Microfabrics and zircon U–Pb (SHRIMP) chronology of mylonites from the Patos shear zone (Borborema Province, NE Brazil)

The influence of partial melting and melt migration on the rheology of the continental crust

“…U-Pb ages and structural relationships of migmatites and granites of the above mentioned domains suggest that magmatism and partial melting events span for a period of at least ~25 Ma (Archanjo et al 2008, Viegas et al 2014. U-Pb ages in granites and migmatites from the eastern domain constrain magmatic and migmatitic activity in the interval of ~595 -575 Ma, while leucogranitic veins rooted in the Espinho Branco migmatite yield crystallization ages of ~565 Ma (Viegas et al 2014). Furthermore, magnetic fabrics of the migmatites indicate that partial melting was coeval with granite emplacement and HT-LP metamorphism in the Patos shear zone ).…”

“…The dataset described in the following sections represents a summary of the main results already published in Cavalcante et al (2013Cavalcante et al ( , 2014 and Viegas et al (2013Viegas et al ( , 2014.…”

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

“…There are, however, important differences, especially for younger periods. Cear a Central Domain Amaral et al, 2012Araújo et al, 2012Archanjo et al, 2008Castro et al, 2012Costa et al, 2013Fetter et al, 2000Martins et al, 2009Nogueira, 2004Santos et al, 2008a,b Silva et al, 2002Araújo et al, 2010, 2012Garcia et al, 2014Kalsbeek et al, 2013 Rio Grande do Norte Domain Archanjo et al, 2013Dantas et al, 2004Fetter et al, 2000Guimarães et al, 2009Hackspacher et al, 1990Hollanda et al, 2008, 2011 submitted for publication Medeiros et al, 2012Souza et al, 2007Van Schmus et al, 1995Viegas et al, 2014Kalsbeek et al, 2013Van Schmus et al, 2003 Central Subprovince Plutonic rocks Metasedimentary rocks Almeida et al, 2002Archanjo and Fetter, 2004Archanjo et al, 2008Brito Neves et al, 2001aBrito Neves et al, 2001bBrito Neves et al, 2003Brito Neves et al, 2013Cruz and Accioly, 2012Ferreira et al, 2011Guimarães et al, 2004Guimarães et al, 2011Guimarães et al, 2012Hollanda et al, 2010Lages et al, 2013Leite et al, 2000…”

“…7. (vi) Numerous studies have shown that the large transcurrent shear zones of the Borborema Province, which could be interpreted as boundaries between terrains with different evolutionary histories, are a late feature of the Brasiliano Orogeny and that they are not reactivated suture zones (e.g., Neves and Mariano, 1999;Neves et al, 2006;Archanjo et al, 2008;Hollanda et al, 2010;Neves et al, 2012;Viegas et al, 2014; and references cited in these works). An intracontinental character is clearly demonstrated by the fact that most shear zones are contemporaneous or slightly posterior to the voluminous magmatism intruded between 590 and 580 Ma, which, in turn, post-date the early stages of the Brasiliano Orogeny by more than 30 Ma.…”

U–Pb age of the coesite-bearing eclogite from NW Borborema Province, NE Brazil: Implications for western Gondwana assembly

“…600-560 Ma comprises a still imprecise time interval defined by zircon and monazite. However, several authors have attributed this period to the installation of major shear zones in the Ceará Central and Médio Coreaú domains (Monié et al, 1997;Fetter et al, 2003;Archanjo et al, 2013;Viegas et al, 2014). In the Cariré region, rounded concordant zircon grains extracted from high-pressure mafic granulites and the rims of zircon grains from a host granodiorite from the same region yielded ages of 589 ± 8.9 Ma and 587 ± 31 Ma, respectively (Amaral et al, 2012).…”