North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Greenbrier Site (3IN1), AR;
Reference: Johnson, D., T. Carr, and M. Watters. (1999). Geophysical Investigations at the Greenbrier Site, Site 3IN1, Batesville, Arkansas. Hemisphere Field Services, Minneapolis, Minnesota. Submitted to the Arkansas Archeological Survey.
Hemisphere Field Services, Inc. (formerly IMA Consulting) conducted a geophysical investigation at the Greenbrier Site (3IN1), Batesville, Arkansas, using a G-858 cesium magnetometer, a RM-15 resistance meter, and a RAMAC Ground Penetrating Radar (GPR) system. The survey was conducted from 24 to 26 June 1999. The work was conducted for the Arkansas Archeological Survey. Hemisphere Field Services provided the funding for the geophysical investigation.
The Greenbrier Site is located in north central Arkansas, in the White River valley, east of Crowley's Ridge. The archaeological background of the Greenbrier Site is not well documented. The area is thought to be Late Mississippian c. 1300. The site is known for its shell tempered pottery and Nodina points and has been compared to Parkin and a site in Ravendon, in the Osarks. It is an area also known for looting, as hundreds of pots have been stolen from burials.
Dr. Julie Morrow directed the archaeological investigations on the site. The purpose of this geophysical work was to determine the most suitable non-destructive technique for detecting subsurface archaeological features at the site.
The magnetic and resistance survey covered a total area of 1,600 square meters (four 20x20-meter grids). Both magnetic and resistance data were collected using a 0.5-meter line spacing. Magnetic data were collected approximately every 0.1 meter. Resistance data were collected using an interval of 0.5 meter. A GPR survey was conducted on one 20x20-meter grid. Radar transacts were 1 meter apart.
Geophysical investigations at the Greenbrier Site were successful and the magnetic and resistance surveys have mapped 7 possible structures. The resistance survey has detected what may be post molds around 2 of the structures. The GPR survey also successfully mapped possible archaeological features at the site, although the features are not as well defined.
Some of the interpreted features were evident in both magnetic and resistance data, some features were mapped by only the magnetic survey, and some by only the resistance survey. If the investigation had been conducted using a single geophysical method, some significant features would not have been located. Therefore, it is important at this site that future geophysical investigations use both magnetic and resistance methods. Future GPR surveys should be conducted over targets selected based on resistance and magnetic surveys.