Gold nuggets are a rare and valuable find, but how do these giant nuggets form inside quartz veins? A recent study has shed light on this mystery, revealing that earthquakes play a crucial role in triggering the formation of these massive gold deposits.
Gold naturally forms in quartz, which is the second-most abundant mineral in Earth’s crust after feldspar. Quartz veins are cracks in the rock that are filled with mineral-rich hydrothermal fluids. These fluids carry gold atoms from deep within the Earth’s crust and deposit them in the quartz veins.
According to Chris Voisey, a geologist at Monash University in Australia, gold often forms in quartz, but the formation of large gold nuggets has been a puzzling phenomenon for researchers. These giant nuggets are found clustered in quartz veins, and they represent up to 75% of all the gold ever mined.
The study, published in the journal Nature Geoscience, reveals that earthquakes trigger the formation of large gold nuggets in quartz veins. The researchers found that the largest nuggets occur in orogenic gold deposits, which are deposits that form during earthquakes. Quartz, being a piezoelectric mineral, creates its own electric charge in response to geologic stress, such as the stress generated by earthquakes.
During an earthquake, rocks fracture, allowing hydrothermal fluids to flow up into the quartz veins and deposit dissolved gold. The stress of the earthquake also causes the quartz veins to generate an electric charge, which reacts with the gold and causes it to solidify into nuggets. Gold preferentially solidifies onto existing gold deposits, forming clusters that grow larger with each seismic event.
To test this theory, the researchers conducted experiments in the lab, simulating the effect of an earthquake on quartz crystals submerged in a liquid containing gold. The results confirmed that under geologic stress, quartz can produce a large enough voltage to precipitate gold out of solution. Gold preferentially solidifies on existing gold deposits in quartz veins, explaining the formation of large gold nuggets.
While the study provides insights into the formation of giant gold nuggets, it does not offer new clues for mining companies seeking to locate these valuable deposits. However, the researchers suggest that a device detecting piezoelectric signals from quartz at depth could help identify potential areas for gold mining.
In conclusion, the study highlights the important role earthquakes play in triggering the formation of giant gold nuggets in quartz veins. Understanding this process could lead to new insights into gold deposit formation and exploration techniques in the future.
