Skip to main content Accessibility help

Beyond the Kubler Index

  • D. D. Eberl (a1) and B. Velde (a2)


The value of peak width at half-height for the illite 001 XRD reflection is known as the Kubler index or the illite ‘crystallinity’ index. This measurement, which has been related to the degree of metamorphism of very low-grade, pelitic rocks, is a function of at least two crystal-chemical factors: (1) illite X-ray scattering domain size; and (2) illite structural distortions (especially swelling). Reynolds' NEWMOD computer program is used to construct a grid with which these two contributions to illite peak width can be determined independently from measurements of the 001 peak width at half-height and the Środoń intensity ratio. This method yields more information about changes undergone by illite during metamorphism than application of the Kubler index method alone.



Hide All
Ahn, J.H., Peacor, D.R. & Coombs, D.S. (1988) Formation mechanisms of illite, chlorite and mixed-layer illite- chlorite in Triassic volcanogenic sediments from the Southland Syncline, New Zealand. Contrib. Min. Pet., 99, 82–89.
Baronnet, A. (1982) Ostwald ripening in solution. The case of calcite and mica. Estudios Geoldgicos, 38, 185–198.
Baronnet, A. (1984) Growth kinetics of the silicates. Miner. 62, 187232.
Blenkinsop, T.G. (1988) Definition of low-grade metamorphic zones using illite crystallinity. J. Met. Geol., 6, 623–636.
Drever, J.I. (1973) The preparation of oriented clay mineral specimens for X-ray diffraction analysis by a filter-membrane peel technique. Am. Miner., 58, 553–554.
Eberl, D.D. & Srodon, J. (1988) Ostwald ripening and interparticle diffraction effects for illite crystals. Am. Miner., 73, 1335–1345.
Eberl, D.D., Srodon, J., Lee, M., Nadeau, P.H. & Northrop, H.R. (1987) Sericite from the Silverton caldera, Colorado: Correlation among structure, composition, origin, and particle thickness. Am. Miner., 72, 914–934.
Frey, M. (1987) Very low-grade metamorphism of clastic sedimentary rocks. Pp. 17 in: Low Temperature Metamorphism(Frey, M., editor). Blackie, London.
Guilhaumou, N., Jouaffre, D., Velde, B. & Beny, C. (1988) Raman microprobe analysis on gaseous inclusions from the diagenetically altered Terres Noires. Bull Min. Ill, 577586.
Hunziker, J.C., Frey, M., Clauer, N., Dallmeyer, R.D., Friedrichsen, H., Flehmig, W., Hochstrasser, K., Roggwiler, P. & Schwander, H. (1986) The evolution of illite to muscovite: Mineralogical and isotopic data from the Glarus Alps, Switzerland. Contrih. Min. Pet., 92, 157–180.
Jennings, S. & Thompson, G.R. (1986) Diagenesis of Plio-Pleistocene sediments of the Colorado River delta, southern California. J. Sed. Pet., 56, 89–98.
Kisch, H.J. (1983) Mineralogy and petrology of burial diagenesis (burial metamorphism) and incipient metamorphism in clastic rocks. Pp. 513541 in: Diagenesis in Sediments and Sedimentary Rocks, 2(Larsen, G. & Chilingar, G.V., editors). Elsevier, Amsterdam.
Kisch, H.J. (1987) Correlation between indicators of very low-grade metamorphism. Pp. 227300 in: Low Temperature Metamorphism(Frey, M., editor). Blackie, London.
Kisch, H.J., Frey, M. (1987) Appendix: Effect of sample preparation on the measured 10 A peak width of illite (illite "crystallinity"). Pp. 301304 in: Low Temperature Metamorphism(M. Frey, editor). Blackie, London.
KluG, H.P. & Alexander, L.E. (1974) X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials. Wiley, New York.
Kralik, M., Krumm, H. & Schramm, J.M. (1987) Low grade and very low grade metamorphism in the northern calcareous Alps and in the greywacke zone: Ulite-crystallinity data and isotopic ages. Pp. 164178 in: Geodynamics of the Eastern Alps (Fliigel, H.W. & Faupl, P., editors). Deuticke, Vienna.
Krumm, H. (1984) Anchimetamorphose im Anis und Ladin (Trias) der Nördlichen Kalkalpen zwischen Arlberg und Kaisergebirge-ihre Verbeitung und deren baugeschichtliche Bedeutung. Geol. Rdsch., 73, 223–257.
Kubler, B. (1964) Les argiles, indicateurs de metamorphisme. Rev. Inst. Frang. Petrol, 19, 1093–1112.
Kubler, B. (1967) La cristallinite de Tillite et les zones tout a fait superieures du metamorphisme. Pp. 105121 in: Etages Tectoniques (Collogue de Neuchatel). Inst. Geol. Neuchatel Univ.
Kubler, B., (1968) Evaluation quantitative du metamorphisme par la cristallinite de Tillite. Buii. Centre Rech. Pau-SNPA, 2, 385–397.
McHardy, W.J., Wilson, M.J. & Tait, J.M. (1982) Electron microscope and X-ray diffraction studies of filamentous illitic clay from sandstones of the Magnus Field. Clay Miner., 17, 23–39.
Nadeau, P.H. Wilson, M.J. McHardy, W.J. & Tait, J.M. (1984a) Interparticle diffraction: A new concept for interstratified clays. Clay Miner., 19, 757–769.
Nadeau, P.H. Wilson, M.J. McHardy, W.J. & Tait, J.M. (1984b) Interstratified clays as fundamental particles. Science, 225, 923–925.
Reynolds, R.C. (1980) Interstratified clay minerals. Pp. 249303 in: Crystal Structures of Clay Minerals and their X-ray Identification (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.
Srodon, J. (1984) X-ray diffraction of illitic materials. Clays Clay Miner., 32, 337–349.
Srodon, J. & Eberl, D.D. (1984) Illite. Pp. 495544 in; Reviews in Mineralogy, 13, (Bailey, S.W., editor), Mineralogical Society of America, Washington, DC.
Sunagawa, I., Koshino, Y., Asakura, M. & Yamamoto, T. (1975) Growth mechanisms of some clay minerals. Fortschr. Miner., 52, 217–224.
Thompson, G.R. & Hower, J. (1975) The mineralogy of glauconite. Clays Clay Miner., 23, 289–300.
Velde, B., Suzuki, T. & Nicot, E. (1986) Pressure-temperature-composition of illite/smectite mixed-layer minerals: Niger Delta mudstones and other examples. Clays Clay Miner., 34, 435–441.

Beyond the Kubler Index

  • D. D. Eberl (a1) and B. Velde (a2)


Altmetric attention score

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