Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-13T07:03:43.916Z Has data issue: false hasContentIssue false
  • English
  • Français

Crystallographic textures

Published online by Cambridge University Press:  05 July 2018

G. E. Lloyd ,
N.-H. Schmidt ,
D. Mainprice  and
D. J. Prior
G. E. Lloyd
Affiliation:
Department of Earth Sciences, The University, Leeds LS2 9JT, England; and Centre Geologique et Geophysique, U.S.T.L., 34060 Montpellier Cedex, France
N.-H. Schmidt
Affiliation:
Danish National Research Centre Riso, Postbox 49, DK-4000, Roskilde, Denmark
D. Mainprice
Affiliation:
Laboratoire de Tectonophysique, U.S.T.L., 34060 Montpellier Cedex, France
D. J. Prior
Affiliation:
Department of Geology, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, England
Get access Rights & Permissions [Opens in a new window]

Abstract

To material scientists the term texture means the crystallographic orientation of grains in a polycrystal. In contrast, geologists use the term more generally to refer to the spatial arrangement or association of mineral grains in a rock. In this contribution we are concerned with the materials science definition. There are several established techniques available for the determination of crystallographic textures in rocks. It has also been realised that the scanning electron microscope (SEM) is applicable to the study of crystallographic textures via the electron channelling (EC) effect. This provides an image of mineral/rock microstructure (via orientation contrast), as well as a means of accurately indexing their crystal orientations (via electron channelling patterns, ECP). Both types of EC image result from the relationship between incident electron beam and crystal structure, and the subsequent modulation of the backscattered electron (BSE) emission signal according to Bragg's Law. It is a simple matter to switch between the two imaging modes. A related effect, electron backscattering, provides only the diffraction patterns, but has superior spatial resolution and pattern angles.

Due to crystal symmetry restrictions, there is only a limited range of ECP configurations possible for any mineral. Individual patterns can therefore be identified by comparison with the complete ‘ECP-map’. The location of an individual pattern within the map area is determined by spherical angles, the exact definition of which depends on the type of fabric diagram (e.g. inverse pole figure, pole figure or orientation distribution function). Originally, these angles were measured manually. A computer program (CHANNEL) has been developed which uses a digitisation approach to pattern recognition, derives the required fabric diagrams and also constructs ECP-maps from standard crystal data (i.e. unit cell parameters etc.).

The combination of SEM/EC and CHANNEL dramatically facilitates the study of crystal textures in minerals and rocks, making statistical crystallographic analysis from individual orientations a practicality. The following example applications are considered: (1) crystal structure representation of the Al2SiO5 polymorph system; (2) local crystal texture relationships (epitaxial nucleation) between andalusite and sillimanite grains; (3) bulk rock crystal textures of quartzites; and (4) physical properties (e.g. elastic constants and seismic velocities) determined from bulk rock texture.

Keywords

scanning electron microscopyelectron channellingAl2SiO5 polymorphsquartzcrystal fabricsseismic properties
Type
Research Article
Information
Mineralogical Magazine , Volume 55 , Issue 380 , September 1991 , pp. 331 - 345
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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

Bunge, H. J. (1982) Texture Analysis in Materials Science. Butterworths, London, 593.Google Scholar
Bunge, H. J. (1985) Physical properties of polycrystals, and preferred orientation in deformed metals and rocks. In Preferred orientation in deformed metals and rocks (H.-R. Wenk, ed.). Academic Press, New York, N.Y., 507-25.CrossRefGoogle Scholar
Bunge, H. J. and Esling, C. (1986) Quantitative Texture Analysis. DGM Informationsgesellschaft Verlag.Google Scholar
Burnham, C. W. (1963a) Refinement of the crystal structure of sillimanite. Zeits. Kristall., 118, 127-48.CrossRefGoogle Scholar
Burnham, C. W. (1963a) Refinement of the crystal structure of kyanite. Ibid., 118, 337-60.Google Scholar
Burnham, C. W. and Buerger, M. J. (1961) Refinement of the crystal structure of andalusite. Ibid., 115, 269-90.Google Scholar
Chritianssen, F. G. (1986) Deformation of chromite: SEM investigations. Tectonophys. , 121, 175-96.Google Scholar
Day, H. W. and Kumin, H. G. (1980) Thermodynamic analysis of the aluminium silicate triple point. Amer. J. Sci., 280, 265-87.Google Scholar
Dingley, D. J. (1988) On-line microtexture determi-nation using backscatter Kikuchi diffraction in a scanning electron microscope. In Proc. Eighth Int. Conf. on Textures of Materials (J. S. Kallend and G. Gottstein, eds.), The Metallurgical Society, 189-94.Google Scholar
Dingley, D. J. and Baba-Kishi, K. (1990) Electron backscatter diffraction in the scanning electron microscope. Microscopy and Analysis, Issue 17 (May), 35-\3.Google Scholar
Donnay, J. D. H. and Le Page, Y. (1978) The vicissitudes of the low-quartz setting or the pitfalls of enantiomorphism. Ada Cryst., A34, 584-94.Google Scholar
Doukhan, J.-C, Doukhan, N., Koch, P. S. and Christie, J. M. (1985) Transmission electron mi-croscopy investigation of lattice defects in Al2SiO5 polymorphs and plasticity induced polymorphic transformations. Bull. Mineral., 108, 89–96.Google Scholar
Faivre, G. and Le Goff, J.-J. (1979) Breakdown of Friedel's Law in the Kikuchi patterns of tellurium. Ada Crystal., A35, 604-10.Google Scholar
Ferguson, C. C., Lloyd, G. E. and Knipe, R. J. (1987) Fracture mechanics and deformation processes in natural quartz: a combined Vickers indentation, SEM and TEM study. Can J. Earth Set, 24, 544-55.CrossRefGoogle Scholar
Frondel, C. (1962) Silica Minerals, Dana's System of Mineralogy, Vol. 3. Wiley, New York.Google Scholar
Hobbs, B. E. and Heard, H. C. (1986) Mineral and Rock Deformation: Laboratory Studies-The Paterson Volume. Amer. Geophys. Un., Geophys. Monogr., 36, 324.Google Scholar
Humphreys, F.J. (1988) Experimental techniques for microtexture determination. In Proc. Eighth Int. Conf. on Textures of Materials (J. S. Kallend and G. Gottstein, eds.), The Metallurgical Society, 171-82.Google Scholar
Kallend, J. S. and Gottstein, G. (1988) ICOTOM: Eighth International Conference on Textures of Materials, The Metallurgical Society, Warrendale, Pennsylvania, U.S.A., 1127.Google Scholar
Kerrick, D. M. (1990) The Al2SiO5 polymorphs. Reviews in Mineralogy, 22, Mineralogical Society of America, Washington D.C.Google Scholar
Lloyd, G. E. (1987) Atomic number and crystallo-graphic contrast images with the SEM: a review of backscattered electron techniques. Mineral. Mag., 51, 3–19.CrossRefGoogle Scholar
Lloyd, G. E. and Ferguson, C. C. (1986) A spherical electron channelling pattern map for use in quartz petrofabric analysis. J. Struct. Geol., 8, 517-26.CrossRefGoogle Scholar
Lloyd, G. E. and Knipe, R. J. (1990) Deformation mechanisms active during faulting of quartz upper crustal rocks. Ibid., in press.Google Scholar
Lloyd, G. E. , Ferguson, C. C. and Law, R. D. (1987a) Discriminatory petrofabric analysis of quartz rocks using SEM electron channelling. Tectonophys., 135, 243–9.CrossRefGoogle Scholar
Lloyd, G. E. , Law, R. D. and Schmid, S. M. (1987b) A spherical electron channelling pattern map for use in quartz petrofabric analysis: correction and verification. J. Struct. Geol., 9, 251–3.CrossRefGoogle Scholar
Mainprice, D. (1990) A FORTRAN program to calculate seismic anisotropy from lattice preferred orientation of minerals. Computers & Geosciencies, 16, 385-93.CrossRefGoogle Scholar
Olesen, N. O. and Schmidt, N. H. (1990) The SEM/ECP technique applied on twinned quartz crystals. In Deformation Mechanisms, Rheology and Tectonics (R. J. Knipe and E. H. Rutter, eds.). Geological Society of London Special Publication, 369-74.CrossRefGoogle Scholar
Pearson, W. B. (1962) Structure Reports for 1962, 707-11.Google Scholar
Putnis, A. and McConnell, J. D. C. (1980) Principles of Mineral Behaviour. Elsevier, New York.Google Scholar
Rao, C. N. R. and Rao, K. J. (1978) Phase Transformations in Solids. McGraw Hill, New York.Google Scholar
Sander, B. (1970) An Introduction to the Study of Fabrics of Geological Bodies. English translation, Pergamon Press, Oxford, 641.Google Scholar
Schmidt, N. H. and Olesen, N. O. (1989) Computer-aided determination of crystal-lattice orientation from electron-channeling patterns in the SEM. Canad. Mineral., 27, 15–22.Google Scholar
Smythe, J. R. and Bish, D. L. (1988) Crystal Structures and Cation Sites of the Rock-Forming Minerals. Allen & Unwin.Google Scholar
Vaughan, M. T. and Weidner, D. J. (1978) The relationship of elasticity and crystal structure in andalusite and sillimanite. Phys. Chem. Minerals., 3, 133-44.CrossRefGoogle Scholar
Venables, J. A. and Harland, C. J. (1973) Electron backscattering patterns. Phil. Mag., 27, 1193–200.CrossRefGoogle Scholar
Wenk, H.-R. (1985) Preferred Orientation in Deformed Metals and Rocks: An Introduction to Modern Texture Analysis. Academic Press.Google Scholar
Wenk, H.-R. , Bunge, H. J., Kallend, J. S., Lucke, K., Matthies, S., Pospiech, J. and Van Houtte, P. (1988a) Orientation distributions: representation and determi-nation. In Proc. Eighth Int. Conf. on Textures of Materials (J. S. Kallend and G. Gottstein, eds.), The Metallurgical Society, 17–30.Google Scholar
Wenk, H.-R. , Johnson, G. C. and Matties, S. (19886) Direct determination of physical properties from continuous orientation distributions. J. Appl. Phys., 63, 2876–9.Google Scholar
Winters, J. K. and Ghose, S. (1979) Thermal expansion and high-temperature crystal chemistry of A-SiOs polymorphs. Amer. Mineral., 64, 573-86.Google Scholar