2011 SAGEEP Symposium on the Application of Geophysics to Engineering and Environmental Problems

Previous Excavations and Geophysical Discoveries at a Prehistoric Earthwork Site in Western Michigan

Sherrod, Laura, Brashler, Jan, and Gaff, Donald, 2011, Previous Excavations and Geophysical Discoveries at a Prehistoric Earthwork Site in Western Michigan [abs]: Symposium on the Application of Geophysics to Engineering and Environmental Problems - Charleston, South Carolina (10-14 April 2011).

Students working with Dr. Laura Sherrod using magnetic
gradiometer

Geophysical surveying was performed during the summer of 2010 at the South Flats Earthwork Site (20MU2) in Muskegon County, Michigan. This prehistoric earthwork site is a circular feature of raised earth material located in a present-day young oak forest. The enclosure is approximately 25-30m in diameter and has a width of 4m around the perimeter where the ground relief is altered approximately 0.5m. It is located within the Muskegon State Game Area on a bluff overlooking the Muskegon River. The site was first excavated by the Michigan archaeologist George Quimby in 1937 and has been only moderately disturbed by anthropogenic sources since that time. Recent excavation was performed in 2006 by a team of researchers from Grand Valley State University. This field work clarified the results and aided in the interpretation of the records kept of the 1937 excavation. Additionally, the recent excavations increased overall knowledge of the role that earthwork structures played in the cultures of the time.

Due to the site location on State-owned land, excavation is restricted. Ground penetrating radar and magnetometer surveys were applied at this site to provide an image of the subsurface and facilitate further development of cultural interpretations. Soil composition is predominantly sandy making ground penetrating radar a very effective geophysical tool. Previous excavation units and other recent anthropogenic disturbances are clearly visible in the geophysical results. The earthwork structure itself is identifiable through the ground penetrating radar images and several small-scale geophysical features aid in site interpretation. Results from the surveys provide insight into the prehistoric use of earthworks structures and illustrate the complicated nature of interpreting.

Kurt Friehauf - April 2011