Show simple item record

dc.contributor.authorHuang, G
dc.contributor.authorEager, JK
dc.contributor.authorMayne, NJ
dc.contributor.authorCui, D
dc.contributor.authorManners, J
dc.contributor.authorHebrard, E
dc.contributor.authorLiu, Z
dc.contributor.authorLenton, TM
dc.date.accessioned2021-10-22T08:49:39Z
dc.date.issued2021-10-14
dc.description.abstractIt is widely accepted that atmospheric pO2 < 1 ppm before the Great Oxidation Event. Yet a recent study found fossil micrometeorites (MMs) containing the oxidized iron species wüstite (FeO) and magnetite (Fe3O4) formed 2.7 billion years ago (Ga). How these MMs became oxidized is uncertain. Abundant O2 in the upper atmosphere and iron oxidation by CO2 have been suggested. However, photochemical reactions cannot produce sufficient O2, and oxidation by CO2 can only produce FeO, each individually failing to explain the formation of Fe3O4-only MMs. Using an oxidation model of iron MMs including photochemistry, we show that a >32% CO2 Archean atmosphere and different entry angles can generate the Fe3O4-only and Fe-FeO mixed composition MMs that have been discovered. Oxidation happens in two stages: by CO2 under brief melting, then by O2. Our results challenge existing constraints on Earth’s atmospheric CO2 concentration at 2.7 Ga and support a warm Late Archean despite the ‘faint young Sun’.en_GB
dc.description.sponsorshipScience and Technology Facilities Council (STFC)en_GB
dc.description.sponsorshipUKRIen_GB
dc.description.sponsorshipNatural Environment Research Council (NERC)en_GB
dc.description.sponsorshipChina Scholarship Council.
dc.description.sponsorshipHill Family Scholarship
dc.identifier.citationVol. 366, article 106423en_GB
dc.identifier.doi10.1016/j.precamres.2021.106423
dc.identifier.grantnumberST/R000395/1en_GB
dc.identifier.grantnumberMR/T040866/1en_GB
dc.identifier.grantnumberNE/P013651/1en_GB
dc.identifier.urihttp://hdl.handle.net/10871/127550
dc.language.isoenen_GB
dc.publisherElsevieren_GB
dc.rights.embargoreasonUnder embargo until 14 October 2022 in compliance with publisher policyen_GB
dc.rights© 2021. This version is made available under the CC-BY-NC-ND 4.0 license: https://creativecommons.org/licenses/by-nc-nd/4.0/  en_GB
dc.titleCO2 and O2 oxidized 2.7 Ga micrometeorites in two stages suggesting a >32% CO2 atmosphereen_GB
dc.typeArticleen_GB
dc.date.available2021-10-22T08:49:39Z
dc.identifier.issn0301-9268
exeter.article-number106423en_GB
dc.descriptionThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record en_GB
dc.identifier.journalPrecambrian Researchen_GB
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/en_GB
dcterms.dateAccepted2021-10-02
exeter.funder::Leverhulme Trusten_GB
exeter.funder::Medical Research Council (MRC)en_GB
rioxxterms.versionAMen_GB
rioxxterms.licenseref.startdate2021-10-14
rioxxterms.typeJournal Article/Reviewen_GB
refterms.dateFCD2021-10-22T08:44:19Z
refterms.versionFCDAM
refterms.panelBen_GB


Files in this item

This item appears in the following Collection(s)

Show simple item record

© 2021. This version is made available under the CC-BY-NC-ND 4.0 license: https://creativecommons.org/licenses/by-nc-nd/4.0/  
Except where otherwise noted, this item's licence is described as © 2021. This version is made available under the CC-BY-NC-ND 4.0 license: https://creativecommons.org/licenses/by-nc-nd/4.0/