Why Are Some Rocks in Canada Billions of Years Old?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why are some rocks in Canada billions of years old?

The Big Idea

Some rocks in Canada are about 4 billion years old! They are part of the Canadian Shield, some of the oldest land on Earth. Some of those very old rocks are in the Northwest Territories.

Light Rock Floats

Step one: light rock floats. Continents are made of light rock that floats high on the mantle, like a cork in water. Seafloor is heavier, so it can sink back down.

No Recycling

Step two: no recycling. Heavy seafloor sinks into the mantle at trenches and gets recycled. Light continent rock mostly stays on top, so it can survive.

Billions of Years

Step three: billions of years. Old pieces of continents can last for billions of years. Earth itself is about 4.5 billion years old.

A Closer Look

Let's take a closer look! Continent rock is lighter than seafloor rock. So it floats high instead of sinking. The Canadian Shield is a huge area of ancient rock. Some of it is about 4 billion years old.

Quick Facts

Quick facts! Earth is about 4.5 billion years old. The oldest known rocks in Canada are in the Northwest Territories. The Canadian Shield covers about half of Canada. Seafloor rock is much younger than continent rock.

Think Like a Scientist

Now, think like a scientist! Stretch a string 4.5 meters long to show Earth's age, with 1 meter for each billion years. Mark the oldest Canadian rocks at about 4 meters. Now find where humans appear. It is at the very end, less than a millimeter from the tip! That is how new we are compared to these rocks.

Outro

Canada has some of the oldest rocks on Earth. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!