The site of BC-51 (also known as LA 40395 or 29SJ395) is a small unit-pueblo site south side of the Chaco Wash (opposite to Pueblo Bonito and Pueblo Del Arroyo) in the Chaco Canyon (Washburn et al. 2011:1637). The site was excavated by the University of New Mexico field school between 1936-1937 under Frank Hibben (Washburn et al. 2011:1637). The vessels (two bowls and one pitcher) from this site were used as the control samples for the chemical study performed by Washburn et al. (2011:1637).
In this chemical analysis, theobromine and theophylline were recorded when the "substance was present at 5 ng/mL or higher. At concentrations less than 5ng/mL, signal noise precluded detection with confidence" and "the same convention applies to caffeine except that the quantification limit was 10 ng/mL" (Washburn et al. 2011, Supplementary Material).
Mapping coordinates approximate.
| ID | Other ID | Type | Subtype | Uncal BP (years) | ± 1 σ (years) | Median cal BP (years) | Lower cal BP (years) | Upper cal BP (years) | δ13C | Contaminated? |
|---|---|---|---|---|---|---|---|---|---|---|
| 97 | Sample 52 | ChemicalSample | Caffeine, Theobromine, and Theophylline | |||||||
| 98 | Sample 53 | ChemicalSample | Caffeine, Theobromine, and Theophylline | |||||||
| 96 | Sample 56 | ChemicalSample | Caffeine, Theobromine, and Theophylline |