Paleoproterozoic

The Paleoproterozoic Era is the first part of the three divisions of the Proterozoic eon. It lasted a very long time, from 2,500 to 1,600 million years ago. It is the longest era in Earth's geological history.

This era is split into four smaller time parts called geologic periods: the Siderian, Rhyacian, Orosirian, and Statherian.

During the Paleoproterozoic, a day on Earth was only about 20 hours long. This means there were about 450 days in a year back then! This era was also very important because it is when the continents of the Earth first came together and stayed in place.

Atmosphere

Main articles: Prebiotic atmosphere, Geological history of oxygen, and Great Oxygenation Event

The early Earth's atmosphere was very different from today's air. It was filled mostly with nitrogen, methane, ammonia, carbon dioxide, and other gases that people and animals cannot breathe. This changed when simple plants called cyanobacteria began using sunlight to make food, a process called oxygenic photosynthesis. As these tiny plants grew, they released a lot of dioxygen as a waste product. Over time, this oxygen built up in the air, leading to a big change called the Great Oxidation Event. This event made oxygen levels rise sharply, changing the planet's air and making it possible for animals to breathe millions of years later.

Life

Further information: Symbiogenesis

At the start of the Archean eon, most life was simple single-cell prokaryotic organisms that did not need oxygen. After a big change called the Great Oxygenation Event, many of these old organisms could not survive. This led to a long cold period called the Huronian glaciation.

Later, new types of organisms that could use oxygen began to thrive. This era, called the Paleoproterozoic, is when we find the oldest known fossils of cyanobacteria. Scientists also think that more complex cells, called eukaryotic organisms, began to appear during this time. These changes helped set the stage for more kinds of life to develop later on Earth.

Geological events

During the Paleoproterozoic Era, large collisions between continents happened. These collisions made mountain ranges in many parts of the world, such as South America, West Africa, southern Africa, North America, Greenland, and Europe. These events helped create a supercontinent named Columbia or Nuna.

Volcanic activity formed important mineral deposits in what is now northern Sweden. The oldest pieces of Earth's outer layer also formed in parts of Patagonia's oldest blocks.