An Experimental Program for Obsidian Use-Wear Analysis in Central Mexican Archaeology

Abstract

Obsidian tools are ubiquitous at archaeological sites throughout the pre-Hispanic period (ca. 1500 B.C.–A.D. 1521) in central Mexico. However, the method of high-magnification use-wear analysis has been underutilized for functional interpretations of obsidian tools in the region, especially compared to lithic studies in sub-Saharan Africa, Europe, Oceania, and North America. In order to establish a reliable foundation for future archaeological investigations of obsidian tool functions, I performed approximately 300 experiments with 145 obsidian tool specimens controlling for two obsidian sources, two activity durations, and 29 different materials that were accessible to pre-Hispanic residents of central Mexico. This paper synthesizes results from prior experimental obsidian use-wear studies with the results from my experiments and discusses their broader impacts for use-wear analysts working in all regions as well as specific implications for future use-wear projects in central Mexico. This paper also presents high-quality images of use-wear characteristics and their patterns linked to specific materials in order to stimulate student training and comparisons between studies. Results indicate that the start times for initial use-wear patterns resulting from slicing meat, fish, maize, and soft plants, respectively, can be revised down to 5 min of tool use. There are distinct use-wear patterns for maguey heart scraping and maguey leaf scraping, which are new and crucial findings for archaeologists interested in ancient practices of pulque and fiber production. Finally, human and animal blood residues can be observed microscopically on obsidian tool surfaces and removed for presumptive testing using Hemastix® strips.