3.6. Obsidian Use in the South-Central Andes

Obsidian was knapped into relatively few artifact forms in the south-central Andes. The most common formal stone implement was a bifacially flaked projectile point, but other bifacial tools such as knives and scrapers were also commonly produced throughout the consumption region. The other major technical class for obsidian artifacts were simple flakes. As a sharp, but fragile, cutting implement, a freshly struck obsidian flake was potentially useful for butchery and wool shearing purposes. Dransart (2002: 108-109) reports that in rural communities modern wool shearing is accomplished either with the lid of a tin can that has been folded over so as not to cut the user's hand, or with a broken piece of bottle glass. Contemporary herders in the Colca region report that obsidian flakes, and sometimes broken glass vessels, are used for castrating animals because it was explained that as non-metal tools do not oxidize, they are less likely to introduce infection into the animal (T. Valdevia 2003, pers. comm.).

A distinctive Andean method of camelid slaughter can be accomplished with a small, sharp flake is described by George Miller (1979: 27-36). The ch'illamethod of slaughter consists of laying the animal down, cutting a small incision near the sternum with a small flake of stone, and reaching in and manually breaking the ascending aorta where it leaves the heart. Ethnoarchaeological studies have shown that simple flakes are often used in butchering and shearing, and therefore a prehistoric association between pastoral facilities and lithic flakes, both utilized and unutilized, seems probable.