Organic carbon burial rate

Table 25.1 Organic Carbon Burial Rates Regimes (Pg C/y). in Different Marine Sediment ...

St-Onge, G. and Hillaire-Marcel, C. (2001) Isotopic constraints of sedimentary inputs and organic carbon burial rates in the Saguenay Fjord, Quebec. Marine Geology, 176, 1-22. 

The second way to estimate the availability of organic substance in the benthic realm is to directly determine the organic carbon concentration in surface sediments (TOC) or to calculate the organic carbon burial rate. The simplistic approach to describe the dependence between the C -content and benthic flux rates has proven... 

The carbon isotopic composition of marine limestones is generally interpreted to reflect the rate of organic carbon burial (Forg, molyr ), although a number of other factors are actually involved and may be as significant for particular events or trends. The time rate of change of the of the ocean, can be expressed as (e.g., Kump and Arthur, 1999)... 

These redox cells can operate on a number of scales that depend on the length of the diffusion path from the point that the oxidised form becomes reduced to the point where it reduces another sediment constituent. In some pelagic cores these diffusion paths can be observed in linear portions of the pore-water profiles (e.g. Sawlan Murray, 1983). Here the sedimentation rate and the carbon burial rate are sufficiently low, relative to diffusion, to extend the processes of early diagenesis over tens of metres into the sediment. In coastal environments the sedimentation rate and the concentration and reactivity of the organic matter is often high, which results in a much more complex pattern. In this case, the distances between the cells are much shorter, since by definition the adjustment must occur more rapidly. Like laminar and turbulent flow, there may come a point where the flow of electrons downwards is better dispersed through eddies , which in this case are transitory micro-environments with small-scale three dimensional diffusion, rather than more stable... 

As already noted, a plot of age against Sr/ Sr for the prograding sequence of Red Sea beachrocks illustrates a rise in strontium isotope values with coincident rise in age (Fig. 7). A curve of strontium isotopes against documents a rapid rate of increase in values for both Sr/ Sr and (Fig. 10), similar to the pattern observed by Montanez et al. (1996, 2000) for a Cambrian marine carbonate sequence. Cambrian carbonate and Holocene beachrock strontium isotope levels are remarkably similar (Friedman, 2002), possibly reflecting similar conditions of increased oceanic nutrient levels, primary productivity, and organic carbon burial driven by increased continental flux and associated oceanic sedimentation (Montanez et al,... 

The global rate of carbon burial is 50 x 10 mol per year, four parts carbonate and one part organic carbon. The residence time of the combined surface carbon and carbonate reservoirs is 67,000 years. During this time, a carbon atom is in CO2 for 66,000 years and in the biomass for 1000 years. It gets oxidized and reduced 165 times. This example indicates that organic carbon burial cannot be... 

The main mechanism for removal of organic carbon from the ocean is burial in sediments. This flux is equal to the average global sedimentation rate for marine sediments times their weight percent organic carbon. The total sink... 

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