- composed chiefly of fragments of volcanic origin, as agglomerate, tuff, and certain other rocks; volcaniclastic.
Origin of pyroclastic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- (of rocks) formed from the solid fragments ejected during a volcanic eruption
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for pyroclastic
Online Etymology Dictionary, © 2010 Douglas Harper
- Composed chiefly of rock fragments of explosive origin, especially those associated with explosive volcanic eruptions. Volcanic ash, obsidian, and pumice are examples of pyroclastic materials.
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