The importance of crystal chemistry on REE partitioning between mantle minerals (garnet, clinopyroxene, orthopyroxene, and olivine) and basaltic melts

摘要: Abstract Partitioning of rare earth elements (REEs) between mantle minerals and basaltic melts is fundamental to understanding crystal-melt fractionation processes can be quantitatively described by the lattice strain model. We analyzed published REE Y partitioning data garnet melt REE, Y, Sc olivine using nonlinear regression method, parameterized key parameters in model (D0, r0 E) as functions temperature, pressure, mineral compositions. show that partition coefficients are inversely correlated with temperature correlation Ca content (XCa) convoluted inverse relationship D0 XCa positive XCa. positively Al forsterite pressure. To test validity assumptions simplifications used development, we combined models a recent for clinopyroxene obtain two mineral–mineral models. found model-derived garnet-clinopyroxene olivine-clinopyroxene consistent measured from well-equilibrated eclogite peridotite xenoliths at subsolidus conditions. This demonstrates internal consistency our garnet, olivine, orthopyroxene. Taken collectively, orthopyroxene all suggest importance crystal chemistry, pressure determining melts, composition has only secondary or indirect effect.