Dataciones K-Ar de los granitoides del área La Alberca-Béjar (Sistema Central Español)

Abstract

Late-kynematic granitoids of the Central Iberian Zone (Iberian Variscan Massif) outecrop in the La Alberca-Bejar region (Salamanca, Spain). The granitoids postdate the regional second variscan deformation phase. The country rock is composed by sedimentary rocks of proterozoic and paleozoic age metamorphosed under epizonal conditions. Five K-Ar ages of biotite concentrates from these granitoids show the existence of two magmatic pulses at 280^281 Ma and 269-270 Ma.