North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: On-A-Slant Village (32MO26), ND (1);
Reference: Kvamme, K.L. (1999). Geophysical Investigations at On-A-Slant Village (32MO26), Fort Abraham Lincoln State Park, North Dakota. Department of Anthropology and Center for Advanced Spatial Technologies, University of Arkansas, Fayetteville, Arkansas. Submitted to Dr. Dennis Toom, Department of Anthropology, Anthropology Research, University of North Dakota, Grand Forks, North Dakota.
Geophysical investigations were carried out at On-A-Slant Village (32MO26) in Fort Abraham Lincoln State Park, North Dakota, from July 8-10, 1999. The work was conducted by Dr. Kenneth L. Kvamme, with the assistance of Jo Ann Christein Kvamme (Arkansas Archeological Survey), Richard Allan (University of Arkansas graduate student), and Dr. Dennis Toom, of the University of North Dakota (UND). Two areas of the village were examined. One was the floor area of an earthlodge reconstruction near the site center that required dismantling owing to its deteriorating state. The second area was a portion of the western fortified perimeter of the site adjacent to the park's principal road. These areas were surveyed to identify anomalies of potential archaeological significance in order that they may be avoided or excavated prior to State Park constructions planned in these areas.
With the relatively small size of the earthlodge floor, it was possible to fit a single 10 x 10 m grid within it that covered its entire area. All survey of this lodge was conducted within that grid. Resistance data were sampled every 0.25 x 0.25 m at four depths; magnetic gradiometry data were obtained every 0.125 x 0.25 m. At least 19 anomalies are evident in the processed data. The density of these features undoubtedly reflects the intensity of the prehistoric occupation of this site, but may also be partially due to the disturbed nature of this plot stemming from the earthlodge reconstruction. In other words, some of the features may stem from the effects of the artificial earthlodge and not the prehistoric archaeology. Nevertheless, few of the anomalies coincide with the mapped indications of the earthlodge reconstruction.
Geophysical surveys were also conducted along the western perimeter of On-A-Slant village. In this area, the State Park plans to reconstruct a palisade in the vicinity of the prehistoric one that existed in this area, to improve tourism. A grid of 30 x 20 m was established on the east side of the road and a 20 x 20 m grid was set up on the west side. These areas were completely surveyed by magnetic and electrical resistance methods. Sampling density was set at 0.5 x 1.0 m for the resistance survey while the magnetic data were acquired at a density of 0.25 x 0.5 m. Like the earthlodge survey, the resistance data were sampled at four depths. Several GPR transects 15-20 m in length were also run on each side of the road to support the other results and provide new insights.
A number of strong features are apparent in the resistance data at multiple depths. The magnetic data are much less insightful, in part because of the relatively large amount of iron and steel debris that apparently litters this part of the site. The GPR data corresponds with several of the anomalies detected by other methods, however, there are many additional anomalies that are probably derived from rocks in the soil, rodent burrows, and possibly large prehistoric artifacts or features.