Pleistocene Foraminiferida and Ostracoda from the Island of Procida (Bay of Naples, Italy).

Upper Pleistocene fossiliferous sands located in the north-western area of the Island of Procida at 2.5m above sea level yield assemblages of benthic foraminifers and ostracods. The deposit occurs between the trachytic lava breccias of the Breccia Museo Formation, as a member of the Campanian Ignimbrite (~39.000 ka b.p.), and the pyroclastic deposits of Solchiaro (~ 22.000 ka b.p.). Detailed study of the assemblages has contributed in the reconstruction of the main morpho-evolutionary and palaeoenvironmental phases of this area in the Late Quaternary. The most abundant taxa are the foraminifers Ammonia beccarii and Elphidium crispum, and the ostracods Pontocythere turbida, Cytheridea neapolitana and Semicytherura incongruens. In spite of the ecological preferences of these species, commonly recorded in infralittoral waters, analysis of the entire assemblage indicates an infralittoral/circalittoral palaeoenvironment of 60-30 m below sea level (probably at about 40 m b.s.l.), a silty-sandy substrate and coastal detritic bottom biocoenoses. Preservation of calcareous microfossils is generally poor, probably due to dissolution caused by slightly acidic waters. A low pH palaeoenvironment may also explain the absence of miliolids as well as thin-shelled ostracods. These features are typical of waters affected by volcanic activity, such as carbon dioxide submarine vents.