Patagonian Obsidians: A Geographical and Geochemical Review on a Macroregional Scale

Abstract This work presents a macroregional review of all known geochemical groups and natural obsidian deposits in Argentinian and Chilean Patagonia. After reviewing archaeological and geological antecedents, we compiled information about the geochemical groups, their locations, and the most outstanding characteristics of the obsidian deposits in this area. We found 30 geochemical groups and more than 50 obsidian deposits in Patagonian territory; most were already known from archaeological studies, but eight had been identified only in geological reports and had not been archaeologically discussed. Nine deposits are still geochemically unknown. We observed significant variations in the locations of the deposits and the distribution of the geochemical types and recommend that geoarchaeological-based programs be developed to enhance the scope of our findings.