Bayesian approach to the inversion of magnetic data for near-surface studies. Application to the archaeological site of San Pietro Infine (Southern Italy)

The geophysical prospecting is a key tool for addressing the archaeological research due to its capability to identify buried archaeological features, thus allowing to plan a proper excavation work. To this purpose, the inversion process of the geophysical data has a fundamental role in the accurate modelling of possible anomalies resulting from any geophysical survey. In this note, we propose a new algorithm for the 2D inversion of magnetic data, which is based on a Bayesian probabilistic approach. The effectiveness of the proposed algorithm is tested on synthetic and field magnetic data for retrieving the parameters of the anomaly causative sources. In particular, the field data come from a high-resolution magnetic survey performed in the archaeological area of San Pietro Infine (Caserta, Southern Italy) (Fig. 1a), which is considered by the archaeologists as relevant for the reconstruction of the ancient Roman settlement. In fact, this site is known since pre-classical times, as it represents the junction of a road axis controlled by the fortified walls of the neighboring areas. During the Roman colonization, in the 3rd century BC, the pre-existing road axis was crossed by the Via Latina, as shown by the paving stones found near Santa Maria del Piano. The church of Santa Maria probably is identifiable with the medieval building of San Pietro in Flea (name derived from the roman toponym “Ad Flexum”), mentioned by written sources as a property of Montecassino.