Typological and Geochemical Analysis of Obsidian Artifacts: A Diachronic Study from The Lower Río Verde Valley, Oaxaca, Mexico

This thesis examines the acquisition and use of over 5200 obsidian artifacts throughout prehispanic times (ca. 1800 BC-AD 1522) in the lower Río Verde Valley, Oaxaca, Mexico. This research represents the first systematic study of obsidian artifacts in the region, and focuses on two aspects of the obsidian artifacts. First, I present a technological analysis of artifacts collected from primary contexts which correspond to each prehispanic period. The second part of the thesis presents a geochemical survey of obsidian acquisition through time. Results indicate that each prehispanic period of coastal Oaxaca contained multiple sets of long-distance trade networks centered on major geographical areas. For example, during the Late Formative, obsidian sources from the Basin of Mexico dominated the assemblage, while in previous periods Gulf Coast sources comprised the majority. Additionally, specific technological attributes (e.g., prismatic blades, ground platforms) appear in the lower Verde at roughly the same time as the rest of Mesoamerica. This suggests that, despite being a relatively long distance from many major centers of activity throughout prehispanic times, the lower Verde was very well-informed as to the advancements in obsidian technology through time. Examining which sources were acquired through time in conjunction with changing technologies provides a greater understanding of the broader social, economic, and political patterns occurring in the region