Geophysics and geochemistry; an interdisciplinary approach to archaeology in wetland contexts

Wetlands are a non-renewable resource of high potential for organic archaeological deposits and palaeoenvironmental sequences. This resource is at threat from development and climate change. Only a small percentage of the identified wetlands in North West Europe have been studied with regard to their depth, stratigraphic architecture and the heritage assets they contain. In this paper several case studies are combined to show the variation of radar velocity field with different wetland sediment types. Sediment types are classified based on their physical and chemical properties. The results demonstrate how the application of geophysics can be used to identify archaeological features and interpret them within a wetland landscape. The ground penetrating radar ( GPR) response and geochemical signatures given by archaeological structures and palaeolandscape features, presented here improves the quality and reliability of scientific information derived from archaeological prospection in wetland contexts. More accurate values for the dielectric permittivity of different wetland sediments have been calculated, allowing the response of GPR in wetland contexts to be predicted. Geochemical signatures associated with different sediment types and archaeological structures have also been demonstrated. Both GPR and the geochemical analysis of sediment can be employed across the dryland wetland interface bridging the gap between wetland and dryland archaeology and offers a potential to shape global debates regarding how wetland heritage is managed in the future.