Caracterización geoquímica del plutonismo postmetamórfico del SO del Macizo Hespérico

Abstract

From geochemical, pétrographie and field work the conclusion is reached that post-metamorphic and post-tectonic hercynian plutonites of South Western Spain fit into two well defined magmatic provinces, both following a calc-alkaline trend. The Southern one (Ossa-Morena) has higher Na2 0 + K2 0 / AI2O3 and F / M ratios, and intermediate to basic rocks are common. Moreover plutonic bodies are as a rule small and composite, with zonal ring-like arrangement of pétrographie types. The Northern Province instead lacks mafic rocks and both geochemical ratios are lower. Plutonic bodies here are huge masses closely related to former high-temperature metamorphic areas. Although isotopic evidence is still lacking and more detailed survey will be necessary some petrogenetic hypothesis relating to a plate tectonics model are advanced.