Somewhat ironically, this is largely due to plate tectonics itself. Until now, however, it has been difficult to detrmine just when plate tectonics started. Today, plate tectonics help Earth remain habitable (more on that below).Īccording to the new study, the transition period began about 3.8 billion years ago. Scientists think that plate tectonics helped Earth to become more habitable, assisting in the evolution of simple microorganisms to more complex lifeforms. Now, Earth’s crust is dynamic and active. But then, during the transition to plate tectonics, these new processes took over. Previously, the Earth’s crust was rigid and immobile. This movement, driven by heat from the Earth’s core deep down, fuels a variety of geological processes on or close to the surface, including earthquakes, volcanoes and mountain-building. These plates move around, albeit slowly, on top of a viscous – thick or sticky – layer of the mantle. So what is plate tectonics, anyway? It is a geological process where the Earth’s crust and the top layer of the mantle have broken up into separate massive and rigid plates. Transition to plate tectonics 3.8 billion years ago The researchers published their new peer-reviewed findings in AGU Advances on April 21, 2022. The crystals contain the earliest known evidence of subduction, the process by which one land plate on Earth’s surface dives under another. This new estimate is based on a study of ancient zircon crystals found in South Africa. On April 21, 2022, researchers at Harvard University said they’ve confirmed 3.8 billion years ago as the time when plate tectonics began. But estimates range from 4 billion years ago to as recently as 800 million years ago. How long ago did plate tectonics – the slow movement of great land plates in Earth’s outer shell – begin? We don’t know for certain. The crystals provide evidence that plate tectonics on Earth began about 3.8 billion years ago. A view of the the ancient Barberton Greenstone Belt in South Africa, where the zircon crystals were discovered.
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