The Southern Ischia canyon system: examples of deep sea depositional systems on the continental slope off Campania (Italy)

The Southern Ischia canyon system has been investigated in detail through Multibeam bathymetry and Sparker seismic data and has been put in the geological framework of the deep sea depositional systems off the Campania region. The geological and geomorphological characteristics of the canyon system have been also compared with the characters of the Mediterranean submarine canyons and with the deep sea depositional systems of the Tyrrhenian sea. The Southern Ischia canyon system engraves a narrow continental shelf from Punta Imperatore to Punta San Pancrazio, being limited southwestwards from the relict volcanic edifice of the Ischia Bank. It consists of twenty-two drainage axes, whose planimetric trending has been reconstructed in a sketch morphological map realized through the geological interpretation of Multibeam bathymetry. While the eastern boundary of the canyon system is controlled by extensional tectonics, being limited by a NE-SW trending (anti-Apenninic) normal fault, its western boundary is controlled by volcanism, due to the growth of the Ischia volcanic bank. Submarine gravitational instabilities also acted in relationships to the canyon system, allowing for the individuation of large-scale creeping at the sea bottom and hummocky deposits already interpreted as debris avalanche deposits. Quaternary marine seismic sequences have been reconstructed through a densely spaced seismic grid recorded through a Sparker multitip seismic source, allowing for a detailed observation of steep erosional slopes occurring on the southern flank of the island and related deep sea depositional systems. Important implications of this study will regard the coastal monitoring and beach nourishment of the southern flank of the island, being involved by a strong erosion of marine and coastal systems.

New morpho-bathymetric and tectono-stratigraphic data on Naples and Salerno gulfs (southern tyrrhenian sea, Italy) derived from bathymetric and seismic data analysis and integrated geological interpretation

New morpho-bathymetric and tectono-stratigraphic data on Naples and Salerno Gulfs, derived from bathymetric and seismic data analysis and integrated geologic interpretation are here presented. The CUBE(Combined Uncertainty Bathymetric Estimator) method has been applied to complex morphologies, such as the Capri continental slope and the related geological structures occurring in the Salerno Gulf.The bathymetric data analysis has been carried out for marine geological maps of the whole Campania continental margin at scales ranging from 1:25.000 to 1:10.000, including focused examples in Naples and Salerno Gulfs, Naples harbour, Capri and Ischia Islands and Salerno Valley. Seismic data analysis has allowed for the correlation of main morpho-structural lineaments recognized at a regional scale through multichannel profiles with morphological features cropping out at the sea bottom, evident from bathymetry.Main fault systems in the area have been represented on a tectonic sketch map, including the master fault located northwards to the Salerno Valley half graben. Some normal faults parallel to the master fault have been interpreted from the slope map derived from bathymetric data. A complex system of antithetic faults bound two morpho-structural highs located 20km to the south of the Capri Island. Some hints of compressional reactivation of normal faults in an extensional setting involving the whole Campania continental margin have been shown from seismic interpretation.