Over het archief
Het OWA, het open archief van het Waterbouwkundig Laboratorium heeft tot doel alle vrij toegankelijke onderzoeksresultaten van dit instituut in digitale vorm aan te bieden. Op die manier wil het de zichtbaarheid, verspreiding en gebruik van deze onderzoeksresultaten, alsook de wetenschappelijke communicatie maximaal bevorderen.
Dit archief wordt uitgebouwd en beheerd volgens de principes van de Open Access Movement, en het daaruit ontstane Open Archives Initiative.
Basisinformatie over ‘Open Access to scholarly information'.
Encrustation and trace element composition of Neogloboquadrina dutertrei assessed from single chamber analyses - implications for paleotemperature estimates
Jonkers, L.; de Nooijer, L.J.; Reichart, G.J.; Zahn, R.; Brummer, G.-J.A. (2012). Encrustation and trace element composition of Neogloboquadrina dutertrei assessed from single chamber analyses - implications for paleotemperature estimates. Biogeosciences 9(11): 4851-4860. dx.doi.org/10.5194/bg-9-4851-2012
In: Gattuso, J.P.; Kesselmeier, J. (Ed.) Biogeosciences. Copernicus Publications: Göttingen. ISSN 1726-4170; e-ISSN 1726-4189, meer
|   |
| Auteurs | | Top |
- Jonkers, L.
- de Nooijer, L.J., meer
- Reichart, G.J., meer
|
- Zahn, R.
- Brummer, G.-J.A., meer
|
|
| Abstract |
Crust formation is a common phenomenon in planktonic foraminifera. Because of their different formation mechanism and hence composition, crusts affect the overall test composition and therefore complicate the use of crust-bearing foraminifera in paleoceanography. Such species are often used to estimate subsurface paleotemperatures, and although the influence of encrustation on the trace element/Ca ratio is recognised, it has not been systematically explored between and within tests. Here we use laser ablation ICP-MS to assess the variability in trace element composition of the crust of Neogloboquadrina dutertrei within individual chambers, as well as the effect of compositional heterogeneity of the crust on whole test chemistry. Compositionally, the outer crust differs from inner layer by lower Mg/Ca and Mn/Ca, but is indistinguishable in Sr/Ca. Crust thickness decreases towards the younger chambers, and it may be entirely absent from the last chamber. In contrast to Mn/Ca and Sr/Ca, crustal Mg/Ca ratios show a tendency towards higher values on the younger chambers. These patterns in crust thickness and in crust Mg/Ca indicate that temperature is not the dominant factor controlling crust composition. Temperature estimates based on N. dutertrei, and presumably other crust-forming species too, are therefore biased towards too low values. Through comparison of modern and glacial tests, we show that this bias is not constant and that changes in crust thickness and/or in Mg/Ca values can spuriously suggest temperature changes. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
