Coso Volcanic Field obsidian

The Coso Volcanic Field in Inyo County, in southern eastern California, supplied the main obsidian of the southern Sierra Nevada and the southern San Joaquin Valley. Moore's source guide lists it as the Coso Hot Springs, Joshua and West Sugarloaf Mountain area and notes that quarry and workshop sites there have been studied. Archaeological studies show Coso glass dominating obsidian assemblages in the Kern River drainage and on the western slope of the southern Sierra from Porterville south. In the southern valley sites that Sutton and Des Lauriers tabulated, small debitage makes up most of the Coso material, and finished artifacts are usually projectile points. The opened sources do not describe the glass itself.

Obsidian nodules in the Coso Volcanic Field, Inyo County, California. The opened sources give only the source names and location; the USGS geology page returned an error and was not retried.