THE DEEP-STRUCTURE OF THE EOLIAN ARC NFILICUDI-PANAREA-VULCANO SECTOR) IN LIGHT OF GRAVITY, MAGNETIC AND VOLCANOLOGICAL DATA

The magnetic and gravimetric methods of investigation have been applied to the central sector of the Eolian arc, combined with geovolcanological data, for the purpose of defining the structural framework in which the volcanism developed. The processing of the magnetic and gravimetric data involved 3D modeling of the volcanic bodies and the application of a ''depth separation filter'', in order to subtract from the measured field the effect caused by the subaerial and submarine volcanic edifices and by all surface inhomogeneities. Magnetic and gravimetric 2.5D modeling on selected profiles has also been done, in a joint interpretation of the magnetic and gravimetric data, constrained by volcanological knowledge. The interpretation of the final maps and profiles has demonstrated the existence of extensional tectonics, resulting in the development of horst and graben. Volcanism occurs in the graben areas. In particular, the Salina-Lipari-Vulcano magmatic axis has developed in a very deep articulated graben of lithospheric importance and completely filled by volcanic deposits and intrusive bodies. The origin of this structure and of the associated igneous activity is suggested to be related to trans-tensional tectonics along a Plio-Pleistocene regional strike-slip fault system.