Geophysical Investigations at the Nezekaw Terrace Mound Group (Site 13AM82), Effigy Mounds National Monument, Allamakee County, Iowa

Author(s): Steven L. De Vore

Year: 2009


The National Park Service’s Midwest Archeological Center and Effigy Mounds National Monument staffs with the University of Nebraska-Lincoln graduate student and the Volunteer-In-Parks participants conducted geophysical investigations at the Nezekaw Terrace Mound Group (Site 13AM82) located on the Effigy Mounds National Monument in Allamakee County, Iowa. The geophysical investigations were conducted between June 8 and 14, 2008. The archeological investigations were requested by an anthropology graduate student at the University of Nebraska-Lincoln as part of his Masters Thesis archeological project at Effigy Mounds National Monument. The project was located within the Yellow River or North Unit of the park on the east side of the visitors center above the confluence of the Mississippi River and the Yellow River.

During the investigations, 3,721 square meters or 0.92 acres were surveyed with a single fluxgate gradiometer and a dual fluxgate gradiometer system, a conductivity meter, a resistance meter and twin probe array, and a ground penetrating radar cart system with a 400 mHz antenna. The geophysical project was divided into two units, EFMO1 and EFMO2, which were separated by an upland drainageway. The geophysical data collected at the selected project areas provided information of the physical properties of the subsurface materials. Several geophysical anomalies were identified during the investigation of the two project areas. The resistance, ground penetrating radar, magnetic, and conductivity anomalies represented the outlines of buried mound remnants at EFMO1, while the integrity of the two mounds at EFMO2 was also documented as a result of the magnetic, resistance, and conductivity surveys within the survey area. It is recommended that additional geophysical investigations be undertaken at the Nezekaw Terrace Mound Group to identify buried archeological resources associated with the geophysical anomalies identified at the National Park Service unit.

Cite this Record

Geophysical Investigations at the Nezekaw Terrace Mound Group (Site 13AM82), Effigy Mounds National Monument, Allamakee County, Iowa. Steven L. De Vore. Midwest Archeological Center Technical Report ,No. 118. Lincoln, Nebraska: United States Department of the Interior, National Park Service, Midwest Archeological Center. 2009 ( tDAR id: 376137) ; doi:10.6067/XCV8CR5T3H

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min long: -91.27; min lat: 43.059 ; max long: -91.165; max lat: 43.131 ;

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