Multimethodological approach to investigate urban and suburban archaeological sites

Geophysical prospecting methods are considered valuable techniques for non-destructive detection of shallow buried features of archaeological interest. Usually detection is possible because the physical property of the target features contrasts with the surrounding medium. All methods measure the variations of single physical parameters, therefore if these are used singularly, they could not permit a complete location and characterization of anomalous bodies. The probability of a successful result rapidly increases if a multimethodological approach is adopted, according to the logic of objective complementarity of information and of global convergence toward a high quality multiparametric imaging of the buried structures. The prospection techniques most frequently used in archaeological sites are the Ground-Penetrating Radar (GPR), fluxgate differential magnetic (FDM) and Electrical Resistivity Tomography (ERT). Following the above outlined approach, we have integrated geophysical methods which measure the variations of potential field (magnetic gradiometric method) with active methods which measure the variations of physical properties due to the body's geometry and volume (GPR and ERT). In the present chapter some of these integration methodologies will be described and it will be shown how these have been applied to four case studies in urban and suburban areas, three in Italy and one in Turkey. In particular, the integration techniques have been tested using all three or two of the mentioned methods, depending on the conditions of the investigated sites. The first site of interest is located in an area in the Aurunci Natural Regional Park (Italy) along the ancient Appian Way; the second site is located in an urban context in the city of Rome (Italy) near the Santa Balbina's church complex. In these two sites, it has been possible to acquire data employing only two of the three available geophysical methods (GPR and ERT). The third investigated site, where it has been possible to use all three methods (GPR, ERT, FDM) is located in a suburban area in Cerveteri about 40 Km far from the city of Rome (Italy). The fourth investigated site, where have been employed the magnetic gradiometer and GPR methods, is in the archaeological site of Heraion Teichos (Turkey).