Deformation mechanisms, mineral chemistry and zircon U-Pb geochronological constraints in the south Patos shear zone: implications for the crustal evolution of the Borborema Province, NE Brazil

The southern boundary of the Patos Shear Zone (PSZ) is characterized by mylonites resulting from deformation Paleoproterozoic basement gneisses, Neoproterozoic metavolcanic and metasedimentary rocks, granitic granodioritic intrusions. Among latter, Santa Terezinha Catingueira plutons show stretched shapes in agreement with shear zone’s regional trend. Recrystallized quartz grains these accommodate dislocation creep. host banded gneisses similar structures to plutons. Quartz crystallographic fabrics mainly record activity basal prism slip planes local contribution rhomb planes, whilst feldspar clasts evidence intracrystalline larger porphyroclasts. These characteristics suggest that shearing occurred at lower-amphibolite facies conditions. U-Pb zircon data for pluton yields an age 625 ± 7 Ma, which, coupled elongated shape microstructure, suggests its emplacement was pre-kinematic relation zone. Post-emplacement elongation granite body along strike-slip Such structural geochronological constraints highlight close association between magma zone during distinct stages Brasiliano-Pan-African orogeny Borborema Province.