North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Graphic/Image:
Project Name: Plum Grove Historic House Site, IA;
Reference: De Vore, S. L. (1999). Magnetic Gradient and Electromagnetic Conductivity Investigations of the Plum Grove Historic House Site, Johnson County, Iowa. National Park Service, Intermountain Support Office-Santa Fe. Prepared for the State Historica Society of Iowa, Des Moines, Iowa.
Magnetic gradient data at Plum Grove Historic House. The magnetic gradient data contain numerous anomalies which related to both historic activities and modern disturbances. The modern disturbances include buried water/utility lines, the interpretive garden fence, the renovated brick house, brick sidewalks, the asphalt drive and parking lot, informational and interpretive signs and the chain link boundary fence. There is a large anomalous area surrounding the house that appears to represent intact cultural features. Excavations have confirmed the existence of an extensive trash deposit. At the extreme southern edge of the survey area, there is a cluster of anomalies that may represent other farm outbuildings. In the southeast corner of the grid, there are a series of linear anomalies and several small concentrations of anomalies. These may represent fence lines or outbuilding locations.