Vitrophyre

A vitrophyre is a porphyritic volcanic rock in which phenocrysts are embedded in a glassy matrix. Vitrophyres are contrasted from typical porphyritic rocks in that the latter has both crystalline phenocrysts (larger grains) and a crystalline matrix (smaller grains), whereas the former has a distinctly glassy matrix.[1] Vitrophyres can be alternatively described as rocks having vitrophyric texture.[2] This texture results from the rapid quenching of a lava where phenocrysts had started to form prior to eruption.[3]

Example of a rhyolitic vitrophyre; large phenocrysts are set in the black glassy matrix


See also

References
  1. Best, Myron G. (2002). Igneous and Metamorphic Petrology. Blackwell Publishing. p. 27. ISBN 9781405105880.
  2. Winter, John D. (2014). Principles of Igneous and Metamorphic Petrology. Pearson. p. 40. ISBN 9781292021539.
  3. Philpotts, Anthony; Ague, Jay (2009). Principles of Igneous and Metamorphic Petrology. Cambridge University Press. p. 198. ISBN 9780521880060.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.