Rapid and accurate U–Th dating of ancient carbonates using inductively coupled plasma-quadrupole mass spectrometry

Autor: Eline Sallé, Edwige Pons-Branchu, Sophie Ayrault, Norbert Frank, Markus Hermann Eisele, Eric Douville
Přispěvatelé: Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochrononologie Traceurs Archéométrie (GEOTRAC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochimie Des Impacts (GEDI), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2010
Předmět:
Zdroj: Chemical Geology
Chemical Geology, Elsevier, 2010, 272 (1-4), pp.1-11. ⟨10.1016/j.chemgeo.2010.01.007⟩
Chemical Geology, 2010, 272 (1-4), pp.1-11. ⟨10.1016/j.chemgeo.2010.01.007⟩
ISSN: 0009-2541
DOI: 10.1016/j.chemgeo.2010.01.007
Popis: Here, the potential for rapid and accurate U–Th dating technique of marine aragonite skeletons (deep-sea corals, Lophelia pertusa) and secondary calcite deposits (speleothems and stalagmites) has been explored using inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS). The analytical procedure includes a largely simplified chemical separation technique for uranium (U) and thorium (Th) using UTEVA resin. The developed technique permits simultaneous quantification of uranium [238U] and thorium [232Th] concentrations and their respective isotopic composition, required for U-series disequilibrium dating. Up to 50 U–Th dates per day can be achieved through ICP-QMS with δ234U and δ230Th reproducibility (2σ) of 3–4‰ and 1%, respectively. The high sensitivity (> 3.0 × 105 cps/ppb) together with low background (< 0.5 cps) on each mass between 228 and 236 amu allowed U–Th dating of ancient deep-water corals (15–260 kyr) and stalagmites (30–85 kyr) at precision levels of less than 2%. Consequently, the combination of simplified chemistry using UTEVA with state-of-the-art ICP-QMS isotopic measurements that do not require a U–Th separation step now provides an extremely rapid and low-cost U-series dating technology. The level of precision is most convenient for numerous geochronological applications, such as the determination of climatic influences on ecosystem development and carbonate precipitation. As a first-example application we present ICP-QMS U–Th dates of North Atlantic deep-water coral fragments retrieved in the southeastern Porcupine Seabight (MD01-2463G, Mound Therese), indicating a purely interglacial growth of deep-water corals on so-called carbonate mounds over several climate cycles.
Databáze: OpenAIRE
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