Lithium and halogens in lunar samples

Lithium and the halogen elements, F, Cl, Br and I have been measured in soils, breccias and rock samples from all Apollo missions. With the exception of the anorthosites, the fluorine content of the lunar samples is in the same range as for C1 chondrites. Contrary to fluorine the other halogen concentrations show large variations. The lowest concentrations are found in the mare basalts of Apollo 15 and 17, the highest in some highland breccias. Lithium correlates well with some of the incompatible elements in both mare basalts and 'KREEP'-containing highland soils and breccias. From the observed ratios it is evident that in the bulk composition of the Moon Li is neither enriched nor depleted; it belongs to the group of non-refractory elements. From the correlation of Li with some refractory elements (Be, La, etc.) a value of 50:50 for the refractory to non-refractory portion of the Moon is inferred without any further assumption, thus confirming previous estimates of other workers. (author)