Earth’s Core Contains a Vast Reservoir of Gold — And It’s Leaking Toward the Surface

Earth’s core holds an enormous amount of gold, and this precious metal is slowly making its way into the planet’s crust, according to a new study.

Volcanic Rocks Reveal Traces of Precious Metals

Researchers analyzed isotopes found in volcanic rocks that emerged from deep beneath the lithosphere and identified traces of precious metals — including gold. The data suggest that these elements began their journey by leaking from the core and were gradually transported upward by convecting magma until reaching the planet’s upper layers.

“When we saw the first results, we realized we had literally struck gold!” says geochemist Nils Messling from the University of Göttingen in Germany. “Our data confirm that materials from the core, including gold and other precious metals, are leaking into the Earth’s mantle.”

Gold in the Crust: Just the Tip of the Iceberg

Although we can access gold in the crust, it represents only a tiny fraction of the total amount present on the planet. Studies indicate that more than 99% of Earth’s gold is trapped in the metallic core — enough to cover the entire planet’s surface in a layer 50 centimeters (20 inches) thick.

That deep concentration makes sense. During Earth’s formation, the heaviest elements sank toward the center in a process known as the “iron catastrophe,” forming the core. Later, meteor impacts delivered additional gold and heavy metals to the surface.

Scientists already knew that the core releases primordial helium and heavy iron isotopes, but they had not determined whether the precious metals found in the crust came from the core or from space.

Ruthenium: The Crucial Clue

A crucial clue came from isotopes of ruthenium, a rare metal. The isotopes found in the core differ subtly from those at the surface.Messling’s team revealed this previously undetectable difference through new analytical techniques.

By applying these methods to volcanic rock samples from the Hawaiian Islands, the scientists identified a significantly higher concentration of ruthenium-100 — an isotope associated with Earth’s core — compared to the ambient mantle.

The discovery indicates that siderophile elements — those that migrated to the core when the Earth was still molten — are gradually returning to the surface. This includes ruthenium, but also palladium, rhodium, platinum, and of course, gold.

Implications for Understanding Earth (and Beyond)

This gold isn’t rising in large quantities, nor is it easily accessible, since the core lies about 2,900 kilometers (1,800 miles) below the surface. However, the finding deepens our understanding of Earth’s internal dynamics — and potentially of other rocky planets as well.

“Our results show that Earth’s core is not as isolated as previously believed,” says geochemist Matthias Willbold, also from the University of Göttingen. “We can now confirm that massive volumes of superheated mantle rock — hundreds of quadrillions of tons — originate at the core-mantle boundary and rise to the surface to form oceanic islands like Hawaii.”

Read the original article on: Science Alert

Read more: Origins of Earth’s Water May Not Be as Complicated as We Thought