Obsidian acquisition networks in northern Ecuador from 1600 to 750 cal BCE

Since a pair of seminal studies in the mid-1990́s, obsidian provenience research in Ecuador has shown limited advancement with regard to analysis of archaeological materials. Investigations of the relevant sources have been the primary focus. While these are important, especially given the complex nature of the major Ecuadorian sources, more investigation is required to analyze how prehispanic populations acquired this material that frequently is used as a proxy for interregional interaction. This article advances our understanding on this front by presenting the portable X-Ray Fluorescence (pXRF) analysis of 401 artifacts from five sites in northern Ecuador with absolute dates spanning from 1600 to 750 cal BCE. The results permit a finer-grained reconstruction of procurement patterns than the typical relative period approach. Three principal findings are proposed: the utilization of Yanaurco-Quiscatola obsidian declined during the period of interest, the Mullumica source became the center of obsidian procurement as the utilization of these other sources fell, and two interregional networks existed that resulted in populations on the northern Ecuadorian coast acquiring obsidian.