An attempt to integration of different geophysical methods (magnetic, GPR and ERT); a case study from the late Roman settlement on the Island of Rab in Croatia

In 2016 within the RED Project Roman Economy in Dalmatia: production, distribution and demand in the light of pottery workshops, 5 selected areas around the Podšilo Bay were geophysically surveyed. During the fieldworks in the Lopar protected area, located in the northeastern part of the Island of Rab a gradiometer, ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) were used. The main aim of the project was to document presence of the Roman architecture in two areas of the bay’s hinterland as suggested earlier by finds of pottery and glass. Geophysical studies conducted in the Lopar area revealed presence of underground remains of ancient structures, probably from the late Roman period and connected with a ceramic production centre at the present seashore. The most interesting results were obtained for the area no. 4, the site where magnetic, georadar and ERT surveys revealed an ancient regular building at 0.4–0.6 m depth. The survey performed in the Lopar area clearly indicates that integration of different geophysical methods enables detailed and effective identification of buried archaeological structures.