Integrated geophysical investigation of the fort frontenac archaeological site

Abstract

Over 100 large objects were located. Numerous smaller objects were noted, some merely chipped from the larger monuments and used as tools. Future excavation can now be precisely directed to known positions to uncover the remaining anomalies. The size and depth of the objects can be assessed to guide priorities in excavation. Owing to the significant contrast in magnetization between the basalt monuments and the soil, the monuments stood out prominently. The chance to use known geometries and magnetizations and compare with observed anomalies and interpretations represented a rare opportunity in geophysical exploration. Interesting lessons and observations can be made when comparing this scaled down version of a magnetic survey to, say, an airborne survey or a mineral or petroleum prospect. Among the factors that can be useful in this comparison are the near-field of the anomaly, scaling factors, varying depth of sources, sampling problems, and verification of assumed model parameters. The site appeared to be remarkably free of nonbasalt anomalies. Since all the pieces of basalt are cultural, i.e., brought to the site by man, all the magnetic anomalies are of some interest to the archaeologists tudying the site. This survey represents an unusual example of a geophysical survey at an archaeological site that produced distinct and significant results. It should be remembered therefore, that most sites do not produce such simple results for interpretation; the anomalies are more than likely obscured by cultural features or local gradients from shallow and deeper geology. Certainly, this survey is an example of a truly fascinating application of geophysics to a nonresource objective. This example and a few similar archaeological exploration projects have already attracted many geophysicists to this application and to related ones such as exploration of toxic waste disposal sites, location of buried utility pipelines, and similar geotechnical applications. Integrated Geophysical Investigation ARCHl.2 of the Fort Frontenac Archaeological Site