New investigations have revealed potential sites for essential metals necessary for establishing a sustainable economy.
The shift toward a sustainable economy requires us to source more essential metals like copper, rare earth elements, and cobalt, which are currently in short supply. Thus, it’s crucial to discover new resources that have formed through different processes in unexplored regions.
On January 8, 2025, new research published in Nature by Dr. Chunfei Chen from the Earth Evolution research team at Macquarie University outlines potential locations and the processes behind the accumulation of critical metals found along the edges of ancient continental cores.
“These cores represent the thickest, bowl-shaped sections of tectonic plates. The molten materials that develop beneath their centers tend to rise and spread towards the outer edges, leading to frequent volcanic activity in those areas,” explains Chen.
Earlier high-pressure experiments conducted by the Earth Evolution group revealed that the initial melts formed at depths of around 200 kilometers are rich in carbonate and have lower silica content compared to most rock melts.
Dr. Chen and his team’s latest experiments indicate that as these melts ascend and spread beneath continental cores, they lose silica and become almost entirely composed of carbonate.
Distinguished Professor Stephen Foley from Macquarie’s School of Natural Sciences clarifies that this transformation in melt composition is linked to the occurrence of critical metals.
“The initial melts can transport a significant amount of critical metals and sulfur; however, our new findings reveal that these elements are released from the melt as it loses silica. This process creates concentrations of critical metals and sulfur in linear patterns around the peripheries of thick continental cores,” says Professor Foley.
The study also substantiates previous findings that mantle samples brought to the surface by volcanoes in these regions contain higher levels of sulfur and copper compared to other continental locations.
This recent research aligns with observations made by scholars at the Australian National University and Geoscience Australia, who noted that critical metals tend to gather around the edges of continental cores, highlighting these regions as crucial targets for future exploration efforts.
