A multidisciplinary study of “Benetutti” thermal waters (Tirso Valley, Sardinia)

We report a multidisciplinary study of "Benetutti" thermal waters based on hydrochemistry, isotopic techniques, structural geology and geophysical surveys. Seven thermal waters and two cold spring waters have been studied. Thermal waters show temperature values ranging between 28 degrees C and 42 degrees C, a medium mineralization and a sodium-chloride chemical hydrofacies. Isotopes of the water molecule allowed verifying that these waters have not been affected by isotopic exchange phenomena with the Sardinian granite complex aquifer. VLF-EM (Very Low Frequency-Electromagnetics) surveys were undertaken for a rapid assessment of the distribution of thermal waters over vast areas. A northeast-southwest trend of high conductivity anomalies was revealed. This trend can be correlated to the occurrence of sub-parallel discontinuities along which thermal waters uprise.