Strain Partitioning along Terrane Bounding and Intraterrane Shear Zones: Constraints from a Long-Lived Transpressional System in West Gondwana (Ribeira Belt, Brazil)

Abstract Shear zones are of localized high strain accommodating differential motion in the lithosphere and impacting crustal rheology deformational history orogenic belts. Although terrane bounding shear widely studied, intraterrane their tectonic significance, especially association with supercontinent assembly, is a largely unexplored topic. The Ribeira Belt (SE Brazil), Neoproterozoic-Cambrian belt from West Gondwana, dissected by crustal-scale NE-trending transcurrent zone system that juxtaposes composite terranes. Despite its extensive coverage complexity, this remains poorly investigated. In paper, we explore thermal regimes, timing ductile shearing using multiscale approach combining structural analysis derived remote sensing field-based data, microstructures, quantitative analysis, multimineral U–Pb geochronology (zircon, titanite, monazite, xenotime). Our combined previously published indicate transitional northeastward increase metamorphic conditions lower greenschist to granulite facies (from 250–300 750–800°C), reflecting different levels exposed. Vorticity finite data complex regime varied contributions pure simple oblate-shape ellipsoids strike-slip prolate-shaped dip-slip reverse zones. set suggests all were developed under subsimple regimes involving thrusting folding followed wrench tectonics. component deformation was accommodated folded domains between Geochronological suggest intermittent activations ca. 900–830 530 Ma, partially coeval at least two major episodes accretion 850–760 Ma 610–585 Ma. spatial temporal record within indicates some relate assembly represent either structures (e.g., Itapirapuã zone) or Ribeira, Figueira, Agudos Grandes zones), whereas others bounding, postcollisional Taxaquara reactivated an intracontinental setting (560–535 Ma).