The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii)
The high-latitude oceans are key areas of carbon and heat exchange between the atmosphere and the ocean. As such, they are a focus of both modern oceanographic and palaeoclimate research. However, most palaeoclimate proxies that could provide a long-term perspective are based on calcareous organisms...
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European Geosciences Union
2020
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Online Access: | http://nora.nerc.ac.uk/id/eprint/528058/ https://nora.nerc.ac.uk/id/eprint/528058/1/bg-17-2825-2020.pdf https://doi.org/10.5194/bg-17-2825-2020 |
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ftnerc:oai:nora.nerc.ac.uk:528058 2023-05-15T18:25:45+02:00 The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) Donald, Hannah K. Foster, Gavin L. Fröhberg, Nico Swann, George E. A. Poulton, Alex J. Moore, C. Mark Humphreys, Matthew P. 2020-05-27 text http://nora.nerc.ac.uk/id/eprint/528058/ https://nora.nerc.ac.uk/id/eprint/528058/1/bg-17-2825-2020.pdf https://doi.org/10.5194/bg-17-2825-2020 en eng European Geosciences Union https://nora.nerc.ac.uk/id/eprint/528058/1/bg-17-2825-2020.pdf Donald, Hannah K.; Foster, Gavin L.; Fröhberg, Nico; Swann, George E. A.; Poulton, Alex J.; Moore, C. Mark; Humphreys, Matthew P. 2020 The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii). Biogeosciences, 17 (10). 2825-2837. https://doi.org/10.5194/bg-17-2825-2020 <https://doi.org/10.5194/bg-17-2825-2020> cc_by_4 CC-BY Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.5194/bg-17-2825-2020 2023-02-04T19:50:51Z The high-latitude oceans are key areas of carbon and heat exchange between the atmosphere and the ocean. As such, they are a focus of both modern oceanographic and palaeoclimate research. However, most palaeoclimate proxies that could provide a long-term perspective are based on calcareous organisms, such as foraminifera, that are scarce or entirely absent in deep-sea sediments south of 50∘ S in the Southern Ocean and north of 40∘ N in the North Pacific. As a result, proxies need to be developed for the opal-based organisms (e.g. diatoms) found at these high latitudes, which dominate the biogenic sediments recovered from these regions. Here we present a method for the analysis of the boron (B) content and isotopic composition (δ11B) of diatom opal. We apply it for the first time to evaluate the relationship between seawater pH, δ11B and B concentration ([B]) in the frustules of the diatom Thalassiosira weissflogii, cultured across a range of carbon dioxide partial pressure (pCO2) and pH values. In agreement with existing data, we find that the [B] of the cultured diatom frustules increases with increasing pH (Mejía et al., 2013). δ11B shows a relatively well defined negative trend with increasing pH, completely distinct from any other biomineral previously measured. This relationship not only has implications for the magnitude of the isotopic fractionation that occurs during boron incorporation into opal, but also allows us to explore the potential of the boron-based proxies for palaeo-pH and palaeo-CO2 reconstruction in high-latitude marine sediments that have, up until now, eluded study due to the lack of suitable carbonate material. Article in Journal/Newspaper Southern Ocean Natural Environment Research Council: NERC Open Research Archive Southern Ocean Pacific Biogeosciences 17 10 2825 2837 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The high-latitude oceans are key areas of carbon and heat exchange between the atmosphere and the ocean. As such, they are a focus of both modern oceanographic and palaeoclimate research. However, most palaeoclimate proxies that could provide a long-term perspective are based on calcareous organisms, such as foraminifera, that are scarce or entirely absent in deep-sea sediments south of 50∘ S in the Southern Ocean and north of 40∘ N in the North Pacific. As a result, proxies need to be developed for the opal-based organisms (e.g. diatoms) found at these high latitudes, which dominate the biogenic sediments recovered from these regions. Here we present a method for the analysis of the boron (B) content and isotopic composition (δ11B) of diatom opal. We apply it for the first time to evaluate the relationship between seawater pH, δ11B and B concentration ([B]) in the frustules of the diatom Thalassiosira weissflogii, cultured across a range of carbon dioxide partial pressure (pCO2) and pH values. In agreement with existing data, we find that the [B] of the cultured diatom frustules increases with increasing pH (Mejía et al., 2013). δ11B shows a relatively well defined negative trend with increasing pH, completely distinct from any other biomineral previously measured. This relationship not only has implications for the magnitude of the isotopic fractionation that occurs during boron incorporation into opal, but also allows us to explore the potential of the boron-based proxies for palaeo-pH and palaeo-CO2 reconstruction in high-latitude marine sediments that have, up until now, eluded study due to the lack of suitable carbonate material. |
format |
Article in Journal/Newspaper |
author |
Donald, Hannah K. Foster, Gavin L. Fröhberg, Nico Swann, George E. A. Poulton, Alex J. Moore, C. Mark Humphreys, Matthew P. |
spellingShingle |
Donald, Hannah K. Foster, Gavin L. Fröhberg, Nico Swann, George E. A. Poulton, Alex J. Moore, C. Mark Humphreys, Matthew P. The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
author_facet |
Donald, Hannah K. Foster, Gavin L. Fröhberg, Nico Swann, George E. A. Poulton, Alex J. Moore, C. Mark Humphreys, Matthew P. |
author_sort |
Donald, Hannah K. |
title |
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
title_short |
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
title_full |
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
title_fullStr |
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
title_full_unstemmed |
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii) |
title_sort |
ph dependency of the boron isotopic composition of diatom opal (thalassiosira weissflogii) |
publisher |
European Geosciences Union |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/528058/ https://nora.nerc.ac.uk/id/eprint/528058/1/bg-17-2825-2020.pdf https://doi.org/10.5194/bg-17-2825-2020 |
geographic |
Southern Ocean Pacific |
geographic_facet |
Southern Ocean Pacific |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/528058/1/bg-17-2825-2020.pdf Donald, Hannah K.; Foster, Gavin L.; Fröhberg, Nico; Swann, George E. A.; Poulton, Alex J.; Moore, C. Mark; Humphreys, Matthew P. 2020 The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii). Biogeosciences, 17 (10). 2825-2837. https://doi.org/10.5194/bg-17-2825-2020 <https://doi.org/10.5194/bg-17-2825-2020> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-17-2825-2020 |
container_title |
Biogeosciences |
container_volume |
17 |
container_issue |
10 |
container_start_page |
2825 |
op_container_end_page |
2837 |
_version_ |
1766207395290152960 |