Brazil

Ecotourism / Speleological Tours - With more than 300 limestone caves, the Speleologic Province Upper Ribeira Valley / Paranapiacaba in the south of São Paulo State is one of the most beautiful karst landscapes in Brazil.

Karstification results from the dissolution of limestone by carbonic acid which is formed as rain passes through the atmosphere picking up carbon dioxide. Limestone is mainly composed of calcite (chemically known as calcium carbonate), a mayor component of marine fossils, whose organic remnants were deposited on ocean seafloors, during the Proterozoic.

The Neoproterozoic Lajeado formation in the southern segment of the Ribeira Belt is supposed to be a remnant of such an ocean floor that might have existed about 800 million years ago, somewhen after the rupture of supercontinent Rodinia and prior to the formation of Gondwana.

See also: Intervales / PETAR - Tours