Mass Production and Procurement at Valle del Azufre: A Unique Archaeological Obsidian Source in Baja California Sur

Abstract

Valle del Azufre is a newly discovered source of high-quality obsidian in central Baja California, which exhibits the most intensive exploitation of any known source in the greater United States Southwest and Northwest Mexico. Over 15 subsurface trenches and at least one adit occur at the source. Evidence for the prehistoric distribution of Valle del Azufre obsidian is presented based on energy-dispersive x-ray fluorescence spectrometry characterization of the source material and artifacts from the Baja California peninsula. Despite the intensity of exploitation at the source, the distribution of Valle del Azufre glass appears to be largely restricted to the central part of the peninsula.

Comparison of XRF and PXRF for analysis of archaeological obsidian from southern Perú

“…While in the U.S. these artifacts were analyzed by Shackley et al (2004) using a laboratory XRF at the University of California, Berkeley. In 2005, as part of a collaborative program to expand materials characterization studies in the Titicaca Basin, Speakman and Popelka-Filcoff visited Puno, Perú with PXRF equipment and reanalyzed the same sixty-eight obsidian artifacts from Jiskairumoko.…”

“…The vast majority of archaeometric-based XRF studies have focused on compositional analyses of obsidian and metals (Carter, 1971;Cobean et al, 1971;Heizer et al, 1965;Shackley, 1988Shackley, , 1990Shackley, , 1991Shackley, , 1992Shackley, , 1995Shackley, , 1998Shackley, , 1994Shackley, , 2002aShackley et al, 1996;Shackley and Tucker, 2001) and to a lesser extent pottery (Adan-Bayewitz et al, 1999;Culbert and Schwalbe, 1987;Garcia-Heras et al, 1997;Hedges and Moorey, 1975;Kuhn, 1987;Poole and Finch, 1972;Trigger et al, 1980).…”

Reassessing obsidian field relationships at Glass Buttes, Oregon

“…The implication, although not discussed by Ambroz et al (2001), is that the Robins Spring residents must have collected obsidian from each of five different zones broadly distributed across the Glass Buttes complex and from another nearby obsidian source. This, in turn, may be interpreted as evidence that these mobile foragers collected raw material from across a relatively wide geographical area, rather than focusing their efforts on a particular quarrying location (e.g, Stocker and Cobean, 1984;Torrence, 1986;Clark, 1989;Shackley et al, 1996). Indeed, the "subsource" zones drawn by Ambroz et al (2001) and their obsidian types at the Robins Spring site nicely coincide with typical daily foraging radii of 5-10 km (Binford, 2001;Morgan, 2008).…”

Sources of archaeological dacite in northern New Mexico

“…Large biface preforms and a broken quartzite hammerstone produced from a quartzite river cobble were also located. After looking at stone tool sources in the North American Southwest for over 30 years, Cerros del Rio dacite is one of the most impressive, similar to the mining at the Valles del Azufre obsidian source in central Baja California (Shackley et al, 1996). Very fortunately this is protected on Bandelier National Monument, and has been for nearly 100 years suggesting that the debitage pile is most likely prehistoric.…”