Exploring foraminiferal Sr/Ca as a new carbonate system proxy
Keul, N.; Langer, G.; Thoms, S.; de Nooijer, L.J.; Reichart, G.-J.; Bijma, J. (2017). Exploring foraminiferal Sr/Ca as a new carbonate system proxy. Geochim. Cosmochim. Acta 314: 374-386. https://dx.doi.org/10.1016/j.gca.2016.11.022 In: Geochimica et Cosmochimica Acta. Elsevier: Oxford,New York etc.. ISSN 0016-7037; e-ISSN 1872-9533, more |  |
| Author keywords | C-system; Proxies; Ammonia; Strontium; DIC; Foraminifera; Sr/Ca; Calibration |
| Authors | | Top | - Keul, N.
- Langer, G.
- Thoms, S.
| - de Nooijer, L.J., more
- Reichart, G.-J., more
- Bijma, J.
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| Abstract | In present day paleoclimate research one of the most pressing challenges is the reconstruction of atmospheric CO2 concentrations. A variety of proxies for several components of the marine inorganic carbon system have been developed in this context (e.g. B isotopes, B/Ca, U/Ca) to allow reconstruction of past seawater pH, HCO3− and CO32− and thereby facilitate estimates of past atmospheric pCO2. Based on culture experiments using the benthic foraminifera Ammonia sp. we describe a positive correlation between Sr/Ca and the carbonate system, namely DIC/bicarbonate ion concentration. Foraminiferal Sr/Ca ratios provide potentially additional constraints on the carbonate system proxy, because the analysis of foraminiferal carbonate Sr/Ca is straightforward and not easily contaminated. Applying our calibration to a published dataset of paleo-Sr/Ca suggests the validity of Sr/Ca as a carbonate system proxy. Furthermore, we explore how our data can be used to advance conceptual understanding of the foraminiferal biomineralization mechanism. |
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