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Rocks Found From The Birth of Planet Earth

What we’ve found are surviving parts of Earth’s primitive mantle that have been preserved for four and a half billion years, and I think that’s kind of exciting!

You don’t need to do the math … 4.5 billion years ago dates back to the birth of Planet Earth and that’s why University of Maryland Professor of Geology Richard Walker is as excited as a geologist can be. He led a team of researchers that discovered a pair of what are being called “birthmarks” made of silicate material formed when Earth was less than 50 million years old.

Is this really big news? According to Walker’s report in the current edition of the journal Science, it’s the first time that original material from the birth of Earth has been discovered. Until now, the accepted scientific belief was that any material from the planet’s original mantle (the layer between the crust and the outer core) was destroyed or changed beyond recognition by collisions with space bodies during the formation of the solar system, especially the big one (the so-called Theia impact) with a Mars-sized body named Theia that created the Moon.

Baffin Island

Baffin Island

This rock-solid belief began to crumble Richard Walker when Walker’s team looked at lava rocks from Baffin Island off the coast of northern Canada and from the Ontong-Java Plateau in the Pacific Ocean, north of the Solomon Islands. They found that these rocks contained a significant amount of an isotope of tungsten-182. So? It turns out that this isotope was only formed from decaying hafnium-182 during the first 50 million years of the solar system and never again. That means it’s an original “birthmark” of Earth.

Location of the Ontong-Java Plateau

Location of the Ontong-Java Plateau

How did these birthmarks survive? The researchers theorize that the mantle under Baffin and Ontong-Java did not experience the same tungsten-removing iron separation that the rest of the mantle experienced during the collisions that destroyed or homogenized the rest of early Earth. It was brought to the surface during volcanic eruptions 60-to-120 million years ago and only now detected by devices that can identify the tungsten-182 isotope.

Now that they know what to look for, Walker believes that more Earth birthmarks will be found and that will lead to a better understanding of the formation of both the planet and the solar system.

Walker is right. That IS kind of exciting.

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Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.
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