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Calchaqui Valley in Argentina Salta-VallesCalchaquies-P3140151.JPG
Calchaquí Valley in Argentina
U-shaped valley in Glacier National Park, Montana, United States Glacier park1.jpg
U-shaped valley in Glacier National Park, Montana, United States
Romsdalen in Western Norway has almost vertical walls. Romsdalen.jpg
Romsdalen in Western Norway has almost vertical walls.
Fljotsdalur in East Iceland, a rather flat valley Fljotsdalur.jpg
Fljótsdalur in East Iceland, a rather flat valley
The Frades Valley in the mountainous region of Rio de Janeiro state, Brazil Vale dos Frades.jpg
The Frades Valley in the mountainous region of Rio de Janeiro state, Brazil
Baemsagol valley of Jirisan, Korea Baemsagol MS3812.JPG
Baemsagol valley of Jirisan, Korea

A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountains or polar areas.


At lower latitudes and altitudes, these glacially formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry a watercourse only rarely. In areas of limestone bedrock, dry valleys may also result from drainage now taking place underground rather than at the surface. Rift valleys arise principally from earth movements, rather than erosion. Many different types of valleys are described by geographers, using terms that may be global in use or else applied only locally.

Formation of valleys

Valleys may arise through several different processes. Most commonly, they arise from erosion over long periods by moving water and are known as river valleys. Typically small valleys containing streams feed into larger valleys which in turn feed into larger valleys again, eventually reaching the ocean or perhaps an internal drainage basin. In polar areas and at high altitudes, valleys may be eroded by glaciers; these typically have a U-shaped profile in cross-section, in contrast to river valleys, which tend to have a V-shaped profile. Other valleys may arise principally through tectonic processes such as rifting. All three processes can contribute to the development of a valley over geological time. The flat (or relatively flat) portion of a valley between its sides is referred to as the valley floor. The valley floor is typically formed by river sediments and may have fluvial terraces.

River valleys

The valley of Halikko River in Halikko, Finland Halikonjokilaakso.jpg
The valley of Halikko River in Halikko, Finland
Valley of Palakaria river springing from Vitosha Mountain, seen in the background, in Bulgaria Palakaria-and-Belchin-3.jpg
Valley of Palakaria river springing from Vitosha Mountain, seen in the background, in Bulgaria

The development of a river valley is affected by the character of the bedrock over which the river or stream flows, the elevational difference between its top and bottom, and indeed the climate. Typically the flow will increase downstream and the gradient will decrease. In the upper valley, the stream will most effectively erode its bed through corrasion to produce a steep-sided V-shaped valley. The presence of more resistant rock bands, of geological faults, fractures, and folds may determine the course of the stream and result in a twisting course with interlocking spurs.

In the middle valley, as numerous streams have coalesced, the valley is typically wider, the flow slower and both erosion and deposition may take place. More lateral erosion takes place in the middle section of a river's course, as strong currents on the outside of its curve erode the bank. Conversely, deposition may take place on the inside of curves where the current is much slacker, the process leading to the river assuming a meandering character. In the lower valley, gradients are lowest, meanders may be much broader and a broader floodplain may result. Deposition dominates over erosion. [1] [2] A typical river basin or drainage basin will incorporate each of these different types of valleys.

Some sections of a stream or river valleys may have vertically incised their course to such an extent that the valley they occupy is best described as a gorge, ravine, or canyon. Rapid down-cutting may result from localized uplift of the land surface or rejuvenation of the watercourse as a result for example of a reduction in the base level to which the river is eroded, e.g. lowered global sea level during an ice age. Such rejuvenation may also result in the production of river terraces. [3]

Glacial valleys

U-shaped valley on the Afon Fathew near Dolgoch, Wales Tal-y-llyn-valley-Dolgoch-01.jpg
U-shaped valley on the Afon Fathew near Dolgoch, Wales
A glaciated valley in the Mount Hood Wilderness showing a characteristic U-shape, the bottom's rocky 'rubble' accretion and the broad shoulders Glacial Valley MtHoodWilderness.jpg
A glaciated valley in the Mount Hood Wilderness showing a characteristic U-shape, the bottom's rocky 'rubble' accretion and the broad shoulders

There are various forms of valleys associated with glaciation. True glacial valleys are those that have been cut by a glacier which may or may not still occupy the valley at the present day. Such valleys may also be known as glacial troughs. They typically have a U-shaped cross-section and are characteristic landforms of mountain areas where glaciation has occurred or continues to take place. [4]

The uppermost part of a glacial valley frequently consists of one or more 'armchair-shaped' hollows, or 'cirques', excavated by the rotational movement downslope of a cirque glacier. During glacial periods, for example, the Pleistocene ice ages, it is in these locations that glaciers initially form and then, as the ice age proceeds extend downhill through valleys that have previously been shaped by water rather than ice. Abrasion the movement of ice and particularly by rock material embedded within it causes the widening and deepening of the valley to produce the characteristic U or trough shape with relatively steep, even vertical sides and a relatively flat bottom.

Interlocking spurs associated with the development of river valleys are preferentially eroded to produce truncated spurs, typical of glaciated mountain landscapes. The upper end of the trough below the ice-contributing cirques may be a trough-end. Valley steps (or 'rock steps') can result from differing erosion rates due to both the nature of the bedrock (hardness and jointing for example) and the power of the moving ice. In places, a rock basin may be excavated which may later be filled with water to form a ribbon lake or else by sediments. Such features are found in coastal areas as fjords. The shape of the valley which results from all of these influences may only become visible upon the recession of the glacier that forms it. [5] A river or stream may remain in the valley; if it is smaller than one would expect given the size of its valley, it can be considered an example of a misfit stream.

A panoramic view of two merging U-shaped valleys in Pirin mountain, Bulgaria Pirin ezera Pano Chairski ezera.jpg
A panoramic view of two merging U-shaped valleys in Pirin mountain, Bulgaria

Other interesting glacially carved valleys include:


A tunnel valley is a large, long, U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. [6] Such valleys can be up to 100 km (62 mi) long, 4 km (2.5 mi) wide, and 400 m (1,300 ft) deep (its depth may vary along its length). Tunnel valleys were formed by subglacial water erosion. They once served as subglacial drainage pathways carrying large volumes of meltwater. Their cross-sections exhibit steep-sided flanks similar to fjord walls, and their flat bottoms are typical of subglacial glacial erosion.


In northern Central Europe, the Scandinavian ice sheet during the various ice ages advanced slightly uphill against the lie of the land. As a result, its meltwaters flowed parallel to the ice margin to reach the North Sea basin, forming huge, flat valleys known as Urstromtäler. Unlike the other forms of glacial valleys, these were formed by glacial meltwaters.

Hooker Valley in Aoraki-Mount Cook National Park.jpg
New Zealand's Hooker Valley at Aoraki / Mount Cook National Park, with Hooker Glacier's terminus at Hooker Lake in the background

Transition forms and shoulders

Look from Paria View to a valley in Bryce Canyon, Utah, with very striking shoulders Paria View at Bryce Canyon NP.jpg
Look from Paria View to a valley in Bryce Canyon, Utah, with very striking shoulders

Depending on the topography, the rock types, and the climate, a variety of transitional forms between V-, U- and plain[ clarification needed ] valleys can form. The floor or bottom of these valleys can be broad or narrow, but all valleys have a shoulder. The broader a mountain valley, the lower its shoulders are located in most cases. An important exception is canyons where the shoulder almost is near the top of the valley's slope. In the Alps – e.g. the Tyrolean Inn valley – the shoulders are quite low (100–200 meters above the bottom). Many villages are located here (esp. on the sunny side) because the climate is very mild: even in winter when the valley's floor is filled with fog, these villages are in sunshine.

In some stress-tectonic regions of the Rockies or the Alps (e.g. Salzburg), the side valleys are parallel to each other, and are hanging. Smaller streams flow into rivers as deep canyons or waterfalls.

Hanging tributary

Bridal Veil Falls in Yosemite National Park flowing from a hanging valley Closeup of Bridalveil Fall seen from Tunnel View in Yosemite NP.JPG
Bridal Veil Falls in Yosemite National Park flowing from a hanging valley
Hanging valley, Ibar (lake) valley, Rila Mountain, Bulgaria Ib'rsko ezero.jpg
Hanging valley, Ibar (lake) valley, Rila Mountain, Bulgaria

A hanging valley is a tributary valley that is higher than the main valley. They are most commonly associated with U-shaped valleys, where a tributary glacier flows into a glacier of larger volume. The main glacier erodes a deep U-shaped valley with nearly vertical sides, while the tributary glacier, with a smaller volume of ice, makes a shallower U-shaped valley. Since the surfaces of the glaciers were originally at the same elevation, the shallower valley appears to be 'hanging' above the main valley. Often, waterfalls form at or near the outlet of the upper valley. [7]

Hanging valleys also occur in fjord systems underwater. The branches of Sognefjord are much shallower than the main fjord. The mouth of Fjærlandsfjord is about 400 meters (1,300 ft) deep while the main fjord nearby is 1,200 meters (3,900 ft) deep. The mouth of Ikjefjord is only 50 meters (160 ft) deep while the main fjord is around 1,300 meters (4,300 ft) at the same point. [8]

Glaciated terrain is not the only site of hanging streams and valleys. Hanging valleys are also simply the product of varying rates of erosion of the main valley and the tributary valleys. The varying rates of erosion are associated with the composition of the adjacent rocks in the different valley locations. The tributary valleys are eroded and deepened by glaciers or erosion at a slower rate than that of the main valley floor; thus the difference in the two valleys' depth increases over time. The tributary valley, composed of more resistant rock, then hangs over the main valley. [9]


Trough-shaped valleys also form in regions of heavy topographic denudation. By contrast with glacial U-shaped valleys, there is less downward and sideways erosion. The severe downslope denudation results in gently sloping valley sides; their transition to the actual valley bottom is unclear. Trough-shaped valleys occur mainly in periglacial regions and in tropical regions of variable wetness. Both climates are dominated by heavy denudation. [10]


Box valleys have wide, relatively level floors and steep sides. They are common in periglacial areas and occur in mid-latitudes, but also occur in tropical and arid regions. [11]


Rift valleys, such as the Albertine Rift and Gregory Rift are formed by the expansion of the Earth's crust due to tectonic activity beneath the Earth's surface.

Terms for valleys

There are many terms used for different sorts of valleys. They include:

Similar geographical features such as gullies, chines, and kloofs, are not usually referred to as valleys.

British regional terms for valleys

Indus River running through the Kohistan Valley in Pakistan Indus Kohistan Pakistan.jpg
Indus River running through the Kohistan Valley in Pakistan

The terms corrie, glen, and strath are all Anglicisations of Gaelic terms and are commonly encountered in place-names in Scotland and other areas where Gaelic was once widespread. Strath signifies a wide valley between hills, the floor of which is either level or slopes gently. [13] A glen is a river valley which is steeper and narrower than a strath. [14] A corrie is a basin-shaped hollow in a mountain. [15] Each of these terms also occurs in parts of the world formerly colonized by Britain. Corrie is used more widely by geographers as a synonym for (glacial) cirque , as is the word cwm borrowed from Welsh. [16]

The word dale occurs widely in place names in the north of England and, to a lesser extent, in southern Scotland. As a generic name for a type of valley, the term typically refers to a wide valley, though there are many much smaller stream valleys within the Yorkshire Dales which are named "(specific name) Dale". [17] Clough is a word in common use in northern England for a narrow valley with steep sides. [18] Gill is used to describe a ravine containing a mountain stream in Cumbria and the Pennines. [19] The term combe (also encountered as coombe) is widespread in southern England and describes a short valley set into a hillside. [20] Other terms for small valleys such as hope, dean, slade, slack and bottom are commonly encountered in place-names in various parts of England but are no longer in general use as synonyms for valley.

The term vale is used in England and Wales to describe a wide river valley, usually with a particularly wide flood plain or flat valley bottom. In Southern England, vales commonly occur between the outcrops of different relatively erosion-resistant rock formations, where less resistant rock, often claystone has been eroded. An example is the Vale of White Horse in Oxfordshire.

Human settlement

Some of the first human complex societies originated in river valleys, such as that of the Nile, Tigris-Euphrates, Indus, Ganges, Yangtze, Yellow River, Mississippi, and arguably the Amazon. In prehistory, the rivers were used as a source of fresh water and food (fish and game), as well as a place to wash and a sewer. The proximity of water moderated temperature extremes and provided a source for irrigation, stimulating the development of agriculture. Most of the first civilizations developed from these river valley communities. Siting of settlements within valleys is influenced by many factors, including the need to avoid flooding and the location of river crossing points.

Notable examples

A view of Orosi, Costa Rica DirkvdM orosi.jpg
A view of Orosí, Costa Rica



The Valley of Flowers in Uttarakhand, India "Flowers Blossom at Valley of Flowers Chamoli, India" 58.jpg
The Valley of Flowers in Uttarakhand, India


The Harau Valley in West Sumatra, Indonesia Harau valley.jpg
The Harau Valley in West Sumatra, Indonesia


The Gudbrandsdalen in Eastern Norway near Gala Gudbrandsdalen sett nordover fra vegen opp mot Gala - Gudbrandsdal Valley Norway.JPG
The Gudbrandsdalen in Eastern Norway near Gålå

North America

Hell's Gate, British Columbia Hells Gate.jpg
Hell's Gate, British Columbia

South America


Extraterrestrial valleys

Numerous elongate depressions have been identified on the surface of Mars, Venus, the Moon, and other planets and their satellites and are known as valles (singular: 'vallis'). Deeper valleys with steeper sides (akin to canyons) on certain of these bodies are known as chasmata (singular: 'chasma'). Long narrow depressions are referred to as fossae (singular: 'fossa'). [21] These are the Latin terms for 'valley, 'gorge' and 'ditch' respectively. The German term 'rille' or Latin term 'rima' (signifying 'cleft') is used for certain other elongate depressions on the Moon. [22]

See also:

See also

Related Research Articles

<span class="mw-page-title-main">Erosion</span> Natural processes that remove soil and rock

Erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.

<span class="mw-page-title-main">Glacier</span> Persistent body of ice that is moving under its own weight

A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.

<span class="mw-page-title-main">Fjord</span> Long, narrow inlet with steep sides or cliffs, created by glacial activity

In physical geography, a fjord or fiord is a long, narrow sea inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Antarctica, the Arctic, and surrounded landmasses of the northern and southern hemispheres. Norway's coastline is estimated to be 29,000 km (18,000 mi) long with its nearly 1,200 fjords, but only 2,500 km (1,600 mi) long excluding the fjords.

Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.

<span class="mw-page-title-main">Geology of the Yosemite area</span>

The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. The first rocks were laid down in Precambrian times, when the area around Yosemite National Park was on the edge of a very young North American continent. The sediment that formed the area first settled in the waters of a shallow sea, and compressive forces from a subduction zone in the mid-Paleozoic fused the seabed rocks and sediments, appending them to the continent. Heat generated from the subduction created island arcs of volcanoes that were also thrust into the area of the park. In time, the igneous and sedimentary rocks of the area were later heavily metamorphosed.

<span class="mw-page-title-main">Pyramidal peak</span> Angular, sharply pointed mountainous peak

A pyramidal peak, sometimes called a glacial horn in extreme cases, is an angular, sharply pointed mountain peak which results from the cirque erosion due to multiple glaciers diverging from a central point. Pyramidal peaks are often examples of nunataks.

<span class="mw-page-title-main">Ridge</span> Long, narrow, elevated landform

A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, with the terrain dropping down on either side. The crest, if narrow, is also called a ridgeline. Limitations on the dimensions of a ridge are lacking. Its height above the surrounding terrain can vary from less than a meter to hundreds of meters. A ridge can be either depositional, erosional, tectonic, or a combination of these in origin and can consist of either bedrock, loose sediment, lava, or ice depending on its origin. A ridge can occur as either an isolated, independent feature or part of a larger geomorphological and/or structural feature. Frequently, a ridge can be further subdivided into smaller geomorphic or structural elements.

<span class="mw-page-title-main">Cirque</span> An amphitheatre-like valley formed by glacial erosion

A cirque is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie and cwm. A cirque may also be a similarly shaped landform arising from fluvial erosion.

<span class="mw-page-title-main">Coulee</span> Type of valley or drainage zone

Coulee, or coulée is a term applied rather loosely to different landforms, all of which refer to a kind of valley or drainage zone. The word coulee comes from the Canadian French coulée, from French couler 'to flow'.

<span class="mw-page-title-main">Glacial landform</span> Landform created by the action of glaciers

Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have extensive occurrences of glacial landforms; other areas, such as the Sahara, display rare and very old fossil glacial landforms.

<span class="mw-page-title-main">Depression (geology)</span> Landform sunken or depressed below the surrounding area

In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms.

<span class="mw-page-title-main">Roche moutonnée</span> Rock formation created by the passing of a glacier

In glaciology, a roche moutonnée is a rock formation created by the passing of a glacier. The passage of glacial ice over underlying bedrock often results in asymmetric erosional forms as a result of abrasion on the "stoss" (upstream) side of the rock and plucking on the "lee" (downstream) side. Some geologists limit the term to features on scales of a metre to several hundred metres and refer to larger features as crag and tail.

<span class="mw-page-title-main">Tunnel valley</span> Glacial-formed geographic feature

A tunnel valley is a U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. They can be as long as 100 km (62 mi), 4 km (2.5 mi) wide, and 400 m (1,300 ft) deep.

Side valleys and tributary valleys are valleys whose brooks or rivers flow into greater ones.

<span class="mw-page-title-main">U-shaped valley</span> Valleys formed by glacial scouring

U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice, called glacial till or glacial erratic.

This glossary of geography terms is a list of definitions of terms and concepts used in geography and related fields, including Earth science, oceanography, cartography, and human geography, as well as those describing spatial dimension, topographical features, natural resources, and the collection, analysis, and visualization of geographic data. It is split across two articles:

<span class="mw-page-title-main">Overdeepening</span> Characteristic of basins and valleys eroded by glaciers

Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the lowest continuous surface line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.

<span class="mw-page-title-main">Scandinavian Mountains</span> Mountain range in Finland, Norway and Sweden

The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The western sides of the mountains drop precipitously into the North Sea and Norwegian Sea, forming the fjords of Norway, whereas to the northeast they gradually curve towards Finland. To the north they form the border between Norway and Sweden, reaching 2,000 metres (6,600 ft) high at the Arctic Circle. The mountain range just touches northwesternmost Finland but are scarcely more than hills at their northernmost extension at the North Cape.

<span class="mw-page-title-main">Valley step</span> Prominent change in the longitudinal slope of a valley

A valley step is a prominent change in the longitudinal slope of a valley, mainly in trough valleys formed by glaciers.

<span class="mw-page-title-main">Edaga Arbi Glacials</span> Palaeozoic geological formation in Africa

The Edaga Arbi Glacials are a Palaeozoic geological formation in Tigray and in Eritrea. The matrix is composed of grey, black and purple clays, that contains rock fragments up to 6 metres across. Pollen dating yields a Late Carboniferous to Early Permian age.


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Extraterrestrial valleys