A new study has shown that gold takes less than a second to form, reports Nature. Although the idea of gold veins forming along geological fault lines isn't new, researchers in the present study have quantified the process and have shown how rapidly minerals are precipitated when hot water suddenly vaporizes due to changes in pressure during an earthquake.
Researchers used a simple thermo-mechanical piston model to estimate the pressure drop experienced by a cavity filled with fluid during an earthquake.
The process of gold formation occurs along the cracks that connect main fault lines in the rocks called 'fault jogs', said Dion Weatherley, seismologist at the University of Queensland in Brisbane, Australia, Nature reports. Also, it isn't just the big earthquakes that are responsible for the mineral deposition; the research team found that even relatively small earthquakes produce enough pressure changes to enable gold to precipitate.
Small bits of gold adding up to make a chunk
Weatherley added that many rocks that have gold deposits have many spider web-like gold veins, which is because the gold has been deposited little by little by small earthquakes.
"You [can] have thousands to hundreds of thousands of small earthquakes per year in a single fault system. Over the course of hundreds of thousands of years, you have the potential to precipitate very large quantities of gold. Small bits add up," Weatherley told Nature.
The study is published in the journal Nature Geoscience.
These gold veins account for a third of all gold deposits known, according to New Scientist. Much of the gold in these deposits is extracted directly.