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Quantifying manganese and nitrogen cycle coupling in manganese‐rich, organic carbon‐starved marine sediments: Examples from the Clarion‐Clipperton fracture zone
Author(s) -
Mogollón José M.,
Mewes Konstantin,
Kasten Sabine
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl069117
Subject(s) - manganese , nitrate , environmental chemistry , total organic carbon , organic matter , ammonium , sedimentary rock , nitrogen , nitrogen cycle , carbon fibers , sedimentation , carbon cycle , dissolved organic carbon , geology , chemistry , environmental science , sediment , geochemistry , materials science , ecology , ecosystem , geomorphology , organic chemistry , composite number , composite material , biology
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 (<0.5 dry wt %) and low sedimentation rates (10 −1 –10 0 mm ky −1 ) show that ammonium generated during organic matter degradation may act as a reducing agent for manganese oxides below the oxic zone. Likewise, at these sedimentary depths, dissolved reduced manganese may act as a reducing agent for oxidized nitrogen species. These manganese‐coupled transformations provide a suboxic conversion pathway of ammonium and nitrate to dinitrogen. These manganese‐nitrogen interactions further explain the presence and production of dissolved reduced manganese (up to tens of μ M concentration) in sediments with high nitrate (>20 μ M ) concentrations.