Evaluation of the diagenetic role of iron as a sulfide buffer at Cape Lookout Bight, North Carolina (USA).

摘要

Organic matter accumulation in marine environments is influenced by a range of factors, including primary production and the degree of subsequent biochemical degradation. Iron availability has important impacts on primary production rate and thus it has been argued that an increase in iron supply to the oceans could result in enhanced primary production and organic matter burial. This study investigates an alternative hypothesis, designated the "Sulfide Buffer/Phosphorous Trap Hypothesis", through a series of "iron addition" macrocosm experiments with modern sediments collected from Cape Lookout Bight (North Carolina). Results of the incubation experiments are used to evaluate the hypothesis that an increase in iron delivery to the sediments can buffer the accumulation of hydrogen sulfide within pore water, enhance the oxygen penetration depth and degree of bioturbation/bioirrigation, and increase the remineralization of organic matter. This biogeochemical hypothesis provides a mechanism that could link iron concentration and organic matter burial in ancient marine environments.