A study from Curtin University in Australia has provided the strongest evidence yet that Earth’s continents were formed by giant meteorites by examining the remains of Earth’s ancient crust, it was reported on Wednesday.
These events were particularly frequent during the first billion years of our planet’s 4.5 billion-year history, the researchers explain in the scientific journal Nature.
The idea that continents originally formed at the sites of giant meteorite impacts had been around for decades, but until now there was little evidence to support this theory.
Dr Tim Johnson of the School of the Arts said, “By examining tiny crystals of the mineral zircon in rocks from the Pilbara Craton in Western Australia, which represent the best-preserved remains of Earth’s ancient crust, we found evidence of these massive meteorite impacts. ” Curtin’s Earth and Planetary Science.
In turn, “studying the composition of the oxygen isotopes in these zircon crystals revealed a ‘top-down’ process, which began with the melting of rocks near the surface and progressed deeper, which is related to the geology of giant meteorite impacts.” effect,” he added. ,
As such, Johnson assures that this research “provides the first convincing evidence that the processes that eventually formed continents began with giant meteor impacts.”
These impacts were “similar to those responsible for the extinction of dinosaurs, but occurred billions of years earlier.”
In this sense, the expert stressed that it is important to understand the formation and current evolution of Earth’s continents, as these land masses are home to most of the planet’s biomass, all humans, and almost all of the planet’s important mineral deposits.
“The continents have major metals such as lithium, tin and nickel, which are essential products for the new green technologies needed to meet our obligation to mitigate climate change,” Johnson said.
These mineral deposits are the end result of a process known as crustal differentiation, which began with the “formation of the first land mass,” the researcher explained.
Finally, he pointed out that data from other regions of Earth’s ancient continental crust “show patterns similar to those recognized in Western Australia.”
“We want to test our findings on these ancient rocks to see if, as we suspect, our model is more widely applicable.”