Extinct Volcanoes May Be an Untapped Source of Rare Metals

Within the deposits of extinct volcanoes around the world, a mysterious magma may be Earth’s new source for rare metals. This iron-rich magma could be full of the metals that help power some of the world’s most important technologies, like smartphones, electric cars, renewable energies and more.

A new study published in Geochemical Perspectives Letters uses a simulation to suggest that these deposits in dormant volcanoes may be a source for in-demand rare earth elements originating from the highly concentrated magma.

“We have never seen an iron-rich magma erupt from an active volcano,” Michael Anenburg, a geochemist at the Australian National University and an author of the study, says in a statement. “But we know some extinct volcanoes, which are millions of years old, had this enigmatic type of eruption.”

As society transitions from fossil fuels to clean energy, demand for rare earth metals is climbing. Though they're called rare metals, they aren't that uncommon. They’re similar in abundance to lead and copper, according to Anenburg. But it’s hard to find these metals in places where they’re concentrated enough to be worth extracting and breaking down.

A previous discovery of rare earth metals from an iron mine in an extinct volcano called Kiruna in Sweden made the researchers question how this finding could exist. They wondered whether it was due to a type of magma that is full of iron.

Anenburg and his team made a simulation in their lab of the rocks and magma in an extinct volcano. Using pressure and extreme heat, they found that the iron-rich magma absorbs the rare earth metals at almost 200 times more than “regular” magma.

“This means the discovery at Kiruna wasn’t an accident,” Anenburg writes in the Conversation. “It’s something we can expect from most, if not all, iron-rich volcanoes.”

The simulation is an interesting approach, says Lingli Zhou, a geologist at Vrije Universiteit Amsterdam who was not involved in the study, to CNN’s Laura Paddison.

“They start from the laboratory and then try to mimic a natural environment, to understand how these rare earths could actually accumulate in a small place in the entire crust,” she tells CNN.

The researchers suggest in the statement that there may be unexplored rare earth metal deposits in volcanoes around the world, in places such as Chile and Australia.

Not all extinct volcanoes may have these rare earth metals though. Only the ones rich with iron.

"But I would say that every one of the iron-rich volcanoes deserves a look, remembering the usual risk in mineral exploration that only a handful of all discoveries actually end up as a profitable operating mine,” Anenburg tells Newsweek’s Tom Howarth.

Anenburg remains hopeful that some iron mining operations may already find rare earths, like Sweden’s Kiruna, and that these operations may be altered to produce rare earth metals as well.

He writes in the Conversation that “this would mean new mines for rare earth elements may not even be required, preventing unnecessary disruption of natural environments.”

Alexa Robles-Gil | | READ MORE

Alexa Robles-Gil is a bilingual science journalist based in New York City. Her work has appeared in the Guardian, Undark, Inside Climate News and more.