The Use of ERT method, for the Detection of Buried Objects in Archaelogical Sites of Apollonia and Bylis, Albania

During the period 2010-2011 geoelectric surveys using Electrical Resistance Tomography (ERT) method, has been carried on two archeological sites of Albania, Bylis and Apollonia. In archaeological site of Bylis, are surveyed two squares with dimensions 30x25. In the “Roman Baths” area, in Apollonia, are surveyed 5 squares around it. The geoelectric surveys of squares, was carried out with 2D parallel profiles with distance between them 1.5m and electrode spacing 1m. The geoelectric system used consists on a multielectrode system which contained the central unit, WDJ-3, the automatic link box WDJZ-3, and two multicore cables with 30 takeouts each. Both,Wenner and Dipole-Dipole arrays have been used. The collected data have been interpreted with the inversion resistivity method. Solving the system of nonlinear equations with Least-Square inversion method, from the measured apparent resistivity values, the true resistivities of the subsurface has been taken. From this study we conclude that the ERT method delineate very well the thickness of cultural layer and the buried archaeological objects inside it. The basement in Bylis area is presented with high resistivity values, characteristic for limestone. Whereas, in the “roman bath” area in Apollonia, the basement is with low resistivity values, characteristic for the clay layer.