%0 Journal Article
%A Pérez-Soba Aguilar, Cecilia María
%A Villaseca González, Carlos
%T Petrogenesis of highly fractionated I-type peraluminous granites:La Pedriza pluton (Spanish Central System)
%D 2010
%@ 1695-6133
%U https://hdl.handle.net/20.500.14352/41913
%X The La Pedriza pluton stands out as the most extensively fractionated granite (Rb < 629; Sr < 2 and Ba < 2 ppm)of the Spanish Central System Batholith. These granites show a strong enrichment in some rare metal contents(Nb = 44, Y = 136, Yb = 10.7, U = 17, Ta = 7, Sc = 15 ppm). The petrography and geochemistry (including Sr-Nd isotopes) reveal that the pluton is composed of at least four units. These are classified as I-type peraluminousleucogranites (A/CNK=1.03-1.17), P-poor (P2O5<0.2 wt%) and Na2O-rich (< 4.24 wt%) exhibiting differences intheir HFSE and REE contents and εNd compositions. Moreover, the units of the La Pedriza granite display differenttrends of fractional crystallization. REE spectra of the two most fractionated units suggest the involvement of afluorine-rich melt in the last stages favouring the crystallization of xenotime and niobotantalates. Intermediatemeta-igneous granulite protoliths are proposed as source rocks. The most evolved units of the La Pedriza plutonshow chemical features convergent to A-type granites; these are explained by extensive fractional crystallizationof a P-poor, I-type granite magma.
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