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| Titel |
The influence of temperature and seawater carbonate saturation state on 13C–18O bond ordering in bivalve mollusks |
| VerfasserIn |
R. A. Eagle, J. M. Eiler, A. K. Tripati, J. B. Ries, P. S. Freitas, C. Hiebenthal, A. D. Wanamaker, M. Taviani, M. Elliot, S. Marenssi, K. Nakamura, P. Ramirez, K. Roy |
| 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 ; 10, no. 7 ; Nr. 10, no. 7 (2013-07-10), S.4591-4606 |
| Datensatznummer |
250018332
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| Publikation (Nr.) |
 copernicus.org/bg-10-4591-2013.pdf |
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| Zusammenfassung |
| The shells of marine mollusks are widely used archives of past climate and
ocean chemistry. Whilst the measurement of mollusk δ18O to develop
records of past climate change is a commonly used approach, it has proven
challenging to develop reliable independent paleothermometers that can be
used to deconvolve the contributions of temperature and fluid composition on
molluscan oxygen isotope compositions. Here we investigate the temperature
dependence of 13C–18O bond abundance, denoted by the measured
parameter Δ47, in shell carbonates of bivalve mollusks and assess
its potential to be a useful paleothermometer. We report measurements on
cultured specimens spanning a range in water temperatures of 5 to
25 °C, and field collected specimens spanning a range of −1 to
29 °C. In addition we investigate the potential influence of
carbonate saturation state on bivalve stable isotope compositions by making
measurements on both calcitic and aragonitic specimens that have been
cultured in seawater that is either supersaturated or undersaturated with
respect to aragonite. We find a robust relationship between Δ47 and
growth temperature. We also find that the slope of a linear regression
through all the Δ47 data for bivalves plotted against seawater
temperature is significantly shallower than previously published inorganic
and biogenic carbonate calibration studies produced in our laboratory and go
on to discuss the possible sources of this difference. We find that changing
seawater saturation state does not have significant effect on the
Δ47 of bivalve shell carbonate in two taxa that we examined, and we
do not observe significant differences between Δ47-temperature
relationships between calcitic and aragonitic taxa. |
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