A well Grado-1 was drilled down to 1108 m reaching mesozoic shelf carbonates which occur in the structural highs in the Lignano – Grado area. The well was completed with geophysical logs in the open hole interval from -700 to -1108 m. The drilling bit met the nummulitic shelf paleogenic limestones at -616,5 m and Mesozoic (Upper Cretaceous) platform around -1007 m. About 400 m thick Palaeogene interval appears affected by open fractures which we consider linked up to a reverse fault and a tectonic duplex of the Palaeogene limestone interval is hypothesized. The feature corresponds to the outer deformation front of the Dinaric thrusts system and looks still active. Palaeogene limestone sequence is analogous to the outcrops in the northern Istria and in the stratigraphy in the oil wells offshore northern Dalmatia. The drilling target was the characterization of the nature of the geothermal resources in the Friuli lower plain and lagoons region, following the long-term investigations of the Department of Civil and Environmental Engineering of the Trieste University.\ud The geothermal resource was found in correspondence of the above mentioned open fracture zone and below it, with salty hot waters at a temperature of 42°C, increasing with depth, and a flow of 25 l/s arriving to the surface with 2,8 pressure bars

<p>Increasing demand for freshwater requires the identification of additional and less-conventional water resources. Amongst these, offshore freshened groundwater is considered a new opportunity to face increasing water demand and has been studied in different parts of the world. Here we focus on the north-eastern Adriatic Sea, where offshore aquifers could be present as a continuation of onshore aquifers. Geophysical data, especially offshore seismic data, as well as onshore and offshore well data were integrated and interpreted to characterize the hydrogeological setting via the interpretation of seismo-stratigraphic sequences. Two areas located in the proximity of the Tagliamento and Isonzo deltas were studied. Well and seismic data suggest that Quaternary sediments, extending from onshore to offshore areas, represent the most promising from an offshore freshwater resources point of view. Firstly, onshore well data confirm the presence of freshwater aquifer systems in proximity to the coastline, supporting the hypothesis of their continuation offshore. Secondly, during the glacial periods, a drop in sea level (about -120 m with respect to today during the Last Glacial Maximum ), provided the total emergence of the northern Adriatic Sea, that represented a fluvial plain, allowing the storage of freshwater. Moreover, a lower sea level position could lead to a higher groundwater gradients towards offshore areas. On the contrary, during the interglacial ones, the sea level was some meters higher than the present one (about +8 m during the last transgression in the Middle/Late Pleistocene), with mainly starved conditions. During the deglaciation phases, the fluvial drainage fed by melting glaciers produced the deposition of sediment above the plain. Below these sediments, the several kilometres thick pre-Quaternary carbonate and terrigenous sequences seem to host mainly salty waters.</p>

The increasing demand for freshwater requires the identification of additional and less-conventional water resources. Amongst these, offshore freshwater systems have been investigated in different parts of the world to provide new opportunities to face increasing water requests. Here we focus on the north-eastern Adriatic Sea, where offshore aquifers could be present as a continuation of onshore ones. Geophysical data, in particular offshore seismic data, and onshore and offshore well data, are interpreted and integrated to characterise the hydrogeological setting via the interpretation of seismo-stratigraphic sequences. We focus our attention on two areas located in the proximity of the Tagliamento and Isonzo deltas. Well and seismic data indicate that the Quaternary sediments, that extend from onshore to offshore areas, are the most promising from an offshore freshwater resources point of view, while the several kilometres thick pre-Quaternary carbonate and terrigenous sequences likely host mainly salty waters.