Diagenetic models of interstitial nitrate profiles in deep sea suboxic sediments1

Abstract

Quantitative models are developed to describe three different profiles of nitrate observed in the porewater of pelagic sediments: nitrification only is observed; a surficial zone of nitrification is underlain by a zone of denitrification; the zone of nitrification is underlain by a zone of no reaction and then a zone of denitrification. Oxygen consumption and nitrate re duction are assumed to be first‐order processes. by fitting the models to observed [NO₃⁻] profiles, we have estimated benthic nitrate and oxygen fluxes, denitrification rates, first‐order rates constants for O₂, organic matter, and NO₃⁻ consumption, and the stoichiometric ratio d[NO₃⁻]:d[O₂].