Eruption
and Erosion
Science tells a different story. About 130 million years ago Gondwana, the supercontinent, broke apart. This caused an enormous volcanic event.
At the time, the area was a giant desert. Lava poured from volcanoes. It covered the desert. As it cooled and hardened, it built up layers of rock.
Waterfalls are formed as a river flows from hard rock to soft rock
The river erodes the soft rock at a faster rate. It forms a step in the river bed.
The hard rock that is left creates a hard ledge. The river falls over the ledge.
The Iguazú River empties into the Paraná River. This is where the borders of Brazil, Argentina, and Paraguay meet. It is known as the Triple Frontier.
Earth’s plates kept moving. The layers were lifted into a high plateau. Faults, or cracks, appeared in them. Water running down the faults eroded, or wore away, the land. The Paraná riverbed formed. Later, the Iguazú River appeared. It fed into the Paraná. Falls formed at the place where these two rivers met.
Today, the falls are farther upstream. This is due to erosion. As water fell into the river, it weathered away rock on the bottom. The upper layers crumbled. Today, the falls look like a giant staircase.
Waterfalls are formed as a river flows from hard rock to soft rock
The river erodes the soft rock at a faster rate. It forms a step in the river bed.
The hard rock that is left creates a hard ledge. The river falls over the ledge.
Brazil
Argentina
Paraná
Iguazú
Paraguay
Into the Rainforest
Water is just part of the beauty around Iguazú Falls. The falls ecosystem is home to a variety of species. Plants. Mammals. Birds. Reptiles. Amphibians. Some species are found nowhere else in the world.
black capuchin monkey
toucan
Beware of the coatis! They can bite your hand when they try to grab your food.
I saw tall palm trees and rosewoods. Papaya fruit hung from small trees.
Blue morpho butterflies fluttered through the air. I also saw a toucan in flight and monkeys in the trees. I got a good view of a young caiman. And coatis seemed to be everywhere! I kept an eye out for jaguars. They live here, too.