Comparing ancient quarries in stable and slowly uplifting coastal area located in eastern Sicily, Italy

Proceedings of the International Conference “GEOSUB 2016″, Ustica, Italy 13 – 16 September, 2016 (Furlani S., Antonioli A., Scicchitano G. & Busetti M. Guest Editors)

Abstract

The coast of the Mediterranean still preserves several remnants of ancient coastal quarries that has been often used to provide insights on the sea-level changes occurred during the last millennia. The southeastern coast of Sicily (Italy) is characterized by the occurrence of more than fifty ancient quarries that have been detailed surveyed and studied from archaeological and geomorphological point of view. Most of these quarries are presently partial submerged and some of them for this reason have been used as marker of ancient sea level, providing important data on relative sea level change and tectonic mobility during the late Holocene. We selected six important and well known ancient quarries located in coastal sectors characterized by different tectonic rates of uplift, e.g. in a stable area (Marzamemi) and in a significant uplifted area (Augusta). The elevation of the deepest floors of the lowest level of the quarries has been measured by an invar rod with respect to present sea level, and corrected for tide at the time of surveys. These data were compared with predicted sea level rise curves for the Holocene using a glacio-hydro-isostatic model. The comparison with the curve for the southeastern Sicily coast yields a tectonic component of relative sea-level change related to regional uplift. Uplift rates ranging between ~ 0 and 0.4 mm/a have been estimated.