A NEW RADIOCARBON PRETREATMENT METHOD FOR MOLLUSCAN SHELL USING DENSITY FRACTIONATION OF CARBONATES IN BROMOFORM

作者:Russo Christopher M; Tripp Jennifer A*; Douka Katerina; Higham Thomas F G
来源:Radiocarbon, 2010, 52(3): 1301-1311.
DOI:10.1017/S0033822200046397

摘要

Coastal archaeological sites that lack organic remains for radiocarbon dating are often abundant sources of molluscan shells. As a substitute for materials such as bone and charcoal, shells can be analyzed with (14)C dating to determine a site's age. Despite their being convenient, non-mobile archaeological artifacts, molluscan shells are plagued by several issues, including carbonate remodeling, in which aragonite in shells is converted to calcite as predicted by thermodynamics. We present here a carbonate density separation technique that addresses the issue of carbonate remodeling. Using a density fractionation with bromoform, aragonite concentrations are enriched in shells that have undergone significant remodeling. The technique has been applied to archaeological shells and has returned dates that are younger than those previously determined for the same shells.

  • 出版日期2010