Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T17:26:31.007Z Has data issue: false hasContentIssue false
  • English
  • Français

Morphology of Clay Minerals in the Smectite-to-Illite Conversion Series by Scanning Electron Microscopy

Published online by Cambridge University Press:  02 April 2024

W. D. Keller ,
R. C. Reynolds  and
Atsuyuki Inoue
W. D. Keller
Affiliation:
Department of Geology, University of Missouri-Columbia, Columbia, Missouri 65211
R. C. Reynolds
Affiliation:
Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755
Atsuyuki Inoue
Affiliation:
Geological Institute, College of Arts and Sciences, Chiba University, Chiba 260, Japan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The morphology of illite/smectite (I/S) from deeply buried bentonites and hydrothermally altered Tertiary volcanic rocks from Japan changes in parallel with the proportion of expandable layers in the I/S. As viewed by scanning electron microscopy, the morphologies range from the typical “cornflake,” “maple leaf,” or “honeycomb” habit of smectite to the typical platy or scalloped (with curled points) habit of illite. Although the changes are more subtle near either end member, at a composition of 60-70% illite layers, the morphology changes from sponge-like or cellular to platy or ribbon-like. The change of morphology at this composition correlates with a change in layer stacking from turbostratic to rotational ordering of the 1Md type. Turbostratic stacking can be thought of as randomly distributed translations of successive layers by any magnitude and in any direction. The rotationally ordered structure, which allows nearly precise juxtaposition of quasihexagonal oxygen surfaces from adjacent layers, probably permits more crystalline regularity in the a-b plane, which promotes a more plate-like or sheet-like habit.

Keywords

Burial diagenesisHydrothermal alterationIllite/smectiteMorphologyScanning electron microscopySmectite-to-illite conversion
Type
Research Article
Information
Clays and Clay Minerals , Volume 34 , Issue 2 , April 1986 , pp. 187 - 197
Copyright
Copyright © 1986, The Clay Minerals Society

References

Altaner, S. A., 1985 Potassium metasomatism and diffusion in Cretaceous K-bentonites from the disturbed belt, northwestern Montana and in the middle Devonian Tioga K-bentonite, eastern U.S.A. Ph.D. dissertation Urbana, Illinois University of Illinois.Google Scholar
Hower, J. and Mowatt, T.C., 1966 The mineralogy of illites and mixed-layer illite/montmorillonites Amer. Mineral. 51 825–854.Google Scholar
Inoue, A., 1983 Potassium fixation by clay minerals during hydrothermal treatment Clays & Clay Minerals 31 81–91.CrossRefGoogle Scholar
Inoue, A., Minato, H. and Utada, M., 1978 Mineralogical properties and occurrence of illite/montmorillonite mixed layer minerals from Miocene volcanic glass in Waga-Omono district Clay Sci. 5 123–136.Google Scholar
Inoue, A. and Utada, M., 1983 Further investigations of a conversion series of dioctahedral mica/smectites in the Shinzan hydothermal alteration area, northeast Japan Clays & Clay Minerals 31 401–412.CrossRefGoogle Scholar
Kerr, P. F., 1951 Preliminary reports, reference clay minerals American Petroleum Institute Research Project 49 .Google Scholar
Mering, J. and Gieseking, J. E., 1975 Smectites Soil Components, Vol. 2, Inorganic Compounds New York Springer-Verlag 97–119.CrossRefGoogle 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
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., 1965 An X-ray study of an ethylene glycol-montmorillonite complex Amer. Mineral. 50 990–1001.Google 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.Google Scholar
Środoń, J., 1980 Precise identification of illite/smectite interstratifications by X-ray powder diffraction Clays & Clay Minerals 28 401–411.CrossRefGoogle Scholar