High-resolution seismic stratigraphy of the Gulf of Pozzuoli (Naples Bay) and relationships with submarine volcanic setting of the Phlegrean Fields volcanic complex

From Siliciclastic to Bioclastic Deposits in the Gulf of Naples: New Highlights from Offshore Ischia and Procida–Pozzuoli Based on Sedimentological and Seismo-Stratigraphic Data

This study discusses the siliciclastic to bioclastic deposits (in particular, the rhodolith deposits) in the Gulf of Naples based on sedimentological and seismo-stratigraphic data. The selected areas are offshore Ischia Island (offshore Casamicciola, Ischia Channel), where a dense network of sea-bottom samples has been collected, coupled with Sparker Multi-tip seismic lines, and offshore Procida–Pozzuoli (Procida Channel), where sea-bottom samples are available, in addition to Sparker seismic profiles. The basic methods applied in this research include sedimentological analysis, processing sedimentological data, and assessing seismo-stratigraphic criteria and techniques. In the Gulf of Naples, and particularly offshore Ischia, bioclastic sedimentation has been controlled by seafloor topography coupled with the oceanographic setting. Wide seismo-stratigraphic units include the bioclastic deposits in their uppermost part. Offshore Procida–Pozzuoli, siliciclastic deposits appear to prevail, coupled with pyroclastic units, and no significant bioclastic or rhodolith deposits have been outlined based on sedimentological and seismo-stratigraphic data. The occurrence of mixed siliciclastic–carbonate depositional systems is highlighted in this section of the Gulf of Naples based on the obtained results, which can be compared with similar systems recognized in the central Tyrrhenian Sea (Pontine Islands).

Integrated Morpho-Bathymetric, Seismic-Stratigraphic, and Sedimentological Data on the Dohrn Canyon (Naples Bay, Southern Tyrrhenian Sea): Relationships with Volcanism and Tectonics

Submarine canyons are geomorphologic lineaments engraving the slope/outer shelf of continental margins. These features are often associated with significant geologic hazard when they develop close to densely populated coastal zones. The seafloor of Naples Bay is deeply cut by two incisions characterized by a dense network of gullies, namely the Dohrn and Magnaghi canyons, which develop from the shelf break of the Campania margin, down to the peripheral rise of the Eastern Tyrrhenian bathyal plain. Seismic-stratigraphic interpretation of multichannel seismic reflection profiles has shown that quaternary tectonics and recent to active volcanism have exerted a significant control on the morphological evolution and source-to sink depositional processes of the Dohrn and Magnaghi submarine canyons. The Dohrn canyon is characterized by relatively steep walls hundreds of meters high, which incise a Middle-Late Pleistocene prograding wedge, formed by clastic and volcaniclastic deposits associated with the paleo-Sarno river system during the Mid-Late Pleistocene. The formation of the Dohrn canyon predates the onset of the volcanic eruption of the Neapolitan Yellow Tuff (NYT), an ignimbrite deposit of ca. 15 ka that represents the bedrock on which the town of Napoli is built. Integrated stratigraphic analysis of high-resolution seismic profiles and marine gravity core data (C74_12) collected along the flanks of the eastern bifurcation of the head of Dohrn Canyon suggests that depositional processes along the canyon flanks are dominated by gravity flows (e.g., fine-grained turbidites, debris flows) and sediment mass transport associated with slope instability and failure.