alluvial fan


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alluvial fan

n.
A fan-shaped accumulation of alluvium deposited at the mouth of a ravine or at the juncture of a tributary stream with the main stream.

alluvial fan

or

alluvial cone

n
(Geological Science) a fan-shaped accumulation of silt, sand, gravel, and boulders deposited by fast-flowing mountain rivers when they reach flatter land

allu′vial fan′


n.
a fan-shaped alluvial deposit formed by a stream where its velocity is abruptly decreased, as at the mouth of a ravine.

al·lu·vi·al fan

(ə-lo͞o′vē-əl)
A fan-shaped mass of sediment, especially silt, sand, gravel, and boulders, deposited by a river when its flow is suddenly slowed. Alluvial fans typically form where a river pours out from a steep valley through mountains onto a flat plain. Unlike deltas, they are not deposited into a body of standing water.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.alluvial fan - a fan-shaped deposit where a fast flowing stream flattens out
geological phenomenon - a natural phenomenon involving the structure or composition of the earth
References in periodicals archive ?
Zurich lies on the alluvial fan of the Sihl, a natural floodplain.
The AVA is situated on an alluvial fan of the Walla Walla River, where the river exits the foothills of the Blue Mountains and enters the Walla Walla Valley.
Multiple contributions from Yangtze University propose an algorithm for analyzing the particle size of gravel from images, apply a truncated Gaussian simulation algorithm to an alluvial fan reservoir, and estimate the best number of data points for Kriging interpolation.
Snow Creek is a tiny village off of Highway 111 near I-10 nestled on an alluvial fan at the foot of the San Jacinto Mountains.
These areas lie on an alluvial fan in the western part of the Kacchi plain; the size and form of this fan is clearly visible in satellite imagery.
If we look more broadly in Gale Crater, we can see that there is a prominent feature that geologists call an alluvial fan.
The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds.
The site is between the north rim of Gale Crater and the base of Mount Sharp on the downslope of an alluvial fan.
Most significant is that all strata in the two successions were deposited in continental environments-mainly fluvial and alluvial fan settings (Nadon 1981; Nadon and Middleton 1985).
The trunk of the stream recharges the alluvial fan and possibly even the Mississippi River alluvial aquifer where alluvial fans and the river alluvium inter-finger.
Potter (1955) considers them to be the remains of a series of coalescing alluvial fan deposits from the ancestral Tennessee, Cumberland, and Mississippi Rivers.
The landing site was located on an alluvial fan at the foot of a mountain range and less than a kilometer from the shoreline of a playa lake.