Abstract:
Recent results from receiver function in Novo Planalto region intensifed the debate about the lithospheric structure through the limit of Tocantins Province and Amazon plate, in central Brazil. Aiming to better characterize this transition and to discuss the geological nature of the lower crust beneath Porangatu line, this work inferred the thickness of the crust beneath shot 2 of Porangatu line, using receiver function, refned the model of the crust, determined the density distribution by gravimetric modeling and integrated the results. Integrated analysis of seismic and gravimetric data highlighted the existence of a distinct crustal domain west of Serra Azul, evidenced by the abrupt thickening of the crust and the high density of these terranes. Vp and density values also showed that the lower crust beneath Porangatu line is mafc. Geophysical results show that the boundary between Tocantins Province and Amazonian Plate is marked by Serra Azul and that this limit is characterized by crustal interfgering and superposition of lower crusts. Differences between Neoproterozoic and older lithospheric mantle related to Amazonian and São Francisco plate are well defned.
Keywords:
Modeling; lithosphere; crust; Moho; Tocantins Province