A Hydrothermal System Along the Coastal Area of Friuli-Venezia Giulia Region (NE Italy)

Abstract

In the Friuli-Venezia Giulia region thennal waters are present in mainly Quaternary confined aquifers along the Adriatic coastal belt between the Tagliamento and lsonzo rivers. A large number of wells, drilled to depths varying between and 500 discharge water with temperatures up to 54 which is utilized in direct uses. Although characterized by low salinity, these waters belong to a regional circulation that mainly develops from Alps and Prealps areas. Geophysical data indicate the presence of an important structural ridge made up of a Mesozoic carbonate sequence along the coastal belt at depths of around 700 m. Temperature distribution maps at 300 and m depth show that the temperature maxima correspond to the structural highs. These observations suggest that the waters of the Quaternary aquifers could be heated by conductive heat transfer from the underlying carbonate formations. in which a convective circulation of thermal waters is hypothesized. The thermal waters within the Mesozoic carbonate complex, a potential reservoir, could be a future target for a wider utilization of the enthalpy geothermal resources of this region.