Geoarchaelogical Study of the Roman Pietra Dell’Oglio Bridge at the Service of the Old Appian Way, Campania, Southern Italy

Abstract

The Pietra dell'Oglio bridge is the only Roman infrastructure that crosses the Ofanto River between Mirabella Eclano (Aeclanum in Campania) and Venosa (Venusia in Basilicata), just near the border between Campania and Basilicata. The bridge was built on a substrate consisting of the stable middle Miocene Cerreta-Bosco di Pietra Palomba Sandstone (ACP) and where the Ofanto River valley is narrower. The current state of the bridge shows that 18 architectural and structural elements are original, 12 were restored, 1 was modified, 4 were reconstructed, and 4 were added in the last century. The original architectural and structural elements (ASEs) are built by the technique of opus quadratum and opus incertum using the pebbles of the Ofanto River and ashlars of phytoclastic travertine and ACP Sandstone cemented by very hard mortar. The opus incertum technique and its use for many bridges in Italy and France suggest that the Pietra dell'Oglio bridge was built between the II and I century BC at the service of a very important public road. The present research is allowed to identify the Pietra dell'Oglio bridge with the Pons Aufidi related to the old Appian Way layout between Mirabella Eclano and Venosa and contributes to improving the knowledge of Roman bridge engineering, particularly in Campania.