Arthur Adams

Low Temperature Isotopic Reequilibration of Calcite

Calcite δ18O, Mg/Ca, and Sr/Ca ratios are considered to be robust palaeotemperature proxies at low P–T conditions, where diffusion is slow and recrystallization can be visibly identified and used to exclude diagenetically altered crystals from paleotemperature calculations e.g. “glassy” vs. “frosty” foraminifera. However, biogenic and abiogenic calcites can isotopically reequilibrate and exchange in calcite-saturated fluids, even at low temperatures (<100 °C) with no visible indicators of textural diagenesis. This exchange process challenges the premise that textural discrimination is sufficient to determine the suitability of calcite for palaeothermometry.

This project will determine the rates, extents and controls of this exchange process at low temperatures in abiogenic and biogenic calcites. This project has received funding from the European Research Council (ERC) under the European Union’s Advanced Grant (AdG), PE10, ERC-2017-ADG (Grant agreement No. 788752).

Scientific collaborators on this project include:

  • Alain Baronnet (Aix-Marseille University)
  • Sylvain Bernard (Sorbonne Université)
  • Lukas P. Baumgartner (University of Lausanne)
  • Deyanira Cisnero-Lazaro (EPFL)
  • Damien Daval (University of Strasbourg)
  • Jinming Guo (EPFL)
  • Olivier Grauby (Aix-Marseille University)
  • Anders Meibom (EPFL)
  • Jarek Stolarski (Polish Academy of Sciences)
  • Torsten Vennemann (University of Lausanne)