Other obsidian sources in the Andes are in need detailed research. In the Andean highlands, studies of the Quispisisa obsidian source (Burger and Glascock 2000;Burger and Glascock 2002) is particularly important as this source has had a long history of use with regional significance extending far beyond the Ayacucho province. Recent work at the high altitude of the Alca source by Rademaker et al. (2004) indicates that extensive obsidian production was occurring on the north slopes of Nevado Firura between 4400 and 4800 masl, above the quarrying work documented by Jennings (2002;Jennings and Glascock 2002). Studies of these production areas will also require detailed examination through excavation because diagnostic materials on the surface of most quarries are slim. Two lithic sources in western Bolivia, the Sora Sora obsidian source and the Querimita basalt source (Giesso 2000;Giesso 2003;Glascock and Giesso 1994;Márquez Ostria, et al. 1975;Ponce Sanginés 1970),were examined by Giesso (2000) and as these materials occurred with frequency in the Tiwanaku core region, the source areas offer potential for providing further insights into Titicaca Basin prehistory that complement those provided here from the Chivay obsidian source.