Of humic substances in marine sediments

Several ideas have been presented in the literature on the formation process of humic substances in marine sediments. Abelson (1967) claimed that polymerization of unsaturated fatty acids in phytoplankters after their death accounts for the formation of kerogen in marine sediments. Abelson and Hare (1971), Hoering (1973), and Hedges (1976) studied reactions between carbohydrates and amino acids under laboratory conditions as a possible formation reaction of humic acid and humin in sediments. They prepared a number of artificial humic acids by reacting glucose with amino acids. The synthetic products resembled natural humic acid and humin. A comprehensive review was published by Abelson (1978). 

GEOCHEMISTRY OF HUMIC SUBSTANCES IN MARINE SEDIMENTS BLACK SEA (Euxinic environment)... 

Tissot B, Durand B, Espitalie J, Combaz A (1974) Influence of nature and diagenesis of organic matter in formation of petroleum. Am Assoc Pet Geol Bull 58 499-506 Vandenbroucke M, Pelet R, Debyser V (1985) Geochemistry of humic substances in marine sediments. In Aiken G R, McKnight D M, Wershaw R L, MacCarthy P (eds) Humic substances in soils, sediments, and water. Wiley, New York, pp 249-273 Whitney G (1990) Role of water in the smectite-to-illite reaction. Clays Clay Minerals 38 343-350... 

Vandenbroucke, M., Pelet, R., and Debyser, Y. (1985). Geochemistry of humic substances in marine environments. In Humic Substances in Soil, Sediment, and Water Geochemistry, Isolation, and Characterization, Aiken, G. R., McKnight, D. M., Wershaw, R. L., and Mac-Carthy, R eds., John Wiley Sons, New York, pp. 249-273. 

Chemical reactions of formation of humic substances in lake sediments may be essentially the same as those in marine environments. Lake sediment humic substances are expected to represent an earlier stage of humification than those from marine sediments. 

Humic substances in marine sediments originate from both marine and terrestrial sources of organic matter, depending on the nature of sedimentary input. In some cases, a set of criteria based on chemical properties makes it possible to determine their origin. However, these criteria are less clear-cut than those established for kerogens. 

Hassett IJ, Banwart WL (1989) The sorption of nonpolar organics by soils and sediments In Sawhney BL, Brown K. (eds) Reactions and movement of organic chemicals in soils Soil Science Society of America, Madison, Wl, pp 31 5p Hayes MHB, Malcom RL (2001) Considerations of compositions and aspects of the structure of humic substances. In Clapp CE, Hayes MHB, Senesi N, Bloom PR Jardine PM, Humic substances and chemical contaminants. Soil Science Society of America, Madison, Wl, pp 1-39 Herbillon AJ, Erankart R, Vielvoye L (1981) An occurrence of interstratified kaoUnite-smectite minerals in a red-black soil top sequence. Clay Miner 16 195-201 Horne RA (1969) Marine chemistry. Wiley, New York... 

Variations in the atomic S/C ratios are more difficult to observe because of experimental uncertainties linked to the determination of organic sulfur. In surface sediments, S/C ratios are within the range 0.01-0.03 and generally decrease from fulvic acids to humic acids to stable residues. In stable residues, sulfur content increases rapidly in the few first meters of burial (see Table 1 Debyser and Gadel, 1981). The presence of sulfur in humic substances from marine sediments was previously noted by Nissenbaum and Kaplan (1972). 

The Hayase procedure [6] discussed in section 10.1.1.2 has also been applied to marine sediments. Sedimentary fulvic acid exhibited increasing hydrophilic character with increasing molecular weight. The method used was effective for hydrophobichydrophilic characterization of humic substances. 

Laane, R.W.P.M. and Kramer, C.3.M., 1984. Complexation of Cu + with humic substances in relation to different extraction procedures of sandy and silty marine sediments. In C.3.M. Kramer and 3.C. Duinker (eds), Complexation of Trace Metals in Natural Waters. Nijhoff/3unk Publ., the Hague, pp. 345-348. 

Publications on humic substances are dominated by discussions on humic acids and fulvic acids, with relatively little discussion of humin. The former two fractions can be dissolved in aqueous media which facilitates their isolation and study. The geochemistry of humin is discussed by Hatcher et al. in Chapter 11 the presence and nature of humin in various environments are also discussed in a number of other chapters in this book. For example, Stevenson (Chapter 2) discusses humin from soils, Ishiwatari (Chapter 6) provides a rather extensive discussion of humin from lake sediments, and Vandenbroucke et al. (Chapter 10) consider humin in marine sediments. 

In addition to direct extraction of humic substances, the amount of humic substances has been estimated by subtracting the amount of biochemicals (sum of lipids, amino acids or proteins, and carbohydrates) from the total organic matter in the sediments (Kemp and Johnston, 1979). In this chapter, this difference is called nonbiochemicals, although no doubt there is much overlap between nonbiochemicals and extracted humic substances. As shown in Table 2, nonbiochemicals amount to 42-58% of the total organic matter in two Japanese lake sediments, but in the Great Lake (North America) sediments nonbiochemicals amount to 70-79% of the total organic matter on average. The latter values are close to those observed for marine sediments (Ishiwatari, 1979). 

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