Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-27T20:16:05.269Z Has data issue: false hasContentIssue false
  • English
  • Français

An electron optical study of muscovite breakdown in pelitic xenoliths during pyrometamorphism

Published online by Cambridge University Press:  05 July 2018

A. J. Brearley
A. J. Brearley*
Affiliation:
Department of Geology, The University, Manchester, M13 9PL
Get access Rights & Permissions [Opens in a new window]

Abstract

Transmission electron microscopy and analytical electron microscopy have been used to study the breakdown reaction of muscovite during pyrometa-morphism. The transformation has been shown to be topotactic in nature, with the orientations of the product biotite and alkali feldspar being strongly controlled by the precursor phase. Microprobe investigations indicate that the reaction is probably isochemical with no detectable interaction with adjacent phases. Chemical analyses of the products carried out by AEM have enabled a possible balanced reaction to be calculated. It is proposed that the spatial distribution of the product minerals can be interpreted in terms of diffusion of species from one domain in the crystal to another over distances of 5 to 10 µm as a result of chemical potential gradients which develop during the reaction. The reaction probably occurred under conditions of declining temperature between 900 and 750 °C over a period of 4–5 days. This time period was insufficient to enable the reaction to reach completion as indicated by the presence of relics of muscovite coexisting with K-feldspar, corundum, biotite, hercynite, and mullite.

Keywords

muscovite breakdownelectron microscopypelitic xenolithspyrometamorphism
Type
Rates of Metamorphic Reactions
Information
Mineralogical Magazine , Volume 50 , Issue 357 , September 1986 , pp. 385 - 397
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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

Anderson, D.E., and Buckley, G.R. (1973) Contrib. Mineral. Petrol. 40, 87-104.Google Scholar
Atherton, M.P. (1965) In Controls of metamorphis.(W. S. Pitcher and G. W. Flinn, eds.). Oliver and Boyd, Edinburgh.Google Scholar
Barber, D.J. (1970) J. Mater. Sci. 5, 1-8.Google Scholar
Bell, I.A., and Wilson, C.J.L. (1977) Phys. Chem. Minera. 2, 153-69.Google Scholar
Brearley, A.J. (1984) Unpubl. Ph.D. thesis, Univ. of Manchester.Google Scholar
Cameron, W.E. (1977) Am. Mineral. 62, 747-55.Google Scholar
Carmichael, D.M. (1969) Contrib. Mineral. Petrol. 20, 244-67.Google Scholar
Champness, P.E. (1977) Ann. Rev. Earth Planet. Sci. 5, 203-26.Google Scholar
Champness, P.E. and Lorimer, G.W. (1971) Contrib. Mineral. Petro. 33, 171-83.Google Scholar
Chatterjee, N.D., and Johannes, W. (1974) Ibid. 48, 89-114.Google Scholar
Christian, J.W. (1975) Transformations in metals and alloys. I. Equilibrium and general kinetic theor. Pergamon Press, Oxford.Google Scholar
Cliff, G., and Lorimer, G.W. (1975) J. Microsc. 103, 203-7.Google Scholar
Guidotti, C.V. Cheney, J.T., and Conatore, P.D. (1975) Am. Mineral. 60, 849-53.Google Scholar
Helgeson, H.C. Delaney, J.M. Nesbitt, H.W., and Bird, D.K. (1978) Am. J. Sci. 278, 1-229.Google Scholar
Hobbs, L.W. (1983) Radiation damage.In Quantitative Electron Microscopy.Proc. 25th Scottish Universities Summer School in Physics, 1983.Google Scholar
Jaeger, J.C. (1957) Am. J. Sci. 255, 306-18.Google Scholar
Kwak, T.A.P. (1968) Geochim. Cosmochim. Acta. 32, 1222-9.Google Scholar
McClachlan, D. (1978) Can. Mineral. 16, 415-25.Google Scholar
McGill, R.J., and Hubbard, F.H. (1981) In Qualitative microanalysis with high spatial resolution(G. W. Lorimer M.H. Jacob P.D.ig, eds.). The Metals Society.Google Scholar
Nakajima, Y, and Ribbe, P.H. (1981) Am. Mineral. 66, 142-7.Google Scholar
Putnis, A., and McConnell, J.D.C. (1980) Principles of mineral behaviour.Blackwell Scientific Publications. Roberts, J.L. (1975) Geol. Soc. Am. Abst. with Programs, 6-7, 844-5.Google Scholar
Robie, R.A., Hemingway, B.S., and Fisher, J.R. (1978) U.S. Geol. Survey. Bull. 1452, 452.pp.Google Scholar
Smith, J.V., and Ribbe, P.H. (1966) J. Geol. 74, 197-217.Google Scholar
Veblen, D.R., and Buseck, P.R. (1981) Am. Mineral. 66, 1107-34.Google Scholar
Veblen, D.R., and Buseck, P.R. and Ferry, J.M. (1984) Ibid. 68, 1160-8.Google Scholar
Whittaker, E.J.W. (1985) Crystallograph. Pergamon Press, Oxford.Google Scholar
Wirth, R. (1985) Neues Jahrb. Mineral. Abh. 152, 101-12.Google Scholar