14C-AMS as a tool for archaeological investigation: Implications for Human Settlement in South America

Abstract

In this paper, we present an overview of 14C methods, Accelerator Mass Spectrometry (AMS) techniques, and their applications to radiocarbon dating of archaeological sites in South America. We describe sample preparation methods to be applied to archaeological bone samples as well as useful sample selection strategies to help achieve reliable AMS-based 14C results. Application of criteria to determine bone quality (to assess lack of alteration and degradation) before and during sample preparation, and the use of a modified ultrafiltration method to extract collagen from these kinds of materials have enabled us to obtain reliable radiocarbon results. Two applications will be presented to illustrate these issues: a) Paleodietary inferences from isotopic measurements on human bone and teeth from the populations of the central mountains of Argentina, and b) the implication of new 14C determinations obtained from two segments of a single mastodon bone recovered from Monte Verde, that previously differed by more than 5,000 years.