Alterations ofin vivoelemental dietary signatures in archaeological bone: evidence from the Roonka Flat Dune, South Australia

Abstract

Thermogravimetric and multi-element analyses of archaeological human rib and modem mammal controls from the lower Murray River region of South Australia indicate that magnesium, strontium, and barium concentrations in the archaeological bone have been altered significantly by post-mortem chemical reactions in the burial environment. Ionic exchanges between soil solution and buried bone resulted in lower bone magnesium concentrations and higher bone strontium and barium concentrations. Much of the remaining magnesium is associated with diagenetic calcite. Although the archaeological bone exhibits increased hydroxyapatite crystal size, the strontium and barium increases are not correlated with crystal growth. The complex interactions of these post-depositional chemical processes will complicate attempts to reconstruct in vivo elemental values from archaeological bone.