eprintid: 10150122 rev_number: 8 eprint_status: archive userid: 699 dir: disk0/10/15/01/22 datestamp: 2022-06-14 09:03:08 lastmod: 2023-05-28 06:10:08 status_changed: 2022-06-14 09:03:08 type: article metadata_visibility: show sword_depositor: 699 creators_name: Shi, Wei creators_name: Mills, Benjamin JW creators_name: Li, Chao creators_name: Poulton, Simon W creators_name: Krause, Alexander J creators_name: He, Tianchen creators_name: Zhou, Ying creators_name: Cheng, Meng creators_name: Shields, Graham A title: Decoupled oxygenation of the Ediacaran ocean and atmosphere during the rise of early animals ispublished: pub divisions: C06 divisions: F57 divisions: B04 divisions: UCL keywords: Ediacaran, atmospheric oxygen, oceanic sulfate, isotope mass balance, metazoan evolution note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: The Ediacaran Period (∼635 to 541 Ma) witnessed the early diversification and radiation of metazoans, in the form of the Ediacaran Biota. This biological revolution, beginning at ∼575 Ma, has been widely attributed to a temporally restricted episode of deeper ocean oxygenation, potentially caused by a contemporaneous rise in atmospheric oxygen levels. However, quantitative geochemical-record-driven estimates of Ediacaran atmospheric and oceanic redox evolution are lacking, and hence possible links between oceanic and atmospheric oxygenation remain speculative. Here, after screening for possible post-depositional alteration, we utilize paleogeographically-diverse carbon and sulfur isotope records from South China, Oman and USA-Mexico, to develop a biogeochemical isotope mass balance model to quantify Ediacaran atmospheric oxygen and oceanic sulfate evolution. Model results from all three continents indicate that Ediacaran atmospheric oxygen levels rose monotonically between ∼630 Ma and ∼590 Ma, and subsequently remained relatively stable at around 0.6 present atmospheric level for the remainder of the Ediacaran. By contrast, the marine sulfate reservoir appears to have remained relatively stable before ∼575 Ma, with a subsequent large pulse where sulfate concentrations rose to ∼8 mM. These quantitative results indicate that Ediacaran oceanic and atmospheric oxygenation were decoupled, which is consistent with published geochemical records. We propose that the early Ediacaran rise of atmospheric oxygen levels, driven by increased net burial of organic carbon and pyrite, may not have established widespread deep-ocean oxygenation. Instead, later pulsed input of oxidizing power (mainly sulfate) from the continents drove transient episodes of seafloor oxygenation that accompanied radiations of the Ediacaran Biota. date: 2022-08-01 date_type: published publisher: Elsevier BV official_url: https://doi.org/10.1016/j.epsl.2022.117619 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1958862 doi: 10.1016/j.epsl.2022.117619 lyricists_name: Krause, Alexander lyricists_id: AJRKR88 actors_name: Krause, Alexander actors_id: AJRKR88 actors_role: owner full_text_status: public publication: Earth and Planetary Science Letters volume: 591 article_number: 117619 issn: 0012-821X citation: Shi, Wei; Mills, Benjamin JW; Li, Chao; Poulton, Simon W; Krause, Alexander J; He, Tianchen; Zhou, Ying; ... Shields, Graham A; + view all <#> Shi, Wei; Mills, Benjamin JW; Li, Chao; Poulton, Simon W; Krause, Alexander J; He, Tianchen; Zhou, Ying; Cheng, Meng; Shields, Graham A; - view fewer <#> (2022) Decoupled oxygenation of the Ediacaran ocean and atmosphere during the rise of early animals. Earth and Planetary Science Letters , 591 , Article 117619. 10.1016/j.epsl.2022.117619 <https://doi.org/10.1016/j.epsl.2022.117619>. Green open access document_url: https://discovery-pp.ucl.ac.uk/id/eprint/10150122/1/Shi_et_al_2022_EPSL_final.pdf