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Mössbauer Characteristics of Cambrian Glauconite, Central U.S.A.

Published online by Cambridge University Press:  01 July 2024

Robert M. Rolf ,
Clyde W. Kimball  and
I. Edgar Odom
Robert M. Rolf
Affiliation:
Department of Physics, Northern Illinois University, DeKalb, IL 60115, U.S.A.
Clyde W. Kimball
Affiliation:
Department of Physics, Northern Illinois University, DeKalb, IL 60115, U.S.A.
I. Edgar Odom
Affiliation:
Department of Geology, Northern Illinois University, DeKalb, IL 60115, U.S.A.
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Abstract

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Mössbauer characteristics of 57Fe nuclei in 8 samples of mineral glauconite of Cambrian age and one sample of Cretaceous age (slightly disordered) were obtained at temperatures between 50 and 295 K to evaluate the site occupation of iron in the octahedral sheet and the Fe3+/Fe2+ ratio. It was found that the resolution of Mössbauer spectra of glauconite is increased at low temperature.

The octahedral sheet in mineral glauconite is believed to contain two types of cationic environments with slight symmetry differences because of the position of oxygen and hydroxyl ions around the cation sites. One environment consists of two equivalent sites (M2), whereas the other is a single site (M1).

The Mössbauer spectra were fitted to a four-doublet model, two Fe3+ sites (M2 and M1) and two Fe2+ sites, and a three-doublet model, two Fe3+ sites (M2 and M1) and an average Fe2+ site. The former (four-doublet) model yielded lower χ2 and, also, line widths in close agreement with previous studies. However, since the Fe2+ concentration in the samples is low, the error in intensity of the Fe2+ occupation of the M1 and M2 sites leads us to conclude that Fe3+/Fe2+ ratios are more accurate for the three-doublet model.

Calculation of area ratios for the two Fe3+ doublets indicates that trivalent iron is strongly concentrated in the M2 site, which is smaller than the M1 site. Site preference of divalent iron could not be determined. The ratio of Fe3+/Fe2+ obtained from the Mössbauer spectra were usually within 8% of those obtained from chemical analyses.

Type
Research Article
Information
Clays and Clay Minerals , Volume 25 , Issue 2 , April 1977 , pp. 131 - 137
Copyright
Copyright © Clay Minerals Society 1977

References

Annerston, H. (1974) Mössbauer studies of natural biotites: Am. Miner. 59, 143–151.Google Scholar
Arnott, R. A. (1968) Mössbauer studies of iron in glauconite: Unpublished Ph.D. thesis, University of Wisconsin, Madison.Google Scholar
Bailey, S. W. (1975) Cation ordering and pseudosymmetry in layer silicates: Am. Miner. 60, 175–187.Google Scholar
Bancroft, G. M. (1973) Mössbauer spectroscopy: Halsted Press, New York.Google Scholar
Bowen, L. H., Weed, S. G. and Stevens, J. G. (1969) Mössbauer study of micas and their potassium-depleted products: Am. Miner. 54, 72–84.Google Scholar
Bradley, W. F. and Grim, R. E. (1961) Mica clay minerals. In: The X-ray Identification and Crystal Structure of Clay Minerals. Mineralogical Society of London.Google Scholar
Haggstrom, L., Wäppling, R. and Annersten, H. (1969) Mössbauer study of oxidized iron silicate minerals: Phys. Stat. Sol. 33, 741–748.CrossRefGoogle Scholar
Hofmann, U., Fluck, E. and Kuhn, P. (1967) Mössbauer spectrum of the iron in glauconite: Angew. Chem. Int. Ed. 6, 561–562.CrossRefGoogle Scholar
Hughes, Randall and Bohor, Bruce (1970) Random clay powders prepared by spray-drying: Am. Miner. 55, 1780–1786.Google Scholar
Lindqvist, B. (1962) Polymorphic phase changes during heating of dioctahedral layer silicates: Geol. Pören Stockholm Förland 82, 224–229.CrossRefGoogle Scholar
Odom, I. E. (1976) Microstructure, mineralogy and chemistry of Cambrian glauconite pellets and glauconite, central U.S.A.: Clays & Clay Minerals 24, 232–238.CrossRefGoogle Scholar
Stevens, J. G. and Stevens, V. E. (1973) Mössbauer Effect Data Index, p. 156: IFI/Plenun Press, New York.Google Scholar
Tapper, M. and Fanning, D. S. (1968) Glauconite pellets: similar X-ray patterns from individual pellets of lobate and vermiform morphology: Clays & Clay Minerals 16, 275–283.CrossRefGoogle Scholar
Taylor, G. K., Ruotsala, H. P. and Keeling, R. O. Jr. (1968) Analysis of iron in layer silicates by Mössbauer spectroscopy: Clays & Clay Minerals 16, 381–391.CrossRefGoogle Scholar
Tyler, S. A. and Bailey, S. W. (1961) Secondary glauconite in the Biwabic iron-formation of Minnesota: Econ. Geol. 56(6), 1033–1044.CrossRefGoogle Scholar
Weaver, C. E., Wampler, J. M. and Pecuil, T. E. (1967) Mössbauer analysis of iron in clay minerals: Science 156, 504–508.CrossRefGoogle ScholarPubMed