Plate tectonics were active from the beginning of Earth, claim scientists in new study

New study overturns previous belief that plate tectonics developed over billions of years

Scientists have suggested that plate tectonics could have been active from the very beginning on Earth.

The new study of plate tectonics - the scientific theory that the Earth's crust move slowly over hot, viscous mantle rock - defies previous beliefs that tectonic plates developed over the course of billions of years.

Plate tectonics set up the conditions for life

The paper, published in Earth and Planetary Science Letters, is said to have important implications in the fields of geochemistry and geophysics. For example, a better understanding of plate tectonics could help predict whether planets beyond our solar system could be hospitable to life.

"Plate tectonics set up the conditions for life," said Nick Dygert, assistant professor of petrology and geochemistry in UT's Department of Earth and Planetary Sciences and co-author of the study. "The more we know about ancient plate tectonics, the better we can understand how Earth got to be the way it is now."

For the research, Dygert and his team looked into the distribution of two very specific noble gas isotopes: Helium-3 and Neon-22. Noble gases are those that don't react to any other chemical element.

Previous models have explained the Earth's current Helium-3/Neon-22 ratio by arguing that a series of large-scale impacts (like the one that produced the Moon) resulted in massive magma oceans, which degassed and incrementally increased the ratio of the Earth each time.

It could have only raised the Earth's Helium-3/Neon-22 ratio under very specific conditions

However, Dygert believes the scenario is unlikely.

"While there is no conclusive evidence that this didn't happen," he added, "it could have only raised the Earth's Helium-3/Neon-22 ratio under very specific conditions."

Instead, Dygert and his team believe the Helium-3/Neon-22 ratio was raised in a different way.

They suggest it involves the ratio of helium to neon in the mantle beneath the crust increasing as the Earth's crust is continuously formed.

By calculating this ratio in the mantle beneath the crust, and considering how this process would affect the bulk Earth over long periods of time, a rough timeline of Earth's tectonic plate cycling can be established.

"Helium-3 and Neon-22 were produced during the formation of the solar system and not by other means," Dygert explained. "As such, they provide valuable insight into Earth's earliest conditions and subsequent geologic activity."