The Use of ERT, Magnetic and EM High Resolution Methods in Archeological Sites - A Case Study in Apollonia, Albania

During the period 2011-2012, high resolution geoelectric surveys using Electrical Resistance Tomography (ERT), Magnetic and Electromagnetic surveys, has been carried on three archeological sites of Bylis, Apollonia and Tirana Castle, Albania. The geoelectric surveys of squares, was carried out with 2D ERT parallel profiles with distance between them 1.5m or 2m and the distance between electrodes 1m where a multicore cable with 30 takeouts was used. The squares have been surveyed using two geometric configurations, Wenner and Schlumberger arrays. The EM survey grid is 1x 0.5m, whereas the magnetic grid is 1x1m. A 3D interpretation of resistivity profiles has been carried out and the resistivity distribution maps of different depths have been taken. At the same time the 2D map of magnetic anomalies is taken after the appropriate diurnal corrections. The EM 3D maps, show the ground scanning of the conductivity of the underground. From this study we conclude that the ERT method delineates very well the thickness of cultural layer and the buried archaeological objects inside it where the anomalies taken correspond with magnetic anomalies, whereas the EM method delineates very well the conductive clays from the other surrounding formations.