Geoelectric and electromagnetic measurements within an organized archaeological framework: the Marzabotto example

Geophysical prospecting was Performed in the Etruscan settlement of Marzabotto, near Bologna (Italy), to find shallow anthropic structures within an almost homogeneous environment. This paper describes some results of the geoelectric and electromagnetic VLF methods used. Non-standard geoelectric devices, such as the tripotential, twin-probe and the Offset-Wermer methods, were applied. The set of results was compared to classical dipolar sections. The Offset-Wenner device was useful for detecting vertically striking structures. Conversely, the electromagnetic VLF techniques are not suitable for investigating structures with a negligible contrast of conductivity with the environment. Prospecting data generated a general pattern of anomalies and some were confirmed by excavation samples, showing walIs, floors, water wells and other remains of urban structures.