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Finite strain has no influence on the illite crystallinity of tectonized Eocene limestone breccias of the Morcles nappe, Swiss Alps

Published online by Cambridge University Press:  09 July 2018

M. Burkhard  and
N. Badertscher
M. Burkhard*
Affiliation:
Institut de Géologie, Université de Neuchâtel, rue E. Argand 11, CH 2007 Neuchâtel, Switzerland
N. Badertscher
Affiliation:
Institut de Géologie, Université de Neuchâtel, rue E. Argand 11, CH 2007 Neuchâtel, Switzerland
*
*E-mail: martin.burkhard@unine.ch
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Abstract

The relationship between illite crystallinity (IC) and finite strain as well as lattice strain and crystallite size of illite is examined in a series of 27 deformed breccia samples from the inverted limb of the Morcles nappe. The IC is determined independently for limestone components and a red/green clay-silt matrix. The finite strain varies widely (D= 0.8–2.5). The IC values vary from diagenetic to epizonal, but no correlation with finite strain could be established. The spread of IC values is explained by heterogeneities within the protolith which have not been homogenized/ obliterated by the anchizonal to epizonal metamorphic overprint. While limestone pebbles display IC values in agreement with the regional metamorphic conditions, the clay-silt matrix has anomalously high IC values, even after deconvolution of the 10 Å peak to correct for the presence of paragonite/muscovite. No correlation could be established between finite strain, lattice strain and/or crystallite size of illite.

Keywords

finite strainillite crystallinitylimestone brecciasMorcles nappeSwitzerland
Type
Research Article
Information
Clay Minerals , Volume 36 , Issue 2 , June 2001 , pp. 171 - 180
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

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References

Arkai, P., Merriman, R.J., Roberts, B., Peacor, D.R. & Toth, M. (1996) Crystallinity, crystallite size and lattice strain of illite-muscovite and chlorite; comparison of XRD and TEM data for diagenetic to epizonal pelites. Eur. J. Mineral. 8, 1119–1137.CrossRefGoogle Scholar
Arkai, P., Balogh, K. & Frey, M. (1997) The effects of tectonic strain on crystallinity, apparent mean crystallite size and lattice strain of phyllosilicates in low-temperature metamorphic rocks. A case study from the Glarus overthrust, Switzerland. Schweiz. Mineral. Petrogr. Mitt. 77, 27–40.Google Scholar
Burkhard, M. (1988) L’Helvétique de la bordure occidentale du massif de l’Aar (évolution tectonique et métamorphique). Eclog. Geol. Helv. 81, 63–114.Google Scholar
Burkhard, M. & Goy-Eggenberger, D. (2001) Near vertical iso-illite-crystallinity surfaces cross-cut the recumbent fold structure of the Morcles nappe, Swiss Alps. Clay Miner. 36, 157–168.CrossRefGoogle Scholar
Burkhard, M. & Sommaruga, A. (1998) Evolution of the western Swiss Molasse basin: structural relations with the Alps and the Jura belt. Pp. 279–298 in. Cenozoic Foreland Basins of Western Europe (Mascle, A., Puigdefàbregas, C., Luterbacher, H.P. & Fernàndez, M., editor). Spec. Publ. 134. Geological Society, London.Google Scholar
De Keijser, H., Langford, J.I., Mittemeijer, E.J. & Vogels, A.B.P. (1982) Use of the Voigt function in a singleline method for the analysis of X-ray diffraction line broadening. J. Appl. Crystallogr. 15, 308–314.CrossRefGoogle Scholar
De Loys, F. (1928) Monographie géologique de la Dent du Midi. Matériaux Carte géol. Suisse, 58, 80.Google Scholar
Elliott, D. (1970) Determination of finite strain and initial shape from deformed elliptical objects. Geol. Soc. Am. Bull. 81, 2221–2236.CrossRefGoogle Scholar
Flehmig, W. ( 1973 ) Kristallinitätund Infrarotspektroskopie natü rlicher dioktaedrischer Illite. Neues Jahrb. Mineral. Mon. 351–361.CrossRefGoogle Scholar
Flehmig, W. & Langheinrich, G. (1974) Beziehung zwischentekt onische r Deformation und Illit- Kristallinität. Neues Jahrb. Geol. Paläontol. Abh. 146, 325–326.Google Scholar
Frey, M. (1987) Low Temperature Metamorphism. Blackie, Glasgow.Google Scholar
Frey, M. & Robinson, D. (1999) Low Grade Metamorphism. Blackwell Science, Oxford.Google Scholar
Gagnebin, E. (1934) Notice explicative Feuille 483 St- Maurice (Feuille 8 de l’Atlas). P. 6 in: Geologischer Atlas der Schweiz, 1:25 000. Commision Géologique Suisse.Google Scholar
Gendzwill, D.J. & Stauffer, M.R. (1981) Analysis of triaxial ellipsoids; their shapes, plane sections, and plane projections. J. Int. Assoc. Mathematical Geol. 13, 135–152.CrossRefGoogle Scholar
Goy-Eggenberger, D. (1998) Faible métamorphisme de la nappe de Morcles: minéralogie et géochimie. PhD thesis, Neuchâtel Univ. Switzerland.Google Scholar
Kisch, H.J. (1990) Calibration of the anchizone:a critical comparison of illite ‘crystallinity ’ scales used for definition. J. Metam. Geol. 8, 31–46.CrossRefGoogle Scholar
Kübler, B. (1964) Les argiles, indicateurs de métamorphisme. Rev. Inst. Franç. Pétrole 19, 1093–1112.Google Scholar
Kübler, B. (1967) La cristallinité de l’illite et les zones tout à fait supérieures du métamorphisme. Pp. 105–121 in: Etages Tectoniques, Colloque de Neuchâtel 1966 (Geology Institute Neuchâtel). La Baconnière, Neuchâtel, Switzerland.Google Scholar
Mayoraz, R. (1995) Les brèches tertiaires du flanc inverse de la nappe de Morcles et des unités parautochthones (Bas Valais, Suisse). Eclog. Geol. Helv. 88, 321–345.Google Scholar
McCaig, A.M. & Knipe, R.J. (1990) Mass-transport mechanisms in deforming rocks; recognition using microstructural and microchemical criteria. Geology, 18, 824–827.2.3.CO;2>CrossRefGoogle Scholar
Milton, N.J. (1980) Determination of the strain ellipsoid from measurements on any three sections. Tectonophysics, 64, T19 T27.CrossRefGoogle Scholar
NCSA (1997) Image 3.0., ftp://ftp.ncsa.uiuc.edu/Mac/ Image/, Univ. Illinois, USA.Google Scholar
Nyk, R. (1985) Illite crystallinity in Devonian slates of the Meggen mine (Rhenisch Massif). Neues Jahrb. Mineral. Mon. 268–276.Google Scholar
Ramsay, J.G. & Huber, I.M. (1983) The Techniques of Modern Structural Geology Vol. 1. Academic Press, London.Google Scholar
Ramsay, J.G. & Huber, I.M. (1987) The Techniques of Modern Structural Geology Vol. 2. Academic Press, London.Google Scholar
Roberts, B., Merriman, R.J. & Pratt, W. (1991) The influence of strain, lithology and stratigraphical depth on white mica (illite) crystallinity in mudrocks from the vicinity of the Corris slate belt, Wales; implications for the timing of metamorphism in the Welsh Basin. Geol. Mag. 128, 633–645.CrossRefGoogle Scholar
Shimamoto, T. & Ikeda, Y. (1976) A simple algebraic method for strain estimation from deformed ellipsoidal objects-I. Basic theory. Tectonophysics, 36, 315–337.CrossRefGoogle Scholar
Siddans, A. (1971) The origin of slaty cleavage. PhD thesis, Univ. London.Google Scholar
Siddans, A. (1983) Finite strain pattern in some Alpine nappes. J. Struct. Geol. 3/4, 441–448.Google Scholar
Urai, J.L., Means, W.D. & Lister, G.S. (1986) Dynamic recrystallization of minerals. Pp. 161–199 in. Mineral and Rock deformation: Laboratory studies (Hobbs, B. E. & Heard, H.C., editors ). AGU Monograph, 36. American Geophysical Union.Google Scholar
Warren, B.E. & Averbach, B.L. (1950) The effect of cold-work distortion on X-ray patterns. J. Appl. Phys. 21, 595–599.CrossRefGoogle Scholar