Jack Hills facts for kids

Location of the Jack Hills in Australia

Satellite image

The Jack Hills are a group of hills located in Western Australia. These hills are incredibly special because they hold the oldest natural material ever found that came from Earth itself. This material is made up of tiny crystals called zircons.

These zircons formed a very, very long time ago, about 4.4 billion years ago. To give you an idea, that's almost as old as Earth itself! The very oldest and most accurately dated zircon from the Jack Hills is about 4.35 billion years old.

These ancient zircons are found inside a type of rock called a conglomerate. This rock has been changed over time by heat and pressure. Scientists study these tiny zircons to learn about what Earth was like during its earliest period, known as the Hadean eon.

Earth's Oldest Material: Zircons

The zircons from the Jack Hills are like tiny time capsules. They are very strong crystals that can survive extreme heat and pressure. This means they can last for billions of years.

Scientists use special methods to figure out how old these zircons are. By studying them, we can learn about the conditions on Earth when it was first forming. This includes details about early oceans and continents.

Comparing Ancient Rocks

While the Jack Hills zircons are the oldest Earth material, we have found even older rocks that came from space!

Moon Rocks

Astronauts from the Apollo 15 mission brought back a rock from the Moon called the "Genesis Rock." This rock is about 4.46 billion years old. It's one of the oldest rocks ever studied, even though it didn't form on Earth. Later, during Apollo 16, even older rocks were collected from the Moon.

Mars Meteorite

Another ancient visitor is the Allan Hills 84001 meteorite. This rock was blasted off from Mars about 4.5 billion years ago. It then crystallized, or formed its solid structure, about 4.091 billion years ago. This meteorite traveled through space and landed on Earth about 13,000 years ago. Scientists use different dating methods to confirm these incredible ages.

Images for kids

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  Quartz-pebble metaconglomerate (Jack Hills Quartzite), the rock type that contains Earth's oldest dated mineral grains (detrital zircon)