Use of soil apparent electrical resistivity contact sensors for the extensive study of archaeological sites

Abstract

Geoelectrical soil mapping using contact sensors with mobile arrays is a widespread method implemented within Precision Agriculture practices since the 1990s, but only in recent times has it begun to be used extensively in the field of archeology. Vehicle towed equipment for the automatic recording of apparent electrical resistivity (ERa) are highly adaptable to land plot structure and are able to cover large areas quickly. In this article we will give an overview of a specific experience of ERa mapping at two archaeological sites with the VERIS 3150 system. This is a contact-sensor that provides georeferenced measurements at two different depths (0–30/0–90 cm). The process of capture, refinement and normalization of raw data is explained. The work also deals with interpolation procedures used for the creation of continuous surfaces. Finally some examples are offered regarding the identification of buried archaeological and geomorphological features. ERa maps are integrated in a geographical information system (GIS) environment, in order to provide a more reliable basis for interpretation. The advantage of the VERIS 3150 sensor is stressed, in terms of cost over traditional electrical resistivity/conductivity mapping techniques for the acquisition of high-quality archaeological information.