Journal of California and Great Basin Anthropology

The inadequacy of typological approaches has led to our attempts to improve temporal resolution by means of obsidian hydration dating. Increasingly, archaeologists working in the Great Basin have adopted obsidian hydration dating as an adjunct to standard dating techniques, some regarding surface artifact dating as an acceptable extension of the approach (e.g., McGonagle 1979; Bettinger 1980, 1989; Jackson 1984a; Tuohy 1984; Zeier and Elston 1984). While we have reservations about the use of obsidian hydration dating for precise chronometric assessments of surface artifacts (cf. Leach 1988; Bettinger 1989), the technique appears to have merit as a relative dating tool (Michels 1967, 1973; Michels and Tsong 1980; Jackson 1984a). In this paper we report on a study of 115 obsidian artifacts recovered from seven archaeological sites of late Pleistocene-early Holocene age. We begin with general background of the dating method and of our Butte Valley studies, and then turn to the results of our obsidian source and hydration analyses. We conclude with an evaluation of obsidian hydration for delimiting chronological information for the surface archaeological record.