Volcanoes that are rich in iron might be prime locations to find high concentrations of rare earth elements. Recent lab experiments have demonstrated that when iron-rich magmas experience volcanic pressures and temperatures, the resulting iron oxide-apatite (IOA) deposit separates into two unmixable melts, one of which is highly enriched in rare earth elements (REEs).
As reported in a study published in Geochemical perspectives letters, laboratory experiments have shown that volcanic pressures and temperatures cause iron oxide-apatite (IOA) deposits to form, splitting magmas into two immiscible melts, one of which is highly enriched in REEs — up to 200 times more concentrated than in the silicate-rich melts.
Shengchao Yan, a doctoral student at the Chinese Academy of Sciences and lead researcher on the study, explained that when magmatic mixtures are subjected to volcanic conditions, they separate into two distinct components: an iron phosphate (FeP) melt and a silicate melt. This process results in REEs becoming concentrated in the IOA deposits.