The Retezat granitoid body is a magmatic body presenting a very obvious petrographic differentiation: diorite-tonalites, granodiorites and granites.
This one is not well emphasised by the REE content variation, REE patterns and some characteristic calculated ratios as: Eu/Sm, LREE/HREE.
The way of the REE variations is as follows:
* REE content is the same in all identified petrographic entities and in the whole area of the massif;
* S REE presents no specific variation, according to the petrographic type variation;
* LREE / HREE ratios are similar for all petrotypes;
* chondrite-normalized patterns emphasize small or no Eu anomalies for some granites, granodiorites and diorite-tonalites, or obvious negative Eu anomalies for other granites and granodiorites. Generally speaking the allure of the curves are descendant, with an obvious LREE fractionation and nearly flat or a very negative concave shape for HREE. No well delimited fields for each petrotype had been observed.
The interpretation of the REE data points out the necessary existence of the same magma source but a complex magmatic evolution for the whole Retezat massif.
So that, two important moments could be supposed: 1) a deep one, with a deep magmatic source, containing an abundant plagioclase amounts and small quantities of garnet, amphibole and pyroxene for granite and granodiorite rocks; 2) an upper
one, derived from the first one, much more depleting in plagioclase, suitable for the crystallisation of the diorites and some
granodiorites and granites.