[Rockhounds] Magnetic Clues in Australian Rocks Suggest Plate Tectonics Began Over 3 Billion Years Ago

[Kreigh Tomaszewski]

Without plate tectonics, our planet wouldn’t have continents, mountains,
and possibly even life itself. New evidence suggests this geological
process began at least 3.2 billion years ago, a surprisingly early origin.

Geologists debate exactly when our planet’s tectonic plates began to shift.
Estimates vary wildly, ranging from 4 billion to 1 billion years ago, with
general agreement that it began around 2.8 billion years ago.

New research <https://advances.sciencemag.org/content/6/17/eaaz8670> published
today in Science Advances suggests plates deep beneath the surface were
moving as early as 3.2 billion years ago. Ancient rocks from Australia were
found to bear magnetic signatures that could be correlated with lateral
movements during the Archean eon (4 billion to 2.5 billion years ago).

“Basically, this is one piece of geological evidence to extend the record
of plate tectonics on Earth farther back in Earth history,” said Alec
Brenner, a co-author of the study and a geologist from Harvard University’s
Paleomagnetics Lab, in a press release. “Based on the evidence we found, it
looks like plate tectonics is a much more likely process to have occurred
on the early Earth and that argues for an Earth that looks a lot more
similar to today’s than a lot of people think.”

https://gizmodo.com/magnetic-clues-in-australian-rocks-suggest-plate-tecton-1843003975