Supplementary Tables R1 of "Determination of Fe³⁺ and Fe²⁺ partition coefficients between pyroxenes and basaltic melt by in-situ synchrotron Mössbauer spectroscopy"

Pyroxenes (opx and cpx) are the major hosts of Fe3+ and the mineral/melt partition coefficients of Fe3+ and Fe2+ (DFe2+ and DFe3+) are crucial for understanding redox variations during magmatic processes. However, the mineral/melt DFe2+ and DFe3+ for pyroxenes are sparse due to the difficulty in quantifying Fe3+ content of pyroxenes. In this study, we synthesized big pyroxenes and melt and maintained the Fe3+ and Fe2+ contents of the sample by optimizing the high pressure experiment. The DFe2+ and DFe3+ for pyroxenes were obtained by measuring Fe3+ and Fe2+ contents of the opx, cpx and melt with the advanced in-situ synchrotron Mössbauer spectroscopy using a beam size as small as < 10 μm at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). The results reveal that opx and cpx have the opposite effects on the oxygen fugacity of a magmatic system. This study provides a methodology for accurate determination of mineral/melt DFe2+ and DFe3+, and will draw broad interests from the fields of experimental geochemistry and petrology.