Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle
The Paleocene-Eocene Thermal Maximum (PETM, ca. 56 Ma) is marked by a negative carbon isotope excursion (CIE) and increased global temperatures. The CIE is thought to result from the release of 13C-depleted carbon, although the source(s) of carbon and triggers for its release, its rate of release, a...
Published in: | Paleoceanography and Paleoclimatology |
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Online Access: | https://hdl.handle.net/1983/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://research-information.bris.ac.uk/en/publications/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://doi.org/10.1029/2020PA003873 https://research-information.bris.ac.uk/ws/files/234308173/2020PA003873.pdf |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/b87d68a3-5ce2-40b2-a316-0573816a77b1 2024-02-04T10:02:46+01:00 Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle Fontorbe, Guillaume Frings, Patrick De La Rocha, Christina Hendry, Katharine Conley, Daniel 2020-05-01 application/pdf https://hdl.handle.net/1983/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://research-information.bris.ac.uk/en/publications/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://doi.org/10.1029/2020PA003873 https://research-information.bris.ac.uk/ws/files/234308173/2020PA003873.pdf eng eng info:eu-repo/semantics/openAccess Fontorbe , G , Frings , P , De La Rocha , C , Hendry , K & Conley , D 2020 , ' Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle ' , Paleoceanography and Paleoclimatology , vol. 35 , no. 5 , e2020PA003873 . https://doi.org/10.1029/2020PA003873 article 2020 ftubristolcris https://doi.org/10.1029/2020PA003873 2024-01-11T23:44:01Z The Paleocene-Eocene Thermal Maximum (PETM, ca. 56 Ma) is marked by a negative carbon isotope excursion (CIE) and increased global temperatures. The CIE is thought to result from the release of 13C-depleted carbon, although the source(s) of carbon and triggers for its release, its rate of release, and the mechanisms by which the Earth system recovered are all debated. Many of the proposed mechanisms for the onset and recovery phases of the PETM make testable predictions about the marine silica cycle, making silicon isotope records a promising tool to address open questions about the PETM. We analyzed silicon isotope ratios (δ30Si) in radiolarian tests and sponge spicules from the Western North Atlantic (ODP Site 1051) across the PETM. Radiolarian δ30Si decreases by 0.6‰ from a background of 1‰ coeval with the CIE, while sponge δ30Si remains consistent at 0.2‰. Using a box-model to test the Si cycle response to various scenarios, we find the data are best explained by a weak silicate weathering feedback, implying the recovery was mostly driven by non-diatom organic carbon burial, the other major long-term carbon sink. We find no resolvable evidence for a volcanic trigger for carbon release, or for a change in regional oceanography. Better understanding of radiolarian Si isotope fractionation and more Si isotope records spanning the PETM are needed to confirm the global validity of these conclusions, but they highlight how the coupling between the silica and carbon cycles can be exploited to yield insight into the functioning of the Earth System. Article in Journal/Newspaper North Atlantic University of Bristol: Bristol Research Paleoceanography and Paleoclimatology 35 5 |
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University of Bristol: Bristol Research |
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ftubristolcris |
language |
English |
description |
The Paleocene-Eocene Thermal Maximum (PETM, ca. 56 Ma) is marked by a negative carbon isotope excursion (CIE) and increased global temperatures. The CIE is thought to result from the release of 13C-depleted carbon, although the source(s) of carbon and triggers for its release, its rate of release, and the mechanisms by which the Earth system recovered are all debated. Many of the proposed mechanisms for the onset and recovery phases of the PETM make testable predictions about the marine silica cycle, making silicon isotope records a promising tool to address open questions about the PETM. We analyzed silicon isotope ratios (δ30Si) in radiolarian tests and sponge spicules from the Western North Atlantic (ODP Site 1051) across the PETM. Radiolarian δ30Si decreases by 0.6‰ from a background of 1‰ coeval with the CIE, while sponge δ30Si remains consistent at 0.2‰. Using a box-model to test the Si cycle response to various scenarios, we find the data are best explained by a weak silicate weathering feedback, implying the recovery was mostly driven by non-diatom organic carbon burial, the other major long-term carbon sink. We find no resolvable evidence for a volcanic trigger for carbon release, or for a change in regional oceanography. Better understanding of radiolarian Si isotope fractionation and more Si isotope records spanning the PETM are needed to confirm the global validity of these conclusions, but they highlight how the coupling between the silica and carbon cycles can be exploited to yield insight into the functioning of the Earth System. |
format |
Article in Journal/Newspaper |
author |
Fontorbe, Guillaume Frings, Patrick De La Rocha, Christina Hendry, Katharine Conley, Daniel |
spellingShingle |
Fontorbe, Guillaume Frings, Patrick De La Rocha, Christina Hendry, Katharine Conley, Daniel Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
author_facet |
Fontorbe, Guillaume Frings, Patrick De La Rocha, Christina Hendry, Katharine Conley, Daniel |
author_sort |
Fontorbe, Guillaume |
title |
Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
title_short |
Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
title_full |
Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
title_fullStr |
Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
title_full_unstemmed |
Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle |
title_sort |
constraints on earth system functioning at the paleocene-eocene thermal maximum from the marine silicon cycle |
publishDate |
2020 |
url |
https://hdl.handle.net/1983/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://research-information.bris.ac.uk/en/publications/b87d68a3-5ce2-40b2-a316-0573816a77b1 https://doi.org/10.1029/2020PA003873 https://research-information.bris.ac.uk/ws/files/234308173/2020PA003873.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Fontorbe , G , Frings , P , De La Rocha , C , Hendry , K & Conley , D 2020 , ' Constraints on Earth system functioning at the Paleocene-Eocene Thermal Maximum from the marine silicon cycle ' , Paleoceanography and Paleoclimatology , vol. 35 , no. 5 , e2020PA003873 . https://doi.org/10.1029/2020PA003873 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2020PA003873 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
35 |
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5 |
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