| Toca da Boa Vista | |
|---|---|
  Toca da Boa Vista State of Bahia | |
| Location | Campo Formoso |
| Coordinates | 10°09′45″S 40°51′35″W / 10.162500°S 40.859722°W |
| Depth | 50 m (160 ft) |
| Length | 114 km (71 mi) |
| Discovery | 1987 |
| Geology | Limestone |
| Entrances | 1 |
Toca da Boa Vista (BA-082) is located within the municipality of Campo Formoso, 11 km east of the town of Lage dos Negros, in the State of Bahia, Brazil. The area is karstified Salitre formation dolomite bedrock of the Una Group, the brazilian name of the Ediacaran, which is of Precambrian age, about 600 Ma old. This time at the end of the Precambrian was characterized by the beginning of multicellular life, and actually, the sedimentation of limestone was much different from the Mesozoic era. The microorganisms, which later reduced the amount of phosphates and sulfur in the loose sediment on the seabed before diagenesis started, did not yet exist. As a result, the chemistry of this dolomite is unique, and the high amount of phosphor and sulfur caused a unique process of cave formation. Groundwater set the sulfur free which was oxidized by microorganisms and created sulfuric acid, which again dissolved limestone.[1] This process is called hypogene speleogenesis,[2] where the acid which dissolves the limestone originates from the underground, the rock, instead of from the atmosphere.
The cave system is most famous for an enormous number of prehistoric bones, which were found in the cave. 20,000 years ago an enormous river transported dead animals into the cave, which formed massive deposits of bones. More than 50,000 bones have been excavated until now, among them the bones of huge mammals which are now extinct.[3] An example is a 6 m long giant sloth, the newest discovery was a turkey vulture (Cathartes aura) in 2024.[4]
As of 2024[update] this is the longest known cave of Brazil[5] and it has 114 km of mapped passages. There are obstinate statements that it was the longest cave of the Southern Hemisphere, which are based on an article from 1999.[6] At that time the statement was actually correct.
- ^ Cecilia Brooke Sanders. "Geological and Geochemical Explorations of the Salitre Formation Phosphorite, Eastern Brazil" (PDF). Retrieved 2024-10-29.
- ^ Alexander B. Klimchouk. "Hypogene Speleogenesis". Retrieved 2024-10-29.
- ^ Jochen Duckeck. "Toca da Boa Vista". Retrieved 2024-10-29.
- ^ Ronaldo Araujo Leoni, Laís Alves-Silva, João Paulo da Costa, André Vieira de Araújo, Hermínio Ismael de Araújo-Júnior, Mário André Trindade Dantas. "First fossil record of a Turkey vulture (Cathartes aura) in northeast of Brazil: Taxonomy, ichnology, and taphonomic history". Retrieved 2024-10-29.
{{cite web}}: CS1 maint: multiple names: authors list (link) - ^ Sociedade Brasileira de Espeleologia. "As maiores cavernas do Brasil" (in Portuguese). Retrieved 2024-10-29.
- ^ Augusto S. Auler, Peter L. Smart. "TOCA DA BOA VISTA, Bahia state the longest known cave in the Southern Hemisphere". Retrieved 2024-10-29.