The formation and evolution of our planet remains a great mystery. If the planet was 100 years old today, we could say that human beings were born only a month ago. The 6 million years of human history are tiny compared to the 4.5 billion years of Earth.
So the truth is that we can only imagine and speculate about all this long history that we have not witnessed. What did the planet look like a billion years ago? We’ll never know. And yet, from time to time, science discovers startling things about the Earth’s past.
Research conducted at Curtin University and published in the journal Nature has uncovered compelling evidence that what created planet Earth’s continents was – amazingly – the impact of giant meteors during its first billion years. years of life.
Have you ever stopped to think that the Earth is the only known planet, among those in the solar system and outside, where there are continents? And since continents are home to most of the Earth’s biomass, nearly all of the planet’s important mineral deposits, and – of course – home to humans, understanding their formation may also be crucial to understanding the evolution of our own species. .
Tim Johnson, a researcher at Curtin’s School of Earth and Planetary Sciences, says the idea that continents originally formed on giant meteorite impact sites has been around for decades, but that there was little evidence able to support the theory – until now.
How did scientists discover that giant meteors were able to form Earth’s continents?
Researchers have analyzed tiny zircon crystals in rocks found in Australia’s Pilbara Crater – one of only two ancient Archean crusts ever identified on the planet, living remnants of what the planet looked like nearly 100 years ago. 4 billion years.
The study revealed a melting process that started at the surface and then progressed to the bottom, rather than the other way around – which is consistent with the geological effect caused by giant meteor impacts.
Our research provides the first solid evidence that the processes that led to the formation of continents began with giant meteorite impacts – similar to those that caused the extinction of the dinosaurs, but billions of years earlier – Tim Johnson .
Considering that the Earth’s continents are home to critical metals such as lithium, tin and nickel, critically important feedstocks for emerging climate change mitigation technologies, it is d ‘all the more important to understand their formation, which occurred through a process called differentiation of the earth’s crust.
Scientists now plan to test the results in other areas of ancient continental crust around the planet to find out if the pattern is, in fact, universal. For now, we can only imagine the incredibly destructive effect of these meteors that have struck the planet and shaped its surface, and wonder what is left to discover.