Construction of a low-level 14C facility at the University of Arizona

University Of Arizona, Tucson AZ

Investigators

Abstract

With National Science Foundation support, Drs. J. Quade, A. Jull and N. Lifton at the University of Arizona will build a new, state-of-the-art laboratory facility that will permit carbon-14 dating of very old samples, beyond about 45,000 years. Carbon-14 dating is an essential dating technique for archeologists and geologists alike, and its use in samples younger than 40,000 years old is relatively straightforward. In samples older than that, so little of the original carbon-14 is left for dating that samples are easily contaminated by younger carbon-14 in the air and from natural waters, thus making samples appear much younger than they are. The proposed facility at Arizona will be specifically constructed to deal with these old samples by removing minute quantities of contamination, and by thoroughly isolating samples from the atmosphere during the extraction process. If all goes as planned, it will be possible to reliably date previously undatable archeological material in the 40-60,000 years range. Archeologists stand to benefit the most from these new analytical capabilities. As just one example, there is a highly contentious debate among archaeologists over the timing and geographic extent of the coexistence between Neanderthals and anatomically modern human populations in Europe during the period ~30 to 50 14C kyr B.P. In recent decades a complex picture has emerged of the temporal and geographic overlap between Middle and Upper Paleolithic populations. The basis for this view is largely radiocarbon dating of a large number of new and re-excavated sites, mostly using the standard 14C dating method on charcoal. What is suggested from the dating of these sites is that Neanderthal and anatomically modern human populations may have lived adjacent to each other for thousands of years in parts of western Europe. Our facility, once constructed, will be uniquely positioned to examine whether these and other reconstructions of the peopling of Europe are chronologically sound or merely artifacts of contamination. The Department of Anthropology at the University of Arizona recently received an IGERT (Integrative Graduate Education and Research Traineeship Program) grant from NSF intended to train geoarchaeology and archaeology students in one of three research areas: chronometry, paleoecology, and technology. At least one and perhaps two IGERT fellowship students will join this project and make the development and applications of the new extraction lines either all or part of their graduate research. The proposed research described herein is exactly the kind of graduate student training opportunity in innovative new directions envisioned by the IGERT program. When the new extraction lines are constructed relevant archaeological samples will be obtained and analyzed. .