Hostname: page-component-848d4c4894-wg55d Total loading time: 0 Render date: 2024-04-30T20:57:29.476Z Has data issue: false hasContentIssue false

Compositional Variation in Component Layers in Natural Illite/Smectite

Published online by Cambridge University Press:  02 April 2024

B. Velde
Affiliation:
Laboratoire de Géologie, ER 224 C.N.R.S., Ecole Normale Supérieure 46 rue d'Ulm, 75230 Paris, France
A. M. Brusewitz
Affiliation:
Sveriges Geologiska Undersokning, Uppsala 75128, Sweden

Abstract

Published chemical data for suites of mixed-layer minerals from diagenetic sedimentary rocks, hydrothermally altered tufts, and a metasomatic bentonite bed indicate that the layer charge and composition of the different components of illite/smectite (I/S) differ from one geological environment to another. It appears that the composition of the elemental smectite and illite layers in the I/S is more or less constant for samples within each geologic setting. In the examples considered, the smectite layers are predominantly montmorillonitic in character (i.e., the charge is in the octahedral site), whereas the illite layers show different types of charge sites, depending upon the suite studied. Illite layers appear to have about the same charge in all three suites studied, slightly more than 0.7 per O10(OH)2 unit, whereas the smectite layers in the different suites range in charge from about 0.3 to 0.7 per O10(OH)2 unit. Cation-exchange capacities reflect these differences in charge, although not ideally. The differences in the composition of the component layers in each geologic suite of mixed-layer clays are probably due either to differences in the bulk chemistry of the rocks in the different suites or to differences in intensive variables, such as temperature and pressure, of the regime under which they have formed.

Type
Research Article
Copyright
Copyright © 1986, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aagaard, P. and Helgeson, H. C., 1983 Activity relations among silicates and aqueous solutions: II. Chemical and thermodynamic consequences of ideal mixing of atoms on homological sites in montmorillonites, illites, and mixed-layer clays Clays & Clay Minerals 31 207217.CrossRefGoogle Scholar
Aoyagi, A. J. and Kazama, T., 1980 Transformational changes of clay minerals. Zeolites and silica minerals during diagenesis Sedimentology 27 179188.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 5570.Google Scholar
Bystrom, A. M. (1956) Mineralogy of the Ordovician ben-tonite beds at Kinnekulle, Sweden: Sver. Geol. Unders. Ser. C., no. 540, Arsboh 48, 62 pp.Google Scholar
Brusewitz, A. M., 1986 Chemical and physical properties of Paleozoic potassium bentonites from Kinnekulle, Sweden Clays & Clay Minerals 34 442454.CrossRefGoogle Scholar
Chen, P.-Y., Brindley, G. W. and Swineford, A., 1976 Beidellitic clay from Chang-Yuan, Taiwan; geology and mineralogy Clays and Clay Minerals, Proc. 11th Natl. Conf., Ottawa, Ontario, 1962 New York Pergamon Press 221234.Google Scholar
Grim, R. E. and Kulbicki, G., 1961 Montmorillonite high-temperature reaction and classification Amer. Mineral. 46 13291369.Google Scholar
Hoffman, J. and Hower, J., 1979 Clay mineral assemblages as low-grade metamorphic geothermometers; application to the thrust fault disturbed belt of Montana, USA Aspects of Diagenesis 26 5588.CrossRefGoogle Scholar
Hower, J., Eslinger, E. V., Hower, M. E. and Perry, E. A., 1976 Mechanisms of burial metamorphism of argillaceous sediments: 1. Mineralogical and chemical evidence Bull. Geol. Soc. Amer. 87 725737.2.0.CO;2>CrossRefGoogle Scholar
Hower, J. and Mowatt, T.C., 1966 The mineralogy of illites and mixed-layer illite/rnontmorillonites Amer. Mineral. 51 825854.Google Scholar
Inoue, A., Minato, H. and Utada, M., 1978 Mineralogical properties and occurrence of illite/montmorillonite mixed-layer minerals formed from Miocene volcanic glass in Waga-Omono District Clay Sci. 5 123136.Google Scholar
Inoue, A. and Utada, M., 1983 Further investigations of a conversion series of dioctahedral mica/smectites in the Shinzan hydrothermal alteration area northeast Japan Clays & Clay Minerals 31 401412.CrossRefGoogle Scholar
Perry, E. A. and Hower, J., 1970 Burial diagenesis in Gulf Coast pelitic sediments Clays & Clay Minerals 18 165178.CrossRefGoogle Scholar
Pevear, D. R., Williams, V. E. and Mustoe, G. E., 1980 Kaolinite, smectite, and K-rectorite in bentonites; relation to coal rank at Tulameen Clays & Clay Minerals 28 241250.CrossRefGoogle Scholar
Reynolds, R. C., 1980 Interstratified clay minerals Crystal Structure of Clay Minerals and Their X-ray Identification 5 249303.CrossRefGoogle Scholar
Schmidt, B., 1973 Interstitial water composition and geochemistry of deep Gulf Coast shales and sandstones Bull. Amer. Assoc. Petrol. Geol. 57 321337.Google Scholar
Steiner, A., 1968 Hydrothermal rock alteration at Wairakei, New Zealand Clays & Clay Minerals 16 193213.CrossRefGoogle Scholar
Stul, M. S. and Mortier, W. J., 1974 The heterogeneity of the charge density in montmorillonites Clays & Clay Minerals 22 391396.CrossRefGoogle Scholar
Talibudeen, O. and Goulding, K. W. T., 1983 Charge heterogeneity in smectites Clays & Clay Minerals 31 3742.CrossRefGoogle Scholar
Velde, B., 1985 Clay Minerals: A Physico-Chemical Explanation of Their Occurrence Amsterdam Elsevier.Google Scholar
Velde, B. and Brusewitz, A. M., 1982 Metasomatic and non-metasomatic low-grade metamorphism of Ordovician meta-bentonites in Sweden Geochim. Cosmochim. Acta 46 447452.CrossRefGoogle Scholar
Weaver, C. E. and Beck, K. C. (1971) Clay-water diagenesis during burial; how mud becomes gneiss: Geol. Soc. Amer. Spec. Pap. 134, 155 pp.Google Scholar