Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies
Although boron and uranium to calcium ratios (B/Ca, U/Ca) in planktonic foraminifera have recently received much attention as potential proxies for ocean carbonate chemistry, the extent of a carbonate chemistry control on these ratios remains contentious. Here, we use bi-weekly sediment trap samples...
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ftopenunivgb:oai:oro.open.ac.uk:46974 2023-06-11T04:14:59+02:00 Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies Salmon, Kate H. Anand, Pallavi Sexton, Philip F. Conte, Maureen 2016-09-01 application/pdf https://oro.open.ac.uk/46974/ https://oro.open.ac.uk/46974/1/Salmon%20etal%202016.pdf https://doi.org/10.1016/j.epsl.2016.05.016 unknown https://oro.open.ac.uk/46974/1/Salmon%20etal%202016.pdf Salmon, Kate H. <http://oro.open.ac.uk/view/person/khs64.html>; Anand, Pallavi <http://oro.open.ac.uk/view/person/pa2398.html>; Sexton, Philip F. <http://oro.open.ac.uk/view/person/pfs67.html> and Conte, Maureen (2016). Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies. Earth and Planetary Science Letters, 449 pp. 372–381. Journal Item Public PeerReviewed 2016 ftopenunivgb https://doi.org/10.1016/j.epsl.2016.05.016 2023-05-28T05:54:19Z Although boron and uranium to calcium ratios (B/Ca, U/Ca) in planktonic foraminifera have recently received much attention as potential proxies for ocean carbonate chemistry, the extent of a carbonate chemistry control on these ratios remains contentious. Here, we use bi-weekly sediment trap samples collected from the subtropical North Atlantic in combination with measured oceanographic data from the same location to evaluate the dominant oceanographic controls on B/Ca and U/Ca in three depth-stratified species of planktonic foraminifera. We also test the control of biological, growth-related, processes on planktonic foraminiferal B and U incorporation by using foraminifer test area density (μg/μm 2 ) (a monitor of test thickness) and test size from the same samples. B/Ca and U/Ca show little or no significant correlation with carbonate system parameters both within this study and in comparison with other published works. We provide the first evidence for a strong positive relationship between area density (test thickness) and B/Ca, and reveal that this is consistent in all species studied, suggesting a likely role for calcification in controlling boron partitioning into foraminiferal calcite. This finding is consistent with previous observations of less efficient discrimination against trace element ‘impurities’ (such as B), at higher calcification rates. We observe little or no dependency of B/Ca on test size. In marked contrast, we find that U/Ca displays a strong species-specific dependency on test size in all species, but no relationship with test thickness, implicating some other biological control (possibly related to growth), rather than a calcification control, on U incorporation into foraminiferal calcite. Our results caution against the use of B/Ca and U/Ca in planktonic foraminifera as reliable proxies for the ocean carbonate system and recommend that future work should concentrate on improving the mechanistic understanding of how planktonic foraminifer calcification and growth rates regulate boron ... Article in Journal/Newspaper North Atlantic Planktonic foraminifera The Open University: Open Research Online (ORO) Earth and Planetary Science Letters 449 372 381 |
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Open Polar |
collection |
The Open University: Open Research Online (ORO) |
op_collection_id |
ftopenunivgb |
language |
unknown |
description |
Although boron and uranium to calcium ratios (B/Ca, U/Ca) in planktonic foraminifera have recently received much attention as potential proxies for ocean carbonate chemistry, the extent of a carbonate chemistry control on these ratios remains contentious. Here, we use bi-weekly sediment trap samples collected from the subtropical North Atlantic in combination with measured oceanographic data from the same location to evaluate the dominant oceanographic controls on B/Ca and U/Ca in three depth-stratified species of planktonic foraminifera. We also test the control of biological, growth-related, processes on planktonic foraminiferal B and U incorporation by using foraminifer test area density (μg/μm 2 ) (a monitor of test thickness) and test size from the same samples. B/Ca and U/Ca show little or no significant correlation with carbonate system parameters both within this study and in comparison with other published works. We provide the first evidence for a strong positive relationship between area density (test thickness) and B/Ca, and reveal that this is consistent in all species studied, suggesting a likely role for calcification in controlling boron partitioning into foraminiferal calcite. This finding is consistent with previous observations of less efficient discrimination against trace element ‘impurities’ (such as B), at higher calcification rates. We observe little or no dependency of B/Ca on test size. In marked contrast, we find that U/Ca displays a strong species-specific dependency on test size in all species, but no relationship with test thickness, implicating some other biological control (possibly related to growth), rather than a calcification control, on U incorporation into foraminiferal calcite. Our results caution against the use of B/Ca and U/Ca in planktonic foraminifera as reliable proxies for the ocean carbonate system and recommend that future work should concentrate on improving the mechanistic understanding of how planktonic foraminifer calcification and growth rates regulate boron ... |
format |
Article in Journal/Newspaper |
author |
Salmon, Kate H. Anand, Pallavi Sexton, Philip F. Conte, Maureen |
spellingShingle |
Salmon, Kate H. Anand, Pallavi Sexton, Philip F. Conte, Maureen Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
author_facet |
Salmon, Kate H. Anand, Pallavi Sexton, Philip F. Conte, Maureen |
author_sort |
Salmon, Kate H. |
title |
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
title_short |
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
title_full |
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
title_fullStr |
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
title_full_unstemmed |
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies |
title_sort |
calcification and growth processes in planktonic foraminifera complicate the use of b/ca and u/ca as carbonate chemistry proxies |
publishDate |
2016 |
url |
https://oro.open.ac.uk/46974/ https://oro.open.ac.uk/46974/1/Salmon%20etal%202016.pdf https://doi.org/10.1016/j.epsl.2016.05.016 |
genre |
North Atlantic Planktonic foraminifera |
genre_facet |
North Atlantic Planktonic foraminifera |
op_relation |
https://oro.open.ac.uk/46974/1/Salmon%20etal%202016.pdf Salmon, Kate H. <http://oro.open.ac.uk/view/person/khs64.html>; Anand, Pallavi <http://oro.open.ac.uk/view/person/pa2398.html>; Sexton, Philip F. <http://oro.open.ac.uk/view/person/pfs67.html> and Conte, Maureen (2016). Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies. Earth and Planetary Science Letters, 449 pp. 372–381. |
op_doi |
https://doi.org/10.1016/j.epsl.2016.05.016 |
container_title |
Earth and Planetary Science Letters |
container_volume |
449 |
container_start_page |
372 |
op_container_end_page |
381 |
_version_ |
1768371423781322752 |