MODELAGEM TERMOMECÂNICA E CINEMÁTICA DAS BACIAS INTRACONTINENTAIS DO TIPO RIFTE DA REGIÃO DO VALE DO CARIRI, PROVÍNCIA BORBOREMA, NE DO BRASIL

Abstract

The role of the Proterozoic inheritances of the Borborema Province, NE Brazil, on the formation and evolution of Early Cretaceous rift basins is highly accepted by the scientific community, but some underlying causes are still uncertain. The continental shear zones have been widely assigned as being the most relevant inheritances in this case, with some works showing that new faults nucleated from them during the lithospheric stretching. In this work, we use geodynamic numerical modeling to investigate rifting and basin-formation in the Cariri Valley, such as to assess the role of Proterozoic inheritances in the process. The numerical scenarios demonstrate that the rheological configuration is the most prominent feature, mainly the coupling between the upper crust and the lithospheric mantle, as well as the lateral heterogeneity of the mantle. Rifting location occurs in weak layers within the lithosphere, and mantelic heterogeneities have a major role in strain localization when compared to crustal heterogeneities. The shear zones were brittle reactivated only after the onset of rifting and helped to delimit the width of the basins. Thermomechanical modeling; Numerical scenarios; Proterozoic inheritances; Rift nucleation; Borborema Province