Benthic Foraminifera in their role as geochemical archives; ground truthing of palaeo-redox proxies

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https://meetingorganizer.copernicus.org/EGU2019/EGU2019-15789.pdf
Author(s): Petersen, Jassin; Grunert, Patrick
Author Affiliation(s): Primary:
University of Cologne, Institute of Geology and Mineralogy, Cologne, Germany
Volume Title: European Geosciences Union general assembly 2019
Source: Geophysical Research Abstracts, Vol.21; European Geosciences Union general assembly 2019, Vienna, Austria, April 7-12, 2019. Publisher: Copernicus GmbH on behalf of the European Geosciences Union (EGU), Katlenburg-Lindau, Germany. ISSN: 1029-7006
Note: In English
Summary: Foraminiferal research contributing to the elucidation of past climate variability has become more and more combined with geochemical approaches. It is of utmost importance to understand the (palaeo)ecological context of the taxa and species studied before the geochemical data from the foraminiferal test can be correctly interpreted. Moreover, biomineralisation models for foraminifera predict species specific elemental incorporation into the calcite lattice which is confirmed by experimental studies in the laboratory. Therefore, the development of new geochemical proxies based on foraminiferal tests necessitates the use of numerous methodological approaches with contrasting resolution and sensitivity. In this study, we want to explore the application of Mn/Ca and V/Ca as palaeo-redox proxies using traditional wet-chemical methods (ICP-AES and ICP-MS) as well as Laser Ablation ICP-MS and Secondary Ion Mass Spectrometry (SIMS). In this way, we intend to interpret variability related to environmental as well as intrinsic factors (e.g., vital effects). Therefore, we use benthic foraminifera from contrasting study areas and within each sample we study species from different microhabitats. Preliminary results of uncleaned specimens of Uvigerina spp. from IODP site U1385A, SW Iberian Margin, analysed by SIMS show that Mn/Ca and V/Ca could be associated with comparable intra-shell differences. For the use as palaeo-redox proxies the origins of this variability have to be assessed in more detail. Then, it could be possible that benthic foraminifera play a more and more dominant role as proxy carriers for geochemical signatures from low oxygen environments. [Copyright Author(s) 2019. CC Attribution 4.0 License: https://creativecommons.org/licenses/by/4.0/legalcode]
Year of Publication: 2019
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Benthic taxa; Cenozoic; Chemostratigraphy; Continental margin; Cores; Eh; Europe; Expedition 339; Foraminifera; Geochemistry; IODP Site U1385; Iberian Peninsula; Integrated Ocean Drilling Program; Marine sediments; Microfossils; North Atlantic; Northeast Atlantic; Paleo-oceanography; Sediments; Southern Europe; Tests
Coordinates: N373417 N373417 W0100719 W0100720
Record ID: 2019050563
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from European Geosciences Union, Munich, Germany