Prehistoric Use of an Obsidian-Rich Ignimbrite Deposit, Northwestern Patagonia

GARVEY, RAVEN; BARBERENA, RAMIRO; RUGHINI, AGUSTINA A.; FERNÁNDEZ, M. VICTORIA; ROMERO VILLANUEVA, GUADALUPE; MACDONALD, BRANDI LEE

Conferencia; International Obsidian Conference 2021; 2021

Volcanism in and adjacent to the Andes of northwestern Patagonia (36°?37° S) has produced several sources of volcanic glass. For roughly two decades, the prevalence of obsidian in the region?s archaeological record has spurred a concerted effort to document and geochemically characterize these sources, and we now understand the region to be a complex ?source-scape.? Cueva Yagui is an important, serially-reoccupied cave site (ca. 8500 ? 1850 cal BP) in the southern part of this region, located < 1 km from a recently identified obsidian-rich ignimbrite deposit (Cerro Huenul). Not surprisingly, X-ray fluorescence established that 86% of the site?s obsidian artifacts are from this source. However, hydration rim measurements (optical and SIMS) suggest routine scavenging of Huenul obsidian, which has interesting implications for understanding Cueva Yagui inhabitants? stone consumption and related behaviors (e.g., subsistence and settlement patterns). Here, we present and contextualize the Cueva Yagui obsidian data to discuss the economics of immediately local Huenul obsidian, and an intriguing discrepancy between the hydration data and a several-thousand-year gap in the site?s radiocarbon record.