Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-29T05:21:45.102Z Has data issue: false hasContentIssue false
  • English
  • Français

Microscopy and Microanalysis of Magmatic and Metamorphic Minerals – Part 1: Cordierite

Published online by Cambridge University Press:  14 March 2018

Robert Sturm
Robert Sturm*
Affiliation:
Brunnleitenweg 41, A-5061 Elsbethen, Salzburg/Austria
*
Robert.Sturm@sbg.ac.at

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Cordierite represents an orthorhombic (Mg,Fe)Al-silicate (Table 1) that is observed in a wide range of natural occurrences. As outlined in numerous mineralogical overviews published during the past decades, cordierite mainly crystallizes in thermally metamorphosed rocks, particularly in those derived from argillaceous sediments. Additionally, the mineral can be a major constituent of parageneses formed under high-grade regional metamorphism and therefore occurs in respective schists, gneisses and granulites. The metamorphic formation of cordierite is generally restricted to conditions of deficient or low shearing stress producing only moderate lithological pressures. With rising pressure due to transpression cordierite often breaks down to enstatite and sillimanite or, at higher temperature, to sapphirine and quartz (see also Fig. 5). Besides its crystallization in metamorphic rocks, cordierite is also found in specific igneous rocks like peraluminous granites and related high-grade anatectic terrains.

Type
Research Article
Information
Microscopy Today , Volume 16 , Issue 5 , September 2008 , pp. 30 - 37
Copyright
Copyright © Microscopy Society of America 2008

References

(1) Deer, W. A., Howie, R. A. & Zussman, J. (1992): An Introduction to the Rock- Forming Minerals. 2nd ed., Longmans Scientific and Technical, London.Google Scholar
(2) Spear, F. S. (1993): Metamorphic Phase Equilibria and Pressure-Temperature- Time Paths. Mineralogical Society of America (MSA), Washington D.C. Google Scholar
(3) Harker, A. (1939): Metamorphism. 2nd ed., Methuen & Co, London.Google Scholar
(4) Seifert, F. (1970): Low-temperature Compatibility Relations of Cordierite in Haplopelites of the System K2O—MgO—Al2O3—SiO2—H2O. Journal of Petrology 11, 73-100.Google Scholar
(5) Wall, V. J., Clemens, J. D. & Clarke, D. B. (1987): Models for granitoid evolution and source compositions. Journal of Geology 95, 731-750.Google Scholar
(6) Clarke, D. B. (1981): The mineralogy of peraluminous granites; a review. Canadian Mineralogist 19, 3-17.Google Scholar
(7) Clemens, J. D. & Wall, V. J. (1981): Origin and crystallization of some peraluminous (S-type) granitic magmas. Canadian Mineralogist 19, 111-131.Google Scholar
(8) Sturm, R. (2008): Microscopy and Microanalysis of Corona Textures in Eclogitic Greenschists from the Eastern Alps, Austria. Microscopy Today 16/2, 26-31.Google Scholar
(9) Kossmat, F. (1927): Gliederung des varistischen Gebirgsbaus. Abhandlungen der Sächsischen Geologischen Landesanstalt 1, 1-39.Google Scholar
(10) Frasl, G. & Finger, F. (1991): Geologisch-petrographische Exkursion in den österreichischen Teil des südböhmischen Batholiths. Beihefte zum European Journal of Mineralalogy 3, 23-40.Google Scholar
(11) Mirwald, P. W. (1986): Ist Cordierite in Geothermometer? Fortschritte der Mineralogie 64, 119.Google Scholar
(12) Perchuk, L. L. & Lavrent’eva, I. V. (1981): Experimental investigation of exchange equilibria in the system cordierite-garnet-biotite. In: Saxena, S. K. (ed.): Kinetics and Equilibrium in Mineral Reactions, Springer, New York, 199-240.Google Scholar