Determining Biogenic Silica in Marine Samples by Tracking Silicate and Aluminium Concentrations in Alkaline Leaching Solutions
Tóm tắt
This study introduces an alkaline leaching technique for the simultaneous analysis of biogenic silica and aluminium in sediments. Measuring aluminium facilitates the discrimination between silica from the biogenic (BSiO2) and the non-biogenic fraction, because it originates almost solely from the lithogenic phase. The method was tested using fine-grained silicagel, standard clay minerals, artificial sediments, and natural samples ranging from fresh diatoms to aged sediment from different depositional settings. To determine the BSiO2 content, four different models each describing the dissolution curves, but of increasing complexity, were applied and for each different type of sample the optimum model was selected on the basis of F-test statistics. For mixtures of silicagel and clay minerals, the contribution of Si from the dissolution of clay was negligible compared to Si originating from silicagel. For natural samples with high clay content, complex dissolution curves were observed and single-phase first order dissolution was the exception. This deviation from `ideal' behavior could only be recognized because of high-resolution sampling, especially in the first 20 minutes of the experiment. For most of the samples, the distinction between the biogenic silica fraction and the silica originating from dissolution of clays could be made on the basis of the Si/Al ratios and reactivity constants of the dissolving phases calculated with the models. Clay minerals typically dissolve slowly at a Si/Al ratio close to 1–2, depending on the type of clay mineral. In contrast, biogenic silica displays a wide range of reactivities and Si/Al ratios. Fresh biogenic silica from the water column usually has a high reactivity and a low Al content. Aged biogenic silica from the sediments has a lower reactivity, but Si/Al ratios as low as 5 were found. The method as described here therefore presents an accurate method to analyze biogenic silica in marine sediments with a relatively high clay mineral content.
Tài liệu tham khảo
Abelmann A., Gersonde R. and Spiess V. (1990) Pliocene-Pleistocene Paleoceanography in the Weddell Sea. In Geological history of the Polar Oceans: Arctic vs Antarctic (eds. U. and J. Bleil, Thiede), pp. 729–759. Kluwer Academic Press, Dordrecht, Boston, London.
Bathman U. V., Noji T. T. and von Bodungen B. (1990) Copepod grazing potential in late winter in the Norwegian Sea – a factor in the control of of spring bloom development? Mar. Ecol. Prog. Ser. 60, 225–233.
Boudreau B. P. and Ruddick B. R. (1991) On a reactive continuum representation of organic matter diagenesis. Amer. J. Sci. 291, 507–538.
Brzezinski M. A. and Nelson D. M. (1995) The annual silica cycle in the Sargasso Sea near Bermuda. Deep-Sea Research 42, 1215–1237.
Brzezinski M. A., Nelson D. M., Franck V. M. and Sigmon D. E. (2001) Silicon dynamics within an intense open-ocean diatom bloom in the Pacific sector of the Southern Ocean. Deep-Sea Res. II. 48, 3997–4018.
Broecker W. S. and Peng T.-H. (1982) Tracers in the Sea. Eldigio Palisades, New York, 690 pp.
Calvert S. E. (1966) Accumulation of diatomaceous silica in the sediments of the Gulf of California. Geol. Soc. Am. Bull. 77, 569–596.
Conley D. J. (1998) An interlaboratory comparison for the measurement of biogenic silica in sediments. Mar. Chem. 63, 39–48.
DeMaster D. J. (1981) The supply and accumulation of silica in the marine environment. Geochim. Cosmochim. Acta 45, 1715–1732.
Dixit S., van Cappellen P. and van Bennekom A. J. (2001) Processes controlling the solubility of biogenic silica and pore water build-up of silicic acid in marine sediments. Mar. Chem. 73, 333–352.
Eggimann D.W., Manheim F. T. and Betzer P.R. (1980) Dissolution and analysis of amorphous silica in marine sediments. J. Sed. Petr. 51, 215–225.
Eisma D. and van der Gaast S. J. (1971) Determination of opal on marine sediments by X-ray diffraction. Neth. J. Sea Res. 5, 382–389.
Epping E., van der Zee C., Soetaert K. and Helder W. (2002) On the oxidation and burial of organic carbon in sediments of the Iberian Margin and Nazaré Canyon (NE Atlantic). Progress in Oceanography (in press).
Gehlen M. and van Raaphorst W. (1993) Early diagenesis of silica in sandy North Sea sediments: quantification of the solid phase. Mar. Chem. 42, 71–83.
Goldberg E. D. (1958) Determination of opal in marine sediments. J. Mar. Res. 17, 178–182.
Grasshoff K., Ehrhardt M. and Kremling K. (eds) (1983) Methods of seawater analysis, 2nd edn. Verlag Chemie. Winheim, 417 pp.
Griffin J. J., Windom H. and Goldberg E. D. (1968) The distribution of clay minerals in the World Ocean. Deep-Sea Res. 15, 433–459.
Hurd D. C. (1973) Interactions of biogenic opal sediment and sea water in the central equatorial Pacific. Geochim. Cosmochim. Acta 37, 2257–2282.
Hurd D. C. and Birdwhistell S. (1983) On producing a more general model for biogenic silica dissolution. Am. Journ. Sci. 283, 1–23.
Hydes D. J. and Liss P. S. (1976) Fluorimetric method for the determination of low concentrations of dissolved Aluminium in natural waters. Analyst 10, 922–931.
Iler R. K. (1979) The Chemistry of Silica. Wiley-Interscience, New York, 866 pp.
Kamatani A. and Riley J. P. (1979) Rate of dissolution of diatom silica walls in seawater. Mar. Biol. 55, 29–35.
Kamatani A. and Oku O. (2000) Measuring biogenic silica in marine sediments. Mar. Chem. 68, 219–229.
Koning E., Brummer G. J. A., van Raaphorst W., van Bennekom A. J., Helder W. and van Iperen J. M. (1997) Settling, dissolution and burial of biogenic silica in the sediments off Somalia (northwestern Indian Ocean). Deep-Sea Res II 44, 1341–1360.
Koning E. (2002) Biogenic silica cycling in the upwelling are on the Somalian Margin. PhD thesis, University of Utrecht, 152 pp.
Krausse G. L., Schelske C. L. and Davis C. O. (1983) Comparison of three wet-alkaline methods of digestion of biogenic silica in water. Freshw. Biol. 13, 73–81.
Landén A., Holby O. and Hall P. O. J. (1996). Determination of biogenic silica in marine sediments selection of pretreatment method and effect of sample size. Vatten 52, 85–92.
Leinen M. (1977) A normative calculation technique for determining opal in deep-sea sediments. Geochim. Cosmochim. Acta 41, 671–676.
Lerman A. (1979). Geochemical Processes Water and Sediment Environments. Wiley Interscience, New York, Chichester, Brisbane, Toronto, 481 pp.
Lisitzin A. P. (1972) Sedimentation in the world ocean. Soc. Econ. Paleontologists Mineralogists Spec. Pub. 17, 218.
Lyle M., Murray D. W., Finney B. P., Dymond J., Robbins J. M. and Brooksforce K. (1998) The record of late Pleistocene biogenic sedimentation in the eastern tropical Pacific Ocean. Paleocea. 3, 39–59.
Mortlock R. A. and Froelich P. N. (1989) A simple method for the rapid determination of biogenic opal in marine sediments. Deep-Sea Res. 36, 1415–1426.
Mortlock R. A., Charles C. D., Froelich P. N., Zibello M. A., Saltzman J., Hays J. D. and Burckle L. H. (1991) Evidence for lower productivity in the Antarctic Ocean during the last glaciation. Nature 351, 220–223.
Müller P. J. and Schneider R. (1993) An automated method for the determination of opal in sediments and particulate matter. Deep Sea Res. 40, 425–444.
Nelson D. M., Tréguer P., Brzezinski M. A., Leynaert A. and Quéguiner B. (1995) Production and dissolution of biogenic silica in the ocean: Revised global estimates, comparison with regional data and relationship to biogenic silica sedimentation. Global Biogeochem. Cycl. 9, 359–372.
Nelson D. M., DeMaster D. J., Dunbar R. B. and Smith Jr. W. O. (1996) Cycling of organic carbon and biogenic silica in the Southern Ocean: Estimates of water-column and sedimentary fluxes on the Ross Sea continental shelf. J. Geoph. Res. 101(C8), 18519–18532
Pondaven P., Ragueneau O., Treguer P., Hauvespre A., Dezileau L. and Reyss J. L. (2000) Resolving the 'opal paradox' in the Southern Ocean. Nature 405, 168–172.
Postma D. (1993) The reactivity of iron oxides in sediments: A kinetic approach. Geochim. Cosmochim. Acta 57, 5027–5034.
Ragueneau O. and Tréguer P. (1994) Determination of biogenic silica in coastal waters: Applicability and limits of the alkaline digestion method. Mar. Chem. 45, 43–51.
Sayles F. L., Martin W. R., Chase Z. and Anderson R. F. (2001) Benthic remineralization and burial of biogenic SiO2, CaCO O3, organic carbon, and detrital material in the Southern Ocean along a transect at 170W. Deep-Sea Res. II 48, 4323–4383.
Schlüter M. and Rickert D. (1998) Effect of pH on the measurement of biogenic silica. Mar. Chem. 63, 81–92.
Sokal R. R. and Rohlf F. J. (1995) Biometry, the Principals and Practice of Statistics in Biological Research, 3rd edn. Freeman, New York, 887 pp.
Stumm W. and Morgan J. J. (1981) Aquatic Chemistry, 3rd edn. Wiley-Interscience, New York, 780 pp.
Tarutis W. J. (1993) On the equivalence of the power and reactive continuum models of organic matter diagenesis. Geochim. Cosmochim. Acta 57, 1349–1350.
Thunell R. C., Pride C. J., Tappa E. and Muller-Karger F. E. (1994) Biogenic Silica fluxes and accumulation rates in the Gulf of California. Geology 22, 303–306.
Tréguer P., Nelson D. M., van Bennekom A. J., DeMaster D. J., Leynaert A. and Quéguiner B. (1995) The silica cycle in the world ocean: A reestimate. Science 268, 375–379.
Van Bennekom A. J., Jansen J. H. F., van der Gaast S. J., van Iperen J. M., Pieters J. (1989) Aluminium-rich opal: An intermediate in the preservation of biogenic silica in the Zaire (Congo) deep-sea fan. Deep-Sea Res. 36, 173–190.
Van Beusekom J. E. (1989) Wechselwirkungen zwischen gelöstem Aluminium und Phytoplankton in marinen Gewässern. PhD Thesis, University of Hamburg, Germany, 164 pp.