Beneath the Surface
Chapada Diamantina consists of an abundance of beautiful
caverns and caves beneath the surface. These caves contain a vast array of rock
formations and just enough surface light enters to create astonishing, majestic
views. One of the most famous caves in Chapada Diamantina is known as Poço
Azul or “the blue pool.”
Poço Azul lies close to the Paraguaçu River on the eastern side of
Chapada Diamantina. It is known as a “karst” cave in which is created when
limestone networks along with underground water, ultimately dissolving the
limestone. When a certain amount of limestone is eroded from underground water
a sinkhole can develop. This is exactly what has occurred in the case of Poço
Azul in Chapada Diamantina as it lies at the bottom of one of these sinkholes.
This example is a direct correlation to the subject of
Earth’s rocks, specifically sedimentary rocks. Poço Azul’s walls are shaped by
sedimentary rocks, which tell its history over the past billion years. These
sedimentary patterns depict Poço Azul’s history from lands of volcanic
activity to seaside plains to low seas to glacial activity to much warmer seas,
all of which occurred before five-hundred million years ago when penetrating
tectonic activity took over the area.
Within karst caves such as Chapada Diamantina’s gem, Poço
Azul, speleothems are created. These caves are known for this process since
calcium carbonate solutions slowly drips down via “dripstones,” creating
stalactites. The process continues and overtime the calcium carbonate solution
drips down to the floor of the cave, resulting in stalagmites. The karst
topography of Poço Azul is a prime example of how some of its amazing features
come into place to create awe-inspiring scenery.
Overall, the combination of sedimentary rocks crafted
through history with the chemical reactions of calcium carbonate solutions
creating stalagmites and stalactites have made the karst cave of Poço
Azul in Chapada Diamantina a modern spectacle.
Resources
http://www.atlasofwonders.com/2011/11/chapada-diamantina.html
http://gobrazil.about.com/od/Chapada-Diamantina/ss/Poccedilo-Azul.htm
http://geography.about.com/od/physicalgeography/a/karst.htm
http://geology.about.com/cs/basics_roxmin/a/aa011804b.htm
