Mountain chain

A mountain chain is a row of high mountain summits, a linear sequence of interconnected or related mountains,[1] or a contiguous ridge of mountains within a larger mountain range. The term is also used for elongated fold mountains with several parallel chains ("chain mountains").

While in mountain ranges, the term mountain chain is common, in hill ranges a sequence of hills tends to be referred to a ridge or hill chain.

Elongated mountain chains occur most frequently in the orogeny of fold mountains, (that are folded by lateral pressure), and nappe belts (where a sheetlike body of rock has been pushed over another rock mass). Other types of range such as horst ranges, fault block mountain or truncated uplands rarely form parallel mountain chains. However, if a truncated upland is eroded into a high table land, the incision of valleys can lead to the formations of mountain or hill chains.

Zell-Pfarre Peiner Kobla 01
The Karavanks, a single, long mountain chain. This is the Koschuta ridge near Zell, Carinthia

Formation of parallel mountain chains

Satellitenaufnahme der Alpen
In this satellite image of the Alps, the snow limit picks out the individual mountain chains
Централен Балкан
A view of the Balkan Mountains chain

The chain-like arrangement of summits and the formation of long, jagged mountain crests – known in Spanish as sierras ("saws") – is a consequence of their collective formation by mountain building forces. The often linear structure is linked to the direction of these thrust forces and the resulting mountain folding which in turn relates to the fault lines in the upper part of the earth's crust, that run between the individual mountain chains. In these fault zones, the rock, which has sometimes been pulverised, is easily eroded, so that large river valleys are carved out. These, so called longitudinal valleys reinforce the trend, during the early mountain building phase, towards the formation of parallel chains of mountains.

The tendency, especially of fold mountains (e. g. the Cordilleras) to produce roughly parallel chains is due to their rock structure and the propulsive forces of plate tectonics. The uplifted rock masses are either magmatic plutonic rocks, easily shaped because of their higher temperature, or sediments or metamorphic rocks, which have a less robust structure, that are deposited in the synclines. As a result of orogenic movements, strata of folded rock are formed that are crumpled out of their original horizontal plane and thrust against one another. The longitudinal stretching of the folds takes place at right angles to the direction of the lateral thrusting. The overthrust folds of a nappe belt (e.g. the Central Alps) are formed in a similar way.

Although the fold mountains, chain mountains and nappe belts around the world were formed at different times in the earth's history, all during their initial mountain building phases, they are nevertheless morphologically similar. Harder rock forms continuous arêtes or ridges that follow the strike of the beds and folds. The mountain chains or ridges therefore run approximately parallel to one another. They are only interrupted by short, usually narrow, transverse valleys, which often form water gaps. During the course of earth history, erosion by water, ice and wind carried away the highest points of the mountain crests and carved out individual summits or summit chains. Between them, notches were formed that, depending on altitude and rock-type, form knife-edged cols or gentler mountain passes and saddles.

Dominant rocks and mountain forms

Vedauwoo Rocks in winter
The remains of an old mountain chain in the Laramie Mountains, Colorado

Nappe or fold mountains, with their roughly parallel mountain chains, generally have a common geological age, but may consist of various types of rock. For example, in the Central Alps, granitic rocks, gneisses and metamorphic slate are found, while to the north and south, are the Limestone Alps. The Northern Limestone Alps are, in turn, followed by soft flysch mountains and the molasse zone.

The type of rock influences the appearance of the mountain ranges very markedly, because erosion leads to very different topography depending on the hardness of the rock and its petrological structure. In addition to height and climate, other factors are the layering of the rock, its gradient and aspect, the types of waterbody and the lines of dislocation. For hard rock massifs, rugged rock faces (e.g. in the Dolomites) and mighty scree slopes are typical. By contrast, flysch or slate forms gentler mountain shapes and kuppen or domed mountaintops, because the rock is not porous, but easily shaped.

See also

References

  1. ^ Whittow, John (1984). Dictionary of Physical Geography. London: Penguin, p 87. ISBN 0-14-051094-X.

Literature

  • Wissen heute: Geologie. Kaiser-Verlag, Florence/Klagenfurt, 1995
  • Der geologische Aufbau Österreichs. Geologische Bundesanstalt, Springer-Verlag Vienna/ New York
  • PanGeo, Erdwissenschaften in Österreich. Conference proceedings, 200 pp., Sessions on the Neogene, TRANSALP I and II. Univ. Salzburg, 2005
  • Fischer-Lexikon Geographie, pp. 101–129, Frankfurt, 1959
  • Großer Weltatlas, Enzyklopädischer Teil (mountain building, folds and faults, the rock cycle). Publ. ÖAMTC, Vienna, ~1980
  • André Cailleux: Der unbekannte Planet: Anatomie der Erde. Kindlers Universitätsbibliothek, Munich, 1968, Chapters 1 and 3
  • Gebirge, in: Lueger, Otto: Lexikon der gesamten Technik und ihrer Hilfswissenschaften, Vol. 4 Stuttgart, Leipzig, 1906, pp. 316-317.
Alleghanian orogeny

The Alleghanian orogeny or Appalachian orogeny is one of the geological mountain-forming events that formed the Appalachian Mountains and Allegheny Mountains. The term and spelling Alleghany orogeny was originally proposed by H.P. Woodward in 1957.

The Alleghanian orogeny occurred approximately 325 million to 260 million years ago over at least five deformation events in the Carboniferous to Permian period. The orogeny was caused by Africa colliding with North America. At the time, these continents did not exist in their current forms: North America was part of the Euramerica super-continent, while Africa was part of Gondwana. This collision formed the super-continent Pangaea, which contained all major continental land masses. The collision provoked the orogeny: it exerted massive stress on what is today the Eastern Seaboard of North America, forming a wide and high mountain chain. Evidence for the Alleghanian orogeny stretches for many hundreds of miles on the surface from Alabama to New Jersey and can be traced further subsurface to the southwest. In the north, the Alleghanian deformation extends northeast to Newfoundland. Subsequent erosion wore down the mountain chain and spread sediments both to the east and to the west.

Ardestan

Ardestan (Persian: اردستان‎, also Romanized as Ardestān and Ardistān) is a city and capital of Ardestan County, Isfahan Province, Iran. At the 2006 census, its population was 14,698, in 4,077 families.Ardestan is located at the southern foothills of the Karkas mountain chain and is 110 km northeast of Isfahan. It is believed the city has been founded in Sassanian times and was strongly fortified in the 10th century. A Seljuk-era mosque, a bazaar, several ab anbars, and historical houses of the old town are among the tourist attractions of Ardestan. Mulberry, pomegranate and a special kind of fig are the main orchard products of the town.

It has been said that the birthplace of Hassan Modarres.

Calder Hill

Calder Hill is a small mountain chain in the Central New York region of New York. It is located north of Otego, New York. It is made of two main peaks with the highest being 1841 feet.

Calder Hill was named after Godfrey Calder.

Cornish Hill

Cornish Hill is a small mountain chain, made of two main elevations the tallest being 2,231 feet (680 m). Cornish Hill is located in the Central New York region of New York southeast Cooperstown, New York.

Crumhorn Mountain

Crumhorn Mountain is a small mountain chain located in Central New York region of New York by Portlandville, New York.

Dutch Hill (Otsego County, New York)

Dutch Hill is a small mountain chain located in Central New York region of New York northwest of Portlandville, New York. It consists of two peaks the highest being 1699 feet.

Gifford Hill (Otsego County, New York)

Gifford Hill is a small mountain chain in the Central New York Region of New York. It is located northeast of Oneonta, New York. It is made of three main peaks the highest being 1928 feet. Gifford Hill is named for the Gifford Family who moved to the area in 1803 and settled along the Oneonta Creek on what is now called Gifford Hill.The west side of Gifford Hill drains into Oneonta Creek and the east side of the hill drains into Gifford Creek.

Honey Hill (Otsego County, New York)

Honey Hill is a small mountain chain located in Central New York Region of New York north of South Valley, New York. It consists of two main peaks the highest being 2181 feet.

Hoosac Range

The Hoosac Range is a mountain range that forms part of both the Berkshires of western Massachusetts and the southern Green Mountains of Vermont, both of which are part of the greater Appalachian Mountain chain. Notable peaks include Haystack Mountain and Mount Snow in Vermont and Spruce Mountain in Massachusetts, as well as the Berkshires' high point, Crum Hill, which is located in the town of Monroe, Massachusetts.

The 4.75-mile-long (7.64 km) Hoosac Tunnel passes through the range.

Hutchinson Hill

Hutchinson Hill is a small mountain chain in the Central New York Region of New York. It is located east of Rockdale, New York. It is made of two main peaks. The tallest peak is 1884 feet.

Monteregian Hills

The Monteregian Hills (French: Collines Montérégiennes) is a linear chain of isolated hills in Montreal and Montérégie, between the Laurentians and the Appalachians.

Mount Zion (New York)

Mount Zion is a small mountain chain in the Central New York region of New York. It is located southwest of Otego, New York. It is made of two main peaks. One is in Otsego County and the other, being the tallest at 1988 feet, in Delaware County.

North Georgia mountains

The Georgia Mountains Region or North Georgia mountains or Northeast Georgia is an area that starts in the northeast corner of Georgia, United States, and spreads in a westerly direction. The mountains in this region are in the Blue Ridge mountain chain that ends in Georgia. At over 1 billion years of age, the Blue Ridge mountains are among the oldest mountains in the United States and sometimes mistaken to be the oldest mountains in the world (they are only about one third of the age of South Africa's 3.6 billion year old Barberton greenstone belt.). The mountains in this region are also a part of the vast system of North American mountains known as the Appalachian Mountains that spans most of the United States longitudally along the eastern areas of the nation and terminates in Alabama.

The region is known for its ruggedness and scenic beauty. The Cherokee who lived in these mountains called them ᏌᏆᎾᎦ/Sah-ka-na'-ga - "Blue Smoke Mountains

" Large portions of the North Georgia mountains are included in the more than 750,000 acres (3,000 km2) that comprises the Chattahoochee National Forest.

Owen Stanley Range

Owen Stanley Range is the south-eastern part of the central mountain-chain in Papua New Guinea.

Pigeon Hill (New York)

Pigeon Hill is a small mountain chain located in Central New York region of New York located northeast of Burlington, New York. It is made by four main peaks with the highest being 2057 feet.

Rhodope Mountains

The Rhodopes (; Bulgarian: Родопи, Rodopi; Greek: Ροδόπη, Rodopi; Turkish: Rodoplar) are a mountain range in Southeastern Europe, with over 83% of its area in southern Bulgaria and the remainder in Greece. Golyam Perelik is its highest peak at 2,191 meters (7,188 ft). The mountain range gives its name to the terrestrial ecoregion Rodope montane mixed forests that belongs in the temperate broadleaf and mixed forests biome and the palearctic ecozone. The region is particularly notable for its karst areas with their deep river gorges, large caves and specific sculptured forms, such as the Trigrad Gorge.

A significant part of Bulgaria's hydropower resources are located in the western areas of the range. There are a number of hydro-cascades and dams used for electricity production, irrigation and as tourist destinations. In Greece there are also the HPPs of Thisavros and Platanovrysi. The Rhodopes have a rich cultural heritage including ancient Thracian sites such as Perperikon, Tatul and Belintash, and medieval castles, churches, monasteries and picturesque villages with traditional Bulgarian architecture from the 18th and 19th centuries.

Scandinavian Mountains

The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The Scandinavian Mountains are often erroneously thought to be equivalent to the Scandinavian Caledonides, an ancient mountain range and orogen covering roughly the same area. 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, still 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 (Nordkapp).

The mountains are not very high, but are very steep at places; Galdhøpiggen in South Norway is the highest peak in mainland Northern Europe, at 2,469 metres (8,100 ft), Kebnekaise has the highest peak on the Swedish side, at 2,104 m (6,903 ft), whereas the slope of Halti is the highest point in Finland, at 1,324 m (4,344 ft), although the peak of Halti is situated in Norway.

The combination of a northerly location and moisture from the North Atlantic Ocean has caused the formation of many ice fields and glaciers. Temperature drops with increasing altitude; in South Norway, permafrost becomes common from about 1,500 meters above sea level on the western slope, and at about 1,200 meters above sea level on the eastern slope near the border with Sweden. In Northern Norway, permafrost becomes common from around 800 to 900 meters above sea level on the western slope, and some 600 meters above sea level on the eastern slope.The Scandinavian Montane Birch forest and grasslands terrestrial ecoregion is closely associated with the mountain range.

South Hill (New York)

South Hill is a mountain chain in Central New York Region of New York. The chain extends from southeast of East Worcester, New York to southeast of Emmons, New York. The highest elevation of the chain is east of Schenevus, New York at 2231 feet.

Taconic orogeny

The Taconic orogeny was a mountain building period that ended 440 million years ago and affected most of modern-day New England. A great mountain chain formed from eastern Canada down through what is now the Piedmont of the East coast of the United States. As the mountain chain eroded in the Silurian and Devonian periods, sediments from the mountain chain spread throughout the present-day Appalachians and midcontinental North America.

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