New data on historical relative sea level movements in Pozzuoli, phlaegrean Fields, Southern Italy

During the past 2000 years, vertical movements (bradysism) of several meters amplitude have occurred in the active volcanic caldera of the phlaegrean Fields and notably in the bay of Pozzuoli, near Naples (Southern Italy). Biological sea level indicators (boring Lithophaga shells) were documented up to 7 meters above present sea level on the three marble columns of the Roman marketplace. Fossil specimens of the coral Astroides calycularis were also found 7 meters above present sea level, in a former marine cave,1 km east of the Roman marketplace (Rione Terra cliff). Radiocarbon dating of this biological material and the sedimentary filling of an excavated roman structure in Rione Terra suggest that two different crises of submersion of more or less the same amplitude have occurred since Roman times : an Early Middle Age submersion ending between the 5(th) and the 7(th) century AD and a Late Middle Age submersion during the 13(th)-14(th) century AD, preceding the volcanic eruption of Monte Nuovo in 1538. (C) 1999 Elsevier Science Ltd. All rights reserved.