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Very-Low-Grade Metamorphism of Graywackes

  • Helmut G. F. Winkler
Part of the Springer Study Edition book series (SSE)

Abstract

Graywackes are sedimentary clastic rocks which consist of quartz, feldspar, and sheet silicates (micas, chlorite, clay minerals, etc.) and commonly contain rock fragments. If the debris are derived from mafic rocks, metamorphic graywackes show qualitatively the same mineral parageneses as have been discussed in Chapter 12.1 Quantitatively, however, mafic minerals and Ca-Al minerals are commonly present only in minor amounts, whereas white mica and especially quartz occur in larger amounts, The amount of feldspar in metagraywackes may be very different, depending on the initial quartz-to-feldspar ratio in the clastic sediment; feldspar may be very conspicuous.

Keywords

Rock Fragment Mafic Rock Clastic Rock Clastic Sediment White Mica 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Boettcher, A. L. and Wyllie, P. J. 1968. Geochim. Cosmochim. Acta 32: 999–1012.CrossRefGoogle Scholar
  2. Ernst, W. G. 1971. J. Petrol. 12: 413–437.CrossRefGoogle Scholar
  3. Johannes, W., et al. 1971. Contr. Mineral. Petrol. 32: 24–38.CrossRefGoogle Scholar
  4. Newton, R. C, and Smith, J. V. 1967. J. Geol. 75: 268–286.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1979

Authors and Affiliations

  • Helmut G. F. Winkler
    • 1
  1. 1.Institute of Mineralogy and PetrologyUniversity of GöttingenFederal Republic of Germany

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