COAST OF ANCIENT KAULONIA (CALABRIA, ITALY): SUBMERGENCE, LATERAL SHIFTS AND SOURCE OF BUILDING MATERIAL

Archaeological material is concentrated at depths of 5-7 m off Kaulonia, a Greek colony from ~700 to 389 B.C. on the Ionian coast of southern Italy. To interpret coastal evolution here we made the following: a seismic survey; a petrologic analysis of dated sediment in cores and excavations along the coast; and a petrographic study of rock used for building the site's temple. Located in the tectonically active Calabrian Arc, the sector has been subject to considerable rise of land onshore (~1 mm/yr), and an equivalent rate of seafloor subsidence. A distinct Holocene beachrock sandstone and conglomerate sequence is traced 400 m from landward of the beach to the inner shelf. Correlation of this sequence helps define complex coastline migration patterns from before Greek settlement to the present. The shoreline shifted landward, to seaward, and then back to landward due to up-and-down motion in the sector between the alluvial plain behind the beach and innermost shelf. By mid-Holocene, the shoreline had advanced 300 m seaward resulting in emergence of a broad arcuate coastal headland seaward of the site. The shore's return landward then resubmerged the margin and artifacts after Kaulonia's abandonment, probably in Roman time. However, no lagoon, permanent lake, or man-made port for protected anchorage was found. Vessels sailing to Kaulonia were beached and/or anchored nearshore and perhaps within the Assi River mouth. Beachrock sandstone composition in sections on land is similar to sandstone observed offshore and to rock used for temple base construction. Extensive sandstone exposures along the former coast may be one reason Greeks selected this site for colonization.