The Bauer, Kohen W. creator Planavsky, Noah J. author. Reinhard, Christopher T. author. Cole, Devon B. author. text enk London Cambridge University Press 2021 monographic eng 1 online resource (26 pages) : digital, PDF file(s). The stable chromium (Cr) isotope system has emerged over the past decade as a new tool to track changes in the amount of oxygen in earth's ocean-atmosphere system. Much of the initial foundation for using Cr isotopes (δ53Cr) as a paleoredox proxy has required recent revision. However, the basic idea behind using Cr isotopes as redox tracers is straightforward-the largest isotope fractionations are redox-dependent and occur during partial reduction of Cr(VI). As such, Cr isotopic signatures can provide novel insights into Cr redox cycling in both marine and terrestrial settings. Critically, the Cr isotope system-unlike many other trace metal proxies-can respond to short-term redox perturbations (e.g., on timescales characteristic of Pleistocene glacial-interglacial cycles). The Cr isotope system can also be used to probe the earth's long-term atmospheric oxygenation, pointing towards low but likely dynamic oxygen levels for the majority of Earth's history. Title from publisher's bibliographic system (viewed on 05 Feb 2021). Chromium Isotopes Oxidation-reduction reaction Environmental geochemistry 546.532 Elements in geochemical tracers in Earth system science 9781108870443 (ebook) https://doi.org/10.1017/9781108870443 https://doi.org/10.1017/9781108870443 UkCbUP 191014 eng