The provenance of archaeological obsidian artifacts from Northern Chile determined by source-induced X-ray fluorescence

Abstract

A study of provenance of obsidian artifacts from "site 25-Las Estacas", Quebrada de Jorquera (Copiapo, Northern Chile) was carried out by means of X-ray fluorescence, using radioactive sources. Obsidian samples from different Chilean geological regions, located in South Central Chile (Laguna del Maule volcanic area, sources of La Coloradas and La Plata), "Radal Siete Tazas" and the North of Chile (Copiapo Volcano) were analyzed. The analysis was performed using Cd-109 and Am-241 annular excitation sources and X-ray fluorescence. This allowed the determination of Fe, Cu, Rb, Sr, Y, Zr, and Ba concentrations on samples of ground obsidian from the aforementioned sites. The measured Rb, Sr, and Zr concentrations were used to construct discriminant diagrams, which clearly showed clustering of the samples from the different sources, and the association of the archaeological obsidian sample to the Copiapo Volcano source, which is geographically close to the site.