Date of this Version
Journal of Archaeological Science 36 (2009) 387–407
Maize played a major role in Chaco’s interaction with outlying communities in the southern Colorado Plateau. This paper seeks to determine where archaeological corn cobs brought to Chaco Canyon were grown. Strontium-isotope and trace-metal ratios of 180 soil-water and 18 surface-water sites in the Southern Colorado Plateau have revealed possible source areas for some of 37 archaeological corn cobs from Chaco Canyon and 10 archaeological corn cobs from Aztec Ruin, New Mexico. The most probable source areas for cobs that predate the middle-12th-century drought include several Upper Rio Chaco sites (not including Chaco Canyon). There are many potential source areas for cobs that date to the late A.D. 1100s and early 1200s, all of which lie in the eastern part of the study area. Some Athapascan-age cobs have potential source areas in the Totah, Lobo Mesa, and Dinetah regions. One Gallo Cliff Dwelling cob has a strontium-isotope ratio that exceeds all measured soil-water values. Field sites for this cob may exist in association with Paleozoic and Precambrian rocks found 80–90 km from Chaco Canyon. Potential source areas for most Aztec Ruin cobs (many of which were found in rooms dating to the first half of the 13th-century) appear to be associated with a loess deposit that blankets the Mesa Verde and McElmo Dome regions.
12 supplemental files are attached below.
Benson JAS 2009 Possible sources SUPPL 2 Fig S1.tif (4003 kB)
Great house locations in the Four Corners area. Great houses abandoned by A.D. 1130 are shown as white squares. The remaining great houses (black triangles) were abandoned by A.D. 1300. Heavy black line forms the perimeter of the San Juan Basin.
Benson JAS 2009 Possible sources SUPPL 3 Fig S2.tif (19425 kB)
K/Rb histograms of archaeological cobs.
Benson JAS 2009 Possible sources SUPPL 4 Fig S3.gif (1 kB)
Strontium versus Al in four archaeological cob groups.
Benson JAS 2009 Possible sources SUPPL 5 Fig S4.tif (27786 kB)
Locations of all soil samples collected in the Southern Colorado Plateau region. Map numbers are keyed to site 87Sr/86Sr and K/Rb data and site names displayed in Table 2 and Table 4.
Benson JAS 2009 Possible sources SUPPL 6 Fig S5.tif (10783 kB)
87Sr/86Sr histograms of surface-waters in Four Corners area. LPR, lower Piedra River; LOPR, Los Pinos Creek.
Benson JAS 2009 Possible sources SUPPL 7 Fig S6.tif (19302 kB)
87Sr/86Sr values for sites with soil samples collected from multiple depths. CTW, Captain Toms Wash; CKF, Chetro Ketl Field; S10, Penasco Blanco Field; AZR, Aztec Ruin; WER, Weritos Rincon; SR, Salmon Ruin.
Benson JAS 2009 Possible sources SUPPL 8 Table S1.xls (80 kB)
Site information, 87Sr/86Sr and conductivity data for synthetic soil-water samples
Benson JAS 2009 Possible sources SUPPL 9 Table S2.xls (376 kB)
Site information and trace-metal data for Southern Colorado Plateau synthetic soil-waters
Benson JAS 2009 Possible sources SUPPL 10 Table S3.xls (60 kB)
Trace-metal values for Aztec Ruin (AZRU) and Pueblo Bonito (H) cobs
Benson JAS 2009 Possible sources SUPPL 11 Table S4.xls (90 kB)
Trace-metal data for 30 Chaco Canyon cobs
Benson JAS 2009 Possible sources SUPPL 12 Table S5.xls (27 kB)
Site information and 87Sr/86Sr ratios for surface-waters in the Four Corners area