Tracing the mobility of individuals using stable isotope signatures in biological tissues: "locals" and "non-locals" in an ancient case of violent death from Central California

Stable isotope analyses of biological tissues that grow during different phases of life can be used to trace the geographic location of individuals during different windows of time. We apply this principle and reexamine three prehistoric skeletons excavated in 1964 from archaeological site CA-YOL-117 in Central California. Field evidence suggests they were killed as part of a single violent event. We report new radiocarbon dates and Strontium, Oxygen, Carbon, and Nitrogen isotopic data from first molars, third molars, and bone to examine circumstances surrounding their death. Data suggest two of the three individuals were born, and all three lived their teenage years, near the site they were buried in. However, as adults they lived elsewhere, likely to the north along the Sacramento River. Around AD 1450, upon returning to the territory of their childhood years, they were killed and placed in a mass grave. The data invite a more nuanced interpretation of how we view "local" and "non-local" individuals archaeologically. Overall, the analysis provides an interesting glimpse into the nature of warfare and violence among pre-contact hunter-gatherers of Northern California. © 2013 Elsevier Ltd