Iodine proxy evidence for increased ocean oxygenation during the Bitter Springs Anomaly

W. Lu, S. Wörndle, G. P. Halverson, X. Zhou, A. Bekker, R. H. Rainbird, D. S. Hardisty, T. W. Lyons, Z. Lu

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


The Neoproterozoic Bitter Springs Anomaly (BSA; 810-800 Ma) is characterised by an 8 ‰ negative δ13C excursion and is coeval with multiple indicators of increasing oxygenation of the ocean and atmosphere. Here, we use carbonate iodine contents to provide the first constraints on the evolution of local upper ocean redox conditions spanning the BSA. Iodine speciation in seawater is strongly redox sensitive, and carbonates precipitated proximal to O2-depleted water record low I/(Ca + Mg). Data from the Akademikerbreen Group of Svalbard show a major rise of I/(Ca + Mg) during the recovery phase of the BSA. Other relatively high I/(Ca + Mg) values are also associated with rising δ13C throughout the section. Combined with existing palaeoredox proxies (e.g., Cr and S isotopes), our new iodine data most likely reflect an oxygenation event.

Original languageEnglish (US)
Pages (from-to)53-57
Number of pages5
JournalGeochemical Perspectives Letters
StatePublished - 2017

ASJC Scopus subject areas

  • Environmental Chemistry
  • Geology
  • Geochemistry and Petrology


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