Do concentrations of Mn, Eu and Ce in apatite reliably record oxygen fugacity in magmas?

Abstract Apatite is a common accessory mineral in igneous rocks, and its ability to readily accommodate wide range of trace elements means that it may provide useful record magmatic composition processes. Relative abundances redox sensitive apatite could also much-needed probe oxygen fugacity, fO2. Here, examination large data set whole rock compositions used assess the recently proposed, increasingly used, Mn-in-apatite oxybarometer. Correlation apatite-whole Mn partition coefficients with SiO2, calculated melt polymerisation aluminosity, support model where content largely dependent on structure. In more evolved systems, decrease availability non-bridging oxygens silicate melts drives from being incompatible, an compatible element apatite. Magmatic fO2 Ce concentrations zircon shows no discernible correlation content. clearly does not fO2, although be indicating extent evolution. contrast, other have much weaker, or dependence structure composition, supporting assertion records key aspects composition. Eu anomalies chondrite-normalised Rare Earth Element (REE) alternative using A new method for reliably comparing REE controls strong often reflect feldspar crystallisation. are smaller vary weakly positive negative. Predicted strong, negative observed, implying differences Ce3+ Ce4+ compatibility than minerals such as zircon. The cause small unclear. Comparison suggests some control However, narrow data, lack identifiable limit which As such, contents cannot currently reliable indicate trends