Solubility and partitioning of Ar in anorthite, diopside, forsterite, spinel, and synthetic basaltic liquids

The solubility and partitioning of Ar in natural anorthite, diopside, forsterite, spinel, and synthetic iron-free basaltic melts was investigated using a new technique that obviates the postquenching phase separation. It was found that the solubility of Ar in the minerals was surprisingly high. Moreover, the solubility of Ar in different samples of a particular mineral run in the same experiment varied more than the solubility in the same sample run in different experiments, suggesting that noble gases are held in lattice vacancy defects. Moreover, the results of TEM imaging revealed no anomalous microstructures, while EXAFS studies of some samples showed that Kr has no preferred site in the lattices, supporting the defect siting conclusion.