Reconstructing Paleoredox Conditions through a Multitracer Approach: The Key to the Past Is the Present

Knowledge about paleoredox conditions is essential for reconstructing how the oxygenation of the Earth’s surface environment has changed through time and affected the evolution of life on our planet. Some metal stable isotope systems, such as Mo isotopes, record the extent of ocean oxygenation directly. Others, such as Fe isotopes, record redox conditions indirectly through their effects on biological processes that are sensitive to the presence of oxygen. Studies of modern analogs and experiments have improved our understanding of the processes responsible for the observed isotope trends and have helped to advance the use of these isotope tools for paleoredox reconstructions.