4 research outputs found
Long-lived Paleoproterozoic granitic magmatism in the SeridĂł-Jaguaribe domain, Borborema Province-NE Brazil
The northeastern part of the Borborema Province is dominated by Paleoproterozoic migmatitic tonalitic to granitic orthogneisses (CaicĂł Complex) that are the basement for younger, metavolcanosedimentary rock assemblages. Within this complex gneissified,
The bimodal rift-related Juscelândia volcanosedimentary sequence in central Brazil: Mesoproterozoic extension and Neoproterozoic metamorphism
The Barro Alto Complex and Juscelândia volcanosedimentary sequence are exposed in the central part of the Neoproterozoic BrasĂlia belt of central Brazil. The former is a large (approximately 150 km long), boomerang-shaped, mafic-ultramafic, layered com
Fabrics of pre- and syntectonic granite plutons and chronology of shear zones in the Eastern Borborema Province, NE Brazil
We used the fabrics of two granite plutons and U/Pb (SHRIMP) zircon ages to constrain the tectonic evolution of the E-trending Patos shear zone (Borborema Province, NE Brazil). The pre-tectonic Teixeira batholith consists of an amphibole leucogranite locally with aegirine-augite. Zircons from a syenogranite yielded crystallization ages of 591 ± 5 Ma. The batholith fabrics were determined by anisotropy of magnetic susceptibility (AMS) and mineral shape preferred orientation. The fabrics support pre-transcurrent batholith emplacement, as evidenced by: (i) magmatic/magnetic fabrics in low susceptibility (1 mSI) corridors connected to shear zones branching off from Patos. One of these satellite shear zones controlled the syntectonic emplacement of the Serra Redonda pluton, which yields a crystallization age of 576 ± 3 Ma. This late shearing event marks the peak regional deformation that, south of Patos, was coupled to crustal shortening nearly perpendicular to the shear belt. The chronology of the deformational events indicates that the major shear zones of the eastern Borborema are late structures active after the crustal blocks amalgamated