Ground-penetrating radar and geo-electrical simulations of data from the Floridablanca archaeological site

In this work we characterize the electromagnetic response of archaeological remains of a Spanish fortress situated on the Atlantic coast in Patagonia (Argentina). The fortress, part of the Floridablanca colony, founded in the eighteenth century, has been surveyed with non-invasive electromagnetic techniques (ground-penetrating radar (GPR) and the geo-electric method). The surveys indicate the presence of adobe walls of various sizes and width having different preservation states. Use of inversion algorithms alone to interpret the data has not been conclusive in obtaining a reliable model, because many uncertainties remained. To aid the interpretation, we make use of modelling methods to simulate the low- and high-frequency electromagnetic responses of the structures. The walls can be differentiated in spite of the low resistivity contrast with the surrounding media. The resolution of the 500 MHz antenna allows a satisfactory determination of the location of the walls and their conservation state. Similarly, the geo-electrical response has enough sensitivity to detect the inner and major walls. Copyright (c) 2005 John Wiley & Sons, Ltd.