North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Electrical Resistance Survey at Fort Vancouver, Washington
Reference:Kvamme, K.L. (2002). Electrical Resistance Survey at Fort Vancouver, Washington, Report by Archeo-Imaging Lab, Department of Anthropology, University of Arkansas, submitted to Fort Vancouver National Historic Site, National Park Service, Vancouver, Washington.
Electrical resistance survey at the Fort Vancouver National Historic Site was carried out with a Geoscan Research RM-15/MPX-15 in a four parallel twin-probe configuration from May 13-16, 2002, as part of a National Park Service training workshop. The survey utilized 50 cm probe separations, for a half-meter prospecting depth, and encompassed 3,600 m2 in two distinct zones. An eastern grid shows large rectangular anomalies of high resistance that are interpreted as likely structures, possibly representing buried foundations of high resistance materials like concrete, brick, or stone. This view gains support by a series of narrow, interconnected, low resistance linear anomalies that might represent pipe trenches, and by a GIS database that indicates large rectangular structures in this region during the first half of the 20th century. A suspicious anomaly of square shape achieves particular importance because it could point to the foundation of an historic structure that was believed to exist in about the same area.