Morphological and Geochemical Analysis of the Laguna Blanca/Zapaleri Obsidian Source in the Atacama Puna

Abstract

This paper describes a large obsidian deposit located along the southern banks of Laguna Blanca, on the eastern slope of the Jarellón volcanic caldera near the Chilean–Bolivian border. The obsidian at this site occurs in flows or sheets of deflated black or reddish to brown pebbles, redeposited on the shores of a lake. Blocks of obsidian are only found around the caldera rim. Here we analyze the shape of the obsidian pebbles and their geochemistry, comparing them with previously published data. The results indicate that the geochemical composition of the samples strongly matches previous analyses of obsidian from cultural contexts. This obsidian source was one of the most important sites of obsidian procurement since at least the Formative Period in the Atacama Puna region.