Earth’s collection of interlocking plates is unique in the solar system. Scientists connect it to our planet’s other special features, such as its stable atmosphere, protective magnetic field and the abundance of complex life.
But geologists have long debated exactly when Earth’s crust broke into plates, with estimates ranging from the first billion years of the planets 4.5 billion year history to sometime in the last billion.
The actions of tectonic plates shapes far more than just geography. The recycling of Earth’s surface helps to regulate its climate, while the building of continents and mountains releases vital nutrients into the ecosystem.
A new study of rocks from Australia reveals Earth in the act of transitioning to plate tectonics around 3.2 billion years ago.
When geologist Alfred Wegener first proposed the theory of continental drift in 1912, most of his colleagues thought it was ridiculous. How could giant landmasses move? Wegener could not identify the mechanism to drive his theory. It took another five decades for his theory to be explained.
In the decades since, scientists have come to realize that Earth’s magnetic field, atmosphere, stable climate and biodiversity are all linked to plate tectonics. Our comfortable climate largely results from chemical reactions between carbon dioxide in the air and silicate materials, which slowly reduces the level of greenhouse gas in the atmosphere by burying it in sediments.
https://www.quantamagazine.org/ancient-rocks-reveal-when-earths-plate-tectonics-began-20210325/