Coastal quarries of millstones in Italy: new evidence and chronological hypotheses

Flour and oil millstones coastal quarries can be used as sea level markers being excavated along the rocky coasts of the Mediterranean since the last 2 ka BP. Our paper examines some unpublished millstones sites in southern Italy: Capo d’Orlando and Letojanni in Sicily; Soverato, Tropea and Capo dell’Armi in Calabria; Palinuro, Scario and Castellabate in Campania, San Vito-Polignano in Apulia. A review of the use of these artefacts shows the long lasting use of the cylindrical millstone with diameters larger than one meter as a useful tool for processing oil and cereals; their longevity makes it difficult to specify the chronological range of the majority of the studied sites; only one site provides an accurate chronological period of the quarry: at Molare Scario (Sa), due to the presence of stratigraphic deposits dated by radiocarbon. The submergence and age of this site well fit the predicted sea level at the time of their excavation. Using this site as a reference, we have tentatively estimated the age and the elevation with respect to the past mean sea level, for the millstone quarries located at S.Vito di Polignano, Palinuro and Castellabate. These sites are located in tectonically stable coasts of Italy with null or minor vertical land movements, besides the effects of the glacio-hydro-isostatic signal.