Anorthite/fluid partitioning of europium at 650 degree C and 1. 3 kbar

The partition coefficient here depends strongly on the composition of the solution: incorporation of Eu into anorthite is enhanced by a decrease in chlorinity. At a given chlorinity, the partition coefficient depends on the Eu concentration in anorthite, e.g. it decreases from 9-10 to 4 and from 2-3 to 0.1 as the concentration of Eu in anorthite increases from 0.1 to approx 15 000 ppm, for 0.5 and 3.0 mole Cl/litre solutions, respectively. Eu occurs exclusively in the trivalent state in these experiments; its incorporation involves trapping in extended defects as well as cation exchange.