The Coarse Volcanic Rock Industry at the Río Ibáñez 6 West Site, Chilean Patagonia: Assessing Geogenic Versus Anthropogenic Processes

Prentiss et al. (2015, The Coarse Volcanic Rock Industry at Rio Ibáñez 6 west, Aisén Region, Patagonian Chile. Lithic Technology 40:112–127) described a unique assemblage of bifacial and unifacial tools made from coarse volcanic rock at the Río Ibáñez 6 west site in Chilean Patagonia. The artifacts offer significant implications for interpreting the behavior of late pre-Colonial peoples in this region. Garvey and Mena (2016, Re-Analysis of a recently Described Coarse Volcanic Rock Assemblage from Chilean Patagonia. Lithic Technology 41:114–129) challenge this interpretation arguing instead that the items were actually products of natural processes. They offer three tests of the natural versus cultural hypotheses, each with ambiguous results. We develop a frame of reference derived from prior knowledge of geogenic, biogenic and anthropogenic processes for a more direct evaluation of the materials in question. We then provide evidence that the assemblage is the result of human activity and offer an additional comment on differing approaches to archaeological methodology.