The formation of gold deposits has always intrigued scientists. A recent discovery could well clarify this mystery.
An international team, including a researcher from the University of Michigan, has identified a gold-trisulfur complex. This complex plays a key role in the transport of gold from the Earth’s mantle to the surface. The results, published in Proceedings of the National Academy of Sciencesprovide a new understanding of the mechanisms of formation of gold deposits.
Gold deposits associated with volcanoes form in subduction zones. These areas, where an oceanic plate dives under a continental plate, are the site of intense magmatic activity. The gold-trisulfur complex forms under specific conditions of pression and of temperatureallowing the gold to migrate to the surface. Adam Simon, professor at the University of Michigan, emphasizes the importance of this discovery. The thermodynamic model developed by the team shows that the gold-trisulfur complex is essential to explain the high concentrations of gold in certain mineral systems. This advance could improve strategies forexploration mining.
The researchers combined laboratory experiments with thermodynamic models to validate their results. This approach made it possible to accurately predict the conditions necessary for the formation of the gold-trisulfur complex. The results apply to subduction zones around the Pacific Ocean, where there are many active volcanoes.
This study is the result of a collaboration between scientists from China, Switzerland, Australia and France. It makes a significant contribution to the understanding of the geochemical processes involved in the formation of gold deposits. The implications for the mining industry are potentially significant.
Subduction zones, like those surrounding the Pacific Ocean, are complex geological environments. The magma that forms there transports precious elements, including gold, to the surface. The discovery of the gold-trisulfur complex explains why some of these areas are particularly rich in gold.
The researchers hope that these results will make it possible to better target mining explorations. By understanding the specific conditions necessary for the formation of gold deposits, it will be possible to optimize research and reduce associated costs. This discovery opens new perspectives for the mining industry.
Finally, this study highlights the importance of international collaborations in Earth sciences. By combining varied expertise, the researchers were able to develop a robust model that improves our understanding of geological processes. These advances are essential for the sustainable exploitation of mineral resources.
What is a subduction zone?
A subduction zone is a region where a tectonic plate oceanic dips under a continental plate. This process is at the origin of many geological phenomena, such as earthquakes and volcanic eruptions.
In these areas, magma formed in the Earth’s mantle can rise to the surface. This magma carries valuable elements, including gold, which then concentrate in mineral deposits.
Subduction zones are particularly active around the Pacific Ocean, in a region known as the ‘Ring of Fire’. These areas are therefore prime targets for mining exploration.
Understanding the processes that take place in subduction zones is essential for predicting where and how gold deposits form. This also makes it possible to better anticipate the natural risks associated with these regions.
How is gold transported to the surface?
Gold present in the Earth’s mantle is transported to the surface by magma. This process is facilitated by the formation of chemical complexes, such as the gold-trisulfur complex identified in this study.
The gold-trisulfur complex forms under specific conditions of pressure and temperature. These conditions are found in subduction zones, at depths of 30 to 50 miles below the surface.
Once formed, the gold-trisulfur complex is very mobile in the magma. It can thus migrate to the surface, where gold concentrates in mineral deposits.
This discovery allows us to better understand why certain subduction zones are particularly rich in gold. It also opens up new perspectives for mining exploration, making it possible to target the most promising regions.
