Earth's hidden "gold kitchen" may be operating far beneath the ocean floor. Island arcs, chains of volcanoes that develop above subduction zones where one oceanic plate descends beneath another, are often unusually rich in gold. Scientists have debated for years why these regions become so enriched.
New research led by Dr. Christian Timm, a marine geologist at GEOMAR Helmholtz Centre for Ocean Research Kiel, offers a deeper explanation.
"Our research shows that hydrous mantle melting beneath island arcs is a key driver of gold enrichment," says Timm. "In these settings, the mantle behaves like a multi-stage melting system that progressively concentrates gold."
Volcanic Glass Preserves Ancient Magma
To investigate how gold and other noble metals behave during mantle melting beneath submarine subduction zones, the researchers studied 66 volcanic glass samples collected from the seafloor along the Kermadec island arc and the neighboring Havre Trough north of New Zealand.
