How Green Mining Paves The Way To A Sustainable And Net Zero Future July 3, 2021 Share Scientists at the Earth Sciences department of the University of Oxford demonstrate how to directly extract valuable metals from hot salty fluids (brines) trapped in porous rocks at roughly 2km below dormant volcanoes. They propose that this green-mining approach will sustainably provide essential metals for a net-zero future. Magma underneath volcanoes releases metal-rich gasses that ascend toward the surface. These gases separate into brine and steam as the pressure drops. Most of the dissolved metals in the original magmatic gas become concentrated in the dense brine, which gets trapped in porous rock. The less-dense and metal-depleted steam continues to rise to the surface, where it forms fumaroles, the gases, and steam seen at the many active volcanoes around the world.