Stable nitrogen and carbon isotope ratios in bone collagen as indices of prehistoric dietary dependence on marine and terrestrial resources in Southern California
✍ Scribed by Phillip L. Walker; Michael J. Deniro
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 814 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0002-9483
No coin nor oath required. For personal study only.
✦ Synopsis
The ratios of 15N to 14N and 13C to 12C tend to be higher in marine than in terrestrial organisms. The concentrations of these isotopes in human bone collagen consequently can be used to make inferences about the contribution of marine and terrestrial resources to prehistoric diets. The utility of studying 15N/14N and 13C/12C ratios in conjunction with each other is illustrated by our analysis of 40 human burials from archaeological sites in the Santa Barbara Channel area of southern California. The mean 613C and 615N values (in per mil) of collagen from these skeletons decrease progressively from the Channel Islands (613C = -14.0, 615N = + 16.3) to the mainland coast (613C = -14.5, 615N = +14.9) to the interior (613C = -17.2, 615N = +10.9). These data suggest that Indians living on the Channel Islands during the late prehistoric period were heavily dependent on marine resources. The inhabitants of the mainland interior, in contrast, had a diet composed largely of terrestrial foods. From their isotope ratios, it appears that the Indians who lived on the mainland coast consumed a mixed diet containing substantial quantities of both marine and terrestrial resources. Differences in I5N/I4N and 13C/12C ratios of individuals from mainland sites dating from the early and late prehistoric periods show that the marine component of the diet increased substantially through time. These isotopic data are consistent with pathological, faunal, and artifactual evidence of increased marine resource exploitation during the late prehistoric period.