Source location

Location of the Borax Lake source

NAME BORAX LAKE
LOCATION Clear Lake Volcanics, North Coast Ranges, Lake County, California.
CHEMICAL
SOURCE(S) 		Borax Lake.
DESCRIPTION This well-known prehistoric quarry source of obsidian is located near the southern end of Clear Lake about one mile south of Borax Lake. The chemically-variable Borax Lake flow is one of several obsidian sources associated with the Clear Lake Volcanics and has yielded a K-Ar date of approximately 90,000 years. The glass is of rather variable quality for artifact manufacture and ranges in appearance from a translucent gray-black to a pumiceous gray.

This obsidian source is one of the most well-known in California but much of the quarry area has now been obliterated by recent vacation home developments. Intensive use of the source is evidenced by large quantities of manufacturing debris associated with the flow. The presence of fluted points at the source has also been used to suggest long-term use of this toolstone resource. Obsidian from the Borax Lake source has been identified at many sites in the North Coast Ranges, in central California’s Great Valley, and the foothills of the Sierra Nevada Mountains.

Obsidian Hydration: Several different hydration rates have been proposed for this source. Experimental studies indicate that Borax Lake glass hydrates at a faster rate than obsidian from the nearby Napa Valley source.

REFERENCES Anderson 1936
Basgall 1993
Bowman et al. 1973a, 1973b
Donnelly-Nolan et al. 1981
Ericson 1981
Ericson et al. 1976
Frederickson 1989
Frederickson and White 1988
Harrington 1948
Hearn et al. 1995
Heizer and Treganza 1944
Jackson 1974, 1986, 1989
Kaufman 1980
Meighan 1983
Meighan and Haynes 1970
Pastron and Walsh 1989
Rick and Jackson 1992
Tremaine 1989, 1993
CREDITS --

Back to CALIFORNIA SOURCE PAGE
Back to SOURCE CATALOG HOME PAGE
Back to NORTHWEST RESEARCH OBSIDIAN STUDIES LABORATORY

Last Updated: 01/20/2005 Compiled by Northwest Research Obsidian Studies Laboratory