Geology of the Guaribas River Basin

Abstract

Located in the southeastern Piauí mesoregion, the Guaribas river basin integrates a total of eleven Piauí watersheds covering land spread over 18 municipalities. Its configuration includes nine sub-basins, formed by smaller and intermittent water courses, among which the Pitombeira stream, the Canabrava stream, the Grotão stream, the São João stream and the Riachão river, which flow into the Guaribas river stand out which is a tributary of the Itaim River, which flows into the Canindé River, one of the main formators of the Parnaíba River, the second largest river in the Northeast, with an extension of 1,485 km. The lithologies mapped in the basin area comprise basement rocks, represented by the Neo and Mesoproterozoic lithologies (Suite Intrusiva Itaporanga, with coarse intrusive granites and pegmatitic veins and Jaguaretama Complex with schist, rich in micas, and migrated granites); Silurian Sequence (Serra Grande Group represented only by the Ipu Formation with sandstones and conglomerates); Mesodevonian-Eocarboniferous Sequence (represented by the Canindé Group through the Itaim, Pimenteira and Cabeças formations without lithologies from the Longá and Poti formations); and Magmatic rocks, representatives of jurocretaceous magmatism, with outcrops of the Sardinha Formation in the form of a sill intruded in the sandstones of the Cabeças Formation.