The sub-arc mantle has remained oxidized since the Neoproterozoic oxygenation event.

ABSTRACT: The redox state of the sub-arc mantle impacts magma degassing at arc volcanoes and arc-related ore deposits. However, the evolution of the oxygen fugacity (fO₂) of the sub-arc mantle during the Neoproterozoic Oxygenation Event (NOE) remains poorly understood. Here, we applied machine learning to identify arc basalts, then calculated V/Sc ratios of primitive arc basalts since ~0.8 billion years ago (Ga). Our results show that average V/Sc remained nearly constant at ~7.16, suggesting an oxidized sub-arc mantle since ~0.8 Ga. This implies that increased surficial oxygen levels during the NOE may not directly oxidize the sub-arc mantle. Instead, its oxidation likely stems from the influx of oxidized fluids and melts via subducted serpentinized oceanic crust. The persistently oxidiz

SUBMITTER: Liu CT 

PROVIDER: S-EPMC12361464 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature