NEW REFERENCE AND TRACER SOLUTIONS FOR INTEGRATING THE RE-OS SYSTEM INTO THE EARTHTIME INITIATIVE: UPDATES AND FUTURE PLANS

With its siderophilic, chalcophilic and organophilic behaviour, the rhenium and osmium (¹⁸⁷Re-¹⁸⁷Os) isotope system is ideally suited to tackle a range of questions in the fields of geochemistry and cosmochemistry. This has led to advances in our understanding of mantle-crust interactions; hydrocarbon and ore formation; the age of iron meteorites, rates of evolutionary change and extreme and long-lived (Myr) climate perturbations. Over the past three decades a series of innovations in chemical procedures and mass spectrometry has led to an increase in the number of laboratories routinely generating Re-Os data. In order to further improve precision and confidence in the system, we aim to follow the successful approaches of the U-Pb and Ar-Ar communities and integrate Re-Os within the EARTHTIME initiative. This work builds on and complements previous efforts to standardize Re-Os geochronology. Here we present the results from experiments to better determine the stoichiometry of Os salts used in the production of gravimetric reference and tracer solutions for a range of Re-Os geochronological and geochemical applications. These and additional on-going efforts e.g., improved data reduction protocols and inter-calibration experiments will pave the way for the Re-Os chronometer to more fully join the EARTHTIME initiative and better serve the geoscience community.