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Wefing, Anne-marie; Arps, Jennifer; Blaser, Patrick; Wienberg, Claudia; Hebbeln, Dierk; Frank, Norbert. |
High-precision U-series dating of scleractinian cold-water corals is a key chronological tool for studies of past environmental and climate conditions. Here, we tested and optimized an automated chemical extraction system (ESI prepFAST-MC equipped with an Eichrom TRU-resin chromatographic column) for its ability to purify U and Th isotopes for mass spectrometric U-series dating at the sub-‰ precision level. Chemical yields are constantly high, on average around 90% for both U and Th. Analytical blanks are comparable to manual purification (< 0.15 pg U, 0.15 pg Th for a typical sample of 50 mg) and memory effects due to the recycling of the column are mostly insignificant as the carry-over fraction is about 10− 5 for Th and 10− 3 for U isotopes. However,... |
Tipo: Text |
Palavras-chave: U-series dating; PrepFAST-MC; Cold-water corals; South Atlantic; Angola; Past climate. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00409/52058/52761.pdf |
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Dubois-dauphin, Quentin; Bonneau, Lucile; Colin, Christophe; Montero-serrano, Jean-carlos; Montagna, Paolo; Blamart, Dominique; Hebbeln, Dierk; Van Rooij, David; Pons-branchu, Edwige; Hemsing, Freya; Wefing, Anne-marie; Frank, Norbert. |
The Nd isotopic composition (εNd) of seawater and cold-water coral (CWC) samples from the Gulf of Cádiz and the Alboran Sea, at a depth of 280-827 m were investigated in order to constrain mid-depth water mass dynamics within the Gulf of Cádiz over the past 40 ka. εNd of glacial and Holocene CWC from the Alboran Sea and the northern Gulf of Cádiz reveals relatively constant values (-8.6 to -9.0 and -9.5 to -10.4, respectively). Such values are similar to those of the surrounding present-day mid-depth waters from the Mediterranean Outflow Water (MOW; εNd ∼ -9.4) and Mediterranean Sea Water (MSW; εNd ∼ -9.9). In contrast, glacial εNd values for CWC collected at thermocline depth (550-827 m) in the southern Gulf of Cádiz display a higher average value... |
Tipo: Text |
Palavras-chave: Neodymium isotopes; Cold-water corals; Mediterranean outflow water; East Antarctic intermediate water; Mediterranean sea water; Gulf of Cadiz. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00339/45047/44446.pdf |
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