Rare metals such as neodymium, niobium and dysprosium are essential in many modern technologies including wind turbines, electric cars and mobile phones. But finding deposits of these metals is tricky. Now ancient volcanoes are providing geologists with clues.
About 1.3bn years ago Greenland was covered with active volcanoes. Today only the remnants remain, but Adrian Finch, from the University of St Andrews, and colleagues analysed minerals in these volcanic rocks to reveal the journey they had taken.
Starting in the deep mantle, they show how the minerals erupt on to the Earth’s surface, become compressed into sediments and then subduct back down into the mantle via tectonic plate movements.
Last week the team presented its findings at a workshop at the Royal Society in London, suggesting that some minerals have been around this deep earth conveyor belt many times, potentially becoming more concentrated on each loop.
Their findings also show that life on Earth plays a role, interacting with some minerals while they are on the surface. Armed with this understanding, geologists are better equipped to find the locations where rare metals are likely to be emerging and pluck them off the conveyor belt before they disappear back into the earth again.
