3 billion years ago, water may have been shaping Earth’s ancient volcanoes — scientists uncover a clue to how it reached the planet’s deep interior

Water may have been travelling deep beneath Earth’s surface billions of years before modern plate tectonics developed, according to a new study of some of the planet’s oldest volcanic rocks.

Researchers examining ancient formations in Western Australia’s Pilbara region have found evidence that water-rich material could have moved into Earth’s mantle more than three billion years ago. Once underground, the water may have helped generate magma and fuel volcanic eruptions.

The discovery offers a fresh look at how the young Earth functioned. It suggests that the planet’s surface and deep interior were already interacting during a period when Earth was much hotter and its geological systems were very different from those operating today.


The international research team was led by Adelaide University geochemist Dr Eric Vandenburg. The study, published in Nature Communications, proposes that water may have reached the mantle through a process called “dripduction”, rather than through the modern system of plate subduction.

Ancient rocks reveal a different kind of early Earth

Understanding the first few billion years of Earth’s history is difficult because most rocks from that period have been destroyed, altered or recycled by geological activity.

The Pilbara Craton in Western Australia is one of the rare places where ancient rocks have survived in relatively good condition. These formations preserve chemical evidence from a time when Earth was still developing its continents, atmosphere and internal structure.

The rocks examined by researchers formed roughly 3.1 billion years ago. Their chemical composition suggests that water from near the surface had travelled deep into the planet before influencing the production of volcanic magma.

Today, scientists understand that water is carried into Earth’s interior mainly through subduction. At certain boundaries between tectonic plates, one plate is forced beneath another. Water trapped in minerals and oceanic crust can then be transported into the mantle.

As the material heats up, it releases water into surrounding rocks. This lowers the melting point of the mantle and encourages magma formation. The magma may rise toward the surface, feeding volcanoes and contributing to the growth of continents.

However, Earth’s early crust may not have behaved like modern tectonic plates. The young planet was hotter, and its outer shell was likely softer and more unstable.

That has left scientists with a major question: How could surface water have reached the mantle before modern plate tectonics became established?

‘Dripduction’ may have carried water underground

The research team believes the answer could lie in a previously proposed but less familiar geological process known as “dripduction”.

In this model, parts of Earth’s early crust became dense enough to sink into the hotter material below. Rather than forming a large, continuously moving tectonic plate, a water-rich section of crust may have gradually sagged, stretched and dropped into the mantle.

The process can be compared to a heavy drop of liquid falling through a lighter substance. As the dense crust descended, it carried water and other surface materials with it.

Once the buried crust entered hotter parts of Earth’s interior, it began releasing water. That water could have triggered partial melting in the mantle, creating magma that later moved upward and erupted through volcanoes.

The proposed process would have allowed Earth to recycle material between its surface and interior without requiring fully developed plate tectonics.

Dr Vandenburg said the early Earth was not operating exactly like the modern planet, but some of the essential processes may already have been present.

The findings suggest that the movement of water into the mantle may have begun much earlier than previously assumed. They also indicate that volcanic activity on the young Earth may have been influenced by water in ways that were not previously recognised.

Water may have helped build Earth’s early continents

The discovery matters because water is more than a substance carried through the planet. It can change the physical and chemical behaviour of rocks deep inside Earth.

When water enters the mantle, it can make rocks melt at lower temperatures. This helps produce magma, which may eventually rise through the crust and contribute to volcanic eruptions.

Over geological time, volcanic activity has played a major role in building and reshaping continents. It has also helped move chemical elements from Earth’s interior toward the surface.

If water was already reaching the mantle more than three billion years ago, it may have influenced the development of early continental crust much sooner than expected.

The findings could also change how scientists view the young Earth. Rather than being a largely static world waiting for modern plate tectonics to begin, early Earth may have had several active systems capable of moving material through its interior.

This early recycling may have affected the planet’s volcanic behaviour, crust formation and long-term chemical evolution.

Water movement is also important in discussions about the conditions that made life possible. Water helps transport elements and supports chemical reactions that are essential to living systems. Although the study does not directly explain the origin of life, it adds to the understanding of how Earth’s surface and interior became connected.

Chemical evidence provides a window into deep geological history

The researchers reconstructed the ancient process by examining chemical signatures preserved in the rocks.

These signatures can reveal where the materials that formed the rocks originally came from and what conditions they experienced before becoming solid.

The evidence indicates that the volcanic rocks were influenced by material that had interacted with water and later moved deep into Earth. This points to an early connection between the surface environment and the mantle.

Because the rocks are billions of years old, the findings provide an unusual opportunity to study Earth’s internal processes during a period that cannot be observed directly.

The research involved scientists from Adelaide University, Monash University, the Geological Survey of Western Australia, Curtin University, the Australian National University, Cardiff University and the GEOMAR Helmholtz Centre for Ocean Research in Germany.

The team’s work does not suggest that “dripduction” was the only process operating on early Earth. Geological systems are complex, and different parts of the planet may have behaved differently at the same time.

Further research will be needed to establish how widespread the process was, how much water it transported and whether it contributed significantly to the formation of early continents.

Still, the study provides an important clue about the timing of Earth’s internal recycling system.

It suggests that water may have entered the deep Earth long before the modern arrangement of moving tectonic plates. That possibility could lead scientists to reconsider how early volcanic systems formed and how Earth developed into the dynamic planet seen today.

The planet’s oldest rocks are offering a new message: the deep Earth may have been receiving water, producing magma and reshaping the surface billions of years before the arrival of modern plate tectonics.

Frequently asked questions

1. What did scientists discover about Earth’s early history?

Researchers found evidence that water was reaching deep into Earth’s interior more than three billion years ago, potentially influencing magma formation and volcanic activity.

2. What is “dripduction”?

Dripduction is a proposed geological process in which dense, water-rich sections of Earth’s early crust sank or collapsed into the hotter mantle, carrying water underground.

3. How can water trigger volcanic activity?

Water lowers the melting temperature of mantle rocks. When water enters the mantle, it can encourage magma formation, which may rise and feed volcanic eruptions.

4. Why are the Pilbara rocks important?

The Pilbara Craton contains some of Earth’s oldest and best-preserved rocks. Their chemical signatures allow scientists to investigate geological processes that occurred more than three billion years ago.