Integrated full 3D geoelectrical and GPR tomographies in the Ambulatory of the roman “Villa del Casale”(Piazza Armerina)

The “Villa del Casale” is a wonderful Roman Villa excavated in the archaeological site of Piazza Armerina (Sicily) in 1929. Its interest is mainly to be referred to the floor mosaics, among the largest and most beautiful ones of Roman times, of superlative quality. The floor of the Corridor is covered by a wonderful mosaic depicting the hunt and capture of wild animals, so that it is called the “Corridor of the Great Hunting Scene”. The Villa is now under restoration, and during the planning of the restoration a 3D electrical resistivity tomography was performed on the corridor by using an acquisition grid composed by 704 electrodes. Furthermore 25 GPR profiles with 400 MHz antenna were acquired. The 3D ERT survey was carried out by utilizing a new 3D array, named “Maximum Yield Grid” (MYG), that allows a great decrease of the acquisition time and of the invasivity of the ERT investigation in respect of classical arrays. The results show shallow anomalies, that correspond to the canalizations for water drainage and to the concrete basement built below the corridor during a previous restoration intervention, and a diminution of resistivity with depth, related to the aquifer below the Villa.