Chromium isotopic composition of core-top planktonic foraminifera
The chromium isotope system ( 53 Cr/ 52 Cr expressed as δ 53 Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean–atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could pot...
Published in: | Geobiology |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2017
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Online Access: | https://hdl.handle.net/1983/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://research-information.bris.ac.uk/en/publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://doi.org/10.1111/gbi.12198 http://www.scopus.com/inward/record.url?scp=84978219601&partnerID=8YFLogxK |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd 2024-05-12T08:10:08+00:00 Chromium isotopic composition of core-top planktonic foraminifera Wang, Xiangli Planavsky, N. J. Hull, P. M. Tripati, A. E. Zou, H. J. Elder, L. Henehan, M. 2017-01-01 https://hdl.handle.net/1983/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://research-information.bris.ac.uk/en/publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://doi.org/10.1111/gbi.12198 http://www.scopus.com/inward/record.url?scp=84978219601&partnerID=8YFLogxK eng eng https://research-information.bris.ac.uk/en/publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd info:eu-repo/semantics/restrictedAccess Wang , X , Planavsky , N J , Hull , P M , Tripati , A E , Zou , H J , Elder , L & Henehan , M 2017 , ' Chromium isotopic composition of core-top planktonic foraminifera ' , Geobiology , vol. 15 , no. 1 , pp. 51-64 . https://doi.org/10.1111/gbi.12198 article 2017 ftubristolcris https://doi.org/10.1111/gbi.12198 2024-04-17T14:38:18Z The chromium isotope system ( 53 Cr/ 52 Cr expressed as δ 53 Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean–atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope archive. Here, we present the first evaluation of planktonic foraminiferal calcite as an archive of seawater δ 53 Cr. We show that single foraminiferal species from globally distributed core tops yielded variable δ 53 Cr, ranging from 0.1‰ to 2.5‰. These values do not match with the existing measurements of seawater δ 53 Cr. Further, within a single core-top, species with similar water column distributions (i.e., depth habitats) yielded variable δ 53 Cr values. In addition, mixed layer and thermocline species do not consistently exhibit decreasing trends in δ 53 Cr as expected based on current understanding of Cr cycling in the ocean. These observations suggest that either seawater δ 53 Cr is more heterogeneous than previously thought or that there is significant and species-dependent Cr isotope fractionation during foraminiferal calcification. Given that the δ 53 Cr variability is comparable to that observed in geological samples throughout Earth's history, interpreting planktonic foraminiferal δ 53 Cr without calibrating modern foraminifera further, and without additional seawater measurements, would lead to erroneous conclusions. Our core-top survey clearly indicates that planktonic foraminifera are not a straightforward δ 53 Cr archive and should not be used to study marine redox evolution without additional study. It likewise cautions against the use of δ 53 Cr in bulk carbonate or other biogenic archives pending further work on vital effects and the geographic heterogeneity of the Cr isotope composition of seawater. Article in Journal/Newspaper Planktonic foraminifera University of Bristol: Bristol Research Geobiology 15 1 51 64 |
institution |
Open Polar |
collection |
University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
description |
The chromium isotope system ( 53 Cr/ 52 Cr expressed as δ 53 Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean–atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope archive. Here, we present the first evaluation of planktonic foraminiferal calcite as an archive of seawater δ 53 Cr. We show that single foraminiferal species from globally distributed core tops yielded variable δ 53 Cr, ranging from 0.1‰ to 2.5‰. These values do not match with the existing measurements of seawater δ 53 Cr. Further, within a single core-top, species with similar water column distributions (i.e., depth habitats) yielded variable δ 53 Cr values. In addition, mixed layer and thermocline species do not consistently exhibit decreasing trends in δ 53 Cr as expected based on current understanding of Cr cycling in the ocean. These observations suggest that either seawater δ 53 Cr is more heterogeneous than previously thought or that there is significant and species-dependent Cr isotope fractionation during foraminiferal calcification. Given that the δ 53 Cr variability is comparable to that observed in geological samples throughout Earth's history, interpreting planktonic foraminiferal δ 53 Cr without calibrating modern foraminifera further, and without additional seawater measurements, would lead to erroneous conclusions. Our core-top survey clearly indicates that planktonic foraminifera are not a straightforward δ 53 Cr archive and should not be used to study marine redox evolution without additional study. It likewise cautions against the use of δ 53 Cr in bulk carbonate or other biogenic archives pending further work on vital effects and the geographic heterogeneity of the Cr isotope composition of seawater. |
format |
Article in Journal/Newspaper |
author |
Wang, Xiangli Planavsky, N. J. Hull, P. M. Tripati, A. E. Zou, H. J. Elder, L. Henehan, M. |
spellingShingle |
Wang, Xiangli Planavsky, N. J. Hull, P. M. Tripati, A. E. Zou, H. J. Elder, L. Henehan, M. Chromium isotopic composition of core-top planktonic foraminifera |
author_facet |
Wang, Xiangli Planavsky, N. J. Hull, P. M. Tripati, A. E. Zou, H. J. Elder, L. Henehan, M. |
author_sort |
Wang, Xiangli |
title |
Chromium isotopic composition of core-top planktonic foraminifera |
title_short |
Chromium isotopic composition of core-top planktonic foraminifera |
title_full |
Chromium isotopic composition of core-top planktonic foraminifera |
title_fullStr |
Chromium isotopic composition of core-top planktonic foraminifera |
title_full_unstemmed |
Chromium isotopic composition of core-top planktonic foraminifera |
title_sort |
chromium isotopic composition of core-top planktonic foraminifera |
publishDate |
2017 |
url |
https://hdl.handle.net/1983/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://research-information.bris.ac.uk/en/publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd https://doi.org/10.1111/gbi.12198 http://www.scopus.com/inward/record.url?scp=84978219601&partnerID=8YFLogxK |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
Wang , X , Planavsky , N J , Hull , P M , Tripati , A E , Zou , H J , Elder , L & Henehan , M 2017 , ' Chromium isotopic composition of core-top planktonic foraminifera ' , Geobiology , vol. 15 , no. 1 , pp. 51-64 . https://doi.org/10.1111/gbi.12198 |
op_relation |
https://research-information.bris.ac.uk/en/publications/33f8bc5a-14c4-416f-bce9-7c2d12d333fd |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1111/gbi.12198 |
container_title |
Geobiology |
container_volume |
15 |
container_issue |
1 |
container_start_page |
51 |
op_container_end_page |
64 |
_version_ |
1798853540950573056 |