North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Weise Mound (12PR35), IN;
Reference: Schurr, M.R. (1999). Geophysical Surveys of Middle Woodland Mounds in Northwestern Indiana. Department of Anthropology, University of Notre Dame, Notre Dame, Indiana. Prepared for the Division of Historic Preservation and Archaeology, Indiana Department of Natural Resources.
Records were reviewed to compile a list of 99 earthen mounds at 63 archaeological sites located in Lake, Porter, LaPorte, and St. Joseph counties of northwestern Indiana. The management status of each site was determined. Nineteen (19) sites were assessed with field investigations. The field assessments examined a total area of 170.7 acres (69.1 ha). Fourteen of these sites were suitable for geophysical surveys (magnetometry and soil resistivity).
Eight mounds at six sites received geophysical surveys. Resistivity surveys with a twin probe array (0.5 m spacing) covered a total area of 13,120 sq m at sample and transect intervals of 0.5 m. Magnetic surveys with a fluxgate gradiometer covered 8,300 sq m with a sample interval of 0.25 rn along transacts spaced 0.5 m apart.
Ground truthing excavations were conducted at Mud Lake (12LE14) and Goodall (12LE9) under Permit 99007 to evaluate the results of the geophysical surveys. The resistivity surveys were shown to be very effective at detecting mounds that contained a muck soil stratum and areas disturbed by grading. The gradiometer surveys also detected mounds with muck layers. In addition, gradiometer surveys detected intrusive pits that were excavated from just a few years to many decades ago.
The geophysical surveys proved to be highly effective for identifying remnants of some types of earthen mounds, even when the mound remnant was not associated with a visible topographic elevation and could not be identified by visual inspection of the ground surface. The geophysical surveys can also be used to evaluate the integrity of mounds by detecting intrusive pits. The types of surveys used in this project are very efficient tools that should be used to evaluate and manage earthen mounds.