Lapa dos Brejões
Lapa dos Brejões is a complex of caverns formed in Neoproterozoic limestones of the Una Group of caves along the Jacaré river, northeast side of the Irecê sedimentary basin. It is located in the northern portion of the Chapada Diamantina - Polígono das Secas, in the north central part of the State of Bahia, about from the capital Salvador, Brazil. According to local people, the Lapa dos Brejões was discovered in 1877, but the first discoveries inside the cave were published only in 1938 by Father Camilo Torrendt.
Geology
Lapa dos Brejões is one of the most remarkable group of caves in Brazil by the large amplitude of its galleries, halls, skylights, speleothems and its main entrance portico with in height. A collapsed portion called karst canyon divides the cave into two segments, Brejões I and Brejões II, which together sum. Along the canyon one find shelter under the rocks and cave paintings of some sites.Brejões I is made up of two major sub-parallel main galleries that have up to high and wide. It is the main part with of large galleries where the speleothems and the most striking morphological features are concentrated, including two giant collapsed dolines as skylights. Their features are cylindrical with their base wider than the top that reach in diameter, occupied by large piles of blocks of rock and huge pillars anchored to the walls.
Brejões II is meters long and presents several galleries. The Jacaré river, which went through a hole 300 meters before the main entrance, re-appears inside the cave after the initial, and again inside Lapa dos Brejões II, until it finally comes up outside the main entrance to the cave. The Racekiela cavernicula, of the genus Racekiela, is now a new species of cave freshwater sponge first recorded in Brazil.