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Composition of Some Smectites and Diagenetic Illitic Clays and Implications for their Origin

Published online by Cambridge University Press:  02 April 2024

P. H. Nadeau  and
D. C. Bain
P. H. Nadeau
Affiliation:
Department of Mineral Soils, The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen AB9 2QJ, Scotland, United Kingdom
D. C. Bain
Affiliation:
Department of Mineral Soils, The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen AB9 2QJ, Scotland, United Kingdom
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Abstract

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Chemical analysis by X-ray fluorescence (XRF) and calculated structural formulae of clay-size fractions of smectites from Cretaceous bentonites and illitic clays from Cretaceous, Devonian, and Ordovician bentonites and Jurassic and Permian sandstones indicate the nature and extent of various types of ionic substitution. The determination of tetrahedral (Al, Si) and octahedral (Al, Mg, Fe) composition shows the variable chemistry of these materials. Structural formulae of the illitic clays show that they have tetrahedral charges between 0.4 and 0.8 per half unit cell, and can be divided into phengitic types having octahedral charges of 0.2-0.4 and muscovitic types having octahedral charges <0.2. Evaluation of the formulae in the light of X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) data shows that the occupancy of non-exchangeable interlayer sites (predominantly K) varies from 47% to 90% of that of ideal muscovite. In some minerals as much as 20% of these sites is occupied by ammonium ions (determined independently). The amount of surface silicate charge balanced by non-exchangeable cations versus that balanced by exchangeable cations has been examined in conjunction with TEM data and suggests that in most samples the charges are about equal. The octahedral composition of smectites in Cretaceous bentonites precludes their having served as transformation precursors for most of the Cretaceous illitic bentonites. The results suggest that these illitic clays originated by neoformation.

Keywords

BentoniteChemical compositionIlliteInterstratifiedLayer chargePotassiumSmectiteX-ray fluorescence
Type
Research Article
Information
Clays and Clay Minerals , Volume 34 , Issue 4 , August 1986 , pp. 455 - 464
Copyright
Copyright © 1986, The Clay Minerals Society

References

Altaner, S. P., Hower, J., Whitney, G. and Aronson, J. L., 1984 Model for K-bentonite formation: evidence from zoned K-bentonites in the disturbed belt, Montana Geology 12 412–415.2.0.CO;2>CrossRefGoogle Scholar
Boles, J. R. and Franks, S. G., 1979 Clay diagenesis in Wilcox sandstones of southwest Texas: implications of smectite diagenesis on sandstone cementation J. Sed. Pet. 49 55–70.Google Scholar
Brindley, G. W., Brindley, G. W. and Brown, G., 1980 Order-disorder in clay mineral structures Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society 125–195.CrossRefGoogle Scholar
Brown, G., 1984 Crystal structures of clay minerals and related phyllosilicates Phil. Trans. Royal Soc. Lond. A 311 221–240.Google Scholar
Brown, G., Newman, A. D. C., Rayner, J. H., Weir, A. H., Greenland, D. J. and Hayes, M. H. B., 1978 The structures and chemistry of soil clay minerals The Chemistry of Soil Constituents 29–178.Google Scholar
Cooper, J. E. and Abedin, K. Z., 1981 The relationships between fixed ammonium-nitrogen and potassium in clays from a deep well in the Texas Gulf Coast Texas J. Sci. 33 103–111.Google Scholar
Cooper, J. E. and Evans, W. S., 1983 Ammonium-nitrogen in Green River Formation oil shale Science 219 492–493.CrossRefGoogle ScholarPubMed
de Dunoyer Segonzac, G., 1970 The transformation of clay minerals during diagenesis and low grade metamorphism: a review Sedimentology 15 281–376.CrossRefGoogle Scholar
Eslinger, E. V., Highsmith, P., Albers, D. and de Mayo, B., 1979 Role of iron reduction in the conversion of smectite to illite in bentonites in the disturbed belt, Montana Clays & Clay Minerals 27 327–338.CrossRefGoogle Scholar
Farmer, V. C. and Farmer, V. C., 1974 The layer silicates The Infrared Spectra of Minerals London Mineralogical Society 331–363.CrossRefGoogle Scholar
Garrels, R. M., 1984 Montmorillonite/illite stability diagrams Clays & Clay Minerals 32 161–166.CrossRefGoogle Scholar
Gast, R. G., Dixon, J. B. and Weed, S. B., 1977 Surface and colloid chemistry Minerals in Soil Environments Madison, Wisconsin Soil Science Society of America 27–73.Google Scholar
Grim, R. E., Bray, R. H. and Bradley, W. F., 1937 The mica in argillaceous sediments Amer. Mineral. 22 813–829.Google Scholar
Higashi, S., 1978 Dioctahedral mica minerals with ammonium ions Mineralogical J. 9 16–27.CrossRefGoogle Scholar
Hower, J., Eslinger, E. V., Hower, M. and Perry, E. A., 1976 Mechanism of burial metamorphism of argillaceous sediments: I. Mineralogical and chemical evidence Geol. Soc. Amer. Bull. 87 725–737.2.0.CO;2>CrossRefGoogle Scholar
Hower, J. and Mowatt, T. C., 1966 The mineralogy of illites and mixed-layer illite/montmorillonites Amer. Mineral. 51 825–854.Google Scholar
Hutton, J. T. and Elliott, S. M., 1980 An accurate XRF method for the analysis of geochemical exploration samples for major and trace elements using one glass disc Chemical Geol. 29 1–11.CrossRefGoogle Scholar
McHardy, W.J., Wilson, M.J. and Tait, J.M., 1982 Electron microscope and X-ray diffraction studies of filamentous illitic clays from sandstones of the Magnus field Clay Miner. 17 23–39.CrossRefGoogle Scholar
Nadeau, P. H., 1980 Burial and contact metamorphism in the Mancos Shale .CrossRefGoogle Scholar
Nadeau, P. H., 1985 The physical dimensions of fundamental clay particles Clay Miner. 20 499–514.CrossRefGoogle Scholar
Nadeau, P. H., Farmer, V. C., McHardy, W. J. and Bain, D. C., 1985 Compositional variations of the Unterrupsroth beidellite Amer. Mineral. 70 1004–1010.Google Scholar
Nadeau, P. H. and Reynolds, R.C., 1981 Burial and contact metamorphism in the Mancos Shale Clays & Clay Minerals 29 249–259.CrossRefGoogle Scholar
Nadeau, P. H., Tait, J. M., McHardy, W. J. and Wilson, M. J., 1984 Interstratified XRD characteristics of physical mixtures of elementary clay particles Clay Miner. 19 67–76.CrossRefGoogle Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1984 Interstratified clays as fundamental particles Science 225 923–925.CrossRefGoogle ScholarPubMed
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1984 Interparticle diffraction: a new concept for interstratified clays Clay Miner. 19 757–769.CrossRefGoogle Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1985 The conversion of smectite to illite during diagenesis: evidence from some illitic clays from bentonites and sandstones Mineral. Mag. 49 393–400.CrossRefGoogle Scholar
Norrish, K. and Hutton, J. T., 1969 An accurate X-ray spectrographic method for the analysis of a wide range of geological samples Geochim. Cosmochim. Acta 33 431–453.CrossRefGoogle Scholar
Perry, E. A. and Hower, J., 1970 Burial diagenesis in Gulf Coast pelitic sediments Clays & Clay Minerals 18 165–177.CrossRefGoogle Scholar
Reynolds, R. C., Brindley, G. W. and Brown, G., 1980 Interstratified clay minerals Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society 249–303.CrossRefGoogle Scholar
Reynolds, R. C. and Hower, J., 1970 The nature of interlayering in mixed-layer illite-montmorillonites Clays & Clay Minerals 18 25–36.CrossRefGoogle Scholar
Środoń, J., 1980 Precise identification of illite/smectite interstratifications by X-ray powder diffraction Clays & Clay Minerals 28 401–411.CrossRefGoogle Scholar
Środoń, J., Eberl, D. D. and Bailey, S. W., 1984 Illite Micas, Reviews in Mineralogy 13 Washington, D.C. Mineralogical Society of America 495–544.Google Scholar
Środoń, J., Morgan, D. J., Eslinger, E. V., Eberl, D. D. and Karlinger, M. R., 1986 Chemistry of illite/smectite and end-member illite Clays & Clay Minerals .CrossRefGoogle Scholar
Sterne, E.J., Reynolds, R.C. and Zantop, H., 1982 Natural ammonium illites from black shales hosting a stratiform base metal deposit, Delong Mountains, northern Alaska Clays & Clay Minerals 30 161–166.CrossRefGoogle Scholar
Weaver, C. E. and Pollard, L. D., 1973 The Chemistry of Clay Minerals Amsterdam Elsevier 5–23.Google Scholar
Wilson, M. D. and Pittman, E. D., 1977 Authigenic clays in sandstones: recognition and influence on reservoir properties and paleoenvironmental analysis J. Sed. Pet. 47 3–31.Google Scholar
Wright, A. C., Granquist, W. T. and Kennedy, J. V., 1972 Catalysis by layer silicates. I. The structure and thermal modification of a synthetic ammonium dioctahedral clay J. Catalysis 25 65–80.CrossRefGoogle Scholar