Obsidian exchange among hunter-gatherers in Northwestern Patagonia

Abstract

In this paper we explore the exchange of obsidian in the Diamante valley, northwestern Patagonia. Obsidian was rare in the Diamante valley, with high percentages of projectile points and bifaces, and little presence of cores and cortex—all signals of indirect access to sources. We conducted XRF sourcing analysis and technological analysis of nearly 180 obsidian specimens. We also explored least cost path analysis to discuss the access of obsidian from the Diamante valley. We found that Las Cargas was the main source used, followed by Maule 1 and 2, El Peceño, and Coche Quemado. In high contrast, the closest source, Laguna del Diamante, was the least used. We discuss that obsidian exchange had an important role through Highland villages to procure access to the rest of the valley. This also support the idea of the importance of obsidian to minimize risk at high altitude occupations. Finally, we determine the importance of obsidian and other raw materials at a macroscale to define lithic landscapes and their implications for mobility and exchange, by comparing northwestern Patagonia with the Great Basin of the US.