A new geological study shows that Scandinavia was born in Greenland

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In a Finnish outcrop nestled among some of northern Europe's oldest mountains, researchers have discovered traces of a previously hidden part of the Earth's crust that date back 3 billion years. Credit: Andreas Petersen

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In a Finnish outcrop nestled among some of northern Europe's oldest mountains, researchers have discovered traces of a previously hidden part of the Earth's crust that date back 3 billion years. Credit: Andreas Petersen

The oldest Scandinavian foundation was „born” in Greenland, according to a new geological study from the University of Copenhagen. The study helps us understand the origin of the continents and why Earth is the only planet with life in our solar system.

In a Finnish outcrop nestled among some of northern Europe's oldest mountains, researchers have found traces of a previously hidden part of the Earth's crust, dating back 3 billion years and pointing north toward Greenland.

These traces were found in the mineral zircon, which, after chemical analyses, the researchers from the Department of Geosciences and Natural Resource Management said was „born” from Greenland, the „bedrock” on which Denmark and Scandinavia rest, about 3.75 billion years ago. .

„Our data suggest that the oldest part of the Earth's crust beneath Scandinavia originated in Greenland and is about 250 million years older than we previously thought,” says Professor Todd Waite, a geologist in the Department of Earth Sciences and Natural Resource Management.

The researchers' study of zircon showed that, in many ways, its chemical fingerprint matches some of the oldest rocks on the planet, found in the North Atlantic Craton of West Greenland. Findings are Published In the journal Geography.

„Zircon crystals we found in river sands and rocks in Finland indicate that they are much older than anything ever found in Scandinavia, while matching the age of Greenlandic rock samples. At the same time, the results of three independent isotope analyzes confirm that the basement of Scandinavia is mostly related to Greenland,” says Geosciences and Natural Resources. Management analyst Andreas Petersen.

A water world without oxygen

Denmark, Sweden, Norway and Finland rest on top of a part of the Earth's crust called the Fennoscandian Shield or Baltic Shield. Researchers believe that it separated from Greenland as a „seed” and hundreds of millions of years later it „rooted” where Finland is today.

Here, the plate grew as new geological material accumulated around it until it became Scandinavia. At the time the crust separated from Greenland, the planet looked very different than it does today.


Zircon crystals found in river sand and rocks from Finland match the age of Greenland rock samples, but have signatures that indicate they are much older than anything ever found in Scandinavia. Credit: Andreas Petersen

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Zircon crystals found in river sand and rocks from Finland match the age of Greenland rock samples, but have signatures that indicate they are much older than anything ever found in Scandinavia. Credit: Andreas Petersen

„Earth could have been a watery planet, like in the movie Waterworld, but with no oxygen in the atmosphere and no exposed crust. But because it's so far back in time, we can't be sure what it was like,” says Todd Waite.

According to the researchers, the fact that Earth even has a continental crust with granite is very special when they look out into space and compare it to other planets in our galactic neighborhood.

„This is unique in our solar system. Also, liquid water and a granite crust are important factors when identifying the possibility of habitable exoplanets and life beyond Earth,” explains Peterson.

Continents are the key to life

The new study adds pieces to the puzzle of a primitive continent that began long before life truly blossomed on Earth, but which largely paved the way for human and animal life.

„Understanding how continents form helps us understand why ours is the only planet in the Solar System that harbors life. Because without stable continents and water between them, we wouldn't be here. In fact, continents influence both ocean currents and climate. They're critical to life on Earth,” says Peterson.

Also, the new study contributes to a growing number of studies that reject the methods used so far to account for how the continents grew—especially in the first billion years of Earth's history.

„The most commonly used models assume that the Earth's continental crust began to form when the planet formed about 4.6 billion years ago. In contrast, our and many other recent studies suggest that we can identify chemical signatures that show the growth of the continental crust. A billion years later, how the early continents formed.” We may have to rethink what we think about that,” Waite says.

At the same time, the study's results add to previous research that has found similar „seeds” from ancient crusts in other parts of the world.

„Our study gives us another important clue in the mystery of how continents form and spread across Earth—especially in the case of the Fennoscandian Shield. But there's still a lot we don't know. Similar seeds have been found in Australia, South Africa and India, for example, but they all come from the same 'place of origin'.” ' We do not know whether they came or whether they appeared independently of each other in many places on Earth.

„We want to investigate further using the method we used in this study,” concludes Waite.

More information:
Andreas Petersen et al., Eorcian Continental Nucleus for the Fennoscandian Shield and Link to the North Atlantic Craton, Geography (2023) DOI: 10.1130/G51658.1

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