alluvial deposit

alluvial deposit
Material deposited by rivers.

It consists of silt, sand, clay, and gravel, as well as much organic matter. Alluvial deposits are usually most extensive in the lower part of a river's course, forming floodplains and deltas, but they may form at any point where the river overflows its banks or where the flow of a river is checked. They yield very fertile soils, such as those of the deltas of the Mississippi, Nile, Ganges and Brahmaputra, and Huang (Yellow) rivers. They contain most of the world's supply of tin ore, as well as, in some regions, gold, platinum, and gemstones.

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Universalium. 2010.

Look at other dictionaries:

  • alluvial deposit — noun clay or silt or gravel carried by rushing streams and deposited where the stream slows down • Syn: ↑alluvial sediment, ↑alluvium, ↑alluvion • Derivationally related forms: ↑alluvial (for: ↑alluvium) …   Useful english dictionary

  • alluvial fan — Physical Geog. a fan shaped alluvial deposit formed by a stream where its velocity is abruptly decreased, as at the mouth of a ravine or at the foot of a mountain. Also called alluvial cone. [1870 75] * * * ▪ geological feature  unconsolidated… …   Universalium

  • alluvial sediment — noun clay or silt or gravel carried by rushing streams and deposited where the stream slows down • Syn: ↑alluvial deposit, ↑alluvium, ↑alluvion • Derivationally related forms: ↑alluvial (for: ↑alluvium) …   Useful english dictionary

  • deposit — /di poz it/, v.t. 1. to place for safekeeping or in trust, esp. in a bank account: He deposited his paycheck every Friday. 2. to give as security or in part payment. 3. to deliver and leave (an item): Please deposit your returned books with the… …   Universalium

  • alluvial — I. adjective Date: 1802 relating to, composed of, or found in alluvium < alluvial soil > < alluvial diamonds > II. noun Date: 1841 an alluvial deposit …   New Collegiate Dictionary

  • alluvial fan — /əˌluviəl ˈfæn/ (say uh.loohveeuhl fan) noun a fan shaped alluvial deposit formed by a stream where its velocity is abruptly decreased, as at the mouth of a ravine or at the foot of a mountain. Also, alluvial cone …   Australian-English dictionary

  • alluvial soil — noun a fine grained fertile soil deposited by water flowing over flood plains or in river beds • Hypernyms: ↑soil, ↑dirt • Substance Holonyms: ↑alluvial sediment, ↑alluvial deposit, ↑alluvium, ↑alluvion …   Useful english dictionary

  • alluvial fan — noun Date: 1873 the alluvial deposit of a stream where it issues from a gorge upon a plain or of a tributary stream at its junction with the main stream …   New Collegiate Dictionary

  • alluvial fan — allu′vial fan′ n. geo gel a fan shaped alluvial deposit formed by a stream where its velocity is abruptly decreased, as at the mouth of a ravine …   From formal English to slang

  • Alluvial fan — An alluvial fan is a fan shaped deposit formed where a fast flowing stream flattens, slows, and spreads typically at the exit of a canyon onto a flatter plain. A convergence of neighboring alluvial fans into a single apron of deposits against a… …   Wikipedia

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