The "Salinelle" are mud volcanoes located on the south-western slope of mount Etna, on the outskirts of the city of Paterno. The origin of these mud volcanoes is connected to the occurrence of tectonic wedges that form the buried front of the Gela Nappe. The uprising of hydrocarbons, salt water and slurry occurs along shear zones within the Gela Nappe and normal faults that originated during the formation of Mount Etna. The occurrence of heavy oil traces, salt water, methane gas and fragments of limestone and varicoloured shales suggest, according to the model of Brown & Westbrook (1988) and Monaco & Tortorici (1996) that the deeper buried part of the Gela nappe is confined under high pore pressures. Thrust faults within the nappe and younger normal faults favour uprise of the high-pressure fluids which give rise, on the surface, to the "Salinelle" mud volcanoes. The intermittent activity seems to be connected to the release, through shear zones and normal faults, of the high pressure and not to the degassing of Mount Etna magmatic basin.