Water traveled into Earth's interior 3.1 billion years ago, study finds

A team of geologists has discovered that water was already cycling into Earth's deep interior more than 3.1 billion years ago, challenging long-held assumptions about the early planet. The findings, published in Nature Communications, reveal that surface water influenced volcanic activity and mantle chemistry hundreds of millions of years before plate tectonics existed Source: Clarin.

The discovery

Researchers led by Eric Vandenburg (University of Adelaide) analyzed ancient volcanic rocks from the Pilbara Craton in Western Australia, specifically the Whundo Group. Chemical signatures indicated that the mantle beneath this region contained water levels similar to those under modern volcanic arcs Source: Infobae. They also identified the oldest known boninite, a water-rich lava type typically associated with subduction zones Source: Infobae.

How it worked: Dripduction

Instead of modern plate subduction, the team proposes a mechanism called "dripduction," where dense, water-rich sections of the cool outer crust periodically collapsed into the hotter mantle, dragging water with it Source: Clarin. This would release water in the mantle, generating magmas that fed volcanic eruptions Source: Clarin.

Implications

The study suggests that Earth's surface and interior have been exchanging materials much earlier than thought, influencing continental growth, volcanism, and the availability of life-essential elements Source: Infobae. "The Earth wasn't working exactly as it does now, but some key processes were already underway," Vandenburg noted Source: Clarin.