In terms of world tectonics, the country of Brazil is located in the center of the South American plate. Unlike Chili and other countries located on the continent’s western edge, it is largely not a part of the volcanic “Ring of Fire” that circles the upper and lower Pacific Ocean.
And while there thankfully hasn’t been any active volcanic eruptions in Brazil in recent years, there are plenty of signs that the country has seen its share of volcanic activity in the past.
Rio’s Sleeping Giant
Just above Rio de Janeiro is the “Patole”, a 60-mile-long sheet of pure granite that was formed by consolidated igneous rock from an ancient volcanic eruption.
The Patole goes all the way from Ilha do Governador to the mountain range in Petropolis and Nova Friburgo. It was once a massive reservoir of magma which never made its way to ground level, instead forming the Serra dos Orgaos mountains, the mountain range in the state of Rio de Janeiro.
In the ancient past, the Patole probably was a gigantic volcano that has subsequently erupted and entirely been destroyed and eroded.
In the South of Brazil, along the coast of Torres,is the Aparados da Serra National Park. This area, which includes the magnificent Iguazu Falls, was formed by the erosion of volcanic rock.
During the Mesozoic Era — which occurred about 65 million years ago — more than 600,000 square miles of the Parana River basin were filled with about 400,000 cubic miles of basaltic lava from either a single enormous volcano or a series of smaller volcanoes that were active in this region.
About the only potentially active volcano remaining in Brazil is actually on the island of Trindade, located about 620miles east of the Brazilian coast. Currently, the island is inhabited only by a colony of green sea turtles and sea birds.