Chemical Characteristics of Obsidian from Archaeological Sites in Western Mexico and the Tequila Source Area: Implications for Regional and Pan-Regional Interaction Within the Northern Mesoamerican Periphery

A total of 51 obsidian samples from archaeological sites in western Mexico (La Quemada, Totoate, Las Ventanas, Laguna San Marcos) and from the Tequila source area were analyzed chemically by direct-current plasma atomic emission spectrometry (DCP) and instrumental neutron activation analysis (INAA) in an effort to identify the sources of the archaeological obsidian by step-wise discriminant analysis of the data. Surprisingly, only 3 of the 39 archaeological samples (2 from Laguna San Marcos and 1 from Las Ventanas) could be correlated with a Volcán Tequila source (Teuchitlan). Four other groups of archaeological obsidian were recognized. The largest, Group Y, was found to be derived from the La Lobera source located near the Jalisco–Zacatecas border. This source accounted for 12% of La Quemada obsidian and a higher proportion for Las Ventanas and Totoate. Source locations for the remaining three groups could not be determined from the existing chemical data base. These results could indicate that a minimum of interaction took place between La Quemada and the Teuchitlan cultural tradition. It shows that one focus of La Quemada's trade endeavors was in the Río Bolaños/Tlaltenango valleys. This study also indicates that organized obsidian trade between the Mexican core and its outer periphery was probably not a factor between a.d. 400 and 800.