Tectono-sedimentary evolution of the submarine canyons off the southern Ischia island (Naples Bay) during the Late Quaternary

Strong erosion on an underlying substratum and high sediment supply control the creation of the canyons, which are morphological incisions with steep slopes on the seafloor. They are caused by a rapid decline in the base level of erosion, or the level of minimal potential, where all rivers converge and is typically symbolized by sea level. This geological process, which is governed by tectonic phases or isostatic motions of the earth's crust, occurs as a result of a drop in sea level or a relative rise in the topographic surface. It is also necessary to take into account the changes in the depositional regimes brought about by significant volcanic eruptions or variations in the solid supply from rivers. The most significant undersea canyons in the Tyrrhenian region are frequently located in proximity to tectonically active regions. The undersea canyons in Naples Bay have a different genesis. Additionally, the severe volcano-sedimentary aggradation that has affected this region during the Late Pleistocene-Holocene has controlled the birth of the Dohrn and Magnaghi canyons if a tectonic component cannot be ruled out (especially for the deepest sector of the Dohrn canyon). The depositional domains of the continental shelf and slope off Ischia Island have a variety of morphological features, each of which is indicative of a dominant sedimentary or tectonic process and/or a volcanic event. There are indications of submarine landslides caused by catastrophic occurrences (debris avalanches) in hummocky morphologies, relic and/or buried morphologies of volcanic structures, and abrasion and/or depositional terraces that are frequently inhabited by Posidonia oceanica grasses. The depositional shelf break that surrounds the island's northern sector has been severely eroded in accordance with the heads of multiple canyons, such as the Punta Cornacchia head and the Cuma canyon, which are part of a system of undersea canyons that are likely currently undergoing regressive erosion.