| The Passa Tempo Metamorphic Complex is one of several metamorphic complexes that form the Archean sialic crust of the southern São Francisco Craton. It encompasses hypersthene-bearing gneissic rocks, with subordinateNW- or EW-trending mafic-ultramafic bodies and granodioritic to alkali-granitic, weakly foliated, and light-colored granitoids. These granitoids are the product of generalized migmatization that followed granulite-facies metamorphism. To determine the ages of the granulite-facies metamorphism and granitoid genesis, we obtained U-Pb ages on zircon extracted from the mesosome and leucosome of the migmatitic gneisses. For the mesosome, a discordia that intercepts Concordia at 2622 ± 18 Ma is interpreted as a minimum age for granulite-facies... |
