- a deposit of sand, mud, etc., formed by flowing water.
- the sedimentary matter deposited thus within recent times, especially in the valleys of large rivers.
Origin of alluvium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for alluvium
If so, the thickness of the alluvium is at least 1800 ft., and may be much more.
Here I had an opportunity of seeing the material of which the alluvium is composed.Notes on the Fenland
T. McKenny Huges
Strata intersected by a trap dike, and covered with alluvium.A Manual of Elementary Geology
It would be interesting to know the thickness of the alluvium.The Geological Story of the Isle of Wight
J. Cecil Hughes
This growth rarely takes place from the waste of the bed rocks on which the alluvium lies.Outlines of the Earth's History
Nathaniel Southgate Shaler
- a fine-grained fertile soil consisting of mud, silt, and sand deposited by flowing water on flood plains, in river beds, and in estuaries
C17: from Latin; see alluvion
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 alluvium
Online Etymology Dictionary, © 2010 Douglas Harper
- Sand, silt, clay, gravel, or other matter deposited by flowing water, as in a riverbed, floodplain, delta, or alluvial fan. Alluvium is generally considered a young deposit in terms of geologic time.
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