dc.identifier.uri |
http://dx.doi.org/10.15488/1224 |
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dc.identifier.uri |
http://www.repo.uni-hannover.de/handle/123456789/1249 |
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dc.contributor.author |
Howes, Ella L.
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dc.contributor.author |
Kaczmarek, Karina
|
|
dc.contributor.author |
Raitzsch, Markus
|
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dc.contributor.author |
Mewes, Antje
|
|
dc.contributor.author |
Bijma, Nienke
|
|
dc.contributor.author |
Horn, Ingo
|
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dc.contributor.author |
Misra, Sambuddha
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dc.contributor.author |
Gattuso, Jean-Pierre
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dc.contributor.author |
Bijma, Jelle
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dc.date.accessioned |
2017-03-31T06:25:33Z |
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dc.date.available |
2017-03-31T06:25:33Z |
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dc.date.issued |
2017 |
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dc.identifier.citation |
Howes, E.L.; Kaczmarek, K.; Raitzsch, M.; Mewes, A.; Bijma, N. et al.: Decoupled carbonate chemistry controls on the incorporation of boron into Orbulina universa. In: Biogeosciences 14 (2017), Nr. 2, S. 415-430. DOI: https://doi.org/10.5194/bg-14-415-2017 |
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dc.description.abstract |
In order to fully constrain paleo-carbonate systems, proxies for two out of seven parameters, plus temperature and salinity, are required. The boron isotopic composition (δ11B) of planktonic foraminifera shells is a powerful tool for reconstructing changes in past surface ocean pH. As B(OH)-4 is substituted into the biogenic calcite lattice in place of CO2- 3 , and both borate and carbonate ions are more abundant at higher pH, it was suggested early on that B = Ca ratios in biogenic calcite may serve as a proxy for [CO2- 3 ]. Although several recent studies have shown that a direct connection of B = Ca to carbonate system parameters may be masked by other environmental factors in the field, there is ample evidence for a mechanistic relationship between B= Ca and carbonate system parameters. Here, we focus on investigating the primary relationship to develop a mechanistic understanding of boron uptake. Differentiating between the effects of pH and [CO2- 3 ] is problematic, as they co-vary closely in natural systems, so the major control on boron incorporation remains unclear. To deconvolve the effects of pH and [CO2- 3 ] and to investigate their impact on the B= Ca ratio and δ11B, we conducted culture experiments with the planktonic foraminifer Orbulina universa in manipulated culture media: Constant pH (8.05), but changing [CO2- 3 ] (238, 286 and 534 μmol kg-1 CO2- 3 ) and at constant [CO2- 3 ] (276±19.5 μmol kg-1) and varying pH (7.7, 7.9 and 8.05). Measurements of the isotopic composition of boron and the B = Ca ratio were performed simultaneously using a femtosecond laser ablation system coupled to a MC-ICP-MS (multiple-collector inductively coupled plasma mass spectrometer). Our results show that, as expected, δ11B is controlled by pH but it is also modulated by [CO2- 3 ]. On the other hand, the B= Ca ratio is driven by [HCO-3 ], independently of pH. This suggests that B= Ca ratios in foraminiferal calcite can possibly be used as a second, independent, proxy for complete paleo-carbonate system reconstructions. This is discussed in light of recent literature demonstrating that the primary relationship between B= Ca and [HCO-3 ] can be obscured by other environmental parameters. |
eng |
dc.language.iso |
eng |
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dc.publisher |
Göttingen : Copernicus GmbH |
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dc.relation.ispartofseries |
Biogeosciences 14 (2017), Nr. 2 |
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dc.rights |
CC BY 3.0 Unported |
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dc.rights.uri |
https://creativecommons.org/licenses/by/3.0/ |
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dc.subject |
Foraminifera |
eng |
dc.subject |
Orbulina universa |
eng |
dc.subject.ddc |
550 | Geowissenschaften
|
ger |
dc.title |
Decoupled carbonate chemistry controls on the incorporation of boron into Orbulina universa |
eng |
dc.type |
Article |
|
dc.type |
Text |
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dc.relation.issn |
1726-4170 |
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dc.relation.doi |
https://doi.org/10.5194/bg-14-415-2017 |
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dc.bibliographicCitation.issue |
2 |
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dc.bibliographicCitation.volume |
14 |
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dc.bibliographicCitation.firstPage |
415 |
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dc.bibliographicCitation.lastPage |
430 |
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dc.description.version |
publishedVersion |
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tib.accessRights |
frei zug�nglich |
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