Washington [US]Aug. 13 (ANI): Research suggests Earth’s continents were formed by massive meteorite impacts that were especially common during the first billion years of our planet’s four-and-a-half billion-year history.
dr. Tim Johnson, of Curtin’s School of Earth and Planetary Sciences, said the idea that the continents originally formed at sites of giant meteorite impacts had been around for decades, but until now there was little solid evidence to support the theory.
“By examining tiny crystals of the mineral zircon in rocks of the Pilbara Craton in Western Australia, which represents the best-preserved remnant of Earth’s ancient crust, we have found evidence of these giant meteorite impacts,” said Dr. Johnson.
“Studying the composition of oxygen isotopes in these zircon crystals revealed a ‘top-down’ process that begins with the melting of rocks near the surface and progresses deeper, consistent with the geological effect of giant meteorite impacts.
“Our research provides the first solid evidence that the processes that eventually formed the continents began with giant meteorite impacts, similar to those responsible for the extinction of the dinosaurs, but occurring billions of years earlier.” evolution of the Earth’s continents was crucial, as these land masses harbor most of the Earth’s biomass, all humans, and nearly all of the planet’s major mineral deposits.
Last but not least, the continents are home to critical metals such as lithium, tin and nickel, raw materials essential to the emerging green technologies needed to meet our commitment to mitigate climate change,” said Dr. Johnson.
“These mineral deposits are the end result of a process known as crustal differentiation, which began with the formation of the earliest landmasses, of which the Pilbara Craton is just one of many.” Data relating to other areas of ancient continental crust on Earth appears to 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 has wider applicability. , ‘Giant impacts and the origin and evolution of continent’, was published in Nature (ANI)