Geophysical-structural framewok of southern Ribeira Belt

The diversity of works and models presented to explain the evolution and current setting of southern portion of the Ribeira Belt reflects the complexity of the processes involved in such terrains. Based on qualitative (anomalies enhancement) and semi-quantitative (source depths detection) analysis of aeromagnetic data and gravity data modeling, this work presents geophysical-geological-structural models of this region. The integration of qualitative and semi-quantitative analysis, constrained by the geological data, formed the basis for the elaboration of models. The application of methods of anomalies enhancement (qualitative analysis) showed that the lineaments of Taxaquara Fault Zone and Itapirapuã, Morro Agudo and Lancinha shear zones spread under the Paraná Basin. This interpretation was validated by Euler solutions, which located sources with depth greater than 2,000 m, related to these structures. The gravity models, which were elaborated in distinct depth levels, indicate a crustal thinning from NW to SE, with different crustal thickness portions bounded by the shear zones.