FN Archimer Export Format PT J TI Triple iron isotope constraints on the role of ocean iron sinks in early atmospheric oxygenation BT AF HEARD, Andy W. DAUPHAS, Nicolas GUILBAUD, Romain ROUXEL, Olivier BUTLER, Ian B. NIE, Nicole X. BEKKER, Andrey AS 1:1,2;2:1,2;3:3;4:4;5:5;6:1,2,6;7:7,8; FF 1:;2:;3:;4:PDG-REM-GM;5:;6:;7:; C1 Univ Chicago, Dept Geophys Sci, Origins Lab, 5734 S Ellis Ave, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. CNRS, UMR5563, Geosci Environm Toulouse, F-31400 Toulouse, France. IFREMER, Unite Geosci Marines, F-29280 Plouzane, France. Univ Edinburgh, Grant Inst, Sch Geosci, Edinburgh EH9 3JW, Midlothian, Scotland. Carnegie Inst Sci, Earth & Planets Lab, Washington, DC 20015 USA. Univ Calif Riverside, Dept Earth & Planetary Sci, Riverside, CA 92521 USA. Univ Johannesburg, Dept Geol, ZA-2006 Johannesburg, South Africa. C2 UNIV CHICAGO, USA UNIV CHICAGO, USA CNRS, FRANCE IFREMER, FRANCE UNIV EDINBURGH, UK CARNEGIE INST SCI, USA UNIV CALIF RIVERSIDE, USA UNIV JOHANNESBURG, SOUTH AFRICA SI BREST SE PDG-REM-GM IN WOS Ifremer UPR copubli-france copubli-europe copubli-int-hors-europe copubli-sud IF 47.728 TC 15 UR https://archimer.ifremer.fr/doc/00657/76889/78193.pdf LA English DT Article AB The role that iron played in the oxygenation of Earth's surface is equivocal. Iron could have consumed molecular oxygen when Fe3+-oxyhydroxides formed in the oceans, or it could have promoted atmospheric oxidation by means of pyrite burial. Through high-precision iron isotopic measurements of Archean-Paleoproterozoic sediments and laboratory grown pyrites, we show that the triple iron isotopic composition of Neoarchean-Paleoproterozoic pyrites requires both extensive marine iron oxidation and sulfide-limited pyritization. Using an isotopic fractionation model informed by these data, we constrain the relative sizes of sedimentary Fe3+- oxyhydroxide and pyrite sinks for Neoarchean marine iron. We show that pyrite burial could have resulted in molecular oxygen export exceeding local Fe2+ oxidation sinks, thereby contributing to early episodes of transient oxygenation of Archean surface environments. PY 2020 PD OCT SO Science SN 0036-8075 PU Amer Assoc Advancement Science VL 370 IS 6515 UT 000581077200042 BP 446 EP 449 DI 10.1126/science.aaz8821 ID 76889 ER EF