Science Questions

The Earth’s core is made of heavy and dense metals, mostly iron, are the most dense metal at the centre of the core. In other words, if we were to drill down 6000km would we find enormous quantities of things like gold and uranium and osmium? John Burger

We asked our guest Marie Edmonds

Marie - Yes. Certainly what we call refractory elements such as osmium, iron and nickel. Throughout history all of these heavy elements have been migrating towards the core and all the light elements have been migrating to for the crust so yes.

Chris - Aren’t there some companies being formed that want to exploit the minerals that are being brought from the surface in hydrothermal vent systems? Aren’t they enriched with minerals and things that are quite hard to get hold of but because the Earths doing the work geologically for us then that’s a useful way to do it?

Marie - Certainly hydrothermal systems around volcanoes: fluids bring a lot of these metals like gold, silver into the volcanic edifice and they get precipitated into the volcanic system. A very easy way of mining these is to dig into a volcanic edifice where they’re concentrated.

June 2008