Mg/Ca-paleothermometry in the western Mediterranean Sea on planktonic foraminifer species Globigerina bulloides: Constraints and implications

We generated a high-resolution SSTMg/Ca record for the surface-dwelling planktonic foraminifera Globigerina bulloides from the core MD99-2346 collected in the Gulf of Lion, and compared it to that obtained using modern analogue techniques applied to fossil foraminiferal assemblages (SSTMAT). The two...

Full description

Bibliographic Details
Published in:Comptes Rendus Geoscience
Main Authors: Boussetta, Soumaya, Kallel, Nejib, Bassinot, Franck, Labeyrie, Laurent, Duplessy, Jean-claude, Caillon, Nicolas, Dewilde, Fabien, Rebaubier, Helene
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier France-editions Scientifiques Medicales Elsevier 2012
Subjects:
Online Access:https://archimer.ifremer.fr/doc/00139/25047/23181.pdf
https://doi.org/10.1016/j.crte.2012.02.001
https://archimer.ifremer.fr/doc/00139/25047/
Description
Summary:We generated a high-resolution SSTMg/Ca record for the surface-dwelling planktonic foraminifera Globigerina bulloides from the core MD99-2346 collected in the Gulf of Lion, and compared it to that obtained using modern analogue techniques applied to fossil foraminiferal assemblages (SSTMAT). The two temperature records display similar patterns during the last 28,000 years but the SSTMg/Ca estimates are several degrees warmer (similar to+4 degrees C) than SSTMAT. The temperature shift between SSTMg/Ca and SSTMAT remained relatively constant over time. This seems to exclude a bias on the Mg/Ca record associated with salinity or secondary Mg-rich calcite encrustation on the foraminiferal tests during early diagenesis. Therefore, anomalously high Mg/Ca suggests either: (1) the empirical equation for G. bulloides of Elderfield and Ganssen (2000) is incorrect; or (2) there is a specific Mediterranean genotypes of G. bulloides for which a specific Mg/Ca-temperature calibration is needed. (c) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.