Results of an integrated geoarchaeological survey (GPR and borehole coring) of the buried remains of the medieval church of the San Savino Abbey in Jesi (central Italy)

Abstract

An integrated geoarchaeological investigation was carried out at the site of the former San Savino Abbey in Jesi (central Italy, Marche region), combining ground-penetrating radar (GPR) survey with eight full-core geoarchaeological boreholes. The primary objectives were to document the spatial layout of the buried church, reconstruct the stratigraphic sequence of the site, and establish its chronological framework. GPR time slices and three-dimensional amplitude models identified at least two main phases of architectural development: the uppermost phase corresponds to a three-nave Romanesque- Gothic basilica (ca. 40×19 m) with a rectangular apse, confirmed both by surface observations and geophysical data; a deeper phase is indicated by a rounded apse form and possible transverse walls within the nave, tentatively attributed to an earlier medieval building. Geoarchaeological coring revealed three main stratigraphic horizons: an upper destruction-sepulchral horizon associated with the Romanesque-Gothic church and later use as a burial ground (radiocarbon-dated to 1474–1638 AD); a middle, chronologically complex horizon containing redeposited Roman-period ceramics and charcoal dated to 153 BC–79 AD (94.6% probability); and a lower horizon of natural fluvial substrate. The geomorphological analysis indicates that the site was established on a slightly elevated colluvial-alluvial surface within the Esino River floodplain, a position offering relative protection from flooding. The results demonstrate the high potential of combining non-invasive geophysical methods with minimally invasive coring for the investigation of buried architectural heritage.