IDADES U/Pb EM ZIRCÃO E IDADES MODELO (Sm/Nd) DE ORTOGNAISSES E ENCLAVES METAMÁFICOS DA ÁREA DE BARRO VERMELHO-PE, TERRENO ALTO MOXOTÓ, PROVÍNCIA BORBOREMA, NORDESTE DO BRASIL

Constraints from zircon geochronology on the tectonic evolution of the Borborema Province (NE Brazil): Widespread intracontinental Neoproterozoic reworking of a Paleoproterozoic accretionary orogen

“…Orthogneisses with similar ages were also identified in the Rio Grande do Norte Domain Hollanda et al, 2011) and in the Central Subprovince (Melo et al, 2002). However, most Paleoproterozoic ages obtained in orthogneisses and metamafic rocks fall in the range 2.25e1.95 Ga (see below and references in Table 1).…”

Early to Late Paleoproterozoic magmatism in NE Brazil: The Alto Moxotó Terrane and its tectonic implications for the Pre-West Gondwana assembly

“…These data associated with T DM ages and negative εNd (t) values indicate that it was formed in a convergent tectonic environment with reworking of an older Archean continental crust. An alternative possible source is a metasomatized mantle which could also lead to negative εNd (t) values (Menzies et al, 1987), however the first hypothesis is preferred, because of the presence of several inherited zircon grains on the analyzed sample, which suggests indeed the existence of an older continental crust. The second tectono-magmatic episode is represented by the mafic-ultramafic magmatism of the Carmo suite and granitic to granodioritic gneisses of the Pedra d' Agua suite.…”

Geochemistry of orthogneisses and metasedimentary rocks across a proposed terrane boundary in the Central Domain of Borborema Province, NE Brazil: Geodynamic implications

“…U-Pb and Pb-Pb evaporation zircon ages indicate crystallization of their protoliths mainly around 2.1 Ga (Santos, 1995;Brito Neves et al, 2001;Melo et al, 2002;Sá et al, 2002;Santos et al, 2004;Neves et al, 2004Neves et al, , 2006. Only a few chemical analyses are reported in the literature, pointing out to intrusion in a volcanic arc or active margin continental setting (Santos, 1995;Melo, 1998;Sá et al, 2002).…”

“…The analyzed samples of orthogneisses are petrographically akin to dated basement Paleoproterozoic orthogneisses in both Alto Moxotó and Rio Capibaribe terranes, which yielded U-Pb ages in the interval 2.15-1.97 Ga (Santos, 1995;Brito Neves et al, 2001;Melo et al, 2002;Sá et al, 2002;Santos et al, 2004;Neves et al, 2006). Only a few chemical analyses are available for these rocks (Melo, 1998;Sá et al, 2002).…”