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Oxygenation of the Archean atmosphere: New paleosol constraints from eastern India

2014; Geological Society of America; Volume: 42; Issue: 10 Linguagem: Inglês

10.1130/g36091.1

1943-2682

Joydip Mukhopadhyay, Quentin Crowley, Sampa Ghosh, Gautam Ghosh, Kalyan Chakrabarti, Brundaban Misra, Kyle Heron, Sankar Bose,

Paleontology and Stratigraphy of Fossils

Research Article| October 01, 2014 Oxygenation of the Archean atmosphere: New paleosol constraints from eastern India Joydip Mukhopadhyay; Joydip Mukhopadhyay 1Department of Geology, Presidency University, Kolkata 700073, India Search for other works by this author on: GSW Google Scholar Quentin G. Crowley; Quentin G. Crowley * 2Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland *E-mail: crowleyq@tcd.ie. Search for other works by this author on: GSW Google Scholar Sampa Ghosh; Sampa Ghosh 1Department of Geology, Presidency University, Kolkata 700073, India Search for other works by this author on: GSW Google Scholar Gautam Ghosh; Gautam Ghosh 1Department of Geology, Presidency University, Kolkata 700073, India Search for other works by this author on: GSW Google Scholar Kalyan Chakrabarti; Kalyan Chakrabarti 1Department of Geology, Presidency University, Kolkata 700073, India3Atomic Minerals Directorate, Eastern Region, Jharkhand 831002, India Search for other works by this author on: GSW Google Scholar Brundaban Misra; Brundaban Misra 1Department of Geology, Presidency University, Kolkata 700073, India3Atomic Minerals Directorate, Eastern Region, Jharkhand 831002, India Search for other works by this author on: GSW Google Scholar Kyle Heron; Kyle Heron 2Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland Search for other works by this author on: GSW Google Scholar Sankar Bose Sankar Bose 1Department of Geology, Presidency University, Kolkata 700073, India Search for other works by this author on: GSW Google Scholar Geology (2014) 42 (10): 923–926. https://doi.org/10.1130/G36091.1 Article history received: 18 Jul 2014 rev-recd: 31 Jul 2014 accepted: 01 Aug 2014 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Joydip Mukhopadhyay, Quentin G. Crowley, Sampa Ghosh, Gautam Ghosh, Kalyan Chakrabarti, Brundaban Misra, Kyle Heron, Sankar Bose; Oxygenation of the Archean atmosphere: New paleosol constraints from eastern India. Geology 2014;; 42 (10): 923–926. doi: https://doi.org/10.1130/G36091.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract It is widely believed that atmospheric oxygen saturation rose from 10−2 PAL at the Great Oxidation Event (GOE) at ca. 2.4 Ga, but it is unclear if any earlier oxygenation events occurred. Here we report U-Pb zircon data indicating that a pyrophyllite-bearing paleosol, from Keonjhar in the Precambrian Singhbhum Craton of eastern India, formed between 3.29 and 3.02 Ga, making it one of very few known Archean paleosols globally. Field and geochemical evidence suggests that the upper part of the paleosol was eroded prior to unconformable deposition of an overlying sequence of shallow-marine siliciclastic sediments. A negative cerium anomaly within the currently preserved level of the paleosol indicates that ancient oxidative weathering occurred in the original upper soil profile. The presence of redox-sensitive detrital uraninite and pyrite together with a complete absence of pyrophyllite in the overlying sediments indicate that the mineralogical and geochemical features of the paleosol were established prior to the unconformable deposition of the sediments and are not related to subsequent diagenetic or hydrothermal effects. We suggest that a transient atmospheric oxygenation event occurred at least 600 m.y. prior to the GOE and ∼60 m.y. prior to a previously documented Archean oxygenation event. We propose that several pulsed and short-lived oxygenation events are likely to have occurred prior to the GOE, and that these changes to atmospheric composition arose due to the presence of organisms capable of oxygenic photosynthesis. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.