La caldera de la Valle del Bove: sa signification dans l’évolution de l’Etna (Sicile)

The Valle del Bove, situated on the east side of Mount Etna is considered as the result of an important collapse. The structural survey of the continuous rock outcrops in the walls of the depression permits to distinguish several unities belonging to different volcanoes, which have been destroyed by the collapse. The succession of the different volcanic centers shows a migration of the eruptive activity from East to West. The collapse took place only when the main activity was removed to the emplacement of the principal crater now in activity. This E-W direction of migration corresponds to one of the main fault directions of Etna; the collapse and the formation of the caldera is considered as the consequence of a violent pumice explosion or as the result of the westward migration of the magma along this fault.