Isotopic Evidence of Sources for Central California Olivella Beads

Abstract

ABSTRACT Without the large bead production sites present on the Channel Islands, the origin of Olivella beads in central California has been largely speculative. Stable isotope analysis of shell carbonate provides a useful test of source, production, and distribution hypotheses by providing information about the environment of shell formation. We reassess results of previous stable isotope sourcing studies and employ a cluster analysis that suggests most Olivella beads recovered from central California were produced from shell harvested from the Central Coast or Bay Area, but conveyance from southern California also contributed to the bead supply by the end of Phase 1 of the Middle Period (ca. 1,545 BP). Bead production in central California appears decentralized relative to large Channel Island workshops, a difference that likely reinforced the divergent sociopolitical trajectories of the regions.