GNGTS 2022 - Atti del 40° Convegno Nazionale

520 GNGTS 2022 Sessione 3.3 map of the vertical magnetic gradient after the data processing. The most remarkable features emerging from the map are a long-wavelength dipolar anomaly in the central part of the investigated area (A in Fig. 2), which is elongated in the NE-SW direction and is compatible with the presence of the ancient buried Roman Ad Flexum road (Zambardi, 2009), and a shorter wavelength dipolar anomaly with a well-defined geometric shape probably related to the presence of a wall structure (B in Fig. 2). The relatively high number of dipolar magnetic anomalies in the northern side of a much smaller wavelength than those observed in the southern side seems to divide the investigated area into two sub-sectors: one to the north, bordering the modern road giving access to the test site, probably related to buildings (e.g., stationes ) of an ancient urban settlement (Zambardi, 2009), and one to the south, likely used for agricultural and productive purposes given its morphological structure and proximity to the water-course. In order to support our interpretative hypotheses, the developed inversion code has been applied to magnetic data extracted along profiles crossing the most important anomalies observed on the magnetic map of Fig. 2. As an example, Fig. 3a shows the results obtained along the aa’ profile in Fig. 2, where the blue line indicates the field data, and the red line refers to the theoretical magnetic gradient obtained from the inversion and associated with the MAP model in Fig. 3b. The latter shows the presence of a structure large approximately Fig. 3 - a) Comparison between the observed MAG data (blue line) and the calculated gradient (red line) associated with the final MAP model. b) Vertical section of the magnetic susceptibility contrast associated with the final MAP model.