Impact of interrelated and interdependent ecological controls on benthic foraminifera: an example from the Gulf of Guinea

Altenbach, Alexander V.; Lutze, G.; Schiebel, Ralf; Schönfeld, Joachim

doi:10.1016/s0031-0182(03)00463-2

Cited by 62 publications

(30 citation statements)

References 46 publications

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“…The GIK samples were taken with a giant box corer during Meteor cruise M6-5 and the uppermost 1 cm was sampled (Lutze et al, 1988). The samples were taken and stained on board (Lutze and Altenbach, 1991), and were sieved and size fractionated as described by Altenbach et al (2003). The GeoB samples were retrieved during Meteor cruise M41-1 (1986) using a multicorer that was sub-sampled at a sediment depth between 3 and 5 cm.…”

Section: Methodsmentioning

confidence: 99%

Assessment of seawater Nd isotope signatures extracted from foraminiferal shells and authigenic phases of Gulf of Guinea sediments

Kraft

Hathorne

Weldeab

2013

Geochimica et Cosmochimica Acta

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The radiogenic neodymium (Nd) isotope composition of foraminiferal shells provides a powerful archive to investigate past changes in sources and mixing of water masses. However, seawater Nd isotope ratios extracted from foraminiferal shells can be biased by contaminant phases such as organic matter, silicates, or ferromanganese coatings, the removal of which requires rigorous multiple step cleaning of the samples. Here we investigate the efficiency of Flow Through and batch cleaning methods to extract seawater Nd isotope compositions from planktonic foraminifera in a shelf setting in the Gulf of Guinea that is strongly influenced by riverine sediment inputs. Nd isotope analyses of reductively and oxidatively cleaned mono-specific planktonic foraminiferal samples and reductively cleaned mixed benthic foraminifera were complemented by analyses of non-reductively cleaned mono-specific planktonic foraminiferal samples, Fe-Mn coatings of de-carbonated bulk sediment leachates, and the residual detrital fraction of the same sediment.Al/Ca and Mn/Ca ratios of fully cleaned foraminiferal samples reveal indistinguishable levels of cleaning efficiency between the batch and the Flow Through methods and the Nd isotope compositions obtained from application of both methods are identical within error. Furthermore, non-reductively cleaned foraminiferal samples have the same Nd isotope composition as reductively cleaned foraminifera at our study sites. Close to the Niger River mouth the Nd isotope composition of the foraminifera agree with the seawater Nd isotope composition of nearby stations. Based on the combined extracted Nd isotope signatures and element to calcium ratios, as well as rare earth element distribution patterns, we infer that the planktonic foraminiferal Nd isotope signatures reflect bottom water/pore water signatures. The isotopic composition of the bulk de-carbonated sediment leachates (Fe-Mn coatings) differs significantly from the foraminiferal data at this site and probably reflects particles that acquired their ferromanganese/pre-formed pre-formed/ferromanganese coatings in nearby rivers. Therefore, in such river influenced shelf settings foraminiferal shells should be used to obtain unbiased bottom seawater signatures.

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Section: Methodsmentioning

confidence: 99%

Assessment of seawater Nd isotope signatures extracted from foraminiferal shells and authigenic phases of Gulf of Guinea sediments

Kraft

Hathorne

Weldeab

2013

Geochimica et Cosmochimica Acta

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“…and S. bulloides are suboxic indicators, while Kouwenhoven and Van der Zwaan (2004) place them in the most oxyphylic ''group 5''. Regarding correlation with organic flux, Altenbach et al (2003) associate the species S. bulloides with high organic carbon flux and content in sediment. Compilation of Den Dulk et al (2000) classifies both species as shallow infaunal, and their spherical infaunal morphology (Rosoff and Corliss 1992) also supports the choice to include them among the infauna.…”

Section: Microhabitat Distributionmentioning

confidence: 99%

“…Many authors have studied the complex relationship of benthic foraminiferal assemblages with organic flux or oxygen content of bottom waters (e.g. Kaiho 1994Kaiho , 1999Murray 2001;Altenbach et al 2003). In the present study special attention was paid to epibenthic and inbenthic forms, anticipating that their number in the total assemblage reflects trophic conditions and stress.…”

Section: Introductionmentioning

confidence: 99%

Paleoceanography and climate of the Badenian (Middle Miocene, 16.4–13.0 Ma) in the Central Paratethys based on foraminifera and stable isotope (δ18O and δ13C) evidence

Báldi

2005

Int J Earth Sci (Geol Rundsch)

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Benthic foraminifera and stable isotopes analyses revealed changes emerging in the paleoceanographic scenery in the Paratethys. The percentage of inbenthic, oxyphylic taxa and diversity in the benthic foraminiferal assemblage showed increasing food supply (organic matter), decreasing oxygen level and growing stress on the sea floor. Oxygen isotopes measured in planktonic and benthic foraminifera pointed to strengthening stratification during the Badenian period. The carbon isotopes indicated intensified accumulation of light marine organic matter. This increasing stratification trend is especially pronounced by Late Badenian (13.5-13 Ma) when surface water oxygen isotope values are rather negative. A simple two-layer circulation model was worked out for the Badenian Paratethys explaining these characteristic environmental changes. An antiestuarine (lagoonal) circulation is assumed for the Central Paratethys during the Early (16.4-15 Ma) and mid Badenian (15-13.5 Ma). The mid Badenian period of time comprises the short episode of evaporite formation in the Carpathian Foredeep and the Transylvanian Basin. Evidence presented here supported a reversal of circulation to estuarine type after the deposition of salts by Late Badenian (13.5-13 Ma). The Early Badenian antiestuarine circulation is suggested to associate with the high temperatures of the Mid-Miocene Climatic Optimum, and the Late Badenian estuarine circulation with the cooler period following it.

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“…Benthic foraminifers were identified mainly to determine past changes in hydrography and surface water productivity. Oxygenation and carbon flux are the main factors controlling abundance and species composition in deep-sea assemblages (Jorissen et al, 1995;Altenbach et al, 2003).…”

Section: Foraminifersmentioning

confidence: 99%

Site U1302–U1308 methods

Channell¹,

Kanamatsu²,

Sato³

et al. 2006

Proceedings of the IODP

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Impact of interrelated and interdependent ecological controls on benthic foraminifera: an example from the Gulf of Guinea

Cited by 62 publications

References 46 publications

Assessment of seawater Nd isotope signatures extracted from foraminiferal shells and authigenic phases of Gulf of Guinea sediments

Assessment of seawater Nd isotope signatures extracted from foraminiferal shells and authigenic phases of Gulf of Guinea sediments

Paleoceanography and climate of the Badenian (Middle Miocene, 16.4–13.0 Ma) in the Central Paratethys based on foraminifera and stable isotope (δ18O and δ13C) evidence

Site U1302–U1308 methods

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