(Kitco News) – Gold and other precious metals are oozing from Earth’s core into the mantle, and scientists are now finding deposits on the surface, according to a new study published in the journal Nature.
“Earth’s largest gold reserves are not kept inside Fort Knox, the United States Bullion Depository,” researchers from the University of Göttingen said in a release. “In fact, they are hidden much deeper in the ground than one would expect. More than 99.999% of Earth’s stores of gold and other precious metals lie buried under 3,000 km of solid rock, locked away within the Earth’s metallic core and far beyond the reaches of humankind.”
But the researchers were stunned to discover “traces of the precious metal Ruthenium (Ru) in volcanic rocks on the islands of Hawaii that must ultimately have come from the Earth’s core.”
The Earth’s metallic core contains a slightly higher concentration of Ru isotope 100Ru than the rocky mantle. “This is because part of the Ru, 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 of Ru that is contained in the mantle today,” they said. “These differences in 100Ru are so tiny that it was impossible to detect them in the past. Now, new procedures developed by researchers at the University of Göttingen made it possible to resolve them.”
The unusually high 100Ru signal the researchers found in lavas on the Earth’s surface “can only mean that these rocks ultimately originated from the core-mantle boundary,” the release stated.
“When the first results came in, we realised that we had literally struck gold,” said Dr. Nils Messling of Göttingen University’s Department of Geochemistry. “Our data confirmed that material from the core, including gold and other precious metals, is leaking into the Earth’s mantle above.”
“Our findings not only show that the Earth’s core is not as isolated as previously assumed,” added Professor Matthias Willbold. “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 researchers said this means that at least some of the gold and other precious metals that the world relies upon for their monetary value - as well as their industrial and renewable energy applications - may actually have come from the Earth’s core.
“Whether these processes that we observe today have also been operating in the past remains to be proven,” Messling concluded. “Our findings open up an entirely new perspective on the evolution of the inner dynamics of our home planet.”
