Characterisation and interlaboratory comparison of a new calcite reference material for U-Pb geochronology - The “AUG-B6” calcite-cemented hydraulic breccia - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Poster De Conférence Année : 2023

Characterisation and interlaboratory comparison of a new calcite reference material for U-Pb geochronology - The “AUG-B6” calcite-cemented hydraulic breccia

Thomas Blaise
Delphine Bosch
Olivier Bruguier
  • Fonction : Auteur
  • PersonId : 981411
Nathan Cogné
  • Fonction : Auteur
  • PersonId : 1126742
Et Al.
  • Fonction : Auteur

Résumé

We present the mineralogical, geochemical and geochronological characterisation of the calcite-cemented hydraulic breccia "AUG-B6» and propose it as a reference material for calcite U-Pb geochronology. The material consists of millimeter-sized, well-crystalized sparite crystals that formed rapidly and synchronously [1]. LA-ICP-MS mapping shows relatively high U content together with large variations in the U/Pb ratios. As a consequence, randomly localized laser ablation spot analyses (100 – 150 µm) lead to an ideal dispersion in a Tera-Wasserburg space, with spots reflecting different mixing proportions between radiogenic and common Pb endmembers, and very-well constrained isochrons with MSWD ~ 1. An interlaboratory comparison conducted with various equipment for in-situ analyses (LA-Q-ICP-MS, LA-TQ-ICP-MS, LA-HR-ICP-MS) shows very consistent and reproducible ages, within analytical uncertainties, on various AUG-B6 sub-samples. We show that AUG-B6 can be used as a suitable reference material for in-situ calcite U-Pb geochronology to better estimate the long-term excess-variance and to improve the precision and accuracy of measured ages. Reference [1] Pagel M., Bonifacie M., Schneider D.A., Gautheron C., Brigaud B., Calmels D., Cros A., Saint-Bezar B., Landrein P., Sutcliffe C., Davis D., Chaduteau C., 2018. Chemical Geology 481, 1-17, https://doi.org/10.1016/j.chemgeo.2017.12.026.

Domaines

Géochimie
Fichier non déposé

Dates et versions

insu-04187788 , version 1 (25-08-2023)

Identifiants

  • HAL Id : insu-04187788 , version 1

Citer

Thomas Blaise, Romain Augier, Delphine Bosch, Olivier Bruguier, Nathan Cogné, et al.. Characterisation and interlaboratory comparison of a new calcite reference material for U-Pb geochronology - The “AUG-B6” calcite-cemented hydraulic breccia. Goldschmidt Conference 2023, Jul 2023, Lyon, France. ⟨insu-04187788⟩
57 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More