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alluvium

American  
[uh-loo-vee-uhm] / əˈlu vi əm /

noun

  • alluviums,
    plural
  • alluvia
    plural
  1. a deposit of sand, mud, etc., formed by flowing water.

  2. the sedimentary matter deposited thus within recent times, especially in the valleys of large rivers.


alluvium British  
/ əˈluːvɪəm /

noun

  1. a fine-grained fertile soil consisting of mud, silt, and sand deposited by flowing water on flood plains, in river beds, and in estuaries

"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

alluvium Scientific  
/ ə-lo̅o̅vē-əm /
  • alluviums
    plural
  1. 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.


Other Word Forms

Noun Inflected Forms

Etymology

Origin of alluvium

1655–65; < Latin, noun use of neuter of alluvius washed against, equivalent to alluv- ( see alluvion) + -ius, -ium adj. suffix; see -ium

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Deposits of alluvium and volcanic ash have made desirable soil that is among the top 2% in the world.

From Seattle Times Jun. 16, 2023

Paved surfaces end miles from the rock outcrop, so we drive on overgrown rutted two-tracks that cross the loose sandy dune fields that show up on our geologic maps as “QAL”—Quaternary alluvium.

From Scientific American Dec. 15, 2020

Thus, a landscape architect I know savors the very smell of the dirt embedded in his botany texts; it is the alluvium of his life’s work.

From Slate Feb. 4, 2020

The island’s geology — a heart of granite in the west, compacted alluvium in the east — is such that most of it could be hollowed out.

From New York Times Apr. 20, 2017

This alluvium forms one of the deepest and richest soils in the world.

From My Experiences in Manipur and the Naga Hills by James Johnstone, chevalier de Johnstone

Hence it was long and erroneously determined that bare rocks in the neighbourhood of shallow alluvia characterise rich placers, and that the wealthiest mining-regions are poor and stunted in vegetation.

From To The Gold Coast for Gold, Vol. II A Personal Narrative by Sir Richard Francis Burton

But it is not often that borings come to be made in river alluvia.

From The Geological Story of the Isle of Wight by J. Cecil Hughes

Near Orange, for instance, her favourite spots are the alluvia of the Aygues, with their carpets of smooth pebbles no longer visited by the waters.

From The Mason-Bees by Alexander Teixeira de Mattos

We see clearly the alluvia of two streams converging from right and left, and uniting to pass to the sea through Brading Harbour.

From The Geological Story of the Isle of Wight by J. Cecil Hughes

I start with two Mason-bees of the Walls working at their nests on the pebbles in the alluvia of the Aygues, not far from Serignan.

From The Mason-Bees by Alexander Teixeira de Mattos

He pointed out with great clearness the resemblance of the tufaceous matter in the vaults and cellars at Herculaneum and Pompeii to aqueous alluviums, and its distinctness from ejections which had fallen through the air.

From Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology by Sir Charles Lyell

Herculaneum was situated several miles nearer to the volcano, and has, therefore, been always more exposed to be covered, not only by showers of ashes, but by alluviums and streams of lava.

From Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology by Sir Charles Lyell

There are great tracts of alluviums lying along the banks of the Derwent, the Ouse, and the Trent, and the Romney Marsh of Kent along the banks of the Thames.

From The New Gresham Encyclopedia. Vol. 1 Part 1 A to Amide by Various

In the course of ages, a new system of valleys was excavated, so that the rivers ran at lower levels than those at which the first alluviums and sheets of lava were formed.

From The Student's Elements of Geology by Sir Charles Lyell

The whole of them were at first confounded with the superficial alluviums of Europe; and it was long before their real extent and thickness, and the various ages to which they belong, were fully recognised.

From The Student's Elements of Geology by Sir Charles Lyell

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