Refining benthic foraminiferal Mg/Ca-temperature calibrations using core-tops from the western tropical Atlantic: Implication for paleotemperature estimation
| Type | Article | ||||||||
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| Date | 2013-04 | ||||||||
| Language | English | ||||||||
| Author(s) | Tisserand Amandine A.1, 2, Dokken Trond M.1, Waelbroeck Claire3, Gherardi Jeanne Marie1, 3, Scao Vincent1, 3, Fontanier Christophe4, 5, Jorissen Frans4 | ||||||||
| Affiliation(s) | 1 : Uni Res AS, Bergen, Norway. 2 : Univ Bergen, Dept Earth Sci, NO-5007 Bergen, Norway. 3 : LSCE IPSL, Lab CNRS CEA UVSQ, F-91198 Gif Sur Yvette, France. 4 : Univ Angers, Lab Recent & Fossil Bioindicators, UMR CNRS LPGN 6122, F-49045 Angers, France. 5 : Univ Bordeaux 1, Lab Environm Paleoenvironm Ocean & Continentaux, UMR CNRS 5805, F-33405 Talence, France. |
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| Source | Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2013-04 , Vol. 14 , N. 4 , P. 929-946 | ||||||||
| DOI | 10.1002/ggge.20043 | ||||||||
| WOS© Times Cited | 17 | ||||||||
| Keyword(s) | benthic foraminiferal Mg, Ca, intermediate water temperature, equatorial thermocline, western tropical Atlantic Ocean, core-tops | ||||||||
| Abstract | Benthic foraminiferal Mg/Ca has been shown to have great potential as a proxy for reconstructing deep water temperatures. However, the exact relationship between Mg uptake in benthic foraminifera and temperature is still ambiguous, and further exploration and refinement is much needed to reduce uncertainties associated with the method. Here, we present new core-top Mg/Ca data from benthic foraminiferal species from the lower part of the thermocline in the western tropical Atlantic (northern Brazilian margin). This area is unusual in that the changes in carbonate chemistry along the transect are very small, making it an ideal region for isolating and studying the role of temperature in the incorporation of Mg into the benthic shells. Our results show that benthic foraminiferal Mg/Ca largely reflects temperature in this area. Our data are combined with previously published data to produce new and improved Mg/Ca calibration equations for a number of benthic foraminiferal species within the Atlantic Ocean. Our study provides the first C. wuellerstorfi Mg/Ca data for the 46 degrees C temperature range and indicates that C. wuellerstorfi Mg/Ca is strongly controlled by temperature. As a result, the newly established C. wuellerstorfi calibration over the entire 06 degrees C temperature range is significantly improved with respect to previously published C. wuellerstorfi calibrations limited to the coldest part between 0 and 4 degrees C. Other benthic species (Cibicidoides kullenbergi, Globocassidulina subglobosa, Uvigerina peregrina, and Oridorsalis umbonatus) have also been studied, although these results are less conclusive. | ||||||||
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