Sources of imported obsidian at postclassic sites in the Yautepec Valley, Morelos: A characterization study using XRF and INAA

This paper presents the results of obsidian characterization analyses for Middle and Late Postclassic sites in the Yautepec Valley of Morelos, central Mexico. A large sample (N = 390) of obsidian blades from excavated domestic contexts at the site of Yautepec and from surface collected contemporary sites were assigned to a quarry source using X-ray fluorescence (XRF), and a subsample was also analyzed with instrumental neutron activation analysis (INAA). The use of XRF allowed the authors to expand the number of artifacts initially analyzed by INAA. These larger samples of sourced material prove essential to answering research questions regarding regional economies, particularly with regard to issues such as production and exchange. This study demonstrates the complementarity of XRF and INAA and the specific advantages inherent in each of these techniques.