In this study we integrate high-resolution swath bathymetry, single-channel reflection seismic data and gravity coredata, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submergedsector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for areconstruction of the offshore geometry of the NYT caldera collapse – ring fault system, along with the style and timingof deformation of the inner caldera resurgence.Our interpretation shows that the NYT eruption (~15 ka BP) was associated with a caldera collapse bounded by aninward-dipping ring fault system. The ring fault system consists in a 1-2 km wide fault zone that encircles an innercaldera region ~ 5 km in diameter and is often marked by the occurrence of pore fluids ascending through the faultzone, up to the seafloor, particularly in the western sector of the bay. A shallow magmatic intrusion along the ring faultzone was also detected offshore Bagnoli in the eastern part of the Pozzuoli Bay (Sacchi et al., 2014).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 caldera resurgentdome was ~ 9 - 12 mm/year during the period 15.0 – 6.6 ka BP. The style of deformation of the resurgent structure canbe described in terms of a broad doming, accompanied by subordinate brittle deformation, mostly concentrated in asmall apical graben at the summit of the resurgent dome (Cole et al., 2005).Chronostratigraphic calibration of seismic profiles obtained by three tephra layers cored in the Pozzuoli Bayindicates 5 to 25 m of post-Roman differential subsidence and tilting towards ESE of the inner caldera resurgence, asrecorded by the drowning of the infralittoral prograding wedge below the present-day storm wave base.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2014|