Isotopic Imaging Using fsLA Single-Collector ICP-SFMS for Direct U/Th Dating of Small Archaeological Carbonates

Autor: Loïc Martin, Asmodée Galy, Gaëlle Barbotin, Fanny Claverie, Edwige Pons-Branchu, Chantal Tribolo, Norbert Mercier, Christophe Pécheyran
Přispěvatelé: Université de Pau et des Pays de l'Adour (UPPA), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), Géochrononologie Traceurs Archéométrie (GEOTRAC), 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), ANR-18-CE27-0004,ApART,Datations croisées uranium-thorium, uranium-protactinium et carbone-14 de carbonates secondaires en grottes : recherche de critères de validation des échantillons et des âges : Application à l'art pariétal(2018)
Rok vydání: 2022
Předmět:
Zdroj: Analytical Chemistry
Analytical Chemistry, 2022, 94 (7), pp.3046-3055. ⟨10.1021/acs.analchem.1c02241⟩
ISSN: 1520-6882
0003-2700
Popis: International audience; We present a new methodology for the U/Th dating of carbonate materials using femtosecond laser ablation single-collector inductively coupled plasma sector field mass spectrometry (fsLA single-collector ICP-SFMS), isotopic mappings, and image processing. This approach allows working on samples at very low U levels (ng·g$^{–1}$). One of the major advantages of this imaging method is that it allows us to exploit deteriorated samples that could not be analyzed by conventional bulk U/Th dating methods, thanks to the identification of contaminated or leached areas at the scale of a few tens of microns and the subsequent correction for detrital 230Th incorporation. Only a few milligrams of material are required for measurement, which allows us to work on small samples such as shell fragments. The parameters of the fsLA single-collector ICP-SFMS coupling have been carefully optimized to ensure very high sensitivity detection and ultralow background while preserving good plasma robustness and a spatial resolution of 30 × 50 μm$^2$. The accuracy was evaluated from low-level U speleothems previously dated by a conventional U/Th dating technique involving digestion, resin purification, double spike, and detection by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). U/Th ages of two archaeological samples with U at low ng·g$^{–1}$ levels, a giant terrestrial snail shell and a burned ostrich eggshell, were determined. The measured U/Th ages are consistent with the expected ages determined by luminescence dating methods.
Databáze: OpenAIRE
Externí odkaz: