Siderian facts for kids

Look at these cool rock layers called Banded Iron Formations, found in Australia!

The Siderian Period was a very long time ago, from about 2.5 billion to 2.3 billion years ago. It was the first part of the Palaeoproterozoic Era. Before the Siderian came the Neoarchaean Period, and after it was the Rhyacian Period.

This period is super important because of big changes that happened on Earth. Imagine a world very different from ours, with a lot less oxygen in the air!

What Happened During the Siderian Period?

The Siderian Period saw two of the most important events in Earth's history: the rise of oxygen and a huge ice age.

The Great Oxygenation Event: Earth Gets More Oxygen

During the Siderian Period, something amazing happened: Earth's atmosphere started to get a lot more oxygen. This is known as the Great Oxygenation Event.

• How it started: Tiny living things called algae in the oceans began to produce oxygen as a waste product. This was a new kind of life that used sunlight to make food, just like plants do today.
• Iron in the oceans: At first, this new oxygen combined with a lot of iron that was dissolved in the ocean water. When oxygen and iron mixed, they formed a rusty-looking material called magnetite.
• Banded Iron Formations: This magnetite settled down to the ocean floor, forming special layers of rock called Banded Iron Formations (BIFs). These rocks look like stripes of red and gray, showing us how much iron was being pulled out of the water.
• Clearing the oceans: As more and more iron was removed, the oceans, which might have looked greenish before, became clearer.
• Oxygen in the air: Once most of the iron was gone from the oceans, the oxygen had nowhere else to go. So, it started to build up in the atmosphere. This was a huge change for our planet!

The Huronian Glaciation: Earth's Big Freeze

The increase in oxygen might have caused another massive event: the Huronian Glaciation. This was one of the longest and coldest ice ages Earth has ever seen.

• When it happened: This ice age took place during the Siderian Period, roughly between 2.4 billion and 2.3 billion years ago.
• Why it happened: Scientists think that the new oxygen in the atmosphere reacted with gases like methane, which used to keep Earth warm. When methane was removed, the planet cooled down a lot, leading to widespread ice and snow.
• Impact on life: This extreme cold would have been very tough for the simple life forms that existed back then.

Why is the Siderian Period Important?

The Siderian Period set the stage for all future life on Earth. Without the Great Oxygenation Event, our planet would not have the oxygen-rich air we breathe today. This oxygen was necessary for more complex life forms, including animals and humans, to eventually evolve.

See also

In Spanish: Período Siderico para niños