Geophysical Investigations At The Archaeological Site Of Fort Saint Joseph, Niles, Mi

Abstract

Fort St. Joseph in SW Michigan was utilized as a trading post from 1691 until 1781. The exact location of the fort had been unknown for over a century until archaeological investigations during the spring of 1998 recovered numerous 18th Century artifacts along the southeast bank of the St. Joseph River. The site is located between an abandoned mid-20th Century landfill and the St. Joseph River. Shallow geology is comprised of an organic rich surface layer of 0.3m overlying a 19th century silty gray plow zone. Magnetic gradiometer, ground-penetrating radar (GPR), electrical resistivity, and electromagnetic induction (EMI) surveys were employed in the spring of 2002 to guide archaeological excavations. The results of these applications are very encouraging. Intact cultural deposits were recorded from depths ranging between 0.35m and 1.80m. All but one of the five archaeological excavation units opened under the guidance of the geophysical surveys yielded physical evidence of the fort. Cultural deposits associated with the geophysical anomalies include burnt pit features, hearth stones, and a charcoal layer associated with a burnt structure. There are numerous locations on site that require further investigation.