A new study is shaking up our understanding of how Earth’s surface first began to move and change.
Scientists now believe that subduction—the powerful process where parts of the Earth’s outer crust sink deep into the planet’s interior—may have started hundreds of millions of years earlier than previously thought.
This research, published in Nature Communications, comes from an international team of scientists based in Germany, France, and the United States.
They focused on the mysterious Hadean Eon, the earliest period in Earth’s history, which spanned from 4.6 to 4.0 billion years ago.
This era began with Earth’s formation and included a violent collision with a Mars-sized object, which led to the creation of the moon and the complete melting of Earth’s early crust.
Until now, many scientists believed that after this chaotic beginning, Earth settled into a phase known as the “stagnant lid” stage.
In this model, the planet’s outer shell remained rigid and motionless for hundreds of millions of years, while hot rock churned beneath in the mantle. Unlike modern plate tectonics, this early Earth would not have experienced subduction or the creation of new continental crust.
But the new study challenges this long-held view.
To uncover the truth, the research team used two powerful tools. A group in Grenoble, France, studied tiny traces of ancient molten rock trapped inside 3.3-billion-year-old olivine crystals.
These “melt inclusions” carry chemical clues about the conditions under which they formed. In particular, they analyzed strontium isotopes and trace elements—chemical fingerprints that tell scientists about Earth’s geologic activity in the deep past.
Meanwhile, scientists in Germany used advanced computer simulations to understand how these chemical signals relate to physical processes inside early Earth.
Their results suggest that the kinds of chemical signatures found in the crystals can only be explained by active subduction and continent formation during the Hadean Eon.
This means that Earth’s crust was already recycling itself far earlier than expected—and that continents may have begun forming while the planet was still very young.
These findings provide a new glimpse into how Earth evolved from a molten ball of rock into the dynamic, life-supporting planet we know today.
This discovery not only rewrites part of Earth’s early history but also raises fresh questions about how the building blocks of continents—and possibly life itself—emerged so soon after the planet’s birth.
Source: KSR.
