Obsidian Sources and Source Provenance of Archaeological Obsidian in Northern Sonora: The Known and Unknown

Abstract

A recent obsidian provenance study in three sites in the Valle de Altar region of northern Sonora has greatly expanded our understanding of the prehistoric relationship between the southern and northern Sonoran Desert. Based on obsidian source provenance, archaeological sites in the Valle de Altar indicate that contact with the region as far north as west-central and northern Arizona, the northern portion of the Papaquería, the Sierra Pinacate, the Sierra Madre Occidental, and the Basin and Range of Chihuahua was potentially frequent. However, the vast majority of artifacts produced from obsidian were procured apparently locally from an, as yet, unlocated source called here “SON Valle de Altar Unknown.” The purpose here is to discuss the relevant regional geology, the source provenance of the obsidian artifact assemblage, and relationships throughout the greater Sonoran Desert. This project also adds significant data to the Southwest Archaeological Obsidian Project (http://swxrflab.net/).