The Earth’s abundance of precious metals like gold is surprisingly plentiful, but only about 99.999% of its stored resources lie entirely beneath 3,000 kilometers of solid rock and the metallic core. These deposits are locked away deep within the Earth’s interior, beyond the reach of human ingenuity. A new study from the University of Göttingen suggests that a fraction of gold and other precious metal reserves might have emanated from the Earth’s core through the core-mantle boundary.
Earth formed 4.5 billion years ago, and at the time, the core contained a slightly higher abundance of rubidium-100 compared to the surrounding rocky mantle. When silicon dioxide (earth’s crust) cools and solidifies, it retains a slight isotope abundance of rubidium. However, this isotope is not easily detected by standard rock analysis techniques, which rely on comparing isotopic-ratio ratios of isotopes. Researchers solved this problem by dissolving the rock mixture in hot acid, condensing the resulting steam back to a liquid, and then measuring the isotopic signal in concentrated samples. This amplification allowed them to detect the presence of rubidium-100, providing critical insights into the origin of gold.
The Hawaiian Volcano, whose active volcanism is funded by partial molten rock rising from the Earth’s mantle, exhibits an unusually high signal of rubidium-100 in its samples. This suggests that such magmas originate at the core-mantle boundary and rise to Earth’s surface, forming features like the island of Hawai’i. The findings from the study and the University of Göttingen suggest that huge volumes of heat-tolerant mantle material, several hundreds of quadrillion metric tons in size, originated at this boundary and formed elevated oceanic features.
The discovery of ‘core leakage’ from gold deposits provides a new angle for understanding how precious metals such as gold are distributed within the Earth. When magma rises to the surface, particularly along subduction zones or the Earth’s core-mantle boundary, it can mix with sulfur-rich fluids, forming gold-bearing magmas. As these magma vein occur, they are further concentrated in deposits, allowing extracting significant amounts of gold. However, this process continues to reshape and provide new clues about the dynamic processes shaping the Earth’s interior.
In a groundbreaking study, researchers have now provided insights into the origin of major Earth’s gold reserves. By analyzing the radioactive isotopes and using modified rock samples, they have demonstrated that a substantial portion of Earth’s gold and other precious metal deposits吾 are currently discuss whether this pile-up to the surface indicates a new layer of resource extraction or a need to rethink where we search for them.
The publication of “Ru and W isotope systematics in ocean island basalts reveals core leakage” in Nature further highlights the importance of these findings. As part of the larger research project, additional samples and interviews have been provided by the University of Göttingen, unifying the study’s results and offering deeper insights into the puzzle surrounding Earth’s gold reserves. The research underscores the complex interplay of geological processes, such as mantle plumes and radioactive decay, that shape the distribution of valuable minerals on Earth. It also raises questions about the practical implications of this knowledge and whether more exploration of core-mantle zones could yield new discoveries. The study and its implications represent a significant advance in understanding the Earth’s lucrative treasures, shedding light on long-standing concerns about the location of these resources.
