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| Titel |
Mg/Ca temperature calibration for the benthic foraminifers Bulimina inflata and Bulimina mexicana |
| VerfasserIn |
Patrick Grunert, Yair Rosenthal, Frans Jorissen, Ann Holbourn |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250131826
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| Publikation (Nr.) |
 EGU/EGU2016-12270.pdf |
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| Zusammenfassung |
| Bulimina inflata Seguenza 1862 and Bulimina mexicana Cushman 1922 are cosmopolitan,
shallow infaunal benthic foraminifers which are common in the fossil record throughout the
Neogene and Quaternary. The closely related species share a similar costate shell morphology
that differs in the presence or absence of an apical spine. In the present study, we evaluate
the temperature dependency of Mg/Ca ratios of these species from an extensive
set of core-top samples from the Atlantic and Pacific oceans. The results show no
significant offset in Mg/Ca values between B. inflata, B. mexicana, and two other costate
morphospecies when present in the same sample. The apparent lack of significant
inter-specific/inter-morphotype differences amongst the analysed costate buliminds
allows for the combined use of their data-sets for our core-top calibration. Over a
bottom-water temperature range of 3-14∘C, the Bulimina inflata/mexicana group
shows a sensitivity of ∼0.12 mmol/mol/∘C which is comparable to the epifaunal
Cibicidoides pachyderma and higher than for the shallow infaunal Uvigerina spp., the most
commonly used taxa in Mg/Ca-based palaeotemperature reconstruction. B. inflata and
B. mexicana might thus be a valuable alternative in mesotrophic settings where
many of the commonly used species are diminished or absent, and particularly
useful in hypoxic settings where costate buliminds may dominate foraminiferal
assemblages.
This study was financially supported by the Max-Kade-Foundation and contributes to project
P25831-N29 of the Austrian Science Fund (FWF). |
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