mudstone

[muhd-stohn]

Origin of mudstone

First recorded in 1730–40; mud + stone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for mudstone

mudstone

noun
  1. a dark grey clay rock similar to shale but with the lamination less well developed
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

mudstone in Science

mudstone

[mŭdstōn′]
  1. A fine-grained, dark gray sedimentary rock consisting primarily of compacted and hardened silt and clay, similar to shale but without laminations. The proportions of silt and clay in mudstone are approximately equal.
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