Quaternary still-stand landforms and relations with flank instability events of the Palinuro Bank (southeastern Tyrrhenian Sea)

A high-resolution morphological and geological inspection was carried out on the Palinuro Bank (39° 30′N, 14° 48′E), a volcanic complex made by several, coalescent volcanic features located on the Campanian continental slope (Eastern Tyrrhenian Sea, Italy). A shallow (−84 m asl) volcanic edifice, characterized by a flat top modelled surface, is present on its central sector. The use of a very high-resolution Digital Terrain Model allowed recognition of the presence of relict morphologies (perhaps notches/inner margins) related to the past sea-level still-stands. Three depth levels of paleo-shorelines markers are located at −90 m, −100 m, and −123 m, respectively. In addiction, the truncated shape of the cone itself, located between −84 m and −130 m, could be interpreted as a tilted marine terrace. Breaks in slope produced by terrace landforms caused oversteepening that could have triggered lateral collapses both on the northern and southern flanks of the Bank, as suggested by the presence of steep slopes (25–40°) and indicated by acoustic facies on chirp high-resolution mono-channel seismic profiles. The results allow further hypotheses on vertical displacement between the western sector of the Palinuro Bank, where caldera shapes are present, and the central sector, made by shallower volcanic cones. These two sectors also differ in terms of magnetic properties.