Skip to main content Accessibility help

Mixed-layer kaolinite-illite-vermiculite in North Sea shales

  • B. A. Sakharov (a1), H. Lindgreen (a2), A. L. Salyn (a1) and V. A. Drits (a1)


The finest fractions of Upper Jurassic shales from the North Sea and onshore Denmark contain 80–90% of an illite-smectite-vermiculite (I-S-V) mixed-layer mineral and, in addition a phase which has X-ray diffraction (XRD) peaks at 7.20–7.26 Å and 3.56–3.58 Å in air- dried and glycolated specimens. This phase may be a fine kaolinite with a small thickness of coherent scattering domains (CSDs) or alternatively a mixed-layer mineral which has kaolinite as the dominant component. For one sample from the Norwegian well 9/4-3, these alternatives are investigated using the multi-specimen method by which agreement between the experimental pattern and the pattern calculated for one and the same structure is obtained for each of several specimens saturated with different cations and with/without glycolation. It is demonstrated that the modelled XRD patterns for a kaolinite-illite-vermiculite (K-I-V) structure having 0.94 kaolinite, 0.03 illite and 0.03 vermiculite layers and random alternation fit the experimental patterns.



Hide All
Bish, D.L. (1993) Rietveld refinement of the kaolinite structure at 1.5 K. Clays Clay Miner. 41, 738744.
Bogolyobova, L.I., Drits, V.A., Sakharov, B.A., Sokolova, A.L. & Chernyakhovskiy, A.G. (1974) Mixed-layer kaolinite-montmorillonite from a weathering crust in Transcaucasia. Litol. Polezn. Mop. 9, 127133 (in Russian).
Brindley, G.W., Suzuki, T. & Thiry, M. (1983) Interstratified kaolinite/smectites from the Paris Basin; correlations of layer proportions, chemical compositions and other data. Bull. Mineral. 106, 403410.
Cradwick, P.D. & Wilson, M.J. (1972) Calculated X-ray diffraction profiles for interstratified kaolinite-montmorillonite. Clay Miner. 9, 395405.
Djakonov, Yu.S. & Kulikov, G.V. (1975) Structural and genetic characteristics of kaolinite-montmorillonite from weathered effusives (North Kazakhstan). Litol. Polezn. Mop 3, 3243 (in Russian).
Drits, V.A. & Sakharov, B.A. (1976) X-ray Analysis of Mixed-layer Minerals. Nauka, Moscow (in Russian).
Drits, V.A. & Tchoubar, C. (1990) X-ray Diffraction by Disordered Lamellar Structures. Springer Verlag, Berlin.
Drits, V.A., Salyn, A.L. & Sucha, V. (1996) Structural transformations of interstratified illite-smectites from Dolná Ves hydrothermal deposits: dynamics and mechanisms. Clays Clay Miner. 44, 181190.
Drits, V.A., Środoń, J. & Eberl, D.D. (1997b) XRD measurements of mean illite crystallite thickness: reappraisal of the Kubler index and the Scherrer equation. Clays Clay Miner. 45, 461475.
Drits, V.A., Sakharov, B.A., Lindgreen, H. & Salyn, A. (1997a) Sequential structure transformation of illitesmectite- vermiculite during diagenesis in Upper Jurassic shales from the North Sea and onshore Denmark. Clay Miner. 32, 173193.
Drits, V.A., Weber, F., Salyn, A.L. & Tsipursky, S. (1993) X-ray identification of one-layer illite varieties: application to the study of illites around uranium deposits. Clays Clay Miner. 41, 389398.
Hansen, P.L. & Lindgreen, H. (1989) Mixed-layer illite/ smectite diagenesis in Upper Jurassic claystones from the North Sea and onshore Denmark. Clay Miner. 24, 197213.
Hughes, R.E., DeMaris, P.J., White, W.A. & Cowin, D.K. (1987) Origin of clay minerals in Pennsylvanian strata of the Illinois Basin. Proc. Int. Clay Conf., Denver, 97-104.
Lindgreen, H.L. & Hansen, P.L. (1991) Ordering of illitesmectite in the Upper Jurassic claystones from the North Sea. Clay Miner. 26, 105125.
Lindgreen, H., Jacobsen, H. & Jakobsen, H.J. (1991) Diagenetic structural transformations in North Sea Jurassic illite/smectite. Clays Clay Miner. 39, 5469.
Lindgreen, H., Garnajs, J., Besenbacher, F., Lajgsgaard, E. & Stensgaard, I. (1992) Illite-smectite from the North Sea investigated by scanning tunnelling microscopy. Clay Miner. 27, 331342.
Moore, D.M. & Reynolds, R.C. (1989) X-ray Diffraction and the Identification and Analysis of Clay Minerals, pp. 321-322. Oxford University Press, Oxford.
Reynolds, R.C. (1980) Interstratified clay minerals. Pp. 249-305 in: Crystal Structures of Clay Minerals and their X-ray Identification. (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.
Reynolds, R.C. (1986) The Lorenz-polarization factor and preferred orientation in oriented clay aggregates. Clays Clay Miner. 34, 359367.
Sakharov, B.A. & Drits, V.A. (1973) Mixed-layer kaolinite-montmorillonite. Clays Clay Miner. 21, 1517.
Sakharov, B.A., Gilan, Z.I. & Drits, V.A. (1981) Structure characteristics of three component mixed-layer minerals. Litol. Polezn. Iskop. 3, 136142 (in Russian).
Schultz, L.G., Shepard, A.O., Blackmon, P.D. & Starkey, H.C. (1971) Mixed-layer kaolinite-montmorillonite from the Yucatan peninsula, Mexico. Clays Clay Miner. 19, 137150.
Shimoyama, A., Johns, W.D. & Sudo, T. (1966) Montmorillonite-kaolin clay in acid clay deposits from Japan. Proc. Int. Clay Conf, Jerusalem, 1, 225231.
Sudo, T. & Hayashi, H. (1956) Types of mixed-layer minerals from Japan. Clays Clay Miner. 4, 389412.
Wiewiora, A. (1971) A mixed-layer kaolinite-smectite from Lower Silesia, Poland. Clays Clay Miner. 19, 5469. 415-416.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed