Plate tectonics may have been active from the beginning

A new study suggests that plate tectonics – a scientific theory that divides the earth into chunks of crust that move slowly over the viscous hot mantle – could have been active from the beginning of the planet.

The new discoveries challenge earlier beliefs that tectonic plates have been developed over billions of years.

The paper, published in Scientific letters of the Earth and planets, has 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 inviting for life.

"Plate tectonics has created the conditions for life," said Nick Dygert, assistant professor of petrology and geochemistry at UT's Department of Earth and Planet Sciences and co-author of the study. "The more we know about ancient plate tectonics, the better we can understand how Earth has become as it is now."

For his research, Dygert and his team studied the distribution of two very specific isotopes of rare gases: helium-3 and neon-22. Noble gases are those that do not react to any other chemical element.

Previous models explained the current ratio of helium-3 / neon-22 of the Earth arguing that a series of large-scale impacts (similar to those that produced our moon) have driven massive oceans of magma that have degassed and increased the earth every time

Dygert believes however that the scenario is unlikely.

"Although there is no conclusive evidence that this has not been the case, it could only have increased the Earth's Helium-3 / Neon-22 ratio under very specific conditions," he said. declared.

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

As the Earth's crust forms, the ratio of helium to neon in the mantle below the crust increases. By calculating this ratio in the crustal mantle and considering how this process would affect the Earth in bulk over long periods of time, it is possible to establish a rough chronology of the Earth's tectonic plate cycle.

"Helium 3 and Neon 22 were produced during the formation of the solar system and not by any other means," said Dygert. "As such, they provide valuable information about the earliest conditions of the Earth and subsequent geological activity."