Marine geology and morphobathymetry in the Bay of Naples (South eastern Tyrrhenian sea, Italy)

Recent multibeam bathymetry (Elac, Bottomchart MK2) and high resolution seismics (Subbottom Chirp and 1-4 kJ Sparker source), acquired in the frame of an on-going programme of sea-floor mapping of Naples and Salerno Bays (south-eastern Tyrrhenian margin, Italy) and financed by the National Geological Survey of Italy, allows to put new insights into the recent evolution of the bay. The morphology and stratigraphy of the continental shelf and slope appear strongly controlled by the interplay of volcanism and canyoning that acted along the Magnaghi and Dohrn axes. Detailed bathymetry reveals the complexity of the drainage pattern which consists of a previously unknown, dense network of minor tributary channels. At places,the Dohrn and Magnaghi canyon walls are intensively affected by slope instability, as evidenced by numerous submarine slides and scars involving large volumes of sediments. Previously unreported mound-shaped morphological highs ("Bacarozzi" Facies), Holocene reworked sediments and sea-bottom creep appear on acoustic Chirp profiles in the inner sectors of the bay and seem to be related to volcano-sedimentary processes. On the contrary, sedimentation over the shelf at the southern edge of the bay (Sorrento-Capri) seems less influenced by volcanic activity and seabed features include Late Pleistocene regressive sand bodies and Holocene patch reefs, coastal dunes and depositional terraces.