By firing lasers thinner than a human hair at small grains of a mineral extracted from beach sand, Curtin researchers have found evidence of a piece of Earth’s crust almost four billion years old that is is located southwest of WA.
Beach sand sampling site near Augusta.
In a new finding that helps explain the evolution of the uninhabitable planet to life support, lead researcher and doctoral student Maximilian Droellner of the Mineral Systems Group at Curtin School of Earth and Planetary Sciences , said the lasers were used to vaporize portions of individuals. mineral zircon grains and revealed where the grains were eroded, as well as the geological history of the region.
“There is evidence that a piece of crust up to four billion years the size of Ireland has been influencing WA’s geological evolution over the last billion years and is a key ingredient in the rocks formed in WA during that time, ”Droellner said.
“This piece of crust has survived multiple mountain building events between Australia, India and Antarctica and appears to still exist tens of miles deep below the southwest corner of WA.
“When we compare our findings with existing data, it appears that many regions of the world experienced a similar time of early crust formation and preservation.
“This suggests a significant change in the evolution of the Earth about four billion years ago, as meteorite bombardment subsided, the crust stabilized, and life on Earth began to settle.” .
Research supervisor Dr. Milo Barham, also of the Mineral Systems Group at Curtin School of Earth and Planetary Sciences, said no large-scale study had been done in the region before and that the results, compared with existing data, had revealed new and interesting developments. knowledges.
“The edge of the old piece of crust seems to define an important boundary of the crust that controls where economically important minerals are found,” Dr. Barham said.
“Recognizing these ancient remnants of the crust is important for the future of optimized exploration of sustainable resources.
“Studying primitive Earth is a challenge given the sheer amount of time that has elapsed, but it is of great importance to understand the importance of life on Earth and our quest to find it on other planets.”
Droellner, Dr. Barham and research co-supervising professor Chris Kirkland are affiliated with The Institute for Geoscience Research (TIGeR), Curtin’s flagship research institute in Earth Sciences and the research was funded by the Mineral Research Institute of Western Australia.
The full research paper, “A Persistent Hadean-Eoarchean Protocrust in the Western Yilgarn Craton, Western Australia” was published in the journal Newfoundland and can be found online here.