Exchange Implications of Obsidian Source Analysis from the Lower Rio Verde Valley, Oaxaca, Mexico

This article considers the results of instrumental neutron-activation analyses of 61 obsidian artifacts recovered from excavations at four archaeological sites in the lower Río Verde valley on the Pacific coast of Oaxaca, Mexico. Determinations of source locations of these artifacts permit the examination of changes in obsidian exchange patterns spanning the late Middle Formative to the Classic period. The results show that through most of this period the importation of obsidian into the lower Verde region was dominated by sources in the Basin of Mexico and Michoacan. The data allow us to evaluate previous models of interregional relations during the Formative and Classic periods, including interaction with the highland centers of Monte Albán and Teotihuacán.