One of the major goals of alchemy in the Middle Ages was to create gold from other, less expensive materials. Now it appears, if alchemists of that generation could have harnessed the power of the Earth, they might have been successful. A new study says that earthquakes can turn water into gold due to instant vaporization!
When an earthquake strikes, it moves along a rupture in the ground — a fracture called a fault. Big faults can have many small fractures along their length, connected by jogs that appear as rectangular voids. Water often lubricates faults, filling in fractures and jogs. Deep below the Earth’s crust, fluids are rich in dissolved substances like gold and silicate minerals. During an earthquake, the fault jog suddenly opens wider. The water inside the void instantly vaporizes, flashing to steam and forcing silica, which forms the mineral quartz, and gold out of the fluids and onto nearby surfaces due to dramatic drop in pressure.
Geophysicists Dion Weatherley of the University of Queensland in Brisbane and Richard Henley of the Australian National University in Canberra used a thermo-mechanical piston model to simulate the effects of earthquakes, where fluid-filled cavities in the earth can often expand. This expansion lowers the pressure within the cavity, causing the fluid to expand rapidly and vaporize. Gold contained within the liquid is then deposited in small amounts, there by showing how earthquakes turn water into gold. This new study leads the Australian geologists to believe that over 80% of the world’s commercial gold deposits are generated in a flash process, the result of depressurizing earthquakes that rapidly converted mineral-rich fluids into precious veins of gold.
Their study has been published in the journal Nature Geoscience.