I use techniques of stable isotope geochemistry for applications in paleoenvironmental, paleoecological, and archaeological research.
I am particularly interested in understanding hydrogen and oxygen isotope ratios in fossil proteins (from bones and teeth). Bone and other calcified tissues are influenced by an individual's diet and environment, and measurement of their stable isotope ratios can help understand life in the past - migration, diet, and environment.
Hydrogen and oxygen isotopes are recorders of the past environment, including variation in precipitation isotope ratios. As precipitation is taken up by plants, then higher animals, some of the original isotopic variation remains. As a result, one can use the measured isotope ratio in bones of animals and humans to follow the past environment, including determining migration.
In addition, hydrogen isotopes in bone collagen have been shown to inform about trophic levels of humans (and fauna), but further work remains to understand the mechanism and broad applicability more clearly.
Persistent and important archaeological and palaeontological questions, such as the extent of meat eating and dairy consumption by humans have not been answered adequately with current techniques. New method developments are key to answering these questions. More generally, for paleoenvironmental, paleoecological, and archaeological applications the integration of multiple isotope measurements is important to extend the range of inferences that can be made with stable isotope techniques.
I have also worked on chemical preparation techniques for radiocarbon dating of bones and tree rings, as well as on calcium isotope ratios for applications in low-temperature geochemistry and past diet. I have an interest in stable isotope ratios as markers of the weaning process.