Hidden chunk of Earth's crust that seeded birth of 'Scandinavia' discovered through ancient river crystals

By studying river crystals in Finland, researchers have identified traces of a hidden chunk of Earth's crust from the heart of an ancient continent, a new study has found.

The crystals, from the mineral zircon, formed deep within the crust and provide clues as to how some of Europe's oldest bedrock formed 3.75 billion years ago.

To make the discovery, the team studied three geochemistry tracers — uranium–lead, Lutetium–hafnium and Oxygen — to date the crystals and match their signatures to other ancient crust. The analysis revealed that part of the crust is about 250 million years older than scientists previously thought, and that it likely originated in Greenland, according to a University of Copenhagen statement released March 21.

The study sheds light on the formation and growth of Archean cratons, the oldest parts of the continental crust that formed during the Precambrian's Archean era (4 billion to 2.5 billion years ago), when life first arose.

"Understanding how continents formed helps us understand why ours is the only planet in the solar system with life on it," lead author Andreas Petersson, a geochemist at the University of Copenhagen, said in the statement. "Because without fixed continents and water in between them, we wouldn't be here. Indeed, continents influence both ocean currents and climate, which are crucial for life on Earth."

The researchers presented their findings in a study published Dec. 28, 2023, in the journal Geology.

Related: Greenland is losing so much ice, it's getting taller