US Geological Survey


Date of this Version



Journal of Archaeological Science: Reports 3 (2015) 181–187; doi: 10.1016/j.jasrep.2015.06.003


Understanding the linkage and relationship between Chaco Canyon and its residents to surrounding communities has been a primary research question for several decades. This research has focused on identifying the Chacoan road systems, similar architectural designs, and the sourcing of economic and non-economic goods to outlier communities of origin. Extensive fieldwork has been completed to identify potential source regions of Chacoan corncobs, but the San Juan Basin and surrounding regions are vast and many potential agricultural features remain uninvestigated. One such region is the Tohatchi Flats, located near modern day Gallup, New Mexico. This paper uses 87Sr/86Sr ratios from synthetic soil waters, rabbit brush, and modern maize to investigate if this region is consistent with ratios obtained from archeological cobs from Chacoan great houses. Data results demonstrate that Tohatchi flats 87Sr/86Sr ratios are consistent with ratios from Pueblo Bonito cobs prior to AD 1130 but not after. Additionally, this study demonstrates that rabbit brush can serve as a modern proxy for maize, despite a small 87Sr/86Sr ratio offset, which this study concludes requires additional biogeochemical modeling and investigation to understand.