Los ortogneises peralcalinos del borde meridional de la Unidad Malpica-Tuy: caracteres geologicos, mineralogicos, geoquimicos y mineralizaciones de Y-Nb-Zr-TR asociadas

Abstract

This paper summarizes the main tectonic, mineralogical, petrological and geochemical features of the three peralkaline complexes located in the southern end of the Malpica-Tuy Unit, in Galicia (NW Spain). The Porrino and La Guia complexes occur in metasedimentary rocks, mainly graywackes, of the Iberian Massif, while the Pineiro complex is hosted by a pre-Variscan biotite granite. New data concerning the chemical composition and boundaries of the various facies which form the Porrino complex are presented. The data allow up to eight petrological facies to be defined and the origin of these peralkaline bodies to be reinterpreted.