A new study has revealed that Earth’s tectonic plates were formed 3.6 billion years ago and since then have moved continuously.
- Previously, researchers thought that these tectonic plates were formed anywhere from 3.5 billion to 3 billion years ago.
- The new revelations are based on analysis of ancient zircon crystals from the Jack Hills in Western Australia, says LIve Sciecne.
- Some of the zircons date to 4.3 billion years ago, meaning they existed when Earth was a mere 200 million years old.
- Researchers used these zircons, as well as younger ones dating to 3 billion years ago, to decipher the planet’s ongoing chemical record.
What are Plate tectonics?
- A tectonic plate (also called lithospheric plate) is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere, says USGS.
- Plate tectonics refers to how humongous slabs of solid rock glide over Earth’s mantle, the layer just below the crust.
- These continental slabs shift, fracture and collide, causing earthquakes to occur, mountains to grow and oceans to form.
- Besides Earth, no other known planetary bodies have plate tectonics.
- Continental crust is composed of granitic rocks which are made up of relatively lightweight minerals such as quartz and feldspar. That is why these massive slabs of solid rock float despite their tremendous weight.
- By contrast, oceanic crust is composed of basaltic rocks, which are much denser and heavier.
(Source: LIVE Science and USGS)
