Resurgent-dome faults in the offshore of the Campi Flegrei caldera (Pozzuoli Bay, Campania): preliminary results from high-resolution seismic reflection profiles

This paper presents a detailed reconstruction of faults associated with volcano-tectonic activity within the Neapolitan Yellow Tuff caldera (Campi Flegrei, Campania), based on the analysis of very high-resolution seismic reflection profiles in the Pozzuoli Bay. The eruption of the Neapolitan Yellow Tuff and the ensuing collapse of the caldera occurred ~15 kyr and was followed by intra-caldera eruptive activity and resurgence of a central dome. The seismic lines have been calibrated with gravity cores in the upper part of the stratigraphic succession, whereas the position of the Neapolitan Yellow Tuff at higher depths has been inferred by correlation with published seismic reflection data. This reconstruction allowed a tentative chronostratigraphic correlation of intra-caldera seismic reflectors, which involves alternating marine sediments and volcaniclastic deposits from the main intra-caldera eruptions, with the last 15 kyr stratigraphy established on land. We focus here on the apical faults of the resurgent dome, whose throw varies from the sub-metre to several metres scale. The motion on these faults occurred in the last ~5 kyr and was coeval to an intense volcanic activity reported on land. Based on the fault orientation and the age of offset reflectors, at least two sets of high-angle faults that moved at different times are distinguished.