30 Billion Pounds of Gold: Locked Deep in Earth’s Core
A 2025 Nature study (DOI: 10.1038/s41586-025-09003-0) by University of Göttingen geochemists reveals traces of precious metals, like gold and ruthenium, leaking from Earth’s core to the surface via volcanic hotspots in Hawai‘i.
This discovery provides hard evidence for a dynamic core-mantle connection, challenging long-held views of their isolation.
Ruthenium Traces from the Core
The team, led by Nils Messling and Matthias Willbold, studied ocean island basalts (OIBs) from Hawaiian volcanoes like Kīlauea and Lo‘ihi, formed by mantle plumes rising from the core-mantle boundary, ~2,900 km below the surface.
Using high-precision mass spectrometry, they detected isotopic anomalies in ruthenium (100Ru) and tungsten (182W). Ruthenium, more abundant in the core than the mantle, showed elevated 100Ru levels in lava, suggesting core material transport.
Messling noted an excess of s-process Ru isotopes, tied to the core’s formation 4.5 billion years ago. The study estimates less than 0.3% core-derived material explains these anomalies, indicating a subtle but measurable exchange.
A Small Leak, Big Implications
This minute leakage upends the idea that the core has been chemically isolated since Earth’s formation. It suggests a geochemical cycle where trace core materials reach the surface via volcanism over millions of years. Building on prior tungsten anomaly studies, ruthenium provides a clearer core-leak signature.
Gold in the Core: Inaccessible Riches
The core holds vast precious metal reserves—potentially 99.999% of Earth’s gold and other metals – but the study emphasizes that only microscopic traces surface. While some estimate billions of tons of gold locked 2,900 km deep, worth unimaginable sums, mining it is impossible with current technology due to extreme heat and pressure.
“We’re talking traces, not nuggets,” Willbold clarified, underscoring this as a scientific, not commercial, discovery.
Volcanoes as Deep-Earth Observatories
Volcanoes offer a natural lab. Hotspots in Hawai‘i, La Réunion, and Galápagos provide geochemical snapshots of deep Earth. Tracking isotopes across plumes could map material flows, refining models of Earth’s internal dynamics and planetary formation.
Beyond Earth: Cosmic Connections
This finding may apply to Mars or Venus, where similar core leaks could explain surface features.
Future missions might seek isotopic signatures in extraterrestrial rocks.
This study redefines Earth’s core-mantle story, revealing an untouchable wealth of metals and a dynamic planet. What could this mean for planetary science?
(Source: Daily Galaxy)
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