Scientists have discovered that seismic activity drives the formation of large gold nuggets deep underground, shedding new light on how these valuable deposits form, the Guardian reports.
According to the research, the immense forces generated by earthquakes can squeeze quartz, a mineral commonly associated with gold, creating electric fields that aid in the accumulation of the precious metal.
The study, conducted by Australian researchers, discovered that seismic waves produced by earthquakes generate strong enough electric voltages within quartz to draw dissolved gold from fluids that seep into the mineral. These findings, published in Nature Geoscience, provide a possible explanation for the long-standing mystery of how large gold nuggets form in quartz veins, despite typically low gold concentrations in the surrounding fluids.
During laboratory experiments, Dr. Christopher Voisey and his team at Monash University subjected quartz immersed in a gold-containing solution to stresses similar to those experienced during earthquakes. The unique piezoelectric properties of quartz, which generate electric voltage when the mineral is compressed, were found to be sufficient to extract gold from the solution. The result was the formation of gold nanoparticles on the quartz surface, with additional gold building up over time.
This mechanism, known as piezoelectric gold accumulation, could help explain the formation of large, interconnected gold networks within quartz veins, often observed in nature but previously not well understood. The researchers propose that this process could resolve the “gold nugget paradox”—the puzzling question of how significant quantities of gold form from fluids with minimal gold content.
Dr. Taija Torvela, a structural geologist at the University of Leeds, described the study as “thought-provoking” and suggested that it could aid in identifying rich gold deposits. However, she emphasized the importance of additional research to determine whether this process leaves detectable markers on Earth’s surface that can be used in practical applications.
The study’s findings could have significant implications for the gold mining industry, which extracts between 2,500 and 3,000 tonnes of gold per year, with the majority of nuggets coming from quartz veins.
