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.

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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

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alluvium Scientific  

/ ə-lo̅o̅′vē-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.

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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

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

The granite of this round world lies underneath, and the alluvium settles on the surface.

From A New Atmosphere by Hamilton, Gail

Related Words

• clay
• coast
• dirt
• dust
• gravel
• land
• mud
• sand
• shore
• surface
• terrain
• turf