REE patterns in igneous rocks

REE patterns in The REE pattern of an igneous rock is conixolled by the REE chemistry of its igneous rocks source and the crystal-melt equilibria which have taken place during its evolution. 

Europium anomalies are chiefly controlled by feldspars, particularly in felsic magmas, for Eu (present in the divalent state) is compatible in plagiocase and 

Fractionation of the light REE relative to the heavy ones may be caused by the presence of olivine, orthopyroxene and dinopyroxene, for the partition coeflidents increase by an order of magnitude from La to Lu in these minerals. In basaltic and andesitic liquids, however, the REE are all incompatible in each of these minerals and are only slightly fractionated. 

In felsic liquids accessory phases such as sphene, 2ircon, allanite, apatite and monazite may strongly influence an R pattern for although they may be present in only small quantities (often than 1 % of the rock) their very high 

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