The Latera geothermal system (Italy): Chemical composition of the geothermal fluid and hypotheses on its origin

The chemistry of the fluid produced in the Latera geothermal field and the petrology of the hydrothermal minerals found in drill cores and cuttings suggest mixing of a hot NaCl fluid with fluids circulating in carbonate units. Evidence exists of a deep fluid of a possible magmatic origin. The very high temperature (above 400°C) measured in a deep drill hole indicates the presence of a geothermal fluid, possibly at a depth of less than 4 km. Generally high temperatures at depth a are responsible for decarbonation and dehydration of sedimentary rocks and there may even be at depth a fluid that still has magmatic characteristics. However, this fluid is certainly mixed with CaS0 4HCO 3 waters coming from the Mesozoic carbonate rocks below the volcanic cover.