An Essential Quaternary Clock for Earth System Sciences: An Overview of the Theory and Applications of U and Th Decay Series Isotopes for the Dating of Young Igneous and Sedimentary Rocks

Abstract U-series radionuclides provide an essential Quaternary chronometer for both igneous and sedimentary systems. Here, we overview the nuclear theory, geochemical principles, and application of U decay series isotopes for the dating of young igneous and sedimentary rocks. The various radionuclides utilized for these chronometers have a large range of half-lives and geochemical characteristics and, thus, provide temporal information on a wide range of time scales for a wide assortment of Quaternary geological problems. Specific examples are presented of individual applications in both igneous and sedimentary systems, demonstrating how, when combined with other geochemical, geochronological and observational data, the U-series chronometers often add a new gestalt of understanding. We conclude with a historical overview of current and past analytical methodologies and highlight recent enhancements in mass spectrometry that are influencing this field of study.