Earthquakes use electricity to cook giant gold nuggets in quartz ovens: Study

Gold nuggets have long fascinated scientists and prospectors alike, but the precise mechanisms that lead to their formation have remained elusive.

Traditionally found in quartz veins deep underground, these chunky nuggets have puzzled researchers for decades. The mystery has now taken a significant step toward resolution, thanks to new research that links the formation of gold nuggets to the seismic forces generated by earthquakes.

This discovery could change how we understand the processes behind gold deposition and open up new possibilities for locating rich gold deposits.

Earthquakes: The hidden architects of gold

Gold nuggets often form in areas with quartz because it has a special property called piezoelectricity. This means that when quartz is stressed, it can produce electricity. This ability helps in the formation of gold nuggets, making quartz an important factor in finding them.

In a series of groundbreaking lab experiments, Dr. Christopher Voisey and his team at Monash University in Melbourne sought to understand this phenomenon. They immersed quartz samples in water containing dissolved gold and then subjected the quartz to mechanical stresses that mimic the conditions experienced during an earthquake.

The results were remarkable: the stress from the seismic waves created electric fields powerful enough to pull gold from the surrounding fluid and place it onto the quartz surface.

“This mechanism can help explain the creation of large nuggets and the commonly observed highly interconnected gold networks within quartz vein fractures,” the researchers write.

These findings help explain a long-standing puzzle in geology. Fluids that carry gold usually have only tiny amounts of it—about one part per million. With such low concentrations, it seems almost impossible for large gold nuggets, some weighing tens or even hundreds of kilograms, to form.

Yet, they exist, and the answer to this puzzle seems to lie in the electric fields generated by earthquakes. These fields not only extract gold from the fluid but also cause it to accumulate rapidly on the quartz, leading to the formation of sizeable nuggets.

The piezoelectric effect and its implications

The discovery that quartz’s piezoelectric properties can facilitate gold formation has far-reaching implications. For one, it helps explain why gold nuggets are often found “floating” within quartz veins, with no apparent chemical or physical trap to anchor them. The electric fields created by seismic events offer a likely explanation for this. They are strong enough to pull gold from the solution and place it directly onto the quartz.

“Since piezoelectric voltages are instantaneous and leave behind no visible tracer, this can rationalize why gold nuggets commonly appear to be ‘floating’ in quartz veins with no obvious chemical or physical trap,” the researchers note .

The implications of this discovery extend beyond academic curiosity. Understanding the conditions that lead to the formation of gold nuggets could have practical applications in gold prospecting. If scientists can identify markers on the Earth’s surface that indicate past seismic activity and the presence of piezoelectric quartz, they could more accurately target areas with a high potential for gold deposits.

However, as Dr. Taija Torvela, a structural geologist at the University of Leeds, points out, much work remains to be done in translating these findings into practical applications.

“Understanding the mechanism by which these deposits form can potentially help in targeting rich gold deposits, although in order to translate understanding into real practical applications, we would need to know if there are any markers, detectable on Earth’s surface, that this process would leave behind,” she said.

A new era in gold prospecting?

The discovery that the piezoelectric effect in quartz helps form gold nuggets is an important step forward in our understanding of geology.

It opens up new avenues for research and exploration, particularly in the field of gold prospecting. By identifying the conditions that lead to gold deposition, scientists could develop new methods for locating rich gold deposits.

The broader impact of this research may also extend to other mineral deposits. If similar piezoelectric mechanisms are at play in other geological formations, the principles uncovered in this study could help explain the formation of other valuable minerals. As research continues, the findings of Dr. Voisey and his team may prove to be just the beginning of a new understanding of Earth’s hidden treasures.

The research was published in the journal Nature Geoscience .