INTEGRATED INTERPRETATION OF GEOPHYSICAL DATA IN THE ARCHAEOLOGICAL SITE OF EUROPOS (NORTHERN GREECE)

• N. G. Diamanti, G.N. Tsokas, P.I. Tsourlos (Geophysical Laboratory, Dept. of Geology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece)
• A. Vafeidis (Applied Geophysics Laboratory, Dept. of Mineral Engineering Resources, Technical University of Crete, Chania, Crete, Greece)

A multi-method geophysical survey was carried out in a bit of land in an archaeological site, on purpose to study the combined effectiveness and the merits of an integrated approach. The operation took place in the site where the ruins of the ancient city of Europos (N. Greece) are buried.

At first, resistivity mapping was employed to detect the shallower remains of the subsurface structures. Also, resistivity tomographies were carried out along profiles crossing the studied area in perpendicular directions, to obtain further information on the vertical and lateral extent of the buried bodies. The data were inverted using smoothness constrained and robust schemes.

Ground penetratind radar (GPR) measurements were recorded at the same profiles where tomographies were carried out, using a 225 MHz and 450 MHz antenna. GPR profiles supplied meaningful results, particularly when presented as time slices.

The magnetic gradient map of the study area is presented. 2D inversion of magnetic profiles was performed using the Levenberg-Marquadt method. The results of the magnetic data processing are in agreement with the anomalous zones that are revealed by the resistivity prospection.

The results obtained by different methods assisted the interpretation of the 3D subsurface structures inferred by the resistivity tomographies.

A comparison of the results of the applied surveying methodologies is being made, checking for the relative merits and demerits of the different techniques. Their combination is discussed, in terms of providing enhanced views contradicting the use of a single method. Technical disadvantages of the multi_method approach are also pointed out.