Radiocarbon laboratory at the national autonomous university of mexico: First set of samples and new 14c internal reference material

Abstract

This contribution reports the first set of samples and the creation of an internal reference material at the recently opened Radiocarbon Laboratory at the National Autonomous University of Mexico (UNAM). Samples for the initial measurements were selected from archaeological and dating projects on Teotihuacán, one of the largest and best-studied Mesoamerican urban and ceremonial centers. The 14C dates were compared to results obtained by 2 other laboratories in order to assess the results obtained at UNAM and validate the adopted methodology. As part of the quality assurance protocol, an internal reference material was created that consists of charred wood from the Teotihuacán site with a 14C activity in the value range expected for samples from Mesoamerican archaeological sites. Results from 7 analyses have a mean of 1750 ± 16 BP (80.43 ± 0.16 pMC). © 2006 by the Arizona Board of Regents on behalf of the University of Arizona.