GEOPHYSICAL PROSPECTING OF ROMAN KILNS IN NORTH FRANCE

• St. P. Papamarinopoulos, P. G. Stefanopoulos, X. Bafitis, L. Polymenakos (Laboratory of Geophysics, Section of applied Geology and Geophysics, Department of Geology, University of Patras, 261 10 Patras, Greece)
• S. Van Der Leew (Department of Archaeology, University of Sorbone, France)

On a request from the University of Sorbone a team from the University of Patra conducted a full geophysical survey at Aubervil in N.W France facing a very difficult problem. How one could locate something usefull archaeological-ly at less than 1 m depth when the upper layer is full with explosive remains from the first world war? Since several other geophysical groups have failed to answer this question we were prepared to tackle the problem clearly in spite of the obvious risk. Firstly we identified fully all the explosives with a geo-magnetic survey and we confirmed our findings with an additional geoelectro-magnetic survey. Then we performed a geoelectric image study and pin poin-ted all the kilns below the layer of the explosives very clearly. In order to con-firme the geoelectric images we performed georadar studies as well. Then we faced the case of attempting to pass the 500 Hz electromagnetic signal into the soil but the clay content of the soil exhibited problems and initially stopped the signal. Insisting on the notorius georadar's problem and with the use of proper mathematical filters we managed to pass through the horizon full of clay and "saw" the archaeological remains. There fore we had a second picture of the kiln as well. Then the time of the excavators came who confirmed all the evidence produced for them without being killed by the explosives.