Mud volcano fields in the Mt. Etna area (eastern Sicily)

Abstract

In this paper we describe briefly the activity and evolution of four mud volcano fields located in eastern Sicily, around the Mt. Etna edifice. Three of them, called “Salinelle dei Cappuccini”, “Salinelle del Fiume” and “Salinelle del Vallone Salato” based on their location, occur on the southewestern flank of Etna, between the Paternò and Belpasso villages, and are presently active. The fourth one, today extinct, was active on the farest northeastern sector of Etna, along the Ionian Sea coastline. It was called “Salsa di Fondachello” after the name of the closest village. Geologic surveys and well drillings suggest that fluids uprise through pre-existing volcanic necks in the “Salinelle dei Cappuccini” and “Salinelle del Fiume”, while for the “Salinelle del Vallone Salato” an alternative pathway through a fault plane is also proposed. The morphologic evolution of the Etnean mud volcano fields depends mainly on the density of the emitted muds and secondarily on the preexisting ground topography. Chemical analyses revealed that the water coming out from the mud volcanoes originates from a deep aquifer confined in the carbonatic rocks of the Etna basement and that the most abundant escaping gas is CO2 of magmatic origin. The “Salsa di Fondachello” first activity is associated with the occurrence of the destructive Val di Noto earthquake, on January 11th, 1693. It was again active from 1795 to 1832. Its last activity, started in March 1847, came to an end with the collapse of the mud volcano. Today a weak methane emission is the only evidence of endogenous activity in this area.