A research team, including a University of Michigan scientist, has made a significant breakthrough in understanding how gold deposits are formed. Gold is commonly found in volcanic or magmatic rocks on the surface, but its formation process has been debated among researchers. The new study reveals that a specific type of sulfur and high pressures/temperatures at depths of 50-80 kilometers beneath active volcanoes play a crucial role in transferring gold from the Earth’s mantle to magma.
The researchers found that gold complexes with sulfur ions, forming a gold-trisulfur complex, is highly mobile in the molten sections of the mantle. This complex can then rise to the surface through subduction zones, where tectonic plates meet and create conditions for magma formation. The study suggests that these processes are responsible for the formation of many active volcanoes around the world, including those in New Zealand, Indonesia, Japan, Russia, Alaska, and the western United States.
According to Adam Simon, U-M professor of Earth and environmental sciences, this discovery provides a robust understanding of what causes certain subduction zones to produce gold-rich ore deposits. The study’s findings can improve exploration and provide valuable insights into how the Earth’s past influences society today.
Source: https://www.forbes.com/sites/davidbressan/2024/12/25/new-study-explains-how-gold-reaches-earths-surface