Experimentally revisiting the REE partition coefficients between zircon and silicate melt

Abstract

Zircon is an important silicate mineral to help understand the evolution of geochemistry and genesis of magma in early planets. The composition of evolved magma can be deduced from the concentrations of elements in zircon and their partition coefficients between zircon and silicate melt. Although the phosphorus (P) contents range from ~100 to ~100000 ppm in extraterrestrial zircon, the effects of P on REE partition coefficients between zircon and silicate melt are still debated. Here we have studied the effect of P contents on the partition coefficients of elements between zircon and silicate melt using high-temperature experiment. With the increase of phosphorus content, the partition coefficients of alkaline elements and Al between zircon and silicate melt show a negative and positive trend, respectively, and there is no effect on itself and Ti. It is worth mentioning that phosphorus content has a negligible effect on REE partitioning, indicating that the REE partition coefficients in this study can be applied to extraterrestrial zircon even with varying P concentrations. After filtering out altered zircon and combining the experimentally updated partition coefficients of REE, the characteristic of evolved melt equilibrated with early protogenetic zircon can thus be yielded and then help to understand early magmatism on the planets.