Oldest dated rocks facts for kids

The oldest dated rocks on Earth are incredibly ancient pieces of our planet's history. Scientists study these rocks to understand how Earth formed and changed over billions of years. Finding and dating these rocks helps us learn about the very early days of our planet.

A sample of gneiss from the Acasta River area of Canada. This rock is 4.03 billion years old.

Earth's Oldest Rocks: A Journey Through Time

Scientists use special methods, like radiometric dating, to figure out how old rocks are. This helps them find the oldest rocks on Earth.

Moon Rocks: A Piece of Earth's Past

• Some of the oldest rocks found on Earth actually came from the Moon. This is important because scientists believe the Moon was once part of Earth! This idea is called the giant impact hypothesis.
• During the Apollo 16 mission, astronauts brought back a Moon rock called Lunar sample 67215. This rock is about 4.46 billion years old. Even though it came from the Moon, it is considered one of the oldest known rocks on Earth.
• Another Moon rock, nicknamed "Big Bertha", was collected during the Apollo 14 mission. It contains a tiny piece of Earth rock that is 4 billion years old! This shows how rocks can travel between Earth and the Moon.

Tiny Crystals: Earth's Oldest Material

• The oldest material that definitely came from Earth is a tiny mineral called zircon. These zircons are like tiny time capsules.
• Scientists found a zircon crystal in the Jack Hills area of Western Australia. This tiny crystal is an amazing 4.404 billion years old! It is the oldest piece of Earth ever dated.
• Other very old zircons from the same area are about 4.35 billion years old. These tiny crystals tell us about the very early conditions on our planet.

Ancient Rock Formations: The Acasta Gneiss

• The oldest known rock formation on Earth is the Acasta Gneiss. It is found in the Canadian Shield in the Northwest Territories, Canada.
• This rock formation is made of very old igneous rock and gneiss. Gneiss is a type of rock that has been changed by heat and pressure deep inside the Earth.
• The Acasta Gneiss formed from ancient mountain chains that have been worn down by glaciers over billions of years.
• Scientists dated the Acasta Gneiss by studying the zircons found within its rocks. It is about 4.03 billion years old, making it the oldest large rock formation on Earth.

Images for kids

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  The Moon rock "Big Bertha", collected on the 1971 Apollo 14 mission, contains an Earth meteorite that is 4 billion years old.

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  Fragment of Acasta Gneiss

See also

In Spanish: Rocas datadas más antiguas para niños