Caracterización geoquímica de los leucogranitos de Núria y los gneises de Queralbs (Pirineos Orientales)

Abstract

New geochemical data indicates that Núria granite and Queralbs gneiss probably do not belong to the same intrusive complex as has been suggested in some previous works. Besides the lack of direct links in the model of «Christmas Tree» originally proposed, the Y and Nb contents does not favor the model of a rapakivi A-type intrusion. By contrast, low deformation and intrusive contacts in the Núria granite show an age clearly younger than the protolith of the Queralbs gneiss while Rb-(Y+Nb) trace element data show a «syn-collision granites» affinity. On the other hand, Núria leucogranites show a higher absolute concentration in P2O5, and Rb,.and lower MgO, V, Ba, Zr and Ti than Queralbs gneiss. A Ti/Zr vs. SiO2 and a triangular Zr/300-TiO2-P2O5 diagram are used to demonstrate the different origin and evolution of their parental magmas