Stable Isotope Geobiology

Stable isotopes are tools that geobiologists use to investigate natural and experimental systems, with questions ranging from those aimed at modern environments and extant microorganisms, to deep time and the ancient Earth. In addition to a wide range of timescales, stable isotopes can be applied over a vast range of spatial scales. Isotope studies inform our understanding of bulk planetary compositions, global element cycles, down to the metabolism of single cells. With roots extending back to the first half of the twentieth century (Urey, 1947), stable isotope geobiology recently emerged as a scientific discipline with questions rooted in geology and Earth history, with methods adopted from nuclear chemistry