alluvial fan (s) (noun)
, alluvial fans (pl)
A gently sloping wedge-shaped mass of sediment deposited by a stream where it comes from a narrow canyon onto a plain or valley floor: Alluvial fans
accumulate at and spread from the base of dry mountain ranges where a mountain stream, no longer confined to its narrow channel, deposits its coarse sediment into a large sloping apron-like structure at the point where it comes out onto the plain.
When a stream divides into branching and intertwining lower channels that are separated by islands or sandbars, they twist their way through the fan format and carry sediment from the fan's apex to its fringes and so become alluvial fans.
Alluvial fans also develop in front of melting glaciers, when the water flows out from the ice and spreads out a large amount of coarse debris with it.
Large alluvial fans have deposits that exist in different sizes within the fan, with the bigger pieces of sediment dropping closest to the mountains and the finer materials deposited farther away as the water moves along.
alluvial flat, river flat (s) (noun)
; alluvial flats, river flats (pl)
A small plain where gravel, sand, and mud are deposited on the sides of rivers during floods: Alluvial flats usually form where streams leave earth materials in river valleys or deltas.
alluvial mining (s) (noun) (usually no plural)
The process of dredging (scooping out of the mud) or following horizontal tunnels to exploit materials that have been carried, washed, or left behind by running water: Alluvial mining involves the processing of deposits that are carried by rushing streams and located where the water slows down to remove certain elements from a riverbed, channel, etc.
alluvial ore (s) (noun)
, alluvials ores (pl)
Various kinds of valuable mineral particles that have been transported and deposited by a river or a stream: Don, the old prospector, mined the alluvial ore along the river, hoping to find gold.
alluvial plain (s) (noun)
, wash plain, waste plain; alluvial plains, wash plains, waste plains (pl)
A tract of gently sloping land by a river that periodically overflows depositing clay, silt, or gravel which has been brought downstream where the water slows down: Mike and his family decided to pitch their tents on the alluvial plain
near the river because it was flat and sandy.
The waste plains look desolate and barren; however, they may be rich in minerals that have been washed down by the river creating an alluvial plain.
alluvial slope (s) (noun)
, alluvial slopes (pl)
The soil, clay, silt, or gravel that is left by a flowing water surface which goes down and away from a mountainside and merges with a plain or wide valley floor: Alluvial slopes are made up of the surface soil from hills or mountains that have been "washed" by rain during which time the slanting hills deposit bushes and other vegetable matter, plus sand, dirt, and mud slides; all of which are carried down and left in areas of flat land; such as, valleys.
alluvial soil (s) (noun)
, alluvial soils (pl)
The earth developed on flood plains and deltas, having only the characteristics of the clay, silt or gravel carried by rushing streams and deposited where the streams slow down: The alluvial soils
leave a fine-grained earth material consisting of very tine particles of sand and clay, all of which are deposited by water flowing over flood plains or into river beds.
Keith and the other farmers near the mouth of the river found that the alluvial soils were much more fertile than the land farther away from the river.
alluvial terrace (s) (noun)
, alluvial terraces (pl)
A raised embankment or a gently sloping geomorphic surface of loose, unconsolidated earth material that has built up next to the sides of a river valley: The geology teacher, Mr. Lange, told his students that an alluvial terrace
was a land area that came from a previously formed floodplain that was formed by a stream or river.
The alluvial terrace is also know as: a built terrace, a drift terrace, a fill terrace, a stream-built terrace, a wave-built platform, and a wave-built terrace.
alluviation (s) (noun)
, alluviations (pl)
The depositions or formations of sediments or materials that have been carried and left on land areas by running water; such as rivers or streams: Alluviations are the results of sand, silt, mud, or other detritus (loose materials) left by flowing water in river beds, flood plains, lakes, etc.
alluvion (s) (noun)
, alluvions (pl)
1. The flow of water against a shore or bank: The alluvion of the current against the shoreline caused some erosion of soil.
2. Inundation by water or flooding: The newspaper was filled with stories of hardships caused by the alluvion of the river.
3. The increasing of land area along a shoreline by the sand, gravel, and silt that has been deposited by the recession of a river: The surveyor, Mr. Thomas, came to measure the farmer's ground area because the alluvion of the river might have deposited mud, clay, etc. along the river banks and so increased the size of his property.
alluvium (s) (noun)
, alluvia (pl)
Sediment consisting of mud, sand, silt, gravel, and other unconsolidated detrital matter that is carried along and deposited by flowing water: The largest alluvia
tend to accumulate within the water channel itself while particles of clay, silt, and fine sand are small enough to be suspended as the water continues to flow.
When the watercourse overflows its banks, these alluvia can be distributed across a valley floor where such an overbank or flood deposits have become the most common areas in which buried archaeological sites are found.
Some valley-stream areas are composed of deposits of alluvia and those are the places where researchers often find buried archaeological treasures.
1. Characteristic of someone or something that seems to be very old and out of touch with current activities, events, etc.: Alfred appeared very frustrated, saying that his parents had antediluvian
ideas regarding their behavior expectations for him.
2. Descriptive of the period of history before the Biblical Flood, including events, individuals, and animals: The ancient patriarchs living in the antediluvian
days of antiquity foretold of future catastrophes; such as, flooding.
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, more colluvial, most colluvial
A reference to the loose accumulation of rock and soil debris or deposits at the bottom of a slope: When hiking, Eugene and Fritz noticed a colluvial
amount of sediment or earth at the bottom of the cliff.
Colin, the geologist, was fascinated by the colluvial accumulation of rock fragments, silt, sand, and gravel that was deposited at the bottoms of the steep sides of the hills.
Some descending surfaces are formed by the accumulation of small pieces of colluvial rock fragments that have been transported down the sides of hills or mountains by flowing water or snow slides.
Colluvial material typically gathers in the dry valleys of chalk-lands and also at the foot of escarpments or valley sides.
colluvium (s) (noun)
; colluviums, colluvia (pl)
Any of various kinds of sediment deposited by rainwash, removal of fine-grained, surface material by sheets of flowing water, or slow continuous downslope activities; usually at the base of a cliff or slope: Hubert and the other geographers studied the colluvia in the mountains in an effort to understand the results of weather, wind, gravity, flowing water, etc. on the build up of soils in the geological areas.
, cryoablutes; cryoabluted; cryoabluting
The removing or cleansing of the body of undesirable skin blemishes or parts by freezing: Dr. Emmerson told Anita that cryoabluting
the spot on her arm would result in little or no bleeding with minimal or no scar formations.
The dermatologist, Dr. Traviss, successfully cryoabluted the moles and warts from Glenda's skin.
Click on the link for additional information about the historical background of washing and ablutions or cleanliness via washing.
Related "wash" words: