Granates en las rocas intrusivas calcoalcalinas ricas en K de la Unidad Pisuerga-Carrión (Zona Cantábrica, Norte de España)

Abstract

A small scale calcalkaline and late-orogenic intrusive assembly outcrops in the outermost part of the northern branch of Iberian Variscan Chain. Carnet is present as an accesory phase in the intermediate to acidic intrusive host rock (quartzdiorite to granodiorite) and associated metamorphic and igneous enclaves. Garnets are zoned and almandinic in composition; however, three types have been differentiated from compositional variations. Types 7 and 2 garnets are deep origin xenocrists rich in Ca and poor in Mn, whilst Mn rich and Ca poor Type 3 garnets are metamorphic restites. The presence of garnet xenocrists and other geochemical features evidence that melting processes involving stable garnet took place in the origin of the Pisuerga-Carridn intrusive rocks