Probing the partitioning behaviour of Xe using in situ X-ray synchrotron techniques at high P–T conditions

ABSTRACT Understanding crystal/melt xenon (Xe) partitioning at depth is key to properly trace planetary processes using Xe isotopes. Partition coefficients measured on experimental samples recovered at room pressure (P) and temperature (T) span 6 orders of magnitude, potentially due to Xe exsolution from crystals upon quenching. We chose two in situ synchrotron X-ray methods to investigate Xe crystal/melt partitioning under high P and T up to 3 GPa and 1050°C using (1) resistive-heated diamond anvil cell with angle-dispersive diffraction and X-ray fluorescence, and (2) a new protocol using large volume press with energy-dispersive diffraction set-up. Results from both methods are consistent, and Xe is found to be compatible at depth, suggesting the continental crust could be a Xe-rich reservoir. This new protocol advances research to probe geological systems at the higher P–T conditions accessible with large volume press while maintaining homogeneous T throughout the sample.