Rocks from a lost continent that broke up around 150 million years have been accidentaly discovered deep beneath Baffin Island in northern Canada.
The rocks belong to an ancient part of Earth’s continental crust called the North Atlantic craton (NAC).
The remarkable discovery was made entirely by accident when a team of scientists rummaged through a bunch of kimberlite rock samples that had been collected from the Chidliak Kimberlite Province by a diamond exploration company.
In a new article, geologists reveal how the samples they examined displayed a mineral structure that is only seen in rocks belonging to an ancient part of Earth’s continental crust called the North Atlantic craton (NAC).
Portions of this craton have been found across a vast area stretching from Scotland to eastern Canada, via southern Greenland.
Until now, however, no remnants of the NAC had been discovered as far north as Baffin Island. The study authors were therefore extremely surprised to find such striking similarities between their kimberlite samples and the NAC.
What are cratons?
Cratons are highly stable sections of the lithosphere that are billions of years old, and which modern continental plates formed around.
While some cratons remain intact at the center of existing continents, the NAC has long since split into fragments.
The mineral composition of the North Atlantic craton is so unique there is no mistaking it.
Implications for ancient landmass
The discovery of fragments of the NAC in Baffin Island has major implications for our understanding of this ancient landmass.
- It indicates it was some 10 percent larger than previously believed.
- This is the first time that fragments of the planet’s continental plates have been retrieved from such immense depth.
With these samples, we’re able to reconstruct the shapes of ancient continents based on deeper, mantle rocks. We can now understand and map not only the uppermost skinny layer of Earth that makes up 1 percent of the planet’s volume, but our knowledge is literally and symbolically deeper.