A Geophysical Survey of Fort St. Joseph (20be23),Niles, Michigan
Fort St. Joseph is a 17th-18th century French (and later English) mission-garrison-trading post complex located in southwest Michigan. A geophysical survey was performed and the results of the survey were tested through archaeological excavation. The geophysical methods included ground penetrating radar, electromagnetic induction, electrical resistivity, magnetic gradiometry, and magnetic susceptibility. The results of the archaeological excavations demonstrate that magnetic gradiometry was the preferred geophysical method at this particular site. The magnetic gradiometer survey included both terrestrial and possible submerged portions the site. Laboratory analysis of the magnetic susceptibility and magnetic viscosity of soils and rocks demonstrated that the archaeological features at Fort St. Joseph have a statistically significant magnetic contrast with those of the natural soils. This study has the potential to contribute to the fields of French colonial archaeology, wet site archaeology, and soil and rock magnetism. Recommendations for future research are suggested, including investigating a possible submerged cultural resource located a few meters north of the existing riverbank.