the carbonate rocks and evaporites belonging to the Upper Triassic Verbicaro Unit (Iannace et. al., 2007). In particular, the warm deep reservoir has a temperature of ± 45 °C, as indicated by the chalcedony solubility and the SO4–F geothermometers. The warm reservoir is probably located at depths close to 0.9 km, assuming a geothermal gradient of 33 °C km-1. Water leaves the deep reservoir discharges at the surface at 37.3 ± 1.2 °C, with a SO4-Ca composition, after a relatively fast upflow and limited cooling.The upward part of hydrogeological circuit is controlled by local high-angle fault systems as well as by the tectonic window of Sambiase, where the Verbicaro Unit crops out.