A new atlas charts the global distribution of unusual, critical‑metal‑bearing igneous rocks, finding that they often form near the thick and ancient cores of the world’s major continents.
Researchers from Cambridge’s Department of Earth Sciences mapped occurrences of CO2-rich igneous rocks – the world’s primary source of rare earth elements – finding that their distribution is strongly tied to variations in Earth’s rigid outer layer, the lithosphere.
Thicker lithosphere is key to creating the right rocks for enrichment, say the researchers, allowing pockets of molten rock to become trapped at depth where they slowly steep to concentrate metals.
The findings, published in the journal Nature Geoscience, could be used to guide the search for new rare earth deposits, said Dr Emilie Bowman, lead author of the study from Cambridge Earth Sciences. “Our research is beginning to provide a kind of predictive power for where we can expect these rocks and, by extension, their associated rare earth element deposits, to form.”
Rare earth elements are used in the production of many everyday and advanced technologies, including smartphones and clean energy solutions such as wind turbines and electric vehicles.
