Obsidian sourcing and dynamic trade patterns at Izapa, Chiapas, Mexico: 100 BCE-400 CE

Recent research on Mesoamerican economies has demonstrated that Prehispanic trade networks were not static, but constantly evolving. Relationships between peoples in different settlements and regions shift as social, political, and economic circumstances change. One question that results from these findings is how significant events such as sociopolitical decline or abandonment affect exchange networks. This study investigates changes in obsidian procurement during a period of widespread upheaval across southern Mesoamerica, ca. 100-250 CE, from the perspective of a surviving capital on the Pacific coast of Chiapas, Mexico. X-Ray Fluorescence (XRF) analysis using a Bruker Tracer III-V was conducted for obsidian collected from Terminal Formative (100 BCE-250 CE) and initial Early Classic (250-400 CE) domestic contexts to evaluate how obsidian procurement patterns at the ancient city of Izapa were affected by events in neighboring regions. Obsidian results are compared to known shifts in sociopolitical relationships as observed through ceramics, burials, and art styles. Data indicate that residents of Izapa shifted trade from east to west over the Terminal Formative to Early Classic period transition. Patterns correspond with sociopolitical turmoil at the Guatemalan highland capital of Kaminaljuyú and the rise of the central Mexican city of Teotihuacan. Results also indicate, however, that economic relationships may continue even in places where political affiliations have been severed. Results suggest that datasets for different artifact classes, when viewed independently, introduce additional nuance into the questions of collapse and resilience of ancient societies.