An updated reporting of rhodolith deposits in the offshore of Ischia (Gulf of Naples,Italy)

In this work, the occurrence of rhodolith deposits on the sea bottom of the Ischia offshore is highlighted on the base of sedimentological data coming from samples collected during the marine geological mapping of the Ischia Island. These sea bottom samples are rich in bioclasts mainly gravelly sands in size. These deposits prevail in the eastern Ischia offshore, on the relict volcanic edifice of the Ischia Bank and on the genetically related parasitic vent and in the Ischia Channel. Subordinately, these deposits occur also in the northern Ischia offshore, where they unconformably overlie debris avalanches and on the top of the Forio Bank. Seismo-stratigraphic data on the Ischia Bank show that rhodolith deposits correspond to a wide wedge-shaped unit occurring on the top of the volcanic edifice, unconformably overlying the volcanic rocky substratum. In the Ischia Channel they are probably inter-layered in the highstand deposits.