The tectonics and geodynamics of Mt. Etna: Synthesis and interpretation of geological and geophysical data

Abstract

The eastern flank of Mt. Etna is traversed by faults of the Aeolian-Maltese system, which has the role of a transform fault in the Calabrian-Sicilian arc and divides it into two parts: toward the east, its Ionian part has the characteristics of an active margin, while in its western part, subduction is blocked and the area shows a collisional regime. The synthesis of the tectonic data on the volcano, its substratum, its periphery, and on this sector of the Apenninic-Maghrebian chain, reveals a complex situation: this is largely due to the proximity of the volcano to the Aeolian-Maltese fault system and also to the evolution of the stress field, in relation to the growth of the Etnean edifice. Today the geophysical data indicate a compressive stress field at depth (10 km), with σ1 being oriented N-S. At depths of <10 km, below and within the volcano, stress distribution is modified by various factors such as magmatism, burden of the volcanic edifice, and gravity. On a more general scale, at the surface, compression in the chain is continuing. The transforming Aeolian-Maltese fault system delimits two sectors in the volcano: toward the west, the neotectonic and geophysical data indicate that Mt. Etna functions in a compressive context, modified at the surface by the presence of the volcano and its activity, while toward the east the data testify to an extensional stress regime, which controls north-eastern Sicily and a significant portion of Calabria.