Evaluating the Gridded Agricultural Field Model in Chaco Canyon, New Mexico, Using Geophysical Remote Sensing

Abstract

Recent geophysical remote sensing, including ground-penetrating radar and magnetometry, has been used to investigate three areas within Chaco Canyon, New Mexico, predicted to contain prehispanic agricultural fields. These localities include a well-known but enigmatic area of large grid patterns near the Chetro Ketl great house, which are visible from the air but not at ground level. The gridded area has been interpreted by many researchers as an agricultural field system, and this perspective has in turn been utilized to model agricultural land use throughout the canyon, particularly intensification associated with emergent social complexity. The geophysical surveys revealed evidence of buried features at all three study areas, but the patterns expressed by these features do not clearly conform to the pattern predicted in the gridded agricultural field model. We argue that the surficial grid pattern seen at the Chetro Ketl field is an unusual example of land modification in the canyon and thus unlikely to represent typical Chacoan agricultural field systems. Instead, canyon residents employed a diverse range of agricultural techniques suited to the variable and patchy nature of canyon hydrology and soils.