Conclusions

Abstract

Large scale GPR and magnetic maps of the near-surface need not be used as only discovery and exploration tools, which has traditionally been the case. As the two techniques are measuring and displaying very different aspects of buried natural and cultural landscapes, they can be used in conjunction to study both human and environmental changes over time. In two examples (Colorado and Connecticut) the magnetic maps were capable of displaying areas of burning, or were in some areas cluttered with so much surface metal that cultural feature definition was impaired. When those magnetic measurements were used to help interpret geological and architectural units visible with GPR, the utility of using both in conjunction was proved. Other examples in England and Ireland produced excellent maps using one or the other method, but were complemented when the two datasets were used in conjunction. The method employed here is to use GPR and magnetics in combination concentrated first on understanding small areas by interpreting two-dimensional profiles as a way to recognize what about the ground was being measured by each technique. When that was accomplished an analysis of the larger landscape-sized sites was possible.