Scientists can use various clues to find out what’s beneath the Earth’s surface without having to do any excavation, including firing super thin lasers thinner than a human hair at the minerals found in the beach sand.
This technique has been used in a new study that points to a piece of the Earth’s crust about 4 billion years the size of Ireland, which has been located under Western Australia and has influenced geological evolution. of the area for millions of millennia.
It could be able to provide clues as to how our planet went from being uninhabitable to supporting life.
Researchers think that the huge expanse of crust would have greatly influenced the formation of rocks as ancient materials mixed with new ones, having first appeared as one of the earliest and most surviving protocrust formations on the planet. to multiple mountain building events.
“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,” says PhD student in geology and lead author Maximilian Dröellner, of the University of Curtin in Australia.
“This suggests a significant change in the evolution of the Earth about 4 billion years ago, as meteorite bombardment subsided, the crust stabilized, and life on Earth began to settle.”
The lasers were used to vaporize mineral zircon grains, extracted from sand taken from rivers and beaches in Western Australia.
Technically known as inductively coupled plasma mass spectrometry induced by laser ablation, the method allows scientists to date the grains and compare them to others to see where they might have come from.
This gave the team a view of the crystalline basement beneath the Earth’s surface in this particular region, showing where the grains had originally eroded, the forces used to create them, and how they had been eroded. has been accumulating the geology of the region over time.
In addition to the importance of the remaining proto-crust that still exists, about 100,000 square kilometers (38,610 square miles), the boundaries of the block will also help scientists figure out what else lies beneath the Earth’s surface and how they might have evolved to be in its current state.
“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,” says research supervising geologist Milo Barham of Curtin University.
“Recognizing these ancient remnants of the crust is important for the future of optimized exploration of sustainable resources.”
As expected after 4 billion years, there is not much left of the original crust of the Earth to study, which makes findings like this even more interesting and useful for experts, giving us a important window into the distant past.
The displacement of the earth’s crust and the eddy of the hot mantle below are difficult to predict and trace backwards. When evidence of interior motion and geology can be found on the surface, scientists are therefore very willing to make use of it.
Later, the results of the study described here could also help scientists looking at other planets: how these planets form, how their oldest crust is formed, and even how alien life might settle there.
“Studying Earth early 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,” says Barham.
The research has been published in the journal Terra Nova.