Scientists can use a variety of clues to figure out what’s going on below the earth’s surface including shooting superfine lasers thinner than a human hair into minerals found in beach sand without actually doing any digging.
The technique has been used in a new study that points to a 4-billion-year-old piece of Earth’s crust the size of Ireland sitting beneath Western Australia and influencing the area’s geological evolution for millions of millennia.
It may provide clues as to how our planet went from being uninhabitable to supporting life.
The researchers think that the vast expanse of the Earth’s crust would have had a major impact on rock formation, as old materials mixed with new, first emerged as one of the planet’s earliest protocrustic formations, and survived multiple mountain-building events.
“Comparing our findings with existing data, it appears that many regions of the world experienced similar timing of early crustal formation and preservation.” says Maximilian Dröellner, PhD student in geology and lead authorfrom Curtin University, Australia.
“This suggests a significant change in Earth’s evolution around 4 billion years ago, as the meteorite bombardment subsided, the crust stabilized, and life began to emerge on Earth.”
Lasers were used to vaporize zircon mineral grains from sand sampled from rivers and beaches in Western Australia.
Technically known as laser ablation split-flow-inductively coupled plasma-mass spectrometry, the technique allows scientists to date grains and compare them to others to see where they came from.
This gave the team insight into the crystalline basement beneath the Earth’s surface in this particular region – showing where the grains were originally eroded, the forces used to create them and how the region’s geology has developed over time.
Along with the importance of the Protocrusian remains – about 100,000 square kilometers (38,610 square miles) – the block’s boundaries will help scientists determine what else might be lurking beneath the Earth’s surface, and what it might look like. evolved to be in its current state.
“The ancient crustal margin defines an important crustal boundary that controls where economically important minerals are found” says geologist Milo Barham, head of the studyfrom Curtin University.
“Recognizing these ancient crustal remnants is critical to the future of optimized sustainable resource exploration.”
As you’d expect after 4 billion years, there’s not much left to learn from Earth’s original crust, which makes finds like this all the more interesting and useful to experts – giving us an important window into the distant past.
It is difficult to predict the displacement of the Earth’s crust and the rotation of the warm mantle beneath it. map retrospectively. If evidence of internal movement and geology is found on the surface, scientists are there for it very eager to use.
In addition, the results of the research described here could help scientists looking at other planets – how these planets formed, how their earliest crust formed, and even how alien life might have originated on them.
“Given the magnitude of the past, studying the early Earth is difficult, but it is of great importance to our understanding of the importance of life on Earth and our quest to find it on other planets.” Barham says.
The study was published in the journal New land.
