In this study we integrate high-resolution swath bathymetry, single channel reflection seismic data and gravitycore data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution ofthe submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. Thenew data allow for a reconstruction of the offshore geometry of the NYT caldera collapse–ring fault system,along with the style and timing of deformation of the inner caldera resurgence.Our interpretation shows that the NYT eruption (~15 ka BP) was associated with a caldera collapse bounded byan inward-dipping ring fault system. The ring fault system consists in a 1–2 km wide fault zone that encircles aninner caldera region ~5 km in diameter and is often marked by the occurrence of pore fluids ascending throughthe fault zone, up to the seafloor, particularly in the western sector of the bay. A shallow magmatic intrusionalong the ring fault zone was also detected offshore Bagnoli in the eastern part of the Pozzuoli Bay.Following the NYT eruption, the inner caldera region underwent significant deformation and resurgence with amaximum cumulative uplift of the offshore structure in the order of 180 m. The net uplift rate of the calderaresurgent dome was ~9–12 mm/year during the period 15.0–6.6 ka BP. The style of deformation of the resurgentstructure can be described in terms of a broad doming, accompanied by subordinate brittle deformation, mostlyconcentrated in a small apical graben at the summit of the resurgent dome.Chronostratigraphic calibration of seismic profiles obtained by three tephra layers cored in the Pozzuoli Bay indicates5 to 25 m of post-Roman differential subsidence and tilting towards ESE of the inner caldera resurgence,as recorded by the drowning of the infralittoral prograding wedge below the present-day storm wave base.
|Numero di pagine||19|
|Stato di pubblicazione||Published - 2014|
All Science Journal Classification (ASJC) codes