The clear episodicity documented by precise ID-TIMS-U-Pb data suggests that granite magmatism in the Iberian Massif did not simply reflect the continuous thermal evolution of a thickened continental crust. Instead, it appears to indicate that the production and emplacement of granite magmas was governed by discrete tectonic events affecting the whole crust-upper mantle system.
Combined isotopic and geochemical evidence supports a purely crustal derivation for the syn-D3, S-type, two-mica granites, through moderate degrees of partial melting of Proterozoic-Cambrian metasediments at mid crustal levels. A deeper origin involving anatexis of lower crustal metaigneous protoliths and possible hybridization with mantle- derived magmas is proposed for the syn-D3 granodiorites and monzogranites. The late-post-D3 granodiorite-monzogranite and biotite-muscovite suites seem to correspond to hybrid magmas produced by mixing of anatectic crustal melts with a juvenile asthenospheric mantle component, followed by further contamination and extensive fractional crystallization (AFC processes).