Geomorphological and archaeological evidence of Roman times shoreline in the La Spezia Gulf

Abstract

Two sites in the western promontory of La Spezia Gulf are illustrated in which the identification of a shoreline slightly lower than present-day is possible. They are the archaeological site of Varignano Cove, a rural settlement of Roman Times where drainage channels in connection with a dock were identified, and a cave in Palmaria Island (Riparo del Pozzale), in which a beach deposit was found in a pit 60 cm below present-day sea level. For both sites chronological attribution is discussed but we particularly focus, for each type of marker, on the sea-level indication and on the error associated to it. Available data point to a position of the 2,100 B.P. shoreline not higher than 45 cm below present-day sea level. This is consistent with a moderate uplift rate, testifying the general tectonic stability of the area in the upper part of the Holocene. The most recent tectonic behaviour of the area is comparable with what is known to be the crustal displacement trend in the area in the past 125,000 years.