North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Cavalry Stable Area, HS-35 (Fort Larned National Historic Site), KS;
Reference: De Vore, S. L. (1999). Geophysical Investigations of Potential 10th Cavalry Stables (HS-35) Location, Fort Larned National Historic Site, Pawnee County, Kansas. National Park Service, Intermountain Region, Intermountain Support Office, Santa Fe.
Geophysical investigations were conducted at Fort Larned National Historic Site in Pawnee County, Kansas in June of 1999 in order to establish a baseline data set. The project focused on the search for the Cavalry Stables (HS-35). Built in 1867 as part of a major construction program, the stables were used by Company A of the 10th U. S. Cavalry (i.e., the Buffalo Soldiers). At 6:30 am on January 2, 1869, the stables mysteriously burned to the ground. The stables were reported to be located in a frame building 200 feet by 25 feet located approximately 50 yards southeast of the parade ground. A geophysical investigation was proposed for the potential building location . Magnetic gradient and electromagnetic conductivity surveys were conducted across a 120-meter by 120-meter area adjacent to the Blockhouse (HS-10), the Old Commissary (HS-5), and the New Commissary (HS-4). The geophysical investigations of the potential Cavalry Stables (HS-35) within the Fort Larned National Historic Site have supplemented previous archeological and geophysical investigations of the park. The area provided information on the subsurface features and materials. Post-military disturbances include farm buildings and pens, the irrigation ditch/channel, and the extant park service roads.
The magnetic gradient survey provided information concerning the location of iron artifacts or concentrations of iron artifacts as well as disturbances from the installation of a buried water line, culvert, and buried utility lines. Two rather dense concentrations of magnetic anomalies are found in the central portion of the project area. A light concentration is between these two large concentrations along the east end of the block of grids to the north of the irrigation ditch. These concentrations may be associated with the fort occupation and/or associated with the later farming era. Farm buildings are known to be in this area including hog pens, fences, and other farm outbuildings. To the south of the irrigation ditch there is an area of five strong dipole anomalies in a rectangular area. Another rectangular area southeast of the five anomalies contains a concentration of magnetic anomalies. As one moves away from these areas towards the southwest portion of the geophysical grid, the lack of magnetic anomalies becomes more noticeable.
The electromagnetic conductivity (quadrature phase) survey identified numerous post-military disturbances. These included the water line, culvert, and buried utility lines noted in the magnetic gradient data. The park service road also showed up in the electromagnetic conductivity data. The two large concentrations of magnetic anomalies in the upper center of the geophysical grid are also present in the electromagnetic conductivity data. It appears that the metal (iron) concentration in these two areas is also detectable by the EM38 ground conductivity meter.