26-05-2025
Earth's core holds a vast reservoir of gold - and it's leaking towards the surface
You might think the Earth's largest gold reserves are locked up at Fort Knox.
But Earth's core is rich with the precious metal – and it's slowly making its way up towards us, according to a new study.
Ultra-high precision analysis of volcanic rocks show Earth's core is 'leaking' into rocks above.
And it's bringing gold and other precious metals with it.
Dr Nils Messling, at Göttingen University's Department of Geochemistry, said: 'When the first results came in, we realised that we had literally struck gold!
'Our data confirmed that material from the core, including gold and other precious metals, is leaking into the Earth's mantle above.'
More than 99.999 per cent of Earth's stores of gold lie buried under 2,900km (1,800 miles) of solid rock, locked away within the Earth's metallic core and far beyond the reaches of humankind.
The team analysed rocks on the island of Hawaii, specifically looking at traces of the precious metal ruthenium (Ru).
Compared to the Earth's rocky mantle, the metallic core contains a slightly higher abundance of a particular isotope called 100Ru.
That's because this ruthenium, which was locked in the Earth's core together with gold and other precious metals when it formed 4.5 billion years ago, came from a different source than the scarce amount that is contained in the mantle today.
These differences are so small it was impossible to detect them in the past.
Now, new procedures developed by the research team made it possible to analyse them.
The unusually high 100Ru levels they found in lava on the Earth's surface can only mean that these rocks ultimately originated from the boundary between the Earth's core and mantle.
Professor Matthias Willbold, who also worked on the study, said: 'Our findings not only show that the Earth's core is not as isolated as previously assumed.
'We can now also prove that huge volumes of super-heated mantle material – several hundreds of quadrillion metric tonnes of rock – originate at the core-mantle boundary and rise to the Earth's surface to form ocean islands like Hawaii.'
The findings mean that at least some of the precarious supplies of gold and other precious metals that we currently have access to may have come from the Earth's core.
It's believed that when the Earth was forming, gold and other heavier elements sank down into its interior.
As a result, the majority of gold we currently have access to on the Earth's surface was delivered here by meteors bombarding our planet.
Other elements that could currently be 'leaking' out of the core include palladium, rhodium and platinum.
Despite the findings it's unlikely these precious metals are emerging at a particularly fast rate.
It would also be impossible to drill down to where the Earth's core begins – approximately 2,900km (1,800 miles) - to access the gold contained down there.
The findings were published in the journal Nature.
Earth has an unusually high proportion of precious metals near the surface, which is surprising, as they would usually be expected to settle down near the core of the planet.
Until now, this has been explained by the 'late veneer' theory, which suggests that foreign objects hit Earth, and in the process deposited the precious metals near the surface.
New computer simulations from the Tokyo Institute of Technology took into account the metal concentrations on Earth, the moon and Mars, and suggests that a huge collision could have brought all the precious metals to Earth at once.
The researchers believe that this happened before the Earth's crust formed – around 4.45 billion years ago.
The findings suggest that Earth's history could have been less violent than previously thought.
