F-content variation in mammoth ivory from Aurignacian contexts: Preservation, alteration, and implications for ivory-procurement strategies

This article presents the results of two series of micro-PIXE/PIGE analysis on mammoth ivory samples from four Aurignacian sites in France (Abri Castanet, Grotte d'Isturitz) and Germany (Hohle Fels, Vogelherd). Specifically, we report variation in ivory preservation as indicated by fluorine (F) content and ratios of MgO/CaO from Aurignacian horizons known to contain ivory industries. Though all samples derive from respectively homogenous sedimentary contexts, results show very different pattern of F-content variation among sites. F uptake in ivory is a more complex process than that observed for bone, and the structural/morphological reasons for this are explained. High-resolution data on the archaeological context of the samples from Abri Castanet also allows for examination of the effects of horizontal and vertical distribution on F-content and the sorting of F-content data by sedimentary unit. A definitive model for fluorine uptake during ivory diagenesis will require further investigation, but a close examination of the current data provides novel insight into processes of taphonomy and diagenesis in this exceptional and highly valued raw material, as well as further evidence to support regionally distinct strategies of ivory procurement in the Early Aurignacian. In combination with additional lines of faunal and archaeological evidence, it is demonstrated that ivory procurement in the Swabian Jura focused on fresh local sources of ivory, while procurement strategies in Northern Aquitaine focused on ivory collection from natural deposits of varying age.