Lake Ballivián facts for kids

Lake Ballivián was a huge, ancient lake in the Altiplano region of South America. It's named after Don Manuel Vicente Ballivian, a scholar from Bolivia. This lake was one of several big lakes that formed long ago in the area around Lake Titicaca. It reached a height of about 3,860 meters (12,664 feet) above sea level. Lake Ballivián existed during the late Quaternary period, which was a very long time ago. Scientists think it played a role in how animals spread and developed in the Altiplano. Another old lake, Lake Escara, might have existed at the same time in the southern Altiplano.

What is the Altiplano?

The Altiplano is a very high, flat area in South America. It sits between two large mountain ranges, the Eastern and Western Cordilleras. This high plateau is about 3,800 meters (12,467 feet) above sea level. It covers a huge area of about 200,000 square kilometers (77,220 square miles).

Today, the Altiplano has a dry or semi-dry climate. But in the past, it was home to many large lakes. These lakes grew and shrank many times over thousands of years. You can still see signs of these old lakes, like huge salt flats. Examples include Salar de Uyuni and Salar de Coipasa. The famous Lake Titicaca is also in the northern part of the Altiplano.

Discovering Ancient Lakes

Lake Ballivián and Lake Minchin were some of the first ancient lakes discovered here. Later, in 1984, scientists found evidence of even older lakes. These were named Lake Mataro and Lake Cabana. They existed in the Titicaca basin before Lake Ballivián.

The name Ballivián was first used in 1909. It honors the Bolivian scholar Don Manuel Vicente Ballivian. Sometimes, the name "Ballivián" is used more generally. It can refer to any of the lakes that existed before Lake Titicaca.

How Big Was Lake Ballivián?

Lake Ballivián reached a maximum height of about 3,860 meters (12,664 feet). Another old shoreline at 3,840 meters (12,598 feet) might show a lower lake level. Or it could mean the lake stayed at that level for a long time.

Some old ideas suggested a higher shoreline at 3,900 meters (12,795 feet). But now, scientists believe those higher shorelines belong to Lake Cabana. Lake Cabana existed even before the glaciers arrived.

The surface of Lake Ballivián would have covered a massive area. It was about 13,000 to 14,000 square kilometers (5,000 to 5,400 square miles). This is about one and a half times larger than today's Lake Titicaca.

Where Was Lake Ballivián Located?

Lake Ballivián stretched much farther south than Lake Titicaca does today. Its eastern and western edges were mostly in the same place as Lake Titicaca's current edges. In some spots, there were groups of islands or deep inlets. The Copacabana Peninsula, which exists today, was likely an island or part of an archipelago then.

Signs of Lake Ballivián are found in the Lake Titicaca basin. These include old lake shorelines and layers of clay and sand. These layers are about 70 meters (230 feet) above the current lake level. The Azangaro Formation in Peru and the Ulloma Formation in Bolivia are made of deposits from Lake Ballivián. You can also find its clays around Lake Titicaca.

When Did Lake Ballivián Exist?

Lake Ballivián is from the late Quaternary period. Scientists believe it formed between 600,000 and 500,000 years ago. Fossils found in the lake's sediments support this age.

The time when Lake Ballivián existed in the Titicaca basin might match the time of Lake Escara. Lake Ballivián also came before Lake Minchin. The water levels of Lake Escara were much lower than Lake Ballivián's. This shows that a natural barrier, called the Ulloma-Capalla sill, was present back then.

It's possible that the waters from Lake Ballivián eventually broke through at Calacoto. They might have flowed into the Rio Mauri valley. This could have quickly carved out a new valley, draining the lake. The formation of the Rio Desaguadero outlet may have helped stabilize future lake levels.

How Lake Ballivián Affected Life

During the time of Lake Ballivián, a type of fish called pupfish spread across the southern and central Altiplano. The development of many other water creatures may also have been influenced by Lake Ballivián. These include Heleobia and Hyalella crustaceans. Also, Orestias fish and Biomphalaria snails may have developed new species because of the lake. The sponge Balliviaspongia is even named after Lake Ballivián.

See also

In Spanish: Lago Ballivián para niños