Dense georadar survey for a large-scale reconstruction of the archaeological site of Pyrgi (Santa Severa, Rome)

The Etruscan site of Pyrgi extended over 10 ha along the Tyrrhenian coastline. Fieldwork has so far brought to light the sanctuary and a ceremonial complex at the southern edge of the settlement, whereas additional evidence is provided by a section cut by sea erosion across the site. The archaeological layer is about 2 m thick and includes dry masonry buildings arranged into lots; the most superficial features are disturbed by deep agricultural activities and the top layer includes scattered building material (limestone and tuff blocks). At this site, the efficacy of geophysical prospections are generally affected by the nearby presence of the beach's magnetic sand and the railway line. The use of dense ground penetrating radar (GPR) data proved to be the most suitable method in the mapping of buried archeological structures and made it possible to map out the topographic layout of the area which is currently under excavation. The dense three-dimensional georadar (GPR) data highlight the presence of structures implanted at different topographic levels and provide preliminary information about the main building interventions and planimetric modifications inside the urban lots. The work was extremely useful for the future planning of the archaeological excavation as it makes it possible to reduce the costs and environmental impact of the archaeological activity. The georadar anomalies were confirmed by an archaeological test-trench conducted in the surveyed area.