Obsidian geochemistry, geoarchaeology, and lithic technology in northwestern Patagonia (Argentina)

M. V. FERNÁNDEZ; R. BARBERENA; A. RUGHINI; M. GIESSO; V. CORTEGOSO; V. DURÁN; G. ROMERO VILLANUEVA; K. BORRAZZO; G. LUCERO; R. GARVEY; B. L. MACDONALD; M. D. GLASCOCK

Journal of Archaeological Science: Reports

Elsevier

Lugar: New York; Año: 2017 vol. 13 p. 372 - 381

2352-409X

We studied the organization of mobility of hunter-gatherers groups of northwestern Patagonia (Argentina) from an interdisciplinary perspective. We combined geochemical and technological characterization of archaeological obsidian assemblages from surface and stratigraphic contexts spanning the Holocene, and a preliminary geoarchaeological study of the sources. The goals were to assess the provenance, mode of supply, use, and discard of the obsidian artifacts on the basis of information available on the structure of the two main regional obsidian sources: Cerro Huenul (secondary deposits), located in the lowlands, and Laguna del Maule (primary and secondary outcrops), located in the Andean highlands. On the one hand, we conducted geoarchaeological field sampling at different altitudes of the Barrancas River fluvial deposits to study the geomorphic impact on the secondary structure of the highland source. The preliminary geoarcheological results allow extending the area of availability of this obsidian up to 90 km towards the lowlands from the primary outcrops, also indicating a downriver size-decreasing trend of the nodules. On the other hand, we performed non-destructive XRF analyses on 266 lithic artifacts from sites in northern Neuquén province using a portable spectrometer Bruker Tracer III-V. The artifacts were placed along a continuum of reduction. Of the analyzed artifacts, 89% corresponded to the local Cerro Huenul local source, while 11% to the Laguna del Maule source. While the artifacts made on Cerro Huenul obsidian were represented by the full reduction sequence, those from Laguna del Maule are only represented by advanced stages of reduction. With the goal of assessing different histories of place use, we integrate these results with information on the frequencies of projectile points, ceramic sherds, and rock art motifs for the two main archaeological shelter sites in the region: Cueva Huenul 1 and Cueva Yagui. These archaeological proxies indicates that the two sites have different place use histories, providing a working scheme for the analysis of human use of the regional landscape.