Subglacial meltwater supported aerobic marine habitats during Snowball Earth
The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evid...
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ftpubmed:oai:pubmedcentral.nih.gov:6926012 2023-05-15T16:41:54+02:00 Subglacial meltwater supported aerobic marine habitats during Snowball Earth Lechte, Maxwell A. Wallace, Malcolm W. Hood, Ashleigh van Smeerdijk Li, Weiqiang Jiang, Ganqing Halverson, Galen P. Asael, Dan McColl, Stephanie L. Planavsky, Noah J. 2019-12-17 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926012/ http://www.ncbi.nlm.nih.gov/pubmed/31792178 https://doi.org/10.1073/pnas.1909165116 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926012/ http://www.ncbi.nlm.nih.gov/pubmed/31792178 http://dx.doi.org/10.1073/pnas.1909165116 https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . Proc Natl Acad Sci U S A Physical Sciences Text 2019 ftpubmed https://doi.org/10.1073/pnas.1909165116 2020-06-07T00:28:28Z The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that the outwash of subglacial meltwater supplied oxygen to the synglacial oceans, creating glaciomarine oxygen oases. The confluence of oxygen-rich meltwater and iron-rich seawater may have provided sufficient energy to sustain chemosynthetic communities. These processes could have supplied the requisite oxygen and organic carbon source for the survival of early animals and other eukaryotic heterotrophs through these extreme glaciations. Text Ice Shelf PubMed Central (PMC) Proceedings of the National Academy of Sciences 116 51 25478 25483 |
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English |
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Physical Sciences |
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Physical Sciences Lechte, Maxwell A. Wallace, Malcolm W. Hood, Ashleigh van Smeerdijk Li, Weiqiang Jiang, Ganqing Halverson, Galen P. Asael, Dan McColl, Stephanie L. Planavsky, Noah J. Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
topic_facet |
Physical Sciences |
description |
The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that the outwash of subglacial meltwater supplied oxygen to the synglacial oceans, creating glaciomarine oxygen oases. The confluence of oxygen-rich meltwater and iron-rich seawater may have provided sufficient energy to sustain chemosynthetic communities. These processes could have supplied the requisite oxygen and organic carbon source for the survival of early animals and other eukaryotic heterotrophs through these extreme glaciations. |
format |
Text |
author |
Lechte, Maxwell A. Wallace, Malcolm W. Hood, Ashleigh van Smeerdijk Li, Weiqiang Jiang, Ganqing Halverson, Galen P. Asael, Dan McColl, Stephanie L. Planavsky, Noah J. |
author_facet |
Lechte, Maxwell A. Wallace, Malcolm W. Hood, Ashleigh van Smeerdijk Li, Weiqiang Jiang, Ganqing Halverson, Galen P. Asael, Dan McColl, Stephanie L. Planavsky, Noah J. |
author_sort |
Lechte, Maxwell A. |
title |
Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
title_short |
Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
title_full |
Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
title_fullStr |
Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
title_full_unstemmed |
Subglacial meltwater supported aerobic marine habitats during Snowball Earth |
title_sort |
subglacial meltwater supported aerobic marine habitats during snowball earth |
publisher |
National Academy of Sciences |
publishDate |
2019 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926012/ http://www.ncbi.nlm.nih.gov/pubmed/31792178 https://doi.org/10.1073/pnas.1909165116 |
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Ice Shelf |
genre_facet |
Ice Shelf |
op_source |
Proc Natl Acad Sci U S A |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926012/ http://www.ncbi.nlm.nih.gov/pubmed/31792178 http://dx.doi.org/10.1073/pnas.1909165116 |
op_rights |
https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . |
op_doi |
https://doi.org/10.1073/pnas.1909165116 |
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Proceedings of the National Academy of Sciences |
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116 |
container_issue |
51 |
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25478 |
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25483 |
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1766032368350527488 |