A 4 billion-year-old piece of the Earth’s crust found

Researchers from Curtin University have found evidence of an ancient piece of the Earth’s crust beneath the South-West of Western Australia. The piece is reportedly almost four billion-year-old. According to Scitechdaily, scientists used lasers smaller than a human hair to target microscopic grains of a mineral extracted from beach sand. The Timescales of Mineral Systems Group at Curtin’s School of Earth and Planetary Sciences, led by Ph.D. student Maximilian Droellner, explained that the lasers were used to vaporise the parts of individual grains of the mineral zircon to get details about its original erosion.

Droellner said, “There is evidence that an up to four billion-year-old piece of crust about the size of Ireland has been influencing the geological evolution of WA for the past few billions of years.” He also stated that the particles found in the study is a key ingredient of rocks formed in WA across this time. He explained that the part of crust has survived multiple mountain-building events between Australia, India, and Antarctica and appears to still exist at tens of kilometres of depth under the South-West corner of WA.

When compared to existing data, it is found that not only Australia, India, and Antarctica, but there are other regions around the world that experienced a similar timing of early crust formation and preservation. And this indicates a significant change in the evolution of the Earth some four billion years ago, when meteorite bombardment reduced, crust stabilised and life on Earth started to evolve.

Research supervisor Dr. Milo Barham, said, “The edge of the ancient piece of crust appears to define an important crustal boundary controlling where economically important minerals are found.” He also shared that these remnants of ancient crust will play a crucial role in studying the future of optimised sustainable resource exploration.