A groundbreaking study from the University of Göttingen in Germany has provided compelling evidence that Earth's core is releasing precious metals, such as gold and ruthenium, into the mantle. This discovery challenges long-held geological assumptions about the planet's internal dynamics and the distribution of valuable elements.
The research, published in the journal Nature, analyzed volcanic rocks from Hawaii, specifically from the Kīlauea volcano. Scientists employed advanced isotopic analysis, focusing on ruthenium isotopes, which are predominantly found in the Earth's core. They detected elevated levels of ruthenium-100 (¹⁰⁰Ru) in the Hawaiian lavas, a composition distinct from the mantle, strongly indicating an origin from the core-mantle boundary.
Lead geochemist Nils Messling described the initial findings as "literally striking gold," confirming the hypothesis that core-derived materials are being transported upwards. While the quantities of precious metals reaching the surface are minuscule, the implications for understanding planetary processes are significant. Previously, it was widely believed that Earth's core, formed approximately 4.5 billion years ago, remained geochemically isolated.
This new research proposes a geochemical feedback loop, suggesting that trace amounts of core materials are recycled to the surface over vast geological timescales through volcanic processes. The study indicates that even less than 0.3% of core material reaching the surface is sufficient to account for the observed isotopic anomalies, reinforcing the idea that the core and mantle are more interconnected than previously assumed.
The findings build upon earlier research that identified anomalies in tungsten isotopes in plume-related basalts but lacked definitive proof of a core origin. The ability to trace these anomalies through ruthenium isotopes significantly strengthens the argument for core leakage. The study also has broader implications for understanding the formation of ocean islands like Hawaii, which are situated above deep mantle plumes originating near the core.
The research team, including geochemists Nils Messling and Matthias Willbold from the University of Göttingen, has opened new avenues for understanding Earth's internal structure and the movement of materials from its deepest layers to the surface. These findings could also influence future planetary exploration missions by offering new perspectives on internal processes and the potential origins of surface mineral deposits on other celestial bodies.