loading page

Equilibrated gas and carbonate standard-derived dual (Δ47 and Δ48) clumped isotope values
  • +4
  • Jamie Lucarelli,
  • Hannah M Carroll,
  • Robert N Ulrich,
  • Ben M Elliott,
  • Tyler B Coplen,
  • Robert A Eagle,
  • Aradhna Tripati
Jamie Lucarelli
UCLA

Corresponding Author:[email protected]

Author Profile
Hannah M Carroll
UCLA
Author Profile
Robert N Ulrich
UCLA
Author Profile
Ben M Elliott
UCLA
Author Profile
Tyler B Coplen
US Geological Survey
Author Profile
Robert A Eagle
UCLA
Author Profile
Aradhna Tripati
UCLA
Author Profile

Abstract

Carbonate clumped isotope geochemistry has primarily focused on mass spectrometric determination of m/z 47 CO2 for geothermometry, but theoretical calculations and recent experiments indicate paired analysis of the m/z 47 (13C18O16O) and m/z 48 (12C18O18O) isotopologues (referred to as Δ47 and Δ48) can be used to study non-equilibrium isotope fractionations and refine temperature estimates. We utilize 5,465 Δ47 and 3,400 Δ48 replicate measurements of carbonate samples and standards, and 183 Δ47 and 195 Δ48 replicate measurements of gas standards from 2015-2021 from a multi-year and multi-instrument dataset to constrain Δ47 and Δ48 values for 27 samples and standards, including Devils Hole cave calcite, and study equilibrium Δ47-Δ48, Δ47-temperature, and Δ48-temperature relationships. We compare results to previously published findings and calculate equilibrium regressions based on inter-laboratory values. We report acid digestion fractionation factors, Δ*63-47 and Δ*64-48, and account for their dependence on the initial clumped isotope values of the mineral.