Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism
The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of anci...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2013
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| Online Access: | http://hdl.handle.net/1721.1/78875 https://orcid.org/0000-0002-7144-8537 |
| _version_ | 1811079074122039296 |
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| author | Bontognali, Tomaso R. R. Sessions, Alex L. Allwood, Abigail C. Fischer, Woodward W. Grotzinger, John P. Eiler, John M. Summons, Roger E |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Bontognali, Tomaso R. R. Sessions, Alex L. Allwood, Abigail C. Fischer, Woodward W. Grotzinger, John P. Eiler, John M. Summons, Roger E |
| author_sort | Bontognali, Tomaso R. R. |
| collection | MIT |
| description | The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ33S and 𝛿 [superscript 34]S[subscript CDT]. This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ33S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas 𝛿 [superscript 34]S[subscript CDT] values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H2S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ33S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities. |
| first_indexed | 2024-09-23T11:09:38Z |
| format | Article |
| id | mit-1721.1/78875 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:09:38Z |
| publishDate | 2013 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/788752024-05-15T03:13:50Z Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism Bontognali, Tomaso R. R. Sessions, Alex L. Allwood, Abigail C. Fischer, Woodward W. Grotzinger, John P. Eiler, John M. Summons, Roger E Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Summons, Roger Everett The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ33S and 𝛿 [superscript 34]S[subscript CDT]. This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ33S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas 𝛿 [superscript 34]S[subscript CDT] values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H2S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ33S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities. Exobiology Program (U.S.) Caltech Center for Microanalysis Swiss National Science Foundation 2013-05-14T14:16:28Z 2013-05-14T14:16:28Z 2012-09 2012-05 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/78875 Bontognali, T. R. R., A. L. Sessions, A. C. Allwood, et al. 2012From the Cover: Sulfur Isotopes of Organic Matter Preserved in 3.45-billion-year-old Stromatolites Reveal Microbial Metabolism. Proceedings of the National Academy of Sciences 109(38): 15146–15151. https://orcid.org/0000-0002-7144-8537 en_US http://dx.doi.org/10.1073/pnas.1207491109 Proceedings of the National Academy of Sciences of the United States of America Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) PNAS |
| spellingShingle | Bontognali, Tomaso R. R. Sessions, Alex L. Allwood, Abigail C. Fischer, Woodward W. Grotzinger, John P. Eiler, John M. Summons, Roger E Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title | Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title_full | Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title_fullStr | Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title_full_unstemmed | Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title_short | Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism |
| title_sort | sulfur isotopes of organic matter preserved in 3 45 billion year old stromatolites reveal microbial metabolism |
| url | http://hdl.handle.net/1721.1/78875 https://orcid.org/0000-0002-7144-8537 |
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