- a very fine-grained sandstone, mainly consolidated silt.
Origin of siltstone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a variety of fine sandstone formed from consolidated silt
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
- A fine-grained sedimentary rock consisting primarily of compacted and hardened silt. Siltstones are similar to shale but without laminations. They vary in color from black or gray to brown or red.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.