ARCHAEOLOGY STUDIES IN SOUTHERN ARIZONA USING GROUND-PENETRATING RADAR

Conventional ground penetrating radar (GPR) surveys typically have a maximum depth of penetration of 1/2 to 1 m in the basin-fill sediments of the southwestern United States. Although this depth of penetration is too limited for many engineering and environmental surveys, it is often suitable for archaeological investigations in this region. We have found a center frequency of 500 MHz to be optimum. Radar signals having a center frequency of about 80 MHz produce records with much lower resolution and only slightly greater maximum depth of penetration. Successful GPR surveys have imaged buried plaster and adobe walls, roasting pits, canals, trash pits, plastered floors, and artifacts such as pot sherds and knives. We have found that GPR is a valuable tool for archaeological studies in this area. GPR can provide some of the detailed survey information that has been provided in the past by extensive excavation, but without the high cost of excavation, without the dangers of vandalism when artifacts are exposed, and without disturbing sensitive areas.