Quantifying manganese and nitrogen cycle coupling in manganese‐rich, organic carbon‐starved marine sediments: Examples from the Clarion‐Clipperton fracture zone

Extensive deep‐sea sedimentary areas are characterized by low organic carbon contents and thus harbor suboxic sedimentary environments where secondary (autotrophic) redox cycling becomes important for microbial metabolic processes. Simulation results for three stations in the Eastern Equatorial Pacific with low organic carbon content (20 μM) concentrations. Key Points Clarion‐Clipperton fracture zone sediments are characterized by broad (meter‐scale) suboxic zones Ammonium may provide additional reducing power in carbon‐starved sediments Anaerobic ammonium oxidation may occur in the presence of manganese oxides in suboxic sediments