The longest cave in South America, in the municipality of Campo Formoso in Bahia, Brazil, cut into Ediacaran dolomite of the Una Group at the edge of the Chapada Diamantina. It was not dissolved from above like most limestone caves: groundwater released sulphur from the rock, bacteria oxidised it into sulphuric acid, and the acid ate the passages out from below, a process called hypogene speleogenesis. About 20,000 years ago a river carried dead animals into the system and left huge deposits of bone, which is what makes the cave famous outside caving circles. The ground sloths, sabre-toothed cats and other megafauna from these passages are among the best Pleistocene material in Brazil.
Ice age megafauna bones in an acid-carved cave · Late Pleistocene
This ground is protected. Photograph it, record it, leave it where it lies. On US federal land the Paleontological Resources Preservation Act 2009 makes collecting vertebrate fossils an offence, and penalties are real.
Brazil
See it on the map
This is remote ground. The closest other places on the map are a long way off.
