Exploring foraminiferal Sr/Ca as a new carbonate system proxy. (1st April 2017)

• Record Type: Journal Article
• Authors: Keul, Nina; Langer, Gerald; Thoms, Silke; de Nooijer, Lennart Jan; Reichart, Gert-Jan; Bijma, Jelle
• Is Part Of: Geochimica et cosmochimica acta. Volume 202(2017)
• Page Start: 374
• Page End: 386
• Publication Date: 2017-04-01
• Subjects: C-system -- Proxies -- Ammonia -- Strontium -- DIC -- Foraminifera -- Sr/Ca -- Calibration; Geochemistry -- Periodicals; Meteorites -- Periodicals; Géochimie -- Périodiques; Météorites -- Périodiques; Geochemie; Astrochemie; Electronic journals; 551.905
• DOI: 10.1016/j.gca.2016.11.022
• Languages: English
• ISSNs: 0016-7037

Abstract

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 CO3 2− and thereby facilitate estimates of past atmospheric p CO2 . 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.