The extensive studies on marine sediment revealeddifferent factors that are related to the preservation of OC and are interdependent. Their relative importance is likely to shift in time and space (Cowie et al., 1999). The mechanisms that have received most attention in marine systems are oxygen exposure, protective sorption onto mineralsurfaces, and the chemical composition of the organic matter (Burdige, 2007) while in eutrophic impoundments the volume of sediment deposition was most important (Downing et al., 2008).