Niamh Shackleton
Scientists believe that precious metals like gold are leaking from the Earth's core.
The world's largest gold reserve sits inside the Earth's metallic core and, with this being located beneath 3,000 km of solid rock, it's impossible for us to get our hands on it.
But nature appears to be doing the hard work for us and has slowly been transferring some metals to the Earth's surface from the core, as per a new study conducted by Göttingen University in Germany.
Dr Nils Messling of the university's Department of Geochemistry said of their findings: "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."
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But how did they come to this discovery, I hear you ask? Well, researchers conducted a three-year analysis of Hawaii’s basaltic rocks, which were first created by molten rock rising from the ocean floor, CNN explains.
Heavy metals were later found in these rocks, creating the suspicion that the core was leaking metals such as gold. The metals appear to be bleeding out from the core, which then travels to the mantle and eventually makes its way to the crust.
Dr Messling said of this: "About 40 years ago, people first came up with the theory that maybe the core is losing some material into the mantle, but the signals we got so far were really ambiguous. Now, in my opinion, we have the first very strong evidence that some of the core is actually ending up in the mantle."
To come to this realization, scientists looked at a particular Ru isotope: Ruthenium-100 (100Ru). Per the university, the Earth's core has a higher abundance of this isotope compared to our planet's rocky mantel (which sits between Earth's outer crust and the molten core).
"The mantle has almost no ruthenium in it," explained Dr Messling. "It’s one of the rarest elements on Earth. But Earth is basically made of meteorites that crashed together, and meteorites (contain) ruthenium, which went into the core when the core formed. So the mantle has next to no ruthenium, and the core has all of the ruthenium. The same with gold and platinum."
To determine if the Ruthenium was from the core or mantle, the team looked for 100Ru specifically — a silvery-white metal that is similar in appearance to platinum.
As they found that the Hawaiian rocks had more 100Ru in them than they should, the researchers believe that the rocks were partially formed from materials that traveled to the surface from the Earth's core.
Co-author of the paper, Matthias Willbold, said of this: "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."