Antenor Navarro

It is composed of conglomeratic thick sandstones, containing levels of conglomerates and medium to fine sandstones. In the Brejo das Freiras Sub-basin, the Antenor Navarro Formation is formed by conglomeratic sandstones, with ribbed cross stratification. In the Sousa Sub-basin, the formation has the previously mentioned sandstones, being associated with banks of levels of polymictic conglomerates on the northern border. In the Pombal sub-basin, it is associated to the Malta shear zone, with the occurrence of a polymorphic conglomerate composed of blocks that can reach up to 1.5 m in diameter/length.

Rio Piranhas

It is represented by the upper unit of the Rio do Peixe Group, occurrences are restricted to the southern portion of the Sousa Sub-basin, where it has approximately 100 meters, and can reach up to 300 meters of thickness. Its composition is largely conglomeratic, feldspathic and lytic, poorly selected, light gray to reddish brown, having intercalations of medium to fine sandstones and siltstones.

Formação Sousa

It occupies about 70% of the area of the Sousa and Pombal sub-basins and 50% of the Brejo das Freiras Sub-basin and has a maximum thickness of 800 meters in the Sousa Sub-basin, being able to reach a little more in the Brejo das Freiras Sub-basin. One of the main exhibitions of the upper Sousa Formation is located in the Pedregulho site where a sequence of siltstones, argillites, and fine, brownish sandstones appear, presenting flat-parallel laminations. The lower part is well represented in the locality of Passagem das Pedras where shales dominate the formation.

Cenozoic Coverage

It is represented by the alluvial deposits along the extension of the main rivers, such as the Piranhas and Peixe rivers and their main tributaries. It is composed of sandy, conglomerate sediments as well as clayey portions.