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| Titel |
Copper incorporation in foraminiferal calcite: results from culturing experiments |
| VerfasserIn |
L. J. Nooijer, G. J. Reichart, A. Dueñas-Bohórquez, M. Wolthers, S. R. Ernst, P. R. D. Mason, G. J. Zwaan |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 4, no. 4 ; Nr. 4, no. 4 (2007-07-10), S.493-504 |
| Datensatznummer |
250001849
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| Publikation (Nr.) |
 copernicus.org/bg-4-493-2007.pdf |
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| Zusammenfassung |
| A partition coefficient for copper (DCu) in foraminiferal calcite has
been determined by culturing individuals of two benthic species under
controlled laboratory conditions. The partition coefficient of a trace
element (TE) is an emperically determined relation between the TE/Ca ratio
in seawater and the TE/Ca ratio in foraminiferal calcite and has been
established for many divalent cations. Despite its potential to act as a
tracer of human-induced, heavy metal pollution, data is not yet available
for copper. Since partition coefficients are usually a function of multiple
factors (seawater temperature, pH, salinity, metabolic activity of the
organism, etc.), we chose to analyze calcite from specimens cultured under
controlled laboratory conditions. They were subjected to different
concentrations of Cu2+ (0.1–20 µmol/l) and constant temperature (10 and
20°C), seawater salinity and pH. We monitored the growth of new calcite
in specimens of the temperate, shallow-water foraminifer Ammonia tepida and in the
tropical, symbiont-bearing Heterostegina depressa. Newly formed chambers were analyzed for Cu/Ca
ratios by laser ablation-ICP-MS. The estimated partition coefficient
(0.1–0.4) was constant to within experimental error over a large range of
(Cu/Ca)seawater ratios and was remarkably similar for both species.
Neither did the presence or absence of symbionts affect the DCu, nor
did we find a significant effect of temperature or salinity on Cu-uptake. |
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