3D ERT Survey to Reconstruct Archaeological Features in the Subsoil of the “Spirito Santo” Church Ruins at the Site of Occhiolà (Sicily, Italy).

Three-dimensional Electric Resistivity Tomography (ERT) was undertaken at the archaeological site of Occhiolà (Sicily, Italy) a medieval village, located on the north western part of a hill named “Terravecchia” at 491 m above sea level. The survey was carried out inside the ruins of “Spirito Santo” Church. This paper presents the geophysical results of the 2004 campaign that aimed at exploring the buried extension of the possible crypt and/or tombs inside the church. ERT survey was performed by means of Molisana Apparecchiature Elettroniche (MAE) system with 31 active electrodes. The dipole-dipole array was selected for measurements. Resistivity variations are known to correlate well with the lithological nature of the earth materials, thus providing important information in order to locate buried archaeological remains. The electrical data were visualised in a three-dimensional space by using the iso – resistivity surface. This allowed the three-dimensional position of the anomalies evidenced in the single electrical section in a more effective manner. The results obtained in the survey highlight the presence of regular shape structures probably due to features of archaeological interest.