Native American Use of Non-Quarry Obsidian in Northern Sonoma County: A Preliminary Assessment

Purpose of Study: During a recent archaeological investigation in Alexander Valley, results from obsidian sourcing and flaked stone analyses suggested a greater use of culturally modified non-quarry obsidian than previously identified in Sonoma County. Spurred by these conclusions, this project focuses on identifying the geographic and cultural distribution of obsidian obtained from non-quarry areas. Research is complicated by the lack of geochemically distinct obsidian from these collecting areas, which geochemically sources to Napa Valley and Franz Valley. With the use of social distance and technological organization models, this study proposes to determine the effects that the cultural use of non-quarry obsidian had on the distribution and use of the major regional sources of Napa Valley, Annadel, Mt. Konocti, and Borax Lake. Procedure: Of the 142 Native American archaeological sites in the research area, collections from 25 sites were classified and analyzed. Based on obsidian hydration values. arbitrary analytical periods were established and temporally diagnostic projectile points described. Two contemporaneous sites, CASON-1810 and -1811. were chosen for a more detailed flaked stone analysis. This analysis was designed to generate data applicable for interpretations of various behavioral strategies. Findings: The combination of social distance and technological organization models provide a greater understanding of the various levels of behaviors by peoples in the research area. These models applied to flaked stone data from CASON- 1810 and -1811 suggest two contemporaneous populations: at CASON- 1811 there was a more sedentary group with a flaked stone toolkit of predominately locally obtained obsidian; and at CA-SON-1810 there was a more mobile group with a flexible flaked stone toolkit containing a variety of local and exotic obsidian and chert. Non-quarry obsidian was extensively used by Native Americans during all temporal periods in the Central and South Regions and at selected site in the North Region. It is proposed that in the research area the use of obsidian from non-quarry areas restricted the utilization of obsidian from the major regional sources.