MAGNETOMETER SURVEY: BILLY DIXON ‘WHISKEY RANCH’ ARCHEOLOGICAL SITE – ELLIS COUNTY, KANSAS

The Applied Geophysics class at Fort Hays State University (Kansas) conducted five magnetometer surveys in southern Ellis County, Kansas, using a Geometrics cesium vapor magnetometer. The undergraduate ‘research-experience’ survey targeted anomalies that represented archeological-related features at Billy Dixon’s 1870’s ‘Whiskey Ranch’ trading post along the Fort Hays to Fort Dodge Trail. The total magnetic intensity in the survey area was rather low at 13 nanoTeslas (nT) containing 3 small anomalies. Calculated depths to the centers of the suspect features ranged from 0.8 to 2 m. Subsequent excavation by the Kansas State Historical Society recovered metal artifacts of food cans, cartridge casings, and nails at depths of 4-5 inches. Discrepancy with the calculated versus ground-truthed depths may have been due to how the class interpreted depths using Peter’s half-slope method. Further, interesting interference patterns were superimposed on two of the five surveys and provided insight as to cellphones on student operators. These interference patterns also gave insight into the uniformity of the walking pace of the operators. This project provided a continuing integrative field experience, as well as a connection to the professional world for our students.