Archaeological prospection of wall remains using geoelectrical methods and GPR

Geoelectrical twinpole mapping clearly reveals shallow wall remains of a Roman villa complex built from limestone blocks. A tripole array is introduced that may allow the estimation of the strike direction of linear structures by electrical profiling on a single line. Further geoelectrical investigations, i.e. Wenner profiling and pseudosection, as well as geoelectrical forward modelling have been carried out on a standard profile across prominent anomalies recognized by twinpole mapping. Despite unfavourably low background resistivity (10–20 Ohm · m), ground penetrating radar (GPR) surveys provide useful information. It is demonstrated that additional qualitative information on the nature of archaeological structures (possible identification of a collapsed roof, and of a cellar with collapsed ceiling) and quantitative depth estimates (0·4 m for an isolated wall; minimum of about 0·7–0·8 m for another wall) can be made by integrating the results obtained by all the methods mentioned. © 1997 John Wiley & Sons, Ltd.