1Department of Anthropology, California State University, Chico, 2Department of Anthropology, University of California San Diego, 3Department of Anthropology, San Jose State University, 4Department of Anthropology, California State University, Chico, 5Department of Anthropology, San Jose State University, 6Ohlone Family Consulting Services, Muwekma Ohlone Indian Tribe
Saturday Afternoon, Council Suite
We present isotopic data to explore the relationship between diet and mortuary patterns among 145 human burials interred at the Ryan Mound (CA-ALA-329), a large earthen mound located along the southeastern shoreline of San Francisco Bay. Radiocarbon dating and artifact seriation place the burials within the Middle and Late Period (ca. 200 BC-AD 1770). Previous research in the Bay Area has revealed temporal and regional differences in paleodiets, indicating significant variation in the relative contribution of marine versus terrestrial resources. Early Period populations from the North Bay have significantly elevated δ13C and δ15N values compared to other bayshore groups dating to the Middle and Late Period, suggesting a decline in marine resource consumption through time.
We conducted stable carbon and nitrogen isotope analysis of human bone collagen to track the sources of dietary protein (marine versus terrestrial), and stable carbon isotope analysis of bone apatite to evaluate contributions from all dietary macronutrients. δ13C and δ15N values from the Ryan Mound are more depleted relative to foragers from the North Bay, but are more enriched compared to groups from the South Bay. Although proximity to bay resources explains some of the dietary variation, we also evaluate the relationship between diet and mortuary patterns (e.g. body position, flexure, orientation, burial associations, and location) to address potential differential access to resources within the population.
This study was funded by a CSU-Chico Foundation Scholars Grant, a College of BSS Development Grant, and the James A. Bennyhoff Memorial Award.