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Climate reconstruction using 44/40Ca and 137/134Ba isotopes in annually banded reef corals

English title Climate reconstruction using 44/40Ca and 137/134Ba isotopes in annually banded reef corals
Applicant Samankassou Elias
Number 140618
Funding scheme Project funding
Research institution Département des sciences de la Terre Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Geochemistry
Start/End 01.08.2012 - 31.07.2013
Approved amount 74'880.00
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Keywords (6)

Ba Isotopes; Ca Isotopes; Climate Changes; Sea Level; Geochemistry; Environemental Changes

Lay Summary (English)

Lead
Lay summary

The preliminary study on Ca isotopes in corals reveals that ∂44/40Ca is not significantly influenced by temperature. In most coral genera, the same holds true for salinity. The only factor that needs to be further constrained appears the biocalcification, specifically the pathway of Ca2+ from the solution to calcification centers. The extension of the research topic to include Ba isotopes aims at establishing the method successfully set up in a previous project. We plan to provide the first study applying systematically Ba isotope geochemistry to carbonates. This systematic study represents the initial phase of using Ba isotopic ratio as a proxy to constrain barium sources and diagenetic barium transport in the oceanic cycle to be developed in cooperation with Thomas Nägler (Bern). We expect to evaluate

- Inter-specific variations versus Ca and Ba fractionation using corals cultivated under monitored conditions, with an important link to research at IfM-GEOMAR in Kiel on fractionation in the calcification centers; we collaborate with colleagues in Kiel (Germany) and Monaco.

- Growth rates of coral skeleton versus Ca and Ba fractionation using samples from a modern natural environment, Mahahual in Mexico; Research conducted in collaboration with a colleague from UNAM, Puerto Morelos, Mexico.

- Variations of the Ca and Ba isotopes in fossil corals from cores of IODP Expedition 310 (focusing on the interval between 20’000 and 10’000 years). This part of the project is conducted in collaboration with T. Felis (Bremen, Germany) and G. Camoin (Aix-en-Provence, France).

The overall main goal of the research is to constrain the relationships between external/environmental factors, specifically temperature and salinity, and Ca- and Ba-isotope fractionation for calibrations as proxy records in corals. This will need, in parallel, a better understanding of internal/biological factors such as inter-specific variability, growth rates and mechanisms of biocalcification in order to extract vital effects prior to proxy-based environmental reconstructions.

In particular the Ba isotopic signature (instead of elemental Ba that appears unreliable) in carbonates could be linked with paleoproductivity (continental weathering, upwelling influence the oceanic cycle of Ba), given that Ba reacts like a nutrient in the water column. We anticipate that Ba isotopes may become a fundamental proxy in paleoceanography, given the role Ba plays in the ocean and the finding that the isotope fractionation into barium carbonate is essentially independent from temperature.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Constraints on barium isotope fractionation during aragonite precipitation by corals
Pretet Chloé, van Zuilen Kirsten, Nägler Thomas F., Reynaud Stéphanie, Böttcher Michael E., Samankassou Elias (2016), Constraints on barium isotope fractionation during aragonite precipitation by corals, in The Depositional Record, 1(2), 118-129.
Effect of salinity on the skeletal chemistry of cultured scleractinian zooxanthellate corals: Cd/Ca ratio as a potential proxy for salinity reconstruction
Pretet Chloé, Reynaud Stéphanie, Ferrier-Pagès Christine, Gattuso Jean-Pierre, Kamber Balz S., Samankassou Elias (2014), Effect of salinity on the skeletal chemistry of cultured scleractinian zooxanthellate corals: Cd/Ca ratio as a potential proxy for salinity reconstruction, in Coral Reefs, 33(1), 169-180.
Constraining calcium isotope fractionation (δ44/40Ca) in modern and fossil scleractinian coral skeleton
Pretet Chloé, Samankassou Elias, Felis Thomas, Reynaud Stéphanie, Böhm Florian, Eisenhauer Anton, Ferrier-Pagès Christine, Gattuso Jean-Pierre, Camoin Gilbert (2013), Constraining calcium isotope fractionation (δ44/40Ca) in modern and fossil scleractinian coral skeleton, in Chemical Geology, 340, 49-58.
Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO(3)](2) at ambient temperature.
Böttcher Michael E, Geprägs Patrizia, Neubert Nadja, von Allmen Katja, Pretet Chloé, Samankassou Elias, Nägler Thomas F (2012), Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO(3)](2) at ambient temperature., in Isotopes in environmental and health studies, 48(3), 457-63.

Collaboration

Group / person Country
Types of collaboration
University of Dublin Ireland (Europe)
- Publication
Centre Scientifique de Monaco France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
University of Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Leibnitz-Institut für Ostseeforschung, Rostock Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Bochum Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Goldschmidt Conférence 2013 Talk given at a conference A first - order deep time reconstruction of the marine Sr/Ba ratio from microbial carbonate 25.08.2013 Florence, Italy, Italy Pretet Chloé;
Goldschmidt Conference 2013 Talk given at a conference A Multi-Isotope (H, O, C, S, B, Mg, Ca, Ba) Approach to Study Diagenesis in Black SeA-Type Sediments 25.08.2013 Florence, Italy, Italy Samankassou Elias; Pretet Chloé;
EnviroMetal Isotopes EMI meeting Talk given at a conference Barium isotope fractionation in carbonates: A potential proxy for anthropogenic contaminations? 18.08.2013 Ascona, Switzerland Pretet Chloé;
EGU Meeting 2013 Talk given at a conference New approach to global barium cycle understanding: barium isotopic composition of marine carbonates and seawater. 07.04.2013 Vienna, Austria Samankassou Elias; Pretet Chloé;
EGU Meeting 2013 Talk given at a conference Multi-isotope (C - O - S - H - B - Mg - Ca - Ba) and trace element variations along a vertical pore water profile across a brackish-fresh water transition, Baltic Sea 07.04.2013 Vienna, Austria Pretet Chloé;
Swiss Geosciences Meeting 2012 Talk given at a conference Barium isotope fractionation in carbonates 16.11.2012 Bern, Switzerland Samankassou Elias; Pretet Chloé;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions Nuit de la Science Western Switzerland 2012

Associated projects

Number Title Start Funding scheme
115944 Climate reconstruction using 44/40Ca and 88/86Sr isotopes in annually banded reef corals 01.08.2009 Project funding (special)
144974 Acquisition of QEMSCAN Automated High-Resolution Mineral and Petrographic Analysis. 01.12.2012 R'EQUIP
147139 Swiss participation in the International Ocean Discovery Program (IODP) through membership in the European Consortium for Ocean Research Drilling (ECORD) 01.01.2014 Research Infrastructure
150731 Laboratory multi-scale nano-CT scanner for 3D visualization and 4D experimentation in Earth and Material Sciences 01.05.2014 R'EQUIP

Abstract

The proposal aims at requesting funding for 12 months (August 2012 - July 2013) in continuation of the SNF grant N° 20MA21-115944 (current funding ends July 2012), including the salary for the fourth year of Chloé Pretet (PhD student). We focus on Ca and, additionally, intend to include Ba isotope geochemistry. Sr isotope analysis is being investigated by the Group of A. Eisenhauer at IfM-GEOMAR in Kiel, partner in the frame of ESF EuroMarc project.The preliminary study on Ca isotopes in corals reveals that delta 44/40Ca is not significantly influenced by temperature. In most coral genera, the same holds true for salinity (Pretet et al., submitted a). The only factor that needs to be further constrained appears the biocalcification, specifically the pathway of Ca2+ from the solution to calcification centers. The extension of the research topic to include Ba isotopes aims at establishing the method successfully set up in a previous project (SNF project #200021-107505; von Allmen et al., 2010). We plan to provide the first study applying systematically Ba isotope geochemistry to carbonates. This systematic study represents the initial phase of using Ba isotopic ratio as a proxy to constrain barium sources and diagenetic barium transport in the oceanic cycle to be developed in a project submitted to SNF by Thomas Nägler (Bern) in the frame of CHARON. We expect to evaluate- Inter-specific variations versus Ca and Ba fractionation using corals cultivated under monitored conditions, with an important link to research at IfM-GEOMAR in Kiel on fractionation in the calcification centers; we collaborate with colleagues in Kiel (Germany) and Monaco.- Growth rates of coral skeleton versus Ca and Ba fractionation using samples from a modern natural environment, Mahahual in Mexico; Research conducted in collaboration with a colleague from UNAM, Puerto Morelos, Mexico.- Variations of the Ca and Ba isotopes in fossil corals from cores of IODP Expedition 310 (focusing on the interval between 20’000 and 10’000 years). This part of the project is conducted in collaboration with T. Felis (Bremen, Germany) and G. Camoin (Aix-en-Provence, France).The overall main goal of the research is to constrain the relationships between external/environmental factors, specifically temperature and salinity, and Ca- and Ba-isotope fractionation for calibrations as proxy records in corals. This will need, in parallel, a better understanding of internal/biological factors such as inter-specific variability, growth rates and mechanisms of biocalcification in order to extract vital effects prior to proxy-based environmental reconstructions.In particular the Ba isotopic signature (instead of elemental Ba that appears unreliable; McManus et al., 1998) in carbonates could be linked with paleoproductivity (continental weathering, upwelling influence the oceanic cycle of Ba), given that Ba reacts like a nutrient in the water column. We anticipate that Ba isotopes may become a fundamental proxy in paleoceanography, given the role Ba plays in the ocean and the finding that the isotope fractionation into barium carbonate is essentially independent from temperature (Boettcher et al., 2011).
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