Partitioning of REE between calcite and carbonatitic melt containing P, S, Si at 650-900 °C and 100 MPa.

Carbonatites host some unique ore deposits, especially REE, and fractional crystallization might be a potentially powerful mechanism for control enrichment of carbonatitic magmas by these metals to economically significant levels. At present, data on distribution coefficients of REE during fractional crystallization of carbonatitic melts at volcanic conditions are extremely scarce. Here we present an experimental study of REE partitioning between carbonatitic melts and calcite in the system CaCO-NaCO with varying amounts of PO, F, Cl, SiO, SO at 650-900 °C and 100 MPa using cold-seal pressure vessels and LA-ICP-MS.