Water Isoscapes as a tool for the assessment of region-of-origin and animal movements

VALENZUELA, LUCIANO O

San Rafael

Conferencia; 12th International Conference of Archaeozoology; 2014

The stable isotope abundances of biological tissues often contain information that is of interest to region-of-origin assignment and animal movement in archaeological investigations. The use of stable hydrogen and oxygen isotopes for these studies is a fast growing field due to the predictable geographic variations in the isotope values of meteoric water. Research thus far has mainly used empirical correlations to predict the isotopic values of animals based on the isotope values of their drinking water. A limitation to this approach is that it cannot easily be used in cases where the drinking water is unknown. Therefore, predictions of drinking water isotope values are necessary and usually take the shape of a predictive map, called isoscape. Coupled to the need to develop isoscapes, there is a need to assist correlational predictions, of animal tissues, with the development of process based models that predict the isotopic composition of tissues by also incorporating the animal?s physiology, ecology and environment. Here I present an evaluation of current isoscapes of precipitation, focusing in Argentina, highlighting areas where predicted values depart from measured values. In the presentation I propose a collaborative sampling scheme to improve the accuracy of these isoscapes. Finally, I present two process-based mechanistic models that predict isotope values of vertebrate tissues (Artiodactyla and Primates) that can be applied, as well as expanded, to other species found in the archaeological record. The models were tested with samples from animals raised in captivity along an isotopic range (Artiodactyla) and under controlled diets (Primates).