Résumé
The Neoproterozoic Ribeira-Aracuai belt stretches along the southeastern edge of the Sao Francisco craton of southeastern Brazil and extends south of the cratonic domain for >1000 km. The termination of the craton is spatially correlated with a significant modification of the deformation pattern in the belt: (1) the structural trend bends from due north to northeast, (2) the dominant tectonic flow shifts from orogen-transverse to orogen-normal, and (3) the metamorphic conditions of deformation decrease southwestward from high to medium grade. Finite-element modeling suggests that the presence of a craton within a continent favors strain localization, initiation of continental-scale shear zones, and differential vertical deformations. The southward termination of the Sao Francisco craton may have triggered the development of the complex deformation pattern that characterizes the Ribeira-Aracuai belt.