Volcanological and structural evolution of the Ischia resurgent caldera (Italy) over the past 10 ka.

Abstract

Volcanic activity on the island of Ischia included both effusive and explosive eruptions, mainly occurred in the eastern sector of the island. Vent location, eruption dynamics, transport mechanisms and depositional processes, have been reconstructed for each recognized unit. In the past 10 ka, periods of quiescence alternated with periods of very intense volcanism, which was mainly concentrated at about 5.5 and over the past 2.9 ka. Volcanism was not continuous and strongly influenced by the mechanism of a resurgence phenomenon, which affects the island since about 33 ka. Therefore, it has been hypothesized that magma intrusion and uplift events occurred intermittently. In the past 5.5 ka, volcanic activity has been invariably accompanied by the emplacement of slope instability-related deposits testifying that also slope instability was induced by reactivation of vertical movements, likely related to resurgence.