Alluvial Fan

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alluvial fan

[ə′lüv·ē·əl ′fan]
A fan-shaped deposit formed by a stream either where it issues from a narrow moutain valley onto a plain or broad valley, or where a tributary stream joins a main stream.

Alluvial Fan


a type of relief in the form of a slightly convex fan, formed through the accumulation of loose detrital material in the estuarine part of temporary streams and small rivers where they emerge from mountains onto piedmont plains or from gorges onto broader valleys. It forms as the result of the deposition of material suspended in water when the speed of the current of water decreases owing to a change in gradient. Populated areas are frequently situated on alluvial fans.

References in periodicals archive ?
Rana Ghundai is the only major site known on the large alluvial fan known as the Bori tract, suggesting that this fan was capable of supporting only a modest-sized population in the past.
Alluvial fans are cone-shaped deposits of gravel and sand that accumulate where streams exit mountains.
of the Talgar alluvial fan, demonstrates the existence of a
The Talgar alluvial fan is situated at the juncture between the mountains and the plain.
The age of alluvial fan deposition at a site in the Southern Uplands of Scotland, Earth Surfaces Processes and Landforms 19: 333-48.
An alluvial fan is a fan-shaped deposit formed where fast flowing water flattens, slows, and spreads - typically at the exit of a canyon or mountain pass onto a flatter plain.
At the same time, it will protect 1,378 acres of rare Riversidian alluvial fan sage scrub (RAFSS) habitat.
The report also includes specific recommendations for alluvial fan flooding, a serious concern for residents in Southern California.
The gold deposit consists of coarse gold contained in gravels of buried canyons and gulches entering from the Shoshone Mountain Range into an alluvial fan of Crescent Valley.
The vineyard is bordered by Selby Creek, and the alluvial fan in this vineyard is formed by centuries of periodic flooding which has carried boulders down into the valley.
The major geological formation of the studied area includes: sand dunes, clay (agricultural plains), salt mixture, gypsum and clay, young terraces and alluvial fans which constitute the major part of geological formations of area belonging to igneous and metamorphic facies [7].
lepidus on Indio Mountains Research Station, most of the landscape is represented by rocky slopes, alluvial fans, and adjacent arroyos, so our two observations support the hypothesis that C.