Petrogénesis del plutón monzogranítico peralumínico de Santa Eufemia (Batolito de los Pedroches, Córdoba)

Abstract

The Santa Eufemia pluton is part of the composite magmatic assoclatlon of Los Pedroches batholith, located in the southern branch of the Central Iberian Zone of the Hercynian orogenic belt of Spain. This high-Ievel postkynematic batholith consists of three main types of plutonic rocks: boitite±amphibole granodiorites, biotite-cordierite porphiritic monzogranites and cordierite leucogranites. The Santa Eufemia pluton consists of biotite-cordierite monzogranites, and in a lesser extent of cordierite leucogranites. Scarce enclaves of different type are found in the monzogranites, biotiteplagioclase- eordierite and fine grained porphiritic monzogranite enclaves being the most common. The petrographic, structural and geochemical (major and trace elements) data suggests a compiex evolutionary history of a metasedimentary-source monzogranitic magma with no genetical relationships with more basic magmas such as the one which is now represented by the granodiorite facies of the batholith. Non-minimum melt and reequilibrated source material (secondary restites) mixing during the ortomagmatic evolution of the magma accounts for the compositional heterogenities of the monzogranites. The ultimate product of this evolution is the segregation of a fluid-saturated residual liquid in the final level of intrusion of the magma, leading to the emplacement of leucogranite masses and dikes and the exsolution of a supercritical fluid phase related with the late magmatic recrystallization of sorne mineral phases (muscovite, albite, quartz, tourmaline, topaz), the geochemical removilization of sorne incompatible trace elements (Rb, Cs, Li, Be, Sn, Nb) due to fluid-rock interactions and the formation of periplutonic wolframite-arsenopyritequartz mineralizations.