Chemical Composition of Meteorites
Lanthanum and Other “Incompatible Elements”
La vs. Fe2O3(T) + MgO
Lanthanum is one of many chemical elements that geochemists call “incompatible elements.” Others that commonly appear in reports of rock analyses are Y, Zr, Nb, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Th, and U. Incompatible elements tend to be in higher concentrations in Earth rocks than in meteorites. Among meteorites, only some from the Moon have concentrations in the range of typical terrestrial igneous rocks.
see also Rare Earth Elements (REE) in Lunar Meteorites