A network of 30 seismic stations was installed in the Carajás Mineral Province, in the eastern part of the Amazonian Craton, to study the deep structure of the Earth in this region. The data show that most of the area has high seismic velocities, which usually indicate a thick and stable lithosphere. However, some areas beneath the Carajás and Araguaia Belt show lower velocities. These low-velocity zones suggest a thinner lithosphere and the presence of hotter, more mobile material from the underlying asthenosphere.