Development and decline of the ancient harbor of Neapolis

Archaeological excavations, undertaken since 2004 for the construction of the new Naples subway, have unearthed the harbor basin of the Greco–Roman town of Parthenope–Neapolis, furnishing scientists with the opportunity to recover abundant archaeological remains and a thick succession of diverse infill sediments. The latter underwent sedimentological, paleontological, and volcanological analyses. Compositional data analysis, applied to all three data sets, highlighted three main paleoenvironmental changes in the harbor basin from the Augustan Age up to the 6th century A.D. The beginning of harbor activity is recorded during the 3rd century B.C. when sedimentation was interrupted by intensive dredging of the sea-bottom. The impact of the A.D. 79 Vesuvius eruption, recorded for the first time in the Neapolitan territory, led to a reduction in Posidonia meadows and to an ensuing phase of more restricted water circulation and pollution. At the beginning of the 5th century A.D., an open lagoon environment was established, attesting to coastal progradation. The final closure of this part of the bay occurred at the end of the 5th to the beginning of the 6th century A.D., due to increased alluvial input linked to both natural and anthropogenic causes.