M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)

Prospecting - CSATHÓ Beáta, PATTANTYUS-Á. Miklós: Possibilities and experiences of geophysical prospecting at archaeological sites in Hungary

CSATHÓ Beáta*, PATTANTYUS-Á. Miklós* POSSIBILITIES AND EXPERIENCES OF GEOPHYSICAL PROSPECTING AT ARCHAEOLOGICAL SITES IN HUNGARY Abstract - The present study outlines the applicability of various geophysical methods to archaeological purposes, also pointing out their limitations. The experience gained with magnetic and geoelectric methods in Hungary is discussed in detail and the computer processing of measured data and the economic aspects are outlined. It is to be hoped that in Hungary, too, geophysical surveys will soon become an essential part of archaeological site investigations. Theoretical basis of geophysical prospecting Geological-geophysical prospecting is based on the fact that the geophysical parameters of different geological formations generally differ from one another. The most important physical parameters related to petrology and allowing geophysical prospecting are density, magnetization, elasticity (velocity of wave propagation), resistivity, thermal conductivity and radioactivity, which can be measured by gravity, geomagnetic, seismic, geoelectric, géothermie and radioactive methods, respectively. Depending on the given problem it has to be decided in each case which geophysical parameter should be measured, i. e. which geophysical method should be applied. Frequently the measurement of several petrophysical parameters provides the necessary information, in such a case a reasonable combination of geophysical methods should be used. Applicability of shallow geophysical methods to arhaeology The physical parameters of most objects that are targets of archaeological prospecting differn from those of the surrounding earth therefore the methods developed in geophysics are, or may be made, suitable for detecting them. The branch of geophysics dealing with the prospecting of shallow depths is engineering geophysics. Since - in most cases - archaeological geophysics involves shallow prospecting, it differs from engineering geophysics only in the fact that the targets themselves (the objects that are sought) are generally small and are usually densely located. Conditions for geophysical prospecting of archaeological objects In the previous section the conditions and limitations of archaeological site investigations were outlined. In principle, geophysical prospecting is feasible since the majority of the objects investigated have characteristic physical parameters, differing from those of the environment, and thus, numerous methods applied in geophysics are available for their determination. There are certain conditions, however, that can make the accurate interpretation difficult or even impossible. It is very important how much the parameters of the investigated object differ from those of the environment. The * Eötvös Loránd Geophysical Institute of Hungary H-1440 Budapest, P.O.B. 35.