Relation between sedimentation rate and burial of organic phosphorus and organic carbon in marine sediments

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(90)90326-G· OSTI ID:6991218

Ingall, E D; Van Cappellen, P ^[1]

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1. Yale Univ., New Haven, CT (USA)

Organic carbon and organic phosphorus concentrations in marine sediment cores with known sedimentation rates were determined and collected from the literature. With the exception of organic-rich sediments from upwelling areas, organic phosphorus concentrations in marine sediments do not correlate linearly with organic carbon concentrations. A simple steady state model is developed for the early diagenesis of organic carbon and organic phosphorus in marine sediments. The processes included are sediment burial, pore water diffusion, and bacterial decomposition of organic matter by oxic respiration and sulfate reduction. The model shows that both organic matter preservation and the degree of elemental fractionation between phosphorus and carbon depend strongly on the overall sedimentation rate. Very high sedimentation rates (coastal-deltaic environment) result in a good preservation of deposited organic matter with an initial C/P ratio close to the Redfield value. At very slow sedimentation rates (pelagic environment), the oxidation of the sedimentary organic matter is nearly complete and produces a low C/P residual organic material. This residual organic matter may represent either refractory detrital organic compounds enriched in phosphorus or in situ synthesized low C/P bacterial remains. The high C/P ratios at intermediate sedimentation rates (slope and shelf environment) reflect the preferential regeneration of phosphorus during the incomplete decomposition of the metabolizable organic matter.

• OSTI ID: 6991218
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 54:2; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBON COMPOUNDS
CHEMISTRY
CONCENTRATION RATIO
DIAGENESIS
DRILL CORES
GEOCHEMISTRY
GEOLOGIC HISTORY
GEOLOGIC MODELS
INTERFACES
KINETICS
ORGANIC COMPOUNDS
PHOSPHORUS COMPOUNDS
REACTION KINETICS
ROCKS
SEDIMENT-WATER INTERFACES
SEDIMENTARY ROCKS
SEDIMENTS