Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Valley shopping experience:
1. Compare - without doubt the biggest advantage that the Valley offers shoppers today is the ability to compare thousands of Valley at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Valley? Wrong! If the Valley is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Valley then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Valley? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Valley and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Valley wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Valley then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Valley site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Valley, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Valley, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
This article is about the physical-geographic term. For places named "Valley" see Valley (disambiguation).
in East
Iceland, a rather flat valley
In
geology, a
valley is a Depression (geology) with predominant extent in one direction. A very deep river valley may be called a
canyon or
gorge.
The terms U-shaped valley and V-shaped are descriptive terms of geography to characterize the form of valleys. Most valleys belong to one of these two main types or a mixture of them, at least with respect of the
cross section (geometry) of the slopes or hillsides.
River valleys
. The shoulders of U or V valleys are often located roughly
halfway up the slopes
A valley formed by
River, or
river valley, is usually V-shaped. The exact shape will depend on the characteristics of the stream flowing through it. Rivers with steep gradients, as in mountain ranges, produce steep walls and a narrow bottom. Shallower slopes may produce broader and gentler valleys, but in the lowest stretch of a river, where it approaches its base level, it begins to deposit sediment and the valley bottom becomes a
floodplain.
A V-shaped valley is formed by downcutting when the flowing stream erodes its channel at a higher rate than the sides are eroded. The resulting landform is a narrow canyon with fast water and little bank (
floodplain) on the river sides.
Some broad
V examples are:
Glacial valleys
showing a characteristic U-shape and the broad shoulders in Montana, United States.
A valley carved by
glaciers, or
glacial valley, is normally U-shaped. If we can see the valley, it means the glacier that formed it is no longer there. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice. Floor gradient does not affect the valley's shape, it is the glacier's size that does. Continuously flowing glaciers - espec. in the
ice age - and large sized glaciers carve wide, deep incised valleys.
Examples of U-shaped valleys are found in every mountainous region that has experienced
glaciation, usually during the
Pleistocene Ice Age.Most present U-shaped valleys started as V-shaped before glaciation. The glaciers carved it out wider and deeper, simultaneously changing the shape. This proceeds through the glacial erosion processes of plucking and abrasion, which results in large rocky material (glacial till) being carried in the glacier. A material called boulder clay is deposited on the floor of the valley. As the ice melts and retreats, the valley is left with very steep sides and a wide, flat floor. A river or stream may remain in the valley. This replaces the original stream or river and is known as a misfit stream because it is smaller than one would expect given the size of its valley.
Other interesting glacially-carved valleys are the
Transition forms and valley shoulders
/Utah with very striking shoulders
Depending on the topography, the
rock types and the
climate, a lot of transition forms between V-, U- and plain valleys exist. Their bottoms can be broad or narrow, but characteristic is also the type of valley shoulder. The broader a mountain valley, the lower its shoulders are located in most cases. An important exception are
canyons where the shoulder almost is near the top of the valley's slope. In the Alps - e.g. the Tyrolean Inn River valley - the shoulders are quite low (100-200 meters above the bottom). Many
villages are located here (esp. at the sunny side) because the climate is very mild: even in winter when the valley's floor is completely filled with fog, these villages are in Sunlight.
In some stress-tectonic regions of the Rocky mountains or the Alps (e.g.
Salzburg) the side valleys are parallel to each other, and additionally they are hanging valleys. The brooks flow into the river in form of deep
gorges or
waterfalls. Usually this fact is the result of a violent erosion of the former valley shoulders. A special genesis we find also at arêtes and glacial Cirque (landform), at every Scottish glen, or a northern
fjord.
Hanging valleys
flowing from a hanging valley.
A
hanging valley is a tributary valley with the floor at a higher relief than the main channel into which it flows. They are most commonly associated with U-shaped valleys when 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.
Valley floors
Usually the bottom of a main valley is broad - independent of the U or V shape. It typically ranges from about one to ten kilometres in width and is commonly filled with mountain sediments. The shape of the floor can be rather Horizontal plane, similar to a flat
Cylinder (geometry), or stream terraced.
Side valleys are rather V than U-shaped; near the mouth clammy are possible if it is a hanging valley. The location of the villages depends on the across-valley profile, on
climate and local traditions, and on the danger of
avalanches or landslides. Predominant are places on terraces or alluvial fans if they exist.
Historic siting of villages within the mainstem (hydrology) valleys, however, have chiefly considered the potential of flooding.
== Hollows ==
A
hollow is a small valley or dry stream bed. This term is commonly used in
New England, Arkansas, Missouri and Pennsylvania to describe such geographic features. Also used in
Southern Appalachia, but pronounced "holler." Hollows may be formed by
river valleys such as
Mansfield Hollow or they may be relatively dry clefts with a notch-like characteristic in that they have a height of land and consequent water divide in their bases. A hollow such as this is
Boston Hollow. Tourists in Europe can further visit a lot of
karst,
stalactite and ice hollows (e.g. in Slovenia and
Austria).
Famous valleys
Rift valleys
Rift valleys, such as the Great Rift Valley, are formed by the expansion of the Earth's crust due to Plate tectonics activity beneath the Earth's surface.
Extraterrestrial valleys
The other terrestrial planets and the
natural satellites of our Solar System can also have valley-like features.
List of valleys on the Moon can be formed from a linked chain of
impact craters. Smaller valleys, known as
rilles, may have originated from lava flows or from the contractions of cooling lava sheets.
Besides the lunar
Impact crater, the details of lunar mountain ranges have been well known for more than 300 years (e.g.
Johann Hieronymus Schröter's
Selenotopographische Fragmente of 1791). A lot of linear phenomena like Vallis Rheita or Schröter valley and the famous
Vallis Alpes (see also below) were observed with details less than 1 km (which corresponds to a coin seen from 5-10 km distance)—but the geological genesis was debated until the
Apollo 11 mission in 1969. Astronomers have long been able to observe some highlands and
mountains on Mars, and therefore guessed that there may be valleys, as well. In the 1970s this interpretation was proven correct by results from
space probes. Valleys have also been found on Mercury (planet) and on the volcanic surfaces of
Venus and
Io (moon).
The largest valley in our
solar system is the
Valles Marineris formation on Mars. The
Valles (which were first detected in
1877 by Martian canals) are a huge
canyon system spanning 4,500 x 600 km in area and having a depth up to 8 km. These enormous dimensions are 4-8 times greater than those of the American Grand Canyon. The
Valles is currently understood to have been created by plate tectonics forces like the main
grabens on Earth, rather than by running water. Later, though, it may have been
expanded considerably by erosion, possibly including the action of surface water.
Ice
natural satellite of the gas planets
Jupiter,
Saturn and Neptune were also photographed by the two Voyager program as well as by other space probes. Some linear ruptures in the ice or apparent low areas between hills have been interpreted by astrogeology as tectonic structures or valleys similar to grabens or active geologic
Rift (geology) on Earth.
See also
, Costa Rica.
- Canyon, Vale, Gorge, Channel (geography), Gully
- Clammy, Cliff, Glacial landforms, Side valley
- Geography, Geomorphology, Geodynamics, Glaciology
- Landform, List of mountain ranges
- Geological features of the solar system, List of valleys on the Moon
- List of mountains on Mars, List of lineae on Europa, List of geological features on Titan, (escarpments and rupes).
References
External links
- Univ.of Wisconsin
- Glacial moraine types (LEO dictionary)
- Glossary of Alpine Glacial Landforms
- SAR interferometry (analysis of valley forms in Fig.2 and 6)
- Shoulder of the Swiss Calanca valley near Braggio
- Typical valley sections (=> U valleys and terrace valleys)
- V-shaped valley
Extraterrestrial valleys
- ESA image: Vallis Alpes, bisecting the Lunar Alps
- Valles Marineris and Ophir Chasma, bilingual website (English language and German language)
This article is about the physical-geographic term. For places named "Valley" see Valley (disambiguation).
in East
Iceland, a rather flat valley
In
geology, a
valley is a
Depression (geology) with predominant extent in one direction. A very deep river valley may be called a
canyon or
gorge.
The terms U-shaped valley and V-shaped are descriptive terms of geography to characterize the form of valleys. Most valleys belong to one of these two main types or a mixture of them, at least with respect of the
cross section (geometry) of the slopes or hillsides.
River valleys
. The shoulders of U or V valleys are often located roughly
halfway up the slopes
A valley formed by
River, or
river valley, is usually V-shaped. The exact shape will depend on the characteristics of the stream flowing through it. Rivers with steep gradients, as in mountain ranges, produce steep walls and a narrow bottom. Shallower slopes may produce broader and gentler valleys, but in the lowest stretch of a river, where it approaches its base level, it begins to deposit sediment and the valley bottom becomes a
floodplain.
A V-shaped valley is formed by downcutting when the flowing stream erodes its channel at a higher rate than the sides are eroded. The resulting landform is a narrow canyon with fast water and little bank (floodplain) on the river sides.
Some broad
V examples are:
Glacial valleys
showing a characteristic U-shape and the broad shoulders in Montana, United States.
A valley carved by
glaciers, or
glacial valley, is normally U-shaped. If we can see the valley, it means the glacier that formed it is no longer there. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice. Floor gradient does not affect the valley's shape, it is the glacier's size that does. Continuously flowing glaciers - espec. in the
ice age - and large sized glaciers carve wide, deep incised valleys.
Examples of U-shaped valleys are found in every mountainous region that has experienced glaciation, usually during the Pleistocene Ice Age.Most present U-shaped valleys started as V-shaped before glaciation. The glaciers carved it out wider and deeper, simultaneously changing the shape. This proceeds through the glacial erosion processes of
plucking and
abrasion, which results in large rocky material (glacial till) being carried in the glacier. A material called boulder clay is deposited on the floor of the valley. As the ice melts and retreats, the valley is left with very steep sides and a wide, flat floor. A
river or stream may remain in the valley. This replaces the original stream or river and is known as a
misfit stream because it is smaller than one would expect given the size of its valley.
Other interesting glacially-carved valleys are the
Transition forms and valley shoulders
/Utah with very striking shoulders
Depending on the topography, the
rock types and the
climate, a lot of transition forms between V-, U- and plain valleys exist. Their bottoms can be broad or narrow, but characteristic is also the type of valley shoulder. The broader a mountain valley, the lower its shoulders are located in most cases. An important exception are canyons where the shoulder almost is near the top of the valley's slope. In the Alps - e.g. the
Tyrolean Inn River valley - the shoulders are quite low (100-200 meters above the bottom). Many villages are located here (esp. at the sunny side) because the climate is very mild: even in winter when the valley's floor is completely filled with fog, these villages are in Sunlight.
In some stress-tectonic regions of the Rocky mountains or the Alps (e.g. Salzburg) the
side valleys are parallel to each other, and additionally they are hanging valleys. The brooks flow into the river in form of deep
gorges or waterfalls. Usually this fact is the result of a violent erosion of the former valley shoulders. A special genesis we find also at
arêtes and glacial
Cirque (landform), at every Scottish glen, or a northern
fjord.
Hanging valleys
flowing from a hanging valley.
A
hanging valley is a tributary valley with the floor at a higher relief than the main channel into which it flows. They are most commonly associated with U-shaped valleys when 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.
Valley floors
Usually the bottom of a main valley is broad - independent of the U or V shape. It typically ranges from about one to ten kilometres in width and is commonly filled with mountain
sediments. The shape of the floor can be rather
Horizontal plane, similar to a flat
Cylinder (geometry), or stream terraced.
Side valleys are rather V than U-shaped; near the mouth clammy are possible if it is a
hanging valley. The location of the
villages depends on the across-valley profile, on
climate and local traditions, and on the danger of
avalanches or
landslides. Predominant are places on terraces or alluvial fans if they exist.
Historic siting of villages within the
mainstem (hydrology) valleys, however, have chiefly considered the potential of flooding.
== Hollows ==
A
hollow is a small valley or dry stream bed. This term is commonly used in
New England, Arkansas, Missouri and Pennsylvania to describe such geographic features. Also used in
Southern Appalachia, but pronounced "holler." Hollows may be formed by
river valleys such as Mansfield Hollow or they may be relatively dry clefts with a notch-like characteristic in that they have a height of land and consequent
water divide in their bases. A hollow such as this is Boston Hollow. Tourists in Europe can further visit a lot of karst, stalactite and
ice hollows (e.g. in
Slovenia and Austria).
Famous valleys
Rift valleys
Rift valleys, such as the
Great Rift Valley, are formed by the expansion of the Earth's crust due to Plate tectonics activity beneath the Earth's surface.
Extraterrestrial valleys
The other
terrestrial planets and the natural satellites of our Solar System can also have valley-like features. List of valleys on the Moon can be formed from a linked chain of impact craters. Smaller valleys, known as rilles, may have originated from lava flows or from the contractions of cooling lava sheets.
Besides the lunar
Impact crater, the details of lunar mountain ranges have been well known for more than 300 years (e.g. Johann Hieronymus Schröter's
Selenotopographische Fragmente of
1791). A lot of linear phenomena like Vallis Rheita or Schröter valley and the famous
Vallis Alpes (see also below) were observed with details less than 1 km (which corresponds to a coin seen from 5-10 km distance)—but the geological genesis was debated until the
Apollo 11 mission in 1969. Astronomers have long been able to observe some
highlands and mountains on Mars, and therefore guessed that there may be valleys, as well. In the 1970s this interpretation was proven correct by results from
space probes. Valleys have also been found on Mercury (planet) and on the volcanic surfaces of
Venus and
Io (moon).
The largest valley in our solar system is the
Valles Marineris formation on Mars. The
Valles (which were first detected in 1877 by
Martian canals) are a huge
canyon system spanning 4,500 x 600 km in area and having a depth up to 8 km. These enormous dimensions are 4-8 times greater than those of the American Grand Canyon. The
Valles is currently understood to have been created by plate tectonics forces like the main
grabens on Earth, rather than by running water. Later, though, it may have been
expanded considerably by erosion, possibly including the action of surface water.
Ice natural satellite of the gas planets Jupiter,
Saturn and
Neptune were also photographed by the two
Voyager program as well as by other space probes. Some linear ruptures in the ice or apparent low areas between hills have been interpreted by
astrogeology as tectonic structures or valleys similar to grabens or active geologic
Rift (geology) on Earth.
See also
, Costa Rica.
- Canyon, Vale, Gorge, Channel (geography), Gully
- Clammy, Cliff, Glacial landforms, Side valley
- Geography, Geomorphology, Geodynamics, Glaciology
- Landform, List of mountain ranges
- Geological features of the solar system, List of valleys on the Moon
- List of mountains on Mars, List of lineae on Europa, List of geological features on Titan, (escarpments and rupes).
References
External links
- Univ.of Wisconsin
- Glacial moraine types (LEO dictionary)
- Glossary of Alpine Glacial Landforms
- SAR interferometry (analysis of valley forms in Fig.2 and 6)
- Shoulder of the Swiss Calanca valley near Braggio
- Typical valley sections (=> U valleys and terrace valleys)
- V-shaped valley
Extraterrestrial valleys
Thames Valley Police - Home Page
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From Ware in Hertfordshire to East London, the Regional Park provides leisure activities for all ages, tastes and abilities.
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Specialist sports and luxury vehicle dismantlers. Catalogue and contact details.
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Provides information relating to council services and activities reflecting the tourist, business and wider community of the area.
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News, events, council, services, district guide, business, history, community and links. Upper Weardale, Lower Weardale, Crook District and Bishop Auckland District.
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Aimed primarily at local residents, the site provides information on the Council and its services.
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Hotel and restaurant with golf course. Profile, facilities and information about functions.
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Official website featuring airport information, arrival and departure times, news and job opportunities.
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Blyth Valley is one of six Borough or District Councils in the county of Northumberland. Their official site contains details on the council and its services as well as leisure and ...