Sea-level change and volcano-tectonic interplay. The Gulf of Pozzuoli (Campi Flegrei, Eastern Tyrrhenian Sea) during the last 39 ka

A geological study based on seismic profiles and sediment cores has been accomplished on the Gulf of Pozzuoli, the marine sector of the Campi Flegrei, an active volcanic area located west of the city of Naples (Italy). Detailed seismo-stratigraphic analysis led to the correlation between marine units and the on-land volcanic deposits. The absence of primary pyroclastic beds in cores highlights the role of the shallow marine environment in the reworking of the volcani-clastic sediments. The evolution of the area during the last 39 ka evidences the role of the eustatic change and volcano-tectonic phenomena in the development of the local sedimentary record. Four main phases in the geological evolution have been distinguished. In a first phase the emplacement of two volcanic units V1 (between 60 and 39 ka) and CI (39 ka) took place; a second phase developed between 39 and 15 ka and led to the formation of regressive depositional wedges (FW and LW sedimentary bodies) in the external sectors of the area (outer shelf); the eruption of the Neapolitan Yellow Tuff (15 ka), and the following eruptions that occurred up to 11 ka, constitute the third phase; during the fourth phase (11 ka to Present) generalized marine conditions were established in the area. Distribution and thickness of the sedimentary bodies formed during the latter time span are highly variable and constitute the result of a complex interplay between volcano-tectonic movements and sea-level change.