Phys.org  September 24, 2024 Iron oxide-apatite (IOA) deposits have substantial rare earth elements potential, but their rare earth element (REE) enrichment mechanisms remain uncertain. An international team of researchers (Australia, China) used novel layered piston-cylinder experiments to address these questions. Seventeen magmatic FeP–Si immiscibility experiments, across 800–1150 °C, and at 0.4 and 0.8 GPa, reproduced many natural textural and geochemical features of IOA deposits. Magmatic-hydrothermal fluid bubbles and iron oxide-bubble pairs also formed. The results strongly supported FeP–Si immiscibility as a controlling factor in IOA deposits, although not mutually exclusive with other models. Light REE partition into FeP liquids, preferentially […]