A03_P01
Comparing Apatite and Collagen Radiocarbon dates from a 16th century Cemetery Context – El Japón, Xochimilco, Mexico City
Alarcón Tinajero E1,2, Hadden C2, Cherkinsky A2, Villegas Camposeco B3, Gómez-Valdés J3,4
1Department of Anthropology, University of Georgia, Athens, United States, 2Center for Applied Isotope Studies, University of Georgia, Athens, United States, 3Escuela Nacional de Antropología e Historia, Posgrado en Antropología Física, Mexico City, Mexico, 4Instituto Nacional de Antropología e Historia, Mexico City, Mexico
El Japón is a sixteenth century hamlet site occupying the marshlands of the southern Basin of Mexico in central Mesoamerica. Radiocarbon dating and OxCal modelling of human bone collagen (n=11) identifies a range of burials at El Japón cemetery from 1550-1650 cal. CE. The radiocarbon chronology identifies use of this rural settlement well after the onset of colonial government-sponsored relocation of Indigenous people to larger settlements – congregaciones. Radiocarbon dating in historic archaeology often takes a secondary role in comparison to artifact typologies and reliance on historical records – the Basin of Mexico is no exception. Historically documented information in this work refines chronological modelling beyond stand-alone calibration. Stable isotopic study of bone samples demonstrates similar sources of dietary protein and carbohydrates. Similarity of carbon sources for bone apatite and collagen offers security that both bone fractions are viable radiocarbon dating opportunities. Recent extension of this work examines apatite radiocarbon dates (n=6) from the same bone samples when restricted collagen quality parameters are met – atomic carbon-nitrogen ratios of 3.2-3.3 and collagen yield of 10-20%. No significant difference is found between paired collagen and apatite dates for five of six individuals. Radiocarbon dates from human bone samples in this primarily terrestrial dietary context can be successfully acquired from either collagen or apatite fractions.