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

From extension to shortening: Dating the onset of the Brasiliano Orogeny in eastern Borborema Province (NE Brazil)

“…Given the geochemical constraints, which require a relatively mafic source, it is proposed that two components were involved: (a) basaltic magmas formed by decompression partial melting of the mantle in the late Neoproterozoic and; (b) a Paleoproterozoic component, either basement rocks or sediments derived from it. Paleoproterozoic orthogneisses in the study area have a clear subduction zone signature (Neves and Alcantara, 2010;, which may have been inherited by the protolith of the Altinho orthogneiss.…”

“…Previous studies (Neves and Vauchez, 1995;Neves and Mariano, 1999;Neves et al, 2000Neves et al, , 2004 have shown that the EPSZ consists of several branches comprising high-temperature (HT) and lowtemperature (LT) dextral mylonitic belts. The HT mylonites are characterized by stability of hornblende, recrystallization of feldspars, abundant myrmekite, and grain boundary migration recrystallization of quartz in granitic protoliths.…”

The Zona Transversal Domain of the Borborema Province, northeastern Brazil: Synthesis of the Archean to Cambrian evolution, and new tectonostratigraphic interpretation

“…The Vertentes Orthogneiss unit comprises orthogneisses from monzogranitic to monzodioritic and granodioritic to dioritic compositions, usually with centimetric to decimetric regular layering, with metamafic lenses and granitic sheets, as described by Neves et al (2006Neves et al ( , 2017a, Neves and Alcantara (2010) and Brasilino and Miranda (2017). They are calciumalkaline rocks, of volcanic arc with U-Pb zircon ages between 2127 ± 7 Ma and 2085 ± 15 Ma and may have originated during the subduction stage related to the Rhyacian event (Neves et al 2006(Neves et al , 2017aNeves and Alcantara 2010;Brito Neves et al 2013;França et al 2019).…”

A preserved early Ediacaran magmatic arc at the northernmost portion of the Transversal Zone central subprovince of the Borborema Province, Northeastern South America

“…Nevertheless, there are some few authors who argue against a plate-tectonic accretionary process for the Meso and Neoproterozoic evolution of the Borborema Province (Neves & Alcantara 2010, Neves 2011 According to these researchers, the Borborema Province has behaved as an intracratonic setting since the late Paleoproterozoic. This means that all fold belts and granitic plutonism were the product of lithosphere extension without any formation of oceanic crust, followed by compression due to far-field stresses.…”