It’s not quite Atlantis, but a new model of the early development of continental crusts proposes Earth really did once have lost continents.
They were just a few billion years early to support a fabled civilization.
The idea comes from comparing the age and radioactivity of rocks across the planet. As shown by some papers (Precambrian Research and Lithos), Dr Derrick Hasterok of the University of Adelaide suggests Earth’s continental crust was much thicker, much earlier than current models imply, and continents could have existed as far back as 4 billion years ago before disappearing and leaving little trace.
Those theories are based on an inverse relationship between the age of rocks and their radioactivityin more than 76,000 rock samples from around the world.
Hasterok argues the relationship exists because all the most radioactive early crust has disappeared. Rocks that are fairly radioactive produce heat.
In the early days of Earth, when radioactive isotopes were more abundant, this heat was four times greater. The most radioactive rocks melted, which Hasterok said “Destroys some degree of the knowledge of the old one,” leaving us the impression there was no crustal material there beforehand.
Where a large part of a continent was highly radioactive, Hasterok added, “The rocks became weak and tectonic processes could pull them apart more easily.”
Entire proto-continents may have been destroyed, leaving no trace at all. Like those ones:
Allowing for these processes, Hasterok concludes, the early Earth had more and thicker continental crust than we give it credit. What he doesn’t yet know, and hopes to learn with further study, is whether it had an area a few times the preserved rocks – which would still be less than a single existing continent – or it the extent and thickness of continents 2-4 billion years ago approached what exists today.
Hasterok came to these conclusions by chance. He was attempting to model the radioactivity of parts of Antarctica we have been unable to study directly. Heat from the more radioactive pockets melts glaciers from below, contributing to the speed with which they move. In an effort to improve our understanding of this effect, and its influence on ice melt, Hasterok found himself exploring a field he described as “Much more interesting.”
Yes lost continents and their mysteries are about to be re-discovered! And then, it’s going to get really baffling!