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'.
Evaluation and application of foraminiferal element/calcium ratios: Assessing riverine fluxes and environmental conditions during sapropel S1 in the Southeastern Mediterranean
Mojtahid, M.; Hennekam, R.; de Nooijer, L.J.; Reichart, G.-J.; Jorissen, F.; Boer, W.; Le Houedec, S.; de Lange, G.J. (2019). Evaluation and application of foraminiferal element/calcium ratios: Assessing riverine fluxes and environmental conditions during sapropel S1 in the Southeastern Mediterranean. Mar. Micropaleontol. 153: 101783. https://dx.doi.org/10.1016/j.marmicro.2019.101783
In: Marine Micropaleontology. Elsevier: Amsterdam; New York; Oxford; Tokyo. ISSN 0377-8398; e-ISSN 1872-6186, meer
|  |
| Author keywords |
Sapropel S1; Levantine basin; Productivity; Oxygenation; Salinity; Stable isotopes; Mg/Ca; Ba/Ca; Mn/Ca; Na/Ca |
| Auteurs | | Top |
- Mojtahid, M.
- Hennekam, R., meer
- de Nooijer, L.J., meer
- Reichart, G.-J., meer
|
- Jorissen, F.
- Boer, W., meer
- Le Houedec, S.
- de Lange, G.J.
|
|
| Abstract |
Paleostudies often rely on foraminiferal calcite chemistry, which reflect past sea water condition through so-called proxy relationships. One way to evaluate robustness of these proxy relationships is to test them in well-studied and during well-constrained climate transitions. The southeastern (SE) Mediterranean is a perfect natural laboratory with a large range of past environmental conditions. These range from low productivity well-ventilated waters like they are at present, to poorly ventilated, high productivity conditions during sapropels. We here explore the reliability of recently developed foraminiferal-based proxies (Ba/Ca, Mn/Ca, Na/Ca) as tracers for changes in productivity, oxygenation and salinity during the most recent sapropel S1. We use laser ablation ICP-MS analyses of the planktonic G. ruber and six benthic species (B. alata, G. affinis, G. altiformis, G. orbicularis, H. boueana, U. peregrina). Our results show that planktonic Ba/Ca is a reliable tracer for Ba2+-enriched Nile outflow, where benthic Ba/Ca traces enhanced paleo(export) productivity relatively well. The interpretation of Mn/Ca data is less straightforward, and the low values may suggest a lower precipitation of Mn-oxides under prevailing hypoxia. The decrease in planktonic and benthic Na/Ca is coherent with excess Nile runoff lowering salinities in the <500m water column. However, when applying the existing calibrations, unrealistic salinity values are found, highlighting potential secondary controls on Na-incorporation. Benthic Ba/Ca time series analyses highlight a multicentennial variability in paleo(export) productivity, consistently with redox proxies. We conclude that benthic Ba/Ca records the close coupling between Ba cycling, export productivity, and redox conditions during S1 in the SE Mediterranean. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
