Traditional Stable Isotope Geochemistry

Abstract Traditional stable isotope geochemistry is based on using small atomic mass differences between isotopes of the same element to probe earth system processes. Isotopes fractionate themselves between different phases or molecules in ways that are related to temperature and reaction mechanism. Traditional stable isotopes generally refer to those of carbon, hydrogen, nitrogen, oxygen, and sulfur, elements with relatively low atomic masses that play a significant role in geological and biological processes. The field of stable isotope geochemistry originated in the early to mid-20th century as a tool for paleoclimatology studies. Early scientists took advantage of the temperature-dependent partitioning of stable isotopes of oxygen during calcium carbonate growth to determine temperatures of ancient oceans from sediment cores. Since then, stable isotope geochemistry has expanded to include a wide range of disciplines both inside and outside of geology. Here we focus on stable isotope theory, systems, and measurement techniques relevant to disciplines in the geological sciences. We also discuss applications of traditional stable isotope systematics to hydrology, paleoclimatology, hard rock geology, biogeochemistry, and planetary science.