Textbooks to Change? It’s All About Tectonic Plates
When did tectonic plates begin to move on Earth? Earlier than we thought.
The movement of tectonic plates has divided the continents and formed mountain ranges. They are also responsible for numerous earthquakes and tsunamis. The phenomenon is certainly very old.
The Earth’s crust has been moving since it cooled down
Scientists disagree about when Earth’s crust began its slow dance. Some say it was 2.5 billion years ago, and they have evidence from China. Others say it was 3.2 billion years ago, and they show geochemical changes in the crust to back it up. But the latest research says the tectonic plates moved as soon as Earth cooled enough—more than 4 billion years ago.
It is worth recalling that the Earth’s formation dates back to about 4.567 billion years ago. Our planet began as a hot ball of molten rock, surrounded by ammonia, methane, and water vapor. The latter eventually formed oceans and clouds.
The movement of tectonic plates is supposed to have begun over 4 billion years ago, or in the Hadean. This is the period between the formation of the Earth and the collision of planets that created the Moon. During this time, the crust cooled and hardened, and the oldest known zircon crystals were formed. And they are the evidence in the case.
S-type crystals (found mainly in Australia) are thought to be evidence of tectonic movement on Earth’s surface. These structures form in sedimentary rocks on land, are then pushed into the mantle by tectonic movement, and “return” in granites.
The problem is that these crystals are very difficult to identify. They don’t have a single characteristic, but a whole set of possible trace minerals. So the scientists put artificial intelligence to work and taught the model to distinguish S-type crystals from non-S-type crystals. This tells us that 35 percent of a sample of almost a thousand crystals from Jack Hills in Australia were S-type. Some of them are older than 4.2 billion years. This means that the tectonic machine could have been operating as early as the Hadean.
Unless the crystals entered the mantle by some other route, such as a meteorite impact.
