Pyramidal peak
Encyclopedia
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
top that has been modified by the action of ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
during glaciation and frost
Frost
Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...
weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...
. If the use is unambiguous within a mountain context, then the simple terms peak or horn may be used.
Formation
Ice fields at the head of glacierGlacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
s develop bowl-shaped basins
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
in the sides of a mountain called cirque
Cirque
Cirque may refer to:* Cirque, a geological formation* Makhtesh, an erosional landform found in the Negev desert of Israel and Sinai of Egypt*Cirque , an album by Biosphere* Cirque Corporation, a company that makes touchpads...
s (sometimes called corries or cwms). Cirque glaciers have specific characteristics. They have rotational sliding that abrades the floor of the basin but not the edge and that causes the bowl shape to form and also contributes to the development of the morainal or rock thresholds that separate them from downvalley slopes as well as hold in glacial lake
Glacial lake
A glacial lake is a lake with origins in a melted glacier. Near the end of the last glacial period, roughly 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large deposits of ice in hollows between drumlins or hills. As the ice age ended, these melted to create...
s called tarns. As cirques are formed by glaciation in an alpine environment, the headwall and ridges known as arête
Arete
Areté is the term meaning "virtue" or "excellence", from Greek ἈρετήArete may also be used:*as a given name of persons or things:**Queen Arete , a character in Homer's Odyssey.***197 Arete, an asteroid....
s become more steep and defined. This occurs due to freeze/thaw and mass wasting beneath the ice surface. It is widely held that a common cause for headwall steepening and extension headward is the crevasse
Crevasse
A crevasse is a deep crack in an ice sheet rhys glacier . Crevasses form as a result of the movement and resulting stress associated with the sheer stress generated when two semi-rigid pieces above a plastic substrate have different rates of movement...
s known as bergschrund
Bergschrund
A bergschrund is a crevasse that forms where the moving glacier ice separates from the stagnant ice above. It is often a serious obstacle for mountaineers, who sometimes abbreviate "bergschrund" to "schrund"....
that occur between the moving ice and the headwall. This is a location where plucking and shattering has been seen by observers that explore the crevasses. A completed cirque is exposed as the glacier that was in the cirque melts away, after the periods of glaciation in the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
. When there are three or more of these cirque headwalls and arêtes joined together to form a single peak it creates a pyramid shape with very steep walls and it is called a horn or glacial horn. They are a common shape for mountain tops in well glaciated areas. The number of faces that make up the sides of a horn are dependent on the number of cirques involved in the formation of the peak, but the most common number of faces for a horn to have is three or four.
A glacial horn takes the process to its limits, producing near vertical faces on all sides. In the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
, "Horn" is also the name of very exposed peaks with slope inclinations of 45-60° (e.g. Kitzbühel
Kitzbühel
-Demographic evolution:-Personalities:*Karl Wilhelm von Dalla Torre , entomologist and botanist*Alfons Walde , expressionist painter and architect*Peter Aufschnaiter , mountaineer and geographer...
er Horn).
Examples
Examples of horns include:- The MatterhornMatterhornThe Matterhorn , Monte Cervino or Mont Cervin , is a mountain in the Pennine Alps on the border between Switzerland and Italy. Its summit is 4,478 metres high, making it one of the highest peaks in the Alps. The four steep faces, rising above the surrounding glaciers, face the four compass points...
in ZermattZermattZermatt is a municipality in the district of Visp in the German-speaking section of the canton of Valais in Switzerland. It has a population of about 5,800 inhabitants....
, on the border between Switzerland and Italy, - The KitzsteinhornKitzsteinhornThe Kitzsteinhorn is a mountain in the main chain of the Alps in the district of Kaprun, Salzburg, Austria. The Kitzsteinhorn is part of the Hohe Tauern range in the eastern Alps and reaches a height of above sea level. It was first climbed in 1828 by Johann Entacher.The summit can be reached...
near KaprunKaprunKaprun is a small alpine village in the district of Zell am See in the state of Salzburg, Austria. At the foot of the Kitzsteinhorn Glacier, it is a year round sports centre, with a population of 2,903 ....
in Salzburg, AustriaAustriaAustria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
, - Mt Blanc above ChamonixChamonixChamonix-Mont-Blanc or, more commonly, Chamonix is a commune in the Haute-Savoie département in the Rhône-Alpes region in south-eastern France. It was the site of the 1924 Winter Olympics, the first Winter Olympics...
in eastern France, - Mount ThielsenMount ThielsenMount Thielsen, or Big Cowhorn, is an extinct shield volcano in the Oregon High Cascades, near Mount Bailey. Because Mount Thielsen stopped erupting 250,000 years ago, glaciers have heavily eroded the volcano's structure, creating precipitous slopes and its horn-like peak...
in Oregon, USA, - Mount WilburMount Wilbur (Montana)Mount Wilbur is located in the Lewis Range, Glacier National Park in the U.S. state of Montana Plainly visible from the region of Many Glacier, the peak rises over above Swiftcurrent Lake and is a steep pyramid on three sides. The west slopes of the peak join to ridges along the continental...
in Glacier National Park, Montana, USA, - Reynolds MountainReynolds MountainReynolds Mountain is located in the Lewis Range, Glacier National Park in the U.S. state of Montana. Reynolds Mountain is situated along the Continental Divide and is easily seen from Logan Pass by looking due south from the pass. Hidden Lake is located below Reynolds Mountain to the west....
, Glacier National Park, USA, and - The Grand TetonGrand TetonGrand Teton is the highest mountain in Wyoming's Grand Teton National Park, and a classic destination in American mountaineering.- Geography :...
, WyomingWyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
, USA. - Stob Dearg, (1022 m), GlencoeGlen CoeGlen Coe is a glen in the Highlands of Scotland. It lies in the southern part of the Lochaber committee area of Highland Council, and was formerly part of the county of Argyll. It is often considered one of the most spectacular and beautiful places in Scotland, and is a part of the designated...
, ScotlandScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the... - Mount AssiniboineMount AssiniboineMount Assiniboine, also known as Assiniboine Mountain, is a mountain located on the Great Divide, on the British Columbia/Alberta border in Canada....
, (3618 m), British ColumbiaBritish ColumbiaBritish Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean... - Mount Aspiring/Tititea, OtagoOtagoOtago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...
, New ZealandNew ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga... - Nevado Las AgujasNevado Las AgujasNevado Las Agujas is a pyramidal peak in the Andes of Futrono close to the border of Chile and Argentina. Together with Cerro Chihuío it forms the granitic mountain massif of Nevados Las Agujas which geologically belong to the Northern Patagonian Batholith....
, Los Ríos RegionLos Ríos RegionThe XIV Los Ríos Region is one of Chile's 15 first order administrative divisions. Its capital is Valdivia. Pop. 356,396 . It began to operate as region on October 2, 2007. It was created by subdividing the Los Lagos Region in southern Chile...
, ChileChileChile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far... - Shivling (Garhwal Himalaya)Shivling (Garhwal Himalaya)Shivling is a mountain in the Gangotri Group of peaks in the western Garhwal Himalaya, near the snout of the Gangotri Glacier. It lies in the northern Indian state of Uttarakhand, south of the Hindu holy site of Gaumukh . Its name refers to its status as a sacred symbol of the God - Lord Shiva's...
, UttarakhandUttarakhandUttarakhand , formerly Uttaranchal, is a state in the northern part of India. It is often referred to as the Land of Gods due to the many holy Hindu temples and cities found throughout the state, some of which are among Hinduism's most spiritual and auspicious places of pilgrimage and worship...
, IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...