Mountain

views updated May 21 2018

Mountain

Rock band

For the Record

Selected discography

Sources

When it comes to heavy rock bands, Mountain definitely qualifies. The group was in the vanguard of hard rock/pre-heavy metal bands from the late 1960s, and Leslie Wests thunderous riffing on guitar was a cornerstone of rocks original wall of sound. West was the size of a National Football League lineman, and the band no doubt took its moniker as a monument to his impressive stature. Numerous musicians have played under the Mountain banner over the years, but the group at its most essential consists of just three members: West, bassist Felix Pappalardi, and drummer Corky Laing.

West was born Leslie Weinstein on October 22, 1945, in Forest Hills, New York. He is one of many second generation rock n rollers whose life was changed by seeing Elvis Presley for the first time. Wests uncle was a writer for the Jackie Gleason Show and took him to see a performance of its summer replacement show hosted by Tommy and Jimmy Dorsey. Presley was a guest on the show and West was transfixed. Ive been playing guitar ever since that day, he told Goldmine magazine in 1995. West attended numerous private schools, but a standardized education was not for him. In school they just werent teaching me anything I was interested in, and the teachers were asking me questions I already knew the answers to, and learning dates and all that stuff, it just never appealed to me, he told Goldmine. Instead, he worked as a jeweler for a short time, but mainly spent his time practicing guitar. Wests first band was called the Vagrants, a barely capable Long Island group that specialized in rhythm and blues, and actually recorded the song Respect before Aretha Franklins famous version. The Vagrants recorded several singles for the Vanguard label, and then for Atco. They were assigned to work with producer Felix Pappalardi, who was then riding high as the producer of famed English power trio Cream.

Pappalardi was born in 1939 in the Bronx, New York, and began learning guitar at the age of four. Determined to devote his life to making music, he attended the High School of Music and Art in Manhattan. After stints in college and the United States Army, he returned to New York and fell headlong into the burgeoning Greenwich Village folk scene. Among the musicians he worked with were John Sebastian (soon to be of the Lovin Spoonful), Cass Elliot (future member of the Mamas and the Papas), Richie Havens, and Joan Baez. His early successes as a producer include the Youngbloods seminal single Get Together. His reputation skyrocketed after his work with Cream, whose records Disraeli Gears, Wheels of Fire, and Goodbye he produced and arranged.

West talked about meeting Pappalardi with Goldmine: Atlantic Records sent him down to produce for the Vagrants. He walked in and I think he had just met Cream. He produced our single, we broke up and then he said, Well, if you guys get something together, give

For the Record

Members include Mark Clarke (member 1985-present), bass; Steve Knight (member 1970-72, 1985-present), organ; Corky Laing (born January 26, 1948, in Montreal, Canada; member 1970-72, 1985-present), drums; Bob Mann (member 1974), keyboards; Felix Pappalardi (born 1939 in the Bronx, New York, NY; died on April 17, 1983), bass, vocals; Alan Schwartzberg (member 1974), drums; N.D. Smart II (member 1969), drums; Leslie West (born Leslie Weinstein on October 22, 1945 in Forest Hills, NY), guitar, vocals.

Formed in 1969 in New York City, NY; released debut album, Mountain Climbing, 1970; disbanded, 1972; reformed 1974, 1985, and periodically during the 1990s-2000s.

Addresses: Record company Columbia Records, 550 Madison Ave., New York, NY 10022-3211, (212) 833-8000. Website Leslie West website: http://www.lesliewest.cjb.net.

me a call. Later he began working with Cream, and he said if Id got something together, he would give it a listen, so I called him right away, as soon as he got back from England. He liked it. But then he went in the studio with me and he didnt like my drummer. So I had to get another drummer; I had a bass player and an organ player. Felix didnt like the bass player, so his partner suggested he play bass, so he did. That was the beginning of my solo career.

What is often thought of as the first Mountain album is really a Leslie West solo album, which was not incidentally titled Mountain. Pappalardi plays bass on the record, N.D. Smart played drums, and in an attempt to differentiate the sound from that of Cream, Steve Knight was added on keyboards. The lineup from the West album became a band, and they debuted at San Franciscos Fillmore West in July of 1969. They played a couple of other gigs, and then, by virtue of sharing management with Jimi Hendrix, their fifth show ever was played at Woodstock. I remember hanging around backstage and Janis Joplin had this gorgeous girlfriend she was hanging out with, West told Goldmine about the famed concert. I was in awe of everything there. I remember Creedence Clearwater Revival went on and they did one hit after another. I couldnt believe how many hit singles they had! Our first album I think was just coming out.

Drummer Smart had a falling out with the band after that, and they immediately replaced him with Corky Laing, who had been hanging out with the group, and whose own band had a record produced by Pappalardis wife, Gail Collins. Laing was born on January 26, 1948, in Montreal, Canada. With its lineup solidified for a while, they recorded Mountain Climbing, technically the groups debut, which went gold thanks in large part to the hit single and enduring Mountain classic Mississippi Queen. The group struck gold again with the album Nantucket Sleighride, which featured a jam-heavy title track. After that album, the group quickly recorded another, the ominously titled Flowers of Evil, and a live disc, The Road Goes Ever On. But by then, drugs and dissension in the ranks had made being in the band unbearable, and the group split up.

Papplardi returned to production work. Knight all but vanished. West and Laing joined with ex-Cream bassist Jack Bruce to form the second-tier supergroup West, Bruce and Laing, which recorded three albums before disbanding. From there, West and Laing soldiered on in a group called Leslie Wests Wild West Show. Pappalardiwho suffered hearing damage from his days as a musician, particularly with Mountain, who always played at top volumerejoined in 1974. They recorded the album Avalanche, and then broke up again. After that, West resumed his solo career, though Laing continued to work with him. Albums from this period include The Great Fatsby West was always one to make a joke about his weight at his own expensewith the Leslie West Band. A long fallow period came in the late 70s and early 80s, during which time West did not record. The inner circle of Mountain was sundered forever in 1983 when Pappalardis wife shot and killed him.

West returned in 1985 with a new version of the band that included Laing and bassist Mike Clarke. They recorded the album Go for Your Life in 1986. Wests solo albums Theme and Alligator arrived in the late 80s. Laing meanwhile led a blues band that featured former Rolling Stones guitarist Mick Taylor.

The 90s were a return to even more action for West and Laing separately, and in tandem. West has continued to make solo albums, and has even shed some of his famous poundage. He remains in the limelight these days as a musician, but also as a frequent guest on Howard Sterns syndicated radio show. Laing recently formed the band Cork, featuring former Spin Doctors guitarist Eric Schenkman. Their album Speed ofThoughtwas released in 1999. For years, Laing was also an executive for the Canadian branch of Polygram Records. Mountain continues to tour occasionally, and lineups in the mid-90s occasionally featured former Jimi Hendrix Experience bassist Noel Redding. Needless to say, Mountain without Felix is not the original Mountain, Laing told Goldmine. Its the other two guys, its two-thirds, and we dont try to fool anybody by that.

Selected discography

Mountain Climbing, Windfall, 1970.

Nantucket Sleighride, Windfall, 1971.

Flowers of Evil, Windfall, 1971.

Mountain Live (The Road Goes Ever On), Windfall, 1972.

Best of Mountain, Windfall, 1973.

Twin Peaks, Columbia, 1973.

Avalanche, Columbia, 1974.

Go for Your Life, Scotti Bros., 1986.

Over the Top, Columbia Legacy, 1995.

Leslie West

Mountain, Windfall, 1969.

The Great Fatsby, Phantom, 1975.

Live, Blues Bureau International, 1993.

Dodginthe Dirt, Blues Bureau International, 1994.

Blood of the Sun, Raven, 1996.

As Phat as It Gets, Lightyear, 1999.

West, Bruce & Laing

Why Dontcha, Columbia, 1972.

Whatever Turns You On, Columbia, 1973.

Live n Kickin, Columbia.

Corky Laing

(With Cork) Speed of Thought, Lightyear, 1999

Sources

Books

Graff, Gary, and Daniel Durchholz, editors, MusicHound Rock: The Essential Album Guide, Visible Ink Press, 1999.

Romanowski, Patricia, and Holly George-Warren, editors, The Rolling Stone Encyclopedia of Rock and Roll, Fireside/Simon & Schuster, 1995.

Periodicals

Goldmine, 1995.

Online

Leslie West website, http://www.lesliewest.cjb.net (September 2000).

Daniel Durchholz

Mountains

views updated May 29 2018

MOUNTAINS

CONCEPT

Among the most striking of geologic features are mountains, created by several types of tectonic forces, including collisions between continental masses. Mountains have long had an impact on the human psyche, for instance by virtue of their association with the divine in the Greek myths, the Bible, and other religious or cultural traditions. One does not need to be a geologist to know what a mountain is; indeed there is no precise definition of mountain, though in most cases the distinction between a mountain and a hill is fairly obvious. On the other hand, the defining characteristics of a volcano are more apparent. Created by violent tectonic forces, a volcano usually is considered a mountain, and almost certainly is one after it erupts, pouring out molten rock and other substances from deep in the earth.

HOW IT WORKS

Plate Tectonics

Earth is constantly moving, driven by forces beneath its surface. The interior of Earth itself is divided into three major sections: the crust, mantle, and core. The lithosphere is the upper layer of Earth's interior, including the crust and the brittle portion at the top of the mantle. Tectonism is the deformation of the lithosphere, and the term tectonics refers to the study of this deformation. Most notable among examples of tectonic deformation is mountain building, or orogenesis, discussed later in this essay.

The planet's crust is not all of one piece: it is composed of numerous plates, which are steadily moving in relation to one another. This movement is responsible for all manner of phenomena, including earthquakes, volcanoes, and mountain building. All these ideas and many more are encompassed in the concept of plate tectonics, which is the name for a branch of geologic and geophysical study and of a dominant principle often described as "the unifying theory of geology" (see Plate Tectonics).

CONTENTS UNDER PRESSURE.

Tectonism results from the release and redistribution of energy from Earth's interior. This energy is either gravitational, and thus a function of the enormous mass at the planet's core, or thermal, resulting from the heat generated by radioactive decay. Differences in mass and heat within the planet's interior, known as pressure gradients, result in the deformation of rocks, placing many forms of stress and strain on them.

In scientific terms, stress is any attempt to deform an object, and strain is a change in dimension resulting from stress. Rocks experience stress in the form of tension, compression, and shear. Tension acts to stretch a material, whereas compression is a form of stress produced by the action of equal and opposite forces, whose effect is to reduce the length of a material. (Compression is a form of pressure.) Shear results from equal and opposite forces that do not act along the same plane. If a thick, hardbound book is lying flat, and one pushes the front cover from the side so that the covers and pages are no longer in alignment, is an example of shear.

Rocks manifest the strain resulting from these stresses by warping, sliding, or breaking. They may even flow, as though they were liquids, or melt and thus truly become liquid. As a result, Earth's interior may manifest faults, or fractures in rocks, as well as folds, or bends in the rock structure. The effects can be seen on the surface in the form of subsidence, which is a depression in the crust; or uplift, the raising of crustal materials. Earthquakes and volcanic eruptions also may result.

Orogenesis

There are two basic types of tectonism: epeirogenesis and orogenesis. The first takes its namefrom the Greek words epeiros, meaning "mainland," and genesis, or "origin." Epeirogenesis, which takes the form of either uplift or subsidence, is a chiefly vertical form of movement and plays little role in either plate tectonics or mountain building.

Orogenesis, on the other hand, is mountain building, as the prefix oros ("mountain") shows. Orogenesis involves the formation of mountain ranges by means of folding, faulting, and volcanic activitylateral movements as opposed to vertical ones. Geologists typically use the term orogenesis, instead of just "mountain building," when discussing the formation of large belts of mountains from tectonic processes.

PLATE MARGINS.

Plates may converge (move toward one another), diverge (move away from one another), or experience transform motion, meaning that they slide against one another. Convergence usually is associated with subduction, in which one plate is forced down into the mantle and eventually undergoes partial melting. This typically occurs in the ocean, creating a depression known as an oceanic trench.

There are three types of plate margins, or boundaries between plates, depending on the two types of crusts that interact: oceanic with oceanic, continental with continental, or continental with oceanic. Any of these margins may be involved in mountain formation. Orogenic belts, or mountain belts, typically are situated in subduction zones at convergent plate boundaries and consist of two types.

The first type occurs when igneous material (i.e., rock from volcanoes) forms on the upper plate of a subduction zone, causing the surface to rise. This can take place either in the oceanic crust, in which case the mountains formed are called island arcs, or along continental-oceanic margins. The Aleutian Islands are an example of an island arc, while the Andes range represent mountains formed by the subduction of an oceanic plate under a continental one.

The second type of mountain belt occurs when continental plates converge or collide. When continental plates converge, one plate may "try" to subduct the other, but ultimately the buoyancy of the lower plate (which floats, as it were, on the lithosphere) pushes it upward. The result is the creation of a wide, unusually thick or "tall" belt. An example is the Himalayas, the world's tallest mountain range, which is still being pushed upward as the result of a collision between India and Asia that happened some 30 million years ago. (See Plate Tectonics for more about continental drift and collisions between plates.)

REAL-LIFE APPLICATIONS

What Is a Mountain?

In the 1995 film The Englishman Who Went Up a Hill But Came Down a Mountain, the British actor Hugh Grant plays an English cartographer, or mapmaker, sent in 1917 by his government to measure what is purportedly "the first mountain inside Wales." He quickly determines that according to standards approved by His Majesty, the "mountain" in question is, in fact, a hill. Much of the film's plot thereafter revolves around attempts on the part of the villagers to rescue their beloved mountain from denigration as a "hill," a fate they prevent by piling enough rocks and dirt onto the top to make it meet specifications.

This comedy aptly illustrates the somewhat arbitrary standards by which people define mountains. The British naturalist Roderick Peattie (1891-1955), in his 1936 book Mountain Geography, maintained that mountains are distinguished by their impressive appearance, their individuality, and their impact on the human imagination. This sort of qualitative definition, while it is certainly intriguing, is of little value to science; fortunately, however, more quantitative standards exist.

In Britain and the United States, a mountain typically is defined as a landform with an elevation of 985 ft. (300 m) above sea level. This was the standard applied in The Englishman, but the Welsh villagers would have had a hard time raising their "hill" to meet the standards used in continental Europe: 2,950 ft. (900 m) above sea level. This seems to be a more useful standard, because the British and American one would take in high plains and other nonmountainous regions of relatively great altitude. On the other hand, there are landforms in Scotland that rise only a few hundred meters above sea level, but their morphologic characteristics or shape seem to qualify them as mountains. Not only are their slopes steep, but the presence of glaciers and snow-capped peaks, with their attendant severe weather and rocky, inhospitable soil, also seem to indicate the topography associated with mountains.

Mountain Geomorphology

One area of the geologic sciences especially concerned with the study of mountains is geomorphology, devoted to the investigation of land-forms. Geomorphologists studying mountains must draw on a wide variety of disciplines, including geology, climatology, biology, hydrology, and even anthropology, because, as discussed at the conclusion of this essay, mountains have played a significant role in the shaping of human social groups.

From the standpoint of geology and plate tectonics, mountain geomorphology embraces a complex of characteristic formations, not all of which are necessarily present in a given orogen, or mountain. These include forelands and fore-deeps along the plains; foreland fold-and-thrust belts, which more or less correspond to "foothills" in layperson's terminology; and a crystalline core zone, composed of several types of rock, that is the mountain itself.

ENVIRONMENTAL ZONES.

Mountain geomorphology classifies various environmental zones, from lowest to highest altitude. Near the bottom are flood plains, river terraces, and alluvial fans, all areas heavily affected by rivers flowing from higher elevations. (In fact, many of the world's greatest rivers flow from mountains, examples being the Himalayan Ganges and Indus rivers in Asia and the Andean Amazon in South America.) Farming villages may be found as high as the 9,845-ft. to 13,125-ft. range (3,000-4,000 m), an area known as a submontane, or forested region.

The tree line typically lies at an altitude of 14,765 ft. (4,500 m). Above this point, there is little human activity but plenty of geologic activity, including rock slides, glacial flow, and, at very high altitudes, avalanches. From the tree line upward, the altitude levels that mark a particular region are differentiated for the Arctic and tropical zones, with much lower altitudes in the Arctic mountains. For instance, the tree line lies at about 330 ft. (100 m) in the much colder Arctic zone.

Above the tree line is the subalpine, or montane, region. The mean slope angle of the mountain is less steep here than it is at lower or higher elevations: in the submontane, or forested region, below the tree line, the slope is about 30°, and above the subalpine, in the high alpine, the slope can become as sharp at 65°. In the subalpine, however, it is only about 20°, and because grass (if not trees) grows in this region, it is suited for grazing.

It may seem surprising to hear of shepherds bringing sheep to graze at altitudes of 16,400 ft. (5,000 m), as occurs in tropical zones. This does not necessarily mean that people live at such altitudes; more often than not, mountain dwellers have their settlements at lower elevations, and shepherds simply take their flocks up into the heights for grazing. Yet the ancient Bolivian city of Tiahuanaco, which flourished in about a.d. 600some four centuries before the rise of the Incalay at an almost inconceivable altitude of 13,125 ft. (4,000 m), or about 2.5 times the elevation of Denver, Colorado, America's Mile-High City.

Classifying Mountains

There are several ways to classify mountains and groups of mountains. Mountain belts, as described earlier, typically are grouped according to formation process and types of plates: island arcs, continental arcs (formed with the subduction of an oceanic plate by a continental plate), and collisional mountain belts. Sometimes a mountain arises in isolation, an example being Kilimanjaro in Tanzania, Africa. Another example is Stone Mountain outside Atlanta, an exposed pluton, or a mass of crystalline igneous rock that forms deep in Earth's crust and rises. Many volcanoes, which we discuss later, arise individually, but mountains are most likely to appear in conjunction with other mountains. One such grouping, though far from the only one, is a mountain range, which can be defined as a relatively localized series of peaks and ridges.

RANGES, CHAINS, AND MASSES.

Some of the world's most famous mountain ranges include the Himalayas, Karakoram Range, and Pamirs in central Asia; the Alps and Urals in Europe; the Atlas Mountains in Africa; the Andes in South America; and the Cascade Range, Sierra Nevada, Rocky Mountains, and Appalachians as well as their associated ranges in North America. Ranges affiliated with the Appalachians, for instance, include the Great Smokies in the south and the Adirondacks, Alleghenies, and Poconos in the north.

Several of the examples given here illustrate the fact that ranges are not the largest groupings of mountains. Sometimes series of ranges stretch across a continent for great distances in what are called mountain chains, an example of which is the Mediterranean chain of Balkans, Apennines, and Pyrenees that stretches across southern Europe.

There also may be irregular groupings of mountains, which lack the broad linear sweep of mountain ranges or chains and which are known as mountain masses. The mountains surrounding the Tibetan plateau represent an example of a mountain mass. Finally, ranges, chains, and masses of mountains may be combined to form vast mountain systems. An impressive example is the Alpine-Himalayan system, which unites parts of the Eurasian, Arabian, African, and Indo-Australian continental plates.

OTHER TYPES OF MOUNTAIN.

There are certain special types of orogeny, as when ocean crust subducts continental crustsomething that is not supposed to happen but occasionally does. This rare variety of subduction is called obduction, and the mountains produced are called ophiolites. Examples include the uplands near Troodos in Cyprus and the Taconic Mountains in upstate New York.

Fault-block mountains appear when two continental masses push against each other and the upper portion of a continental plate splits from the deeper rocks. A portion of the upper crust, usually several miles thick, begins to move slowly across the continent. Ultimately it runs into another mass, creating a ramp. This can result in unusually singular mountains, such as Chief Mountain in Montana, which slid across open prairie on a thrust sheet.

Under the ocean is the longest mountain chain on Earth, the mid-ocean ridge system, which runs down the center of the Atlantic Ocean and continues through the Indian and Pacific oceans. Lava continuously erupts along this ridge, releasing geothermal energy and opening up new strips of ocean floor. This brings us to a special kind of mountain, typically resulting from the sort of dramatic plate tectonic processes that also produce earthquakes: volcanoes.

Volcanoes

Most volcanoes are mountains, and for this reason, it is appropriate to discuss them together; however, a volcano is not necessarily a mountain. A volcano may be defined as a natural opening in Earth's surface through which molten (liquid), solid, and gaseous material erupts. The word volcano also is used to describe the cone of erupted material that builds up around the opening or fissure. Because these cones are often quite impressive in height, they frequently are associated with mountains.

Though volcanic activity has been the case of death and destruction, it is essential to the planet's survival. Volcanic activity is the principal process through which chemical elements, minerals, and other compounds from Earth's interior reach its surface. These substances, such as carbon dioxide, have played a major role in the development of the planet's atmosphere, waters, and soils. Even today, soil in volcanic areas is among the richest on Earth. Volcanoes provide additional benefits in their release of geothermal energy, used for heating and other purposes in such countries as Iceland, Italy, Hungary, and New Zealand (see Energy and Earth). In addition, volcanic activity beneath the oceans promises to supply almost limitless geothermal energy, once the technology for its extraction becomes available.

FORMATION OF VOLCANOES.

As noted earlier, land volcanoes are formed in coastal areas where continental and oceanic plates converge. As the oceanic plate is subducted and pushed farther and farther beneath the continental surface, the buildup of heat and pressure results in the melting of rock. This molten rock, or magma, tends to rise toward the surface and collect in magma reservoirs. Pressure buildup in the magma reservoir ultimately pushes the magma upward through cracks in Earth's crust, creating a volcano.

Volcanoes also form underwater, in which case they are called seamounts. Convergence of oceanic plates causes one plate to sink beneath the other, creating an oceanic trench; as a result, magma rises from the subducted plate to fashion volcanoes. If the plates diverge, magma seeps upward at the ridge or margin between plates, producing more seafloor. This process, known as seafloor spreading, leads to the creation of volcanoes on either side of the ridge.

In some places a plate slides over a stationary area of volcanic activity, known as a hot spot. These are extremely hot plumes of magma that well up from the crust, though not on the edge or margin of a plate. A tectonic plate simply drifts across the hot spot, and as it does, the area just above the hot spot experiences volcanic activity. Hot spots exist in Hawaii, Iceland, Samoa, Bermuda, and America's Yellowstone National Park.

CLASSIFYING VOLCANOES.

Volcanoes can be classified in terms of their volcanic activity, in which case they are labeled as active (currently erupting), dormant (not currently erupting but likely to do so in the future), or extinct. In the case of an extinct volcano, no eruption has been noted in recorded history, and it is likely that the volcano has ceased to erupt permanently.

In terms of shape, volcanoes fall into four categories: cinder cones, composite cones, shield volcanoes, and lava domes. These types are distinguished not only by morphologic characteristics but also by typical sizes and even angles of slope. For instance, cinder cones, built of lava fragments, have slopes of 30° to 40°, and are seldom more than 1,640 ft. (500 m) in height.

Composite cones, or stratovolcanoes, are made up of alternating layers of lava (cooled magma), ash, and rock. (The prefix strato refers to these layers.) They may slope as little as 5° at the base and as much as 30° at the summit. Stratovolcanoes may grow to be as tall as 2-3 mi. (3.2-4.8 km) before collapsing and are characterized by a sharp, dramatic shape. Examples include Fuji, a revered mountain that often serves as a symbol of Japan, and Washington state's Mount Saint Helens.

A shield volcano, which may be a solitary formation and often is located over a hot spot, is built from lava flows that pile one on top of another. With a slope as little as 2° at the base and no more than 10° at the summit, shield volcanoes are much wider than stratovolcanoes, but sometimes they can be impressively tall. Such is the case with Mauna Loa in Hawaii, which at 13,680 ft. (4,170 m) above sea level is the world's largest active volcano. Likewise, Mount Kilimanjaro, though long ago gone dormant, is the tallest mountain in Africa.

Finally, there are lava domes, which are made of solid lava that has been pushed upward. Closely related is a volcanic neck, which often forms from a cinder cone. In the case of a volcanic neck, lava rises and erupts, leaving a mountain that looks like a giant gravel heap. Once it has become extinct, the lava inside the volcano begins to solidify. Over time the rock on the exterior wears away, leaving only a vent filled with solidified lava, usually in a funnel shape. A dramatic example of this appears at Shiprock, New Mexico.

VOLCANIC ERUPTIONS.

Volcanoes frequently are classified by the different ways in which they erupt. These types of eruption, in turn, result from differences in the material being disgorged from the volcano. When the magma is low in gas and silica (silicon dioxide, found in sand and rocks), the volcano erupts in a relatively gentle way. Its lava is thin and spreads quickly. Gas and silica-rich magma, on the other hand, brings about a violent explosion that yields tarlike magma.

There are four basic forms or phases of volcanic eruption: Hawaiian, Strombolian, Vulcanian, and Peleean. The Hawaiian phase is simply a fountain-like gush of runny lava, without any explosions. The Strombolian phase (named after a volcano on a small island off the Italian peninsula) involves thick lava and mild explosions. In a Vulcanian phase, magma has blocked the volcanic vent, and only after an explosion is the magma released, with the result that tons of solid material and gases are hurled into the sky. Most violent of all is the Peleean, named after Mount Pelée on Martinique in the Caribbean (discussed later). In the Peleean phase, the volcano disgorges thick lava, clouds of gas, and fine ash, all at formidable velocities.

Accompanying a volcanic eruption in many cases are fierce rains, the result of the expulsion of steam from the volcano, after which the steam condenses in the atmosphere to form clouds. Gases thrown into the atmosphere are often volatile and may include hydrogen sulfide, fluorine, carbon dioxide, and radon. All are detrimental to human beings when present in sufficient quantity, and radon is radioactive.

Not surprisingly, the eruption of a volcano completely changes the morphologic characteristics of the landform. During the eruption a crater is formed, and out of this flows magma and ash, which cool to form the cone. In some cases, the magma chamber collapses just after the eruption, forming a caldera, or a large, bowl-shaped crater. These caldera (the plural as well as singular form) may fill with water, as was the case at Oregon's Crater Lake.

INFAMOUS VOLCANIC DISASTERS.

Volcanoes result from some of the same tectonic forces as earthquakes (see Seismology), and, not surprisingly, they often have resulted in enormous death and destruction. Some remarkable examples include:

  • Vesuvius, Italy, a.d. 79 and 1631: Situated along the Bay of Naples in southern Italy, Vesuvius has erupted more than 50 times during the past two millennia. Its most famous eruption occurred in a.d. 79, when the Roman Empire was near the height of its power. The first-century eruption buried the nearby towns of Pompeii and Herculaneum, where bodies and buildings were preserved virtually intact until excavation of the area in 1748. Another eruption, in 1631, killed some 4,000 people.
  • Krakatau, Indonesia, a.d. 535 (?) and 1883: The most famous eruption of Krakatau occurred in 1883, resulting in the loss of some 36,000 lives. The explosion, which was heard 3,000 mi. away, threw 70-lb. (32-kg) boulders as far as 50 mi. (80 km). It also produced a tsunami, or tidal wave, 130 ft. (40 m) high, which swept away whole villages. In addition, the blast hurled so much dust into the atmosphere that the Moon appeared blue or green for two years. It is also possible that Krakatau erupted in about a.d. 535, causing such a change in the atmosphere that wide areas of the world experienced years without summer. (See Earth Systems for more on this subject.)
  • Tambora, Indonesia, 1815: Another Indonesian volcano, Tambora, killed 12,000 people when it erupted in 1815. As with Krakatau in 535, this eruption was responsible for a year without summer in 1816 (see Earth Systems).
  • Pelée, Martinique, 1902: When Mount Pelée erupted on the Caribbean island of Martinique, it sent tons of poisonous gas and hot ash spilling over the town of Saint-Pierre, killing all but four of its 29,937 residents.
  • Saint Helens, Washington, 1980: Relatively small compared with earlier volcanoes, the Mount Saint Helens blast is still significant because it was so recent and took place in the United States. The eruption sent debris flying upward 1,300 ft. (396 m) and caused darkness over towns as far as 85 mi. (137 km) away. Fifty-seven people died in the eruption and its aftermath.
  • Pinatubo, Philippines, 1991: Dormant for 600 years, Mount Pinatubo began to rumble one day in 1991 and, after a few days, erupted in a cloud that spread ash 6 ft. (1.83 m) deep along a radius of 2 mi. (3.2 km). A U.S. air base 15 mi. (24 km) away was buried. The blast threw 20 million tons (18,144,000 metric tons) of sulfuric acid 12 mi. (19 km) into the stratosphere, and the cloud ultimately covered the entire planet, resulting in moderate cooling for a few weeks.

The Impact of Mountains

Volcanic eruptions are among the most dramatic effects produced by mountains, but they are far from the only ones. Every bit as fascinating are the effects mountains produce on the weather, on the evolution of species, and on human society. In each case, mountains serve as a barrier or separatorbetween masses of air, clouds, and populations.

Wind pushes air and moisture-filled clouds up mountain slopes, and as the altitude increases, the pressure decreases. As a result, masses of warm, moist air become larger, cooler, and less dense. This phenomenon is known as adiabatic expansion, and it is the same thing that happens when an aerosol can is shaken, reducing the pressure of gases inside and cooling the surface of the can. Under the relatively high-pressure and high-temperature conditions of the flatlands, water exists as a gas, but in the heights of the mountaintops, it cools and condenses, forming clouds.

RAIN SHADOWS.

As the clouds rise along the side of the mountain, they begin to release heavy droplets in the form of rain and, at higher altitudes, snow. By the time the cloud crosses the top of the mountain, however, it will have released most of its moisture, and hence the other side of the mountain may be arid. The leeward side, or the side opposite the wind, becomes what is called a rain shadow.

Although they are only 282 mi. (454 km) apart, the cities of Seattle and Spokane, Washington, have radically different weather patterns. Famous for its almost constant rain, Seattle lies on the windward, or wind-facing, side of the Cascade Range, toward the Pacific Ocean. On the leeward side of the Cascades is Spokane, where the weather is typically warm and dry. Though it is only on the other side of the state, Spokane might as well be on the other side of the continent. Indeed, it is associated more closely with the arid expanses of Idaho, whereas Seattle belongs to a stretch of cold, wet Pacific terrain that includes San Francisco and Portland, Oregon.

Much of the western United States consists of deserts formed by rain shadows or, in some cases, double rain shadows. Much of New Mexico, for instance, lies in a double rain shadow created by the Rockies in the west and Mexico's Sierra Madres to the south. In southern California, tall redwoods line the lush windward side of the Sierra Nevadas, while Death Valley and the rest of the Mojave Desert lies in the rain shadow on the eastern side. The Great Basin that covers eastern Oregon, southern Idaho, much of Utah, and almost all of Nevada, likewise is created by the rain shadow of the Sierra Nevada-Cascade chain.

MOUNTAINS AND SPECIES.

One of the most intriguing subjects involved in the study of mountains is their effects on large groups of plants, animals, and humans. Mountains may separate entire species, creating pockets of flora and fauna virtually unknown to the rest of the world. Thus, during the 1990s, huge numbers of species that had never been catalogued were discovered in the mountains of southeast Asia.

The formation of mountains and other landforms may even lead to speciation, a phenomenon in which members of a species become incapable of reproducing with other members, thus creating a new species. When the Colorado River cut open the Grand Canyon, it separated groups of squirrels that lived in the high-altitude pine forest. Over time these populations ceased to interbreed, and today the Kaibab squirrel of the north rim and the Abert squirrel of the south are separate species, no more capable of interbreeding than humans and apes.

HUMAN SOCIETIES AND MOUNTAINS.

Although the Appalachians of the eastern United States are hundreds of millions of years old, most ranges are much younger. Most will erode or otherwise cease to exist in a relatively short time (short, that is, by geologic standards), yet to humans throughout the ages, mountains have seemed a symbol of permanence. This is just one aspect of mountains' impact on the human psyche.

In his 1975 study of symbolism in political movements, Utopia and Revolution, Melvin J. Lasky devoted considerable space to the mountain and its association with divinity through figures such as the Greek Olympians and Noah and Moses in the Bible. Clearly, mountains have proved enormously influential on human attitudes, and nowhere is this more obvious than in relation to the people who live in the mountains. Whether the person is a coal miner from Appalachia or a rancher from the Rockies, a Scottish highlander or a Quechua-speaking Peruvian, the mentality is similar, characterized by a combination of hardiness, fierce independence, and disdain for lowland ways.

These characteristics, combined with the harsh weather of the mountains, have made mountain warfare a challenge to lowland invaders. This explains the fact that Switzerland has kept itself free from involvement in European wars since Napoleon's time, and why the independent Scottish Highlands were long a thorn in England's side. It also explains why neither the British nor the Russian empires could manage to control Afghanistan fully during their struggle over that mountainous nation in the late nineteenth and early twentieth centuries.

Britain eventually pulled out of the "Great Game," as this struggle was called, but Russia never really did. Many years later, the Soviets became bogged down in a war in Afghanistan that they could not win. The war, which lasted from 1979 to 1989, helped bring about the end of the Soviet Union and its system of satellite dictatorships. More than a decade later, as the United States launched strikes against Afghanistan in 2001, a superpower once again faced the challenge posed by one of the poorest, most inhospitable nations on Earth.

But the independence of the mountaineer is deceptive; in fact, mountains have little to offer, economically, other than their beauty and the resources deep beneath their surfaces. In other words, they are really of value only to flatland tourists and mining companies. Since few mountain environments offer much promise agriculturally, the people of the mountains are dependent on the flatlands for sustenance. Gorgeous and rugged as they are, such mountainous states as Colorado or Wyoming might be as poor as Afghanistan were it not for the fact that they belong to a larger political unit, the United States.

WHERE TO LEARN MORE

A Geological History of Rib Mountain, Wisconsin (Web site). <http://www.uwmc.uwc.edu/geography/ribmtn/ribmtn.htm>.

Gore, Pamela. "Physical Geology at Georgia Perimeter College" (Web site). <http://www.gpc.peachnet.edu/~pgore/geology/geo101.htm>.

Kraulis, J. A., and John Gault. The Rocky Mountains: Crest of a Continent. New York: Facts on File, 1987.

Michigan Technological University Volcanoes Page (Web site). <http://www.geo.mtu.edu/volcanoes/>.

Oregon GeologyCascade Mountains (Web site). <http://sarvis.dogami.state.or.us/learnmore/Cascades.HTM>.

Prager, Ellen J., Kate Hutton, Costas Synolakis, et al. Furious Earth: The Science and Nature of Earthquakes, Volcanoes, and Tsunamis. New York: McGraw-Hill, 2000.

Schaer, Jean-Paul, and John Rodgers. The Anatomy of Mountain Ranges. Princeton, NJ: Princeton University Press, 1987.

Sigurdsson, Haraldur. Encyclopedia of Volcanoes. San Diego: Academic Press, 2000.

Silver, Donald M., and Patricia Wynne. Earth: The Ever-Changing Planet. New York: Random House, 1989.

Volcanoes, Glaciers, and Plate Tectonics: The Geology of the Mono Basin (Web site). <http://www.r5.fs.fed.us/inyo/vvc/mono/vg&26pt.htm>.

KEY TERMS

ACTIVE:

A term to describe a volcano that is currently erupting.

COMPRESSION:

A form of stress produced by the action of equal and opposite forces, the effect of which is to reduce the length of a material. Compression is a form of pressure.

CONVERGENCE:

A tectonic process whereby plates move toward each other.

CRUST:

The uppermost division of the solid earth, representing less than 1% of its volume and varying in depth from 3 mi. to 37 mi. (5-60 km). Below the crust is the mantle.

DIVERGENCE:

A tectonic process whereby plates move away from each other.

DORMANT:

A term to describe a volcano that is not currently erupting but is likely to do so in the future.

EPEIROGENESIS:

One of two principal forms of tectonism, the other beingorogenesis. Derived from the Greek words epeiros ("mainland") and genesis ("origins"), epeirogenesis takes the form of either uplift or subsidence.

EXTINCT:

A term to describe a volcano for which no eruption has been known in recorded history. In this case, it is likely that the volcano has ceased to erupt permanently.

GEOMORPHOLOGY:

An area of physical geology concerned with the study of landforms, with the forces and processes that have shaped them, and with the description and classification of various physical features on Earth.

HOT SPOT:

A region of high volcanic activity.

LANDFORM:

A notable topographicalfeature, such as a mountain, plateau, or valley.

LITHOSPHERE:

The upper layer of Earth's interior, including the crust and the brittle portion at the top of the mantle.

MANTLE:

The thick, dense layer of rock, approximately 1,429 mi. (2,300 km) thick, between Earth's crust and its core.

MORPHOLOGY:

Structure or form or the study thereof.

MOUNTAIN CHAIN:

A series of ranges stretching across a continent for a greatdistance.

MOUNTAIN MASS:

An irregular grouping of mountains, which lacks the broad linear sweep of a range or chain.

MOUNTAIN RANGE:

A relatively localized series of peaks and ridges.

MOUNTAIN SYSTEM:

A combination of ranges, chains, and masses of mountains that stretches across vast distances, usually encompassing more than one continent.

OROS:

A Greek word meaning "mountain," which appears in such words as orogeny, a variant of orogenesis; orogen, another term for "mountain" and orogenic, as in "orogenic belt."

OROGENESIS:

One of two principal forms of tectonism, the other being epeiro-genesis. Derived from the Greek words oros ("mountain") and genesis ("origin"), oro-genesis involves the formation of mountain ranges by means of folding, faulting, and volcanic activity. The processes of oro-genesis play a major role in plate tectonics.

PLATE MARGINS:

Boundaries between plates.

PLATE TECTONICS:

The name both of a theory and of a specialization of tectonics. As an area of study, plate tectonics deals with the large features of the lithosphere and the forces that shape them. As atheory, it explains the processes that have shaped Earth in terms of plates and their movement.

PLATES:

Large, movable segments of the lithosphere.

SHEAR:

A form of stress resulting from equal and opposite forces that do not act along the same line. If a thick, hard-bound book is lying flat, and one pushes the front cover from the side so that the covers and pages are no longer aligned, this is an example of shear.

STRAIN:

The ratio between the change in dimension experienced by an object that has been subjected to stress and the original dimensions of the object.

STRESS:

In general terms, any attempt to deform a solid. Types of stress includetension, compression, and shear.

SUBSIDENCE:

A term that refers either to the process of subsiding, on the part of air or solid earth, or, in the case of solid earth, to the resulting formation. Subsidence thus is defined variously as the downward movement of air, the sinking of ground, or a depression in Earth's crust.

TECTONICS:

The study of tectonism, including its causes and effects, most notably mountain building.

TECTONISM:

The deformation of the lithosphere.

TENSION:

A form of stress produced by a force that acts to stretch a material.

TOPOGRAPHY:

The configuration of Earth's surface, including its relief as well as the position of physical features.

UPLIFT:

A process whereby the surface of Earth rises, as the result of either a decrease in downward force or an increase in upward force.

VOLCANO:

A natural opening in Earth's surface through which molten (liquid), solid, and gaseous material erupts. The word volcano is also used to describe the cone of erupted material that builds up around the opening or fissure.

Mountains

views updated Jun 11 2018

MOUNTAINS

MOUNTAINS have an important place in the symbolic geography of religious traditions the world over, although the ways in which mountains are significant have differed. Some have been seen as cosmic mountains, central to an entire worldview; others have been distinguished as places of revelation and vision, as divine dwelling places, or even as geographical manifestations of the divine.

Attitudes toward mountains in general have varied widely. Chinese poets such as Xie Lingyun (fourth to fifth century ce) and Hanshan (eighth to ninth century ce) were attracted by mountains through a sense that these peaks piled one upon the other led not only to the clouds, but to heaven. And yet in the West, the image of jutting mountain peaks touching the clouds has not always had a positive symbolic valence. In the sixteenth and seventeenth centuries, for example, Luther and others held the view that mountains appeared in an otherwise pleasingly symmetrical world only after the flood, which scarred the surface of the earth with "warts and pockmarks" and signaled the fall and decay of nature. Mountains were, in the view of the sixteenth-century English writer Edward Burnet, the ruins of the postdiluvial world, a sign of chaos and fractured creation. However, in the late seventeenth century with the "aesthetics of the infinite" came a new appreciation of the splendor and height of mountains as stretching the imagination toward God. One writer of the time described his response to the Alps as "a delightful Horrour, a terrible Joy, and at the same time, that I was infinitely pleas'd, I trembled" (quoted in Nicolson, 1959, p. 277).

The Cosmic Mountain as Sacred Center

As the center of the world, linking heaven and earth and anchoring the cardinal directions, the mountain often functions as an axis mundi the centerpost of the world; it is a cosmic mountain, central to the order and stability of the cosmos. One of the most important such mountains is Mount Meru, or Sumeru, the mythical mountain that has "centered" the world of the majority of AsiansHindu, Buddhist, and Jain. According to Hindu cosmology, four lotus-petal continents spread out from Mount Meru at the center and beyond them the seven ring-shaped seas and ring-shaped continents of the wider universe. Mount Meru rises heavenward as the seed cup of the world lotus. As an axis mundi, this mountain, rooted deep in the netherworld, rises high through the realms of heaven, where it spreads out to accommodate the cities of all the gods. Interestingly, Meru does not form a peak, for the geographical texts of the Purāas agree that Meru is wider at top than at bottom, true to both its seed-cup prototype and the polytheistic consciousness that accommodates many gods at the top. Meru has four sides of different colors (vara s) and is flanked by four directional mountains. Above Meru stands the polestar, and daily the sun drives his chariot around the mountain. The heavenly Ganges in its descent to earth first touches the top of Meru and then divides into four rivers that run in the four cardinal directions to water the earth.

As the center of the world-circle, or maala, Mount Meru is symbolically repeated in many Hindu temples that take the mountain as an architectural prototype. The śikhara (spire or peak) of the temple rises high above the cavelike womb-chamber of the sanctum and is capped with the cogged, ring-shaped āmalaka, the sun itself, a symbol of the heavens. The mountain is also repeated in the architecture of the Buddhist stupa, the reliquary dome with gateways in the four directions and a multileveled mast at the top marking the bhūmi s ("worlds") that lead to heaven. The mountain symbolism is most elaborately seen in the stupa of Borobudur in Java, which is actually built over a small hill. There one sequentially circumambulates the nine bhūmi s of the cosmos to reach the top. In China and Japan, the vertical dimension of the stupa became attenuated in the structure of the pagoda and came to predominate over the dome-shaped tumulus of the reliquary. Even so, the pagodas of the Far East preserve the basic mountain symbolism of the stupa. In Southeast Asia, one of the many duplicates of Meru is Mount Gunung Agung, the great volcanic mountain that is at the center of the island of Bali. Throughout Bali, individual temples repeat the mountain symbolism and are called meru s. Their nine roof-layers again signify the vertical dimensions of the cosmic mountain linking heaven and earth.

Like Meru, other mountains have been seen as cosmic centers. Mount Hara has a central place in the ancient cosmology of the Zoroastrian tradition. According to the Zamyad Yasht, it was the earth's first mountain, and its roots the source of the other mountains of Iran. Like other cosmic centers, it is the pivot around which the sun and the stars revolve, and like many other sacred mountains, it is also considered to be the source of heavenly waters. In Japan, the great volcanic peaks, among which Fuji is the most famous, have been thought to link earth and heaven. In Morocco, the great Atlas range in the territory of the Berbers is sometimes called the "pillar of heaven." Mountains that center and stand at the quarters of a fourfold cosmos are numerous, as can be seen in the quadrant mountains of China and in the "Encircled Mountain" of the Navajo, around which stand four peaks, each identified with a direction and a color.

Mountains not considered "centers" in any cosmology still share this image of stability and permanence, of both height and unshakable depth. The Book of Psalms speaks of the "foundations" of the mountains and hills. Among the Yoruba, myths stress the durability of the hills and, therefore, their ability to protect. The Yoruba say "Ota oki iku," meaning "The rock never dies." In East Africa, one might receive the blessing "Endure, like Kibo." Kibo is the peak of Mount Kilimanjaro and marks, for the Chagga people, the direction of all that is powerful and honorable.

In a similar vein, there are many traditions of the mountain that stood firm during a great flood. Mount Ararat in Turkey is known as the mountain where Noah found land and the ark came to rest. Among the Native American peoples of the Pacific Northwest, Mount Rainier was a pillar of stability during the flood. Peruvian myths from the Sierran highlands claim the same for several of the high peaks of the Andes.

The mountain as nature's great link between heaven and earth has also been widely symbolized architecturally, as in the case of Meru. In ancient Mesopotamia, the seven-storied ziggurat, with its high temple at the top and its low temple at the bottom, allows for the descent of the divine. The pyramids of Mesoamerican civilization, such as the ruins at Teotihuacán, are clearly aligned to stand at the center of ceremonial avenues. The Pyramid of the Moon at Teotihuacán is further aligned with Mount Cerro Gordo, which it duplicates.

Mountains of Revelation and Vision

There are many mountains that may not have a central role in cosmology but that are, nonetheless, places of powerful contact between the divine and the human. For example, on top of Adam's Peak, or Śrī Pada ("auspicious foot"), in Sri Lanka is a large indentation said to be a footprint. According to Buddhists, it is the footprint of the Buddha himself, matched by a similar imprint at Phra Sat in Thailand. For Hindus, it is the imprint of Śiva; for Muslims, that of Adam; for Christians, that of the apostle Thomas. In any case, the belief that the peak was once trod by one larger than life is held by the people of all four traditions who climb to the top on pilgrimage.

In the Islamic tradition, it was on Mount Hira on the outskirts of Mecca that Muammad heard the revealed word of the Qurʾān. At nearby Mount Arafat, the entire assembly of pilgrims stands from noon to sunset on the ninth day of the ājj pilgrimage. This collective act of standing, before God and around Arafat, is considered by many to be the most powerful moment of the ājj.

Mount Sinai, where Moses encountered Yahveh face to face, is one of the most striking examples of the mountain of revelation. There Yahveh appeared to the Hebrews as a storm, with fire and lightning, or as a cloud that covered the peak. And there Yahveh also appeared directly, when Moses and the elders ascended the mountain and "saw the God of Israel" (Ex. 24:10). In the Elohist and Deuteronomic traditions, Yahveh appeared on Mount Horeb. There Moses enountered Yahveh in the burning bush. And there Elijah stood before the Lord, who, after the rock-breaking wind, the fire, and the earthquake, spoke to him as "a still small voice" (1 Kgs. 19:1112). And Jesus was transfigured upon a high mountain, sometimes said to be Mount Hermon, and appeared to Peter, John, and James with a glowing countenance, in dazzling raiment, and flanked by Moses and Elijah (Mt. 17:18; Mk. 9:28; Lk. 9:2836).

The mountain top is a revelatory landscape, its height offering both the vision of heaven and a broad perspective on earth. Mountain ascent is associated with vision and the acquisition of power, as is clear in the vision quest of many of the Native American traditions and in the ascents of the yamabushi, the mountain ascetics of Japan. In both cases, transformation, including spiritual insight, is part of the mountain experience. For the pilgrim who is not an adept, a shaman, or an initiate, the mountaintop still affords ecstatic vision. In the words of the great Chinese mountain poet Hanshan, "High, high from the summit of the peak, / Whatever way I look, no limit in sight" (Cold Mountain, trans. Burton Watson, New York, 1970, p. 46).

The Dwelling Place of the Divine

For the Hebrews, God's "dwelling place" was surely not Sinai, the place of revelation, but Mount Zion, the sturdy, rocky mount of Jerusalem. Zion, neither lofty nor dramatic, was the firm foundation of Jerusalem, the "City on a hill." Here God was said to dwell in the midst of the people. The awesome mountaintop, where God appears in fire and lightning, is replaced with the security and protection of a fortress mountain.

The hills of Canaan were the high places of powerful local baalim, and Mount Zaphon was the abode of the great Baal Hadad. In the Ras Shamra Ugaritic texts, Baal describes his dwelling place "in the midst of my mountain, the godly Zaphon, in the holy place, the mountain of my heritage, in the chosen spot, the hill of victory" (Clifford, 1972, p. 138). Many of Zaphon's traditions have likely become attached to Zion.

Perhaps the earliest evidence for mountaintop sanctuaries is in the Middle Minoan period (21001900 bce) on Crete, where peak and cave sanctuaries such as those at Mount Juktas, Mount Dikte, and Mount Ida have been found, along with evidence of votive offerings to the goddess. In the Greek mythological tradition, Olympus is the dwelling place of the gods, especially of Zeus, whose cult was widely associated with mountaintops. Hermes, Apollo, Artemis, and Pan had mountain sanctuaries as well.

The hilltop and mountain shrines of both local and widely known gods are also important in the sacred geography of India. Śiva is called Giriśa, the "lord of the mountains." He dwells upon Mount Kailash in the Himalayas and has mountain shrines all over India, such as Śrī Śaila in Andhra Pradesh and Kedara in the Himalayas. Śiva's consort, Pārvatī, is the daughter of the mountain (parvat ), and she too dwells on mountaintops in countless local formsas Vindhyavāsinī in central North India or as Ambikā at Girnār in Gujarat. Similarly, in South India, Skanda has hilltop shrines at Pali and Tirutai, Ayyappan dwells on Mount Śabari in Kerala, and Śri Vekateśvara dwells on the Seven Hills of Tirupati.

In China, there are four mountains that came to be associated with the four directions and four prominent bodhisattva s. Most famous among them is the northern peak, Wutai Shan, associated with Mañjusri, the bodhisattva of wisdom. When the Japanese monk Ennin visited Mount Wutai in the ninth century ce, it was a bustling center of monastic learning and of lay pilgrimage. The others are Mount Jiuhua in the south, Mount Emei in the west, and the hilly island of Putuo Shan off the Zhejiang coast in the east. According to popular tradition, the bodhisattva s associated with these mountains were to be seen not merely in the temples but would take human form and appear as a beggar or an elderly monk to pilgrims along the way.

In addition to this group of four Buddhist mountains there are the five mountains of the Daoist tradition, again situated at the four compass points, with a center mountain shrine at Song Shan in Henan Province. Tai Shan in Shandong Province is perhaps the most famous of the five, with seven thousand stone stairs leading to the top where, next to the Daoist temple, a stone monument stands uninscribed but for the word di ("god"). The poet who was supposed to honor the mountain on this tablet was silenced by its splendor.

Mountains Charged with Divine Power

Japanese traditions recognize many mountain divinitiesthe yama no kami. In a sense, they dwell upon the mountain, but it might be more correct to say that the yama no kami are not really distinct from the mountain itself. In the Shintō traditions of Japan the separation of nature from spirit would be artificial. In the spring, the yama no kami descend from the mountains and become ta no kami, kami of the paddy fields, where they remain for the seasons of planting, growth, and harvest, returning to the mountain in the autumn. Even as the kami change locus, they remain part of the nature they inhabit.

In the Heian period, with increasing Shintō-Buddhist syncretism, the mountain kami came to be seen as forms of Amida Buddha and the various bodhisattva s, and the Shugendō tradition of mountain ascetism began. Among Japan's important mountain sanctuaries are Mount Haguro, Mount Gassan, Mount Yoshino, Mount Omine, and the Kumano mountains, identified with the Pure Land of Amida Buddha. Religious associations called ko organize locally or regionally for the ascent of particular mountains, taking the name of the mountain itself (Fujikō, Kumanokō, etc.).

Many Native American traditions share this sense of the inseparability of mountain and spirit power. The peoples of the Pacific Northwest, for instance, often begin their tales with "Long ago, when the mountains were people." The mountains, such as Tacoma, now known as Rainier, are the mighty ancestors of the past. Farther south, the divine personification of mountains can be seen in Popocatépetl and his spouse Iztaccíhuatl in Mexico or in Chimborazo and his spouse Tungurahua in Ecuador. The Zinacantecos of Chiapas still honor the tutelary ancestors, the Fathers and the Mothers, in shrines at both the foot and summit of their sacred hills. Among the Inca, the localization of power is called huaca, and is often manifest in stones or on mountains, such as the great Mount Huanacauri above Cuzco.

The mountain is the temple. Mount Cuchama in southern California, known as the Place of Creation, was one of the four exalted high places of the native peoples. For worship and initiation, it had no temple, for it was itself nature's own temple. India has many such striking examples of divine mountains, among which is Aruācala (Dawn Mountain) in the Tamil lands of South India. This holy hill is said to be the incandescent hierophany of Śiva and is reverently circumambulated as a temple would be.

Life and Death

As givers of life, mountains are the source of rivers and, thus, the source of fertility. This is made explicit in the relation of the mountain and rice-field kami in Japan. On the south side of Mount Atlas in Morocco, fruits are said to grow spontaneously. And on the mythical Mount Meru the divine trees are said to yield fruits as big as elephants, which burst into streams of nectar when they fall and water the earth with divine waters. As the prophet Amos said of the Land of Israel, "The mountains shall drip sweet wine, and all the hills will flow with it" (Am. 9:13).

Mountains are the source not only of nourishing waters but also of rains and lightning. Storm gods are often associated with mountains: Zeus, Rudra/Śiva, Baal Hadad of Ugarit, Catiquilla of the Inca, and many more.

Mountains, the source of the waters of life, are also seen as the abode of the dead or the path to heaven for the dead. Among the Shoshoni of the Wyoming, for instance, the Teton Mountains were seen primarily as the dangerous place of the dead. The Comanche and Arapaho, who practiced hill burial, held similar beliefs. The Japanese elegy literature makes many references to the mountain resting place of the souls of the dead. A coffin is called a "mountain box," choosing a burial site is called "choosing the mountain," and the funeral procession chants "We go to the mountain!" Throughout the Buddhist world, the stupa, which originally is said to have housed the relics of the Buddha, has become on a miniature scale the symbolic form in which the ashes of the dead are housed.

The Persistence of the Mountain

Through the ages many sacred mountains have accumulated many-layered traditions of myth and pilgrimage. Moriah, the mount of the Temple in Jerusalem, is a good example. First, it was an early Canaanite high place, a threshing floor and sanctuary for harvest offerings. According to tradition, it was there that Abraham came to sacrifice Isaac. And it was there that Solomon built the great Temple, and Nehemiah rebuilt it after the Babylonian exile. And much later, according to Islamic tradition, it was there that Muammad began his ascent from earth to heaven on his mystical "night journey" to the throne of God.

In Mexico, Tepeyac, the hill of the Aztec goddess Tonantzin, became the very place of the apparition of Our Lady of Guadalupe when the Catholic tradition was layered upon indigenous traditions. Similarly, the great mountain-shaped pyramid of Quetzalcoatl at Cholula became, in the age following the conquest, the site of Our Lady of Remedios. In Japan, Mount Koua and Mount Hiei, both charged with the power of their particular kami, became in Buddhist times the respective centers of the Shingon and the Tendai traditions. In countless such cases, the mountain persists as a sacred center, while myths and traditions change.

See Also

Architecture; Center of the World; Cosmology, articles on Buddhist, Hindu, and Jain Cosmologies; Geography; Iconography, article on Buddhist Iconography; Pyramids; Stupa Worship; Temple, articles on Buddhist Temple Compounds, Mesoamerican Temples.

Bibliography

Benson, Elizabeth P., ed. Mesoamerican Sites and World-Views. Washington, D.C., 1981. A collection of essays on the worldview of the ancient Aztec and Maya civilizations by Doris Heyden, Horst Hartung, Linda Schele, and others, along with an essay on the sacred geography of highland Chiapas by Evon Vogt.

Clifford, Richard J. The Cosmic Mountain in Canaan and the Old Testament. Cambridge, Mass., 1972. A study of cosmic mountain traditions of El and Baal in Canaan; the Genesis, Sinai, and Zion traditions of the Old Testament; and the cosmic center in intertestamental literature. Background also provided on the cosmic center and mountain in the ancient Near Eastern traditions of Egypt and Mesopotamia.

Cohn, Robert L. The Shape of Sacred Space: Four Biblical Studies. Chico, Calif., 1981. Four essays on sacred space in the Hebrew Bible: "Liminality in the Wilderness"; "Mountains in the Biblical Cosmos"; "The Sinai Symbol"; and "The Senses of a Center."

Eliade, Mircea. "The Symbolism of the Centre." In Images and Symbols: Studies in Religious Symbolism (1952), translated from the French by Philip Mairet, New York, 1969. One of the several places where Eliade discusses the cosmic mountain and its homologies in the symbolization of the world center.

Evans-Wentz, W. Y. Cuchama and Sacred Mountains. Edited by Frank Waters and Charles L. Adams. Chicago, 1981. An exploration of the significance of Mount Cuchuma in southern California, sacred to the Cochimi, Yuma, and other Native American peoples. Included also is a long chapter titled "Other Sacred Mountains throughout the World" that focuses primarily on the mountains of Japan, India, Central Asia, and North America.

Hori, Ichiro. "Mountains and Their Importance for the Idea of the Other World." In Folk Religion in Japan: Continuity and Change, edited by Joseph M. Kitagawa and Allan L. Miller. Chicago, 1968. A general essay on the significance of mountains in Japan, including their role in cosmology, their rites and pilgrimages, and their sacred waters.

Mullikin, Mary Augusta, and Anna M. Hotchkis. The Nine Sacred Mountains of China. Hong Kong, 1973. An illustrated record of the pilgrimages made by these two women in 1935 and 1936 to the five sacred mountains of the Daoists and the four sacred mountains of the Buddhists in China.

Nicholson, Marjorie Hope. Mountain Gloom and Mountain Glory: The Development of the Aesthetics of the Infinite. Ithaca, N.Y., 1959. The classic Western study of attitudes toward mountains, including theological, philosophical, and emerging scientific dimensions. The focus of the study is the change in the view of mountains in the literature of seventeenth- and eighteenth-century England, from the view that mountains are the "Warts, Wens, Blisters, Imposthumes" on the face of Nature to the view that mountains are the grand natural cathedrals of the divine.

Diana L. Eck (1987)

Mountains

views updated May 14 2018

Mountains

Relative size of mountains

Duration of mountains

Plate tectonics, the force that builds mountains

Isostasy

Types of mountains

Unusual volcanos

Inverted topography

Weather effects of mountains

Mountains effect on evolution

Mountains and humans

Resources

A mountain is a large-scale topographic feature that is set apart from the local landscape by being much higher in elevation (topographic means having to do with the shape of the land surface).

Relative size of mountains

Mountains are taller than hills, but the distinction between hills and mountains is decided entirely by the people that live near them.

Thus, distinguishing mountains from smaller topographic features is partly a matter of perception, rather than of scientific measurement and comparison to a known standard. Absolute elevation above sea level does not make a high point into a mountain nearly so much as local relief does (relief is the difference between topographic high spots and low spots). In a landscape with thousands of feet or more of local relief, a feature several hundred feet tall would be considered an insignificant hill, whereas in Holland, it would be considered a mountain of the first order. Mountains of 4,000 ft (1,219 m), 10,000 ft (3,048 m), and 16,000 ft (4,877 m) may look vastly different on a map, but look equally large when observed in their local environment.

Duration of mountains

Mountains, like every other thing in the natural world, go through a life cycle. They rise, from a variety of reasons, and wear down over time, at various rates. Although humans have always used mountains to represent eternity, individual mountains do not last very long in the powerfully erosive atmosphere of the earth. Mountains on the waterless worlds of Mars and the moon are billions of years old, but earths peaks begin to fracture and dissolve as soon as their rocks are exposed to air. The permanent part of a mountain range is not the shape taken by the rocks at the surface, but the huge folded shapes that the rocks were

deformed into by the original orogenic event. (Orogeny is the process of mountain formation.) Throughout their almost four-billion year history, the continents have been criss-crossed by many immense ranges of mountains. Most of the mountain ranges in the planets history rose and wore away at different times, a long time ago. Where did these mountains go?

A range of mountains may persist for hundreds of millions of years, like the Appalachians. At several different times, the warped, folded rocks of the Appalachians were brought up out of the continents basement and raised thousands of feet by tectonic forces. In order to stand for any considerable length of geologic time, a mountain range must experience continuous uplift. A tectonically quiet mountain range will wear down from erosion in a few million years. In North Americas geologic past, for example, eroded particles from its mountains were carried by streams and dumped into the continents inland seas, some of which were as large as the present-day Mediterranean. Those rivers and seas are gone from the continent, but the sediments that filled them remain, like dirt in a bathtub when the water is drained. The roots of all the mountain ranges that have ever stood in North America still exist, and much of the sand and clay into which the mountains were transformed still exists also, as rock or soil formations. This is true of all the continents of earth.

Plate tectonics, the force that builds mountains

Orogeny is the process of mountain formation. Plate tectonics is the main force of nature responsible for orogeny. This continent-building process may be simply explained:

Earth is covered with a thin, brittle crust. Below the crust is the mantle, a region where solid rock below a certain depth stretches like rubber.

The crust floats on top of earths mantle like the crust of grease that forms on top of a pot of chili or chicken broth in the refrigerator.

Earths crust has been broken into pieces, called plates. The motion of a tireless heat engine that swirls and stirs within Earths mantle, moves the plates.

Isostasy

The thicker parts of the continents float higher than the thinner parts, and any process that thickens the continental crust will bring about the uplift of the thickened portion. Continental crust floats in the mantle, and can be compared to the way an ice cube floats in water. An ice cube floats because it is lighter per unit volume than waterthat is, ice is less dense than liquid water. The ice cube may weigh a few ounces, and rise a centimeter above the waters surface. An iceberg might weigh millions of tons, but float a hundred feet out of the water, because although it is vastly heavier than the ice cube, it is still less dense than water per unit volumeit floats. The more there is of it, the higher it floats. Similarly, any mass of continental crust, no matter how thick, is still less dense per unit volume than the mantle rock beneath it. Thus the edge of the continent begins rising to a higher elevation, and mountains begin to form.

Mountains are generated both at the edges of plates, and within plates. Other processes, such as sedimentation and erosion, modify the shape of the land that has been forged by plate tectonics.

Types of mountains

Island arcs

When the edge of a plate of earths crust runs over another plate, forcing the lower plate deep into earths elastic interior, a long, curved mountain chain of volcanos usually forms on the forward-moving edge of the upper plate. When this border between two plates forms in the middle of the ocean, the volcanic mountains form a string of islands, or archipelago, such as the Antilles and the Aleutians. This is called an island arc.

Continental arcs

When the upper plate is carrying a continent on its forward edge, a mountain chain, like the Cascades or the Andes, forms right on the forward edge. This edge, heavily populated with volcanos, is called a continental arc.

Collisional mountain belt

A continent or island arc runs into a continent, shattering and deforming the rocks of the collision area, and stacking up the pieces into a mountain range. This is how the Appalachians, Alps, and Himalayas were formed: the rocks of their continents were folded just as flat-lying cloth folds when pushed.

Imagine how much taller your school would be if it were squeezed by bulldozers so it remained the same length east to west as it is now, but from north to south measured the width of a school bus. The result would be a tall wall of compressed material, and that is just what a collisional mountain belt is. Collisional mountain belts are one of three types of boundary between plates of Earths crust, along with mid-ocean ridges and inter-plate strike-slip faults. Mountains rise relatively quickly, over a few million years, such as the Appalachians did more than 200 million years ago. As these mountains begin to erode, the topography continually changes and develops. Hard rock layers influence the development of streams, because they resist erosion and form the ridgetops in the mountain range.

One special type of orogeny that can happen during a continental collision is the rise of ophiolite mountains. On rare occasions the crust beneath the ocean floor fractures along the tectonically active coast of a continent, and oceanic crust is thrust up over the shore and forms mountains. This spectacular form of plate-tectonic backfire is not supposed to happen, yet it does often enough to have its own name: obduction, meaning over (ob-) leading (-duction). A piece of oceanic crust, and the mantle rock beneath it, is heaved up onto the land to form mountains. The Taconic Mountains that rose in upstate New York 430 million years ago were an obducted ophiolite, as are the uplands around Troodos in Cyprus.

Fault block mountains: When a continent-sized layer cake of rock is pushed, the upper layers can be pushed more readily than the lower layers. The easy-to-push upper layers split from the deeper rocks, and a broad sheet of the upper crust, a few miles thick, begins to move across the continent. This thrust sheet floats on fluid pressure between the upper and lower sections of the crust. The horizontal split in the crust that separates the motionless lower crust from the floating upper layers is called a detachment fault in English, or a decollement in French.

Like a hydroplaning tractor trailer (viewed in very slow motion), the upper fault block glides until it runs into something. When the thrust sheet runs into something that resists its forward motion, the detachment fault turns into a ramp, leading up to the surface. The moving layer of upper crust is pushed up the ramp-like fault, and the front of the fault block rises out of the ground. The mountains thrown up where the thrust fault reaches the surface are one kind of fault block mountains. The mountains of Glacier National Park slid along a thrust fault over younger rocks, and out onto the Great Plains. Chief Mountain, a remarkable square mountain in Montana, moved to where it is now by sliding out onto the prairie on a thrust fault. The broad, flat fault block it belonged to, called a thrust sheet, has long since disappeared, leaving Chief Mountain standing alone.

Another kind of fault block mountain comes from stretching of earths crust. As the crust stretches, it pulls apart, making long faults that run perpendicular to the direction of pulling. These faults grow and connect with each other, isolating mountain-sized, wedge-shaped fault blocks. Some of these fault blocks begin slipping downward between more stable blocks that still rest on a firm foundation of deep rock. The stable blocks are called horsts, and the sinking blocks, that form valley floors, are called grabens.

Mid-ocean ridge

The longest mountain chain on earth, the mid-ocean ridge system is entirely under water. Twisting down the center of the Atlantic Ocean, it continues through the Indian and Pacific oceans. It is one of three types of boundary between plates of the crust, along with inter-plate strike-slip faults and collisional mountain belts. Along this ridge, lava continuously erupts, releasing heat from the planets interior and extruding new strips of ocean floor.

Stratovolcanos

Popocatepetl, Mt. Fuji, Vesuvius, and Mt. Ararat are all stratovolcanos. The prefix strato- refers to these mountains characteristic layers, the result of alternately erupting ash and lava. Spectacularly tall and pointed, stratovolcanos may grow to an elevation of 2-3 mi (3.2-4.8 km) before collapsing. It is not certain that every stratovolcano collapses into a crater of superheated steam and molten rock. But the continents are dotted with the remains of these mountains self-annihilations, some of whose like has not been witnessed in human history.

Cinder cone

These volcanos build a pile of pyroclastic gravel and boulders (pyroclastic is derived from fire and broken pieces) that forms a pointed or rounded cone. Because they are made of loose material, they quickly erode away unless further eruptions continue to build them.

Shield volcanos

Often solitary volcanic mountains form as a volcano piles up rock above the ocean floor over millions of years. Hawaii, Bermuda, and the Canary Islands are shield volcanos. These islands, and others like them, are the work of hot spots (hot spot is a volcanically active site heated from below by a concentrated flow of heat out of Earths mantle). Iceland is a hot spot that sits astride the mid-ocean ridge system. Shield volcanos also occur on continents, particularly in rift valleys where a continent is being ripped in two. Kilimanjaro is the classic example of a continental shield volcano. Olympus Mons on Mars is another classic shield volcano, and is the largest known mountain in the solar system.

Volcanic necks

In a cinder cone, lava rises through a vertical pipe before it erupts. The mountain resembles a huge pile of gravel. After an old cinder cone becomes extinct, the underground pipes that brought it lava from below solidify, and the pile of erupted material begins to wear away. Solid lava, usually a very hard rock, often fills the extinct volcanos vent. In a cinder cone, the solidified lava will resist the forces of erosion far longer than the ash, cinders, and other loose material of which the volcanic pile is made. Thus, as rain, wind, and frost scrub the soft exterior of the volcano away from the hard interior, a columnar mountain emerges. Shiprock, in New Mexico, and Devils Tower, in Wyoming, are classic examples of these mountains, called volcanic necks.

Exposed plutons

Plutons are masses of hard, visibly crystalline igneous rock that form deep in earths crust. Plutons rise through Earths crust when they are molten, and freeze into solid rock far below the surface. Plutons can be as small as a highway roadcut, or as large as an entire mountain range. Mountains emerge from a landscape as erosive forces strip away the rocks that cover a pluton. A small pluton called a stock forms the granite core of Mount Ellsworth in southern Utah. The Sierra Nevada mountains are entirely made up of massed plutons, collectively called the Sierra Nevada batholith. The Yosemite Valley cuts into the solid granite interior of these mountains.

Unusual volcanos

A rare kind of mountain is the individual volcano with no known relationship to a volcanically active region. Solitary volcanos like these have erupted in tectonically quiet landscapes, such as east Texas of the Cretaceous period, and their cause remains a mystery.

Mesas are flat-topped mountains. They form when a solid sheet of hard rock sits on top of softer rock. The hard rock layer on top, called the caprock, once covered a wide area. The caprock is cut up by the erosive action of streams. Where there is no more caprock, the softer rock beneath washes away relatively quickly. Mesas are left wherever a remnant of the caprock forms a roof over the softer rock below. A cuesta is a mesa that has been tilted, so the caprock forms a slope.

Inverted topography

When lava erupts from a volcano or fissure, it flows downhill like any other liquid, into low spots in the landscape. This is why a river valley makes a convenient path for a lava flow. When the lava has solidified in the lowest part of the valley, it may be harder than the rocks that form the valleys walls. So when water again can flow through the valley, it flows around both sides of the lava flow. Eventually the lava flow has two valleys on either side of it, getting deeper every year. After thousands of years, a mesa will have been created, for the lava flow has become a caprock. This form of mesa is called inverted topography, because the low places become high places.

Outliers and monadnocks: Another term for a mountain made from a plateau worn by erosion is outlier. Not necessarily flat-topped, an outlier can be any hill or mountain left standing as the plateau with which it was once joined erodes farther and farther away. The Tepuis of Venezuela are outliers of a once-widespread plateau. A hard-rock mountain left standing after an entire mountain range has eroded away around it is a monadnock.

Weather effects of mountains

Mountains make a barrier for moving air. The wind pushes air, and clouds in the air, up the mountain slopes. The atmosphere is cooler at high elevations, and there is less of it: lower pressure makes it hard for lowland animals to get enough air to breathe. Dense masses of warm, moist air that move up and over a mountain swell as the air pressure confining them drops away. The air becomes colder in the same way as a pressurized spray cans contents become colder when the cans pressure drops rapidly. (The phrase that describes this phenomenon is adiabatic expansion.) Water that existed as a gas under the high pressure and temperature of the flatlands now condenses into cool droplets, and clouds form over the mountain. As the cloud continues to rise, droplets grow and grow, eventually becoming too heavy to float in the air. The clouds dump rain, and snow, on the mountain slopes.

After topping the crest, however, the clouds may have no more moisture to rain on the other side of the mountain, which becomes arid. This rain shadow is best illustrated in the Sierra Nevada mountains of California, where tall redwood forests cover the ocean-facing side of the mountains, and Death Valley lies in the rain shadow.

Mountains effect on evolution

Sometimes mountains can become refuges for species endangered by the drying climate, or other radical ecological change, in the surrounding lowlands. In this way mountains can influence a species chances to live and prosper. Climatic islands like this may isolate one population from the rest of its species. Entire uncatalogued species of large animals have been found in the 1990s living in the mountains of southeast Asia. As generation succeeds generation, the genetic pattern that defines a population can change during its separation from the rest of its species. An isolated population may even become a species unto itself, unable to reproduce with the population from which it was once separated. This evolutionary phenomenon is called speciation, and mountain topography provides barriers between populations that have made speciation happen.

When the Grand Canyon was cut, speciation occurred in the squirrels that inhabit the high-altitude ponderosa pine forest of the southwest Colorado Plateau. The canyons steep cliffs and desert terrain contained nothing for a squirrel to eat, so individual squirrels did not enter it. The squirrels stayed at home on the south rim or the north rim, and the populations ceased to interbreed with each other. The eventual result has been speciation: the north rims Kaibab squirrel and the south rims Abert squirrel have become separate species.

Mountains and humans

Transportation and communication are more difficult in mountains. Even today, mountain weather sometimes makes flying into mountains risky, and radio signals are blocked by the masses of stone. U.S. interstate highways close down due to snow, ice, and even rockfalls. The difficulty of operating in the mountainous countries of Afghanistan and Vietnam certainly affected the outcomes of the wars fought in those countries.

The thin, stony soil of mountain slopes possesses minimal value as farmland. Mountain meadows and forests provide a good pasture for grazing animals, however, and mountain people often practice pastoral

KEY TERMS

Collisional mountain belt A mountain range that is built when two or more continents run into each other.

Fault block mountains A mountain range formed by horizontal forces that squeeze a continent, fracturing its crust and pushing some crustal blocks upward to form mountains while others drop down to form valleys.

Island arc A string of volcanic mountains that emerge from the sea as islands.

Obduction A geological accident wherein a piece of the oceanic crust gets put on top of the continental crust, as opposed to beneath it as usual.

Ore body A geological formation in which an economically valuable mineral is concentrated.

Plate One of the pieces into which earths crust is broken, which floats on top of the mantle, and is pushed around by tectonic forces.

Shield volcano A broad, low profile volcano consisting of layers of basaltic rock, typically formed in the middle of oceanic plates or on continental rifts.

Stratovolcano A large, steepsided volcanic mountain, often located in an island chain (island arc) or on land in a series of volcanos along a tectonically active coast (continental arc).

Tectonic Having to do with forces that fold and fracture the rocks of planets.

Thrust fault A low-angle reverse fault in which the dip of the fault plane is 45° or less and displacement is primarily horizontal.

Thrust sheet A slab of the crust that gets pushed up on top of a neighboring slab of crust.

Topography The detailed surface features of an area.

Uplift An episode in the history of a region when tectonic forces lift the regions crust to a higher elevation.

Volcanic neck A usually tall, steep mountain of lava rock that solidified in the volcanos throat, stopping up the volcano as it became extinct.

Volcano A mountain that forms around a vent from which lava, ash, or other igneous rock is erupted.

agriculture. Herds of goats, cows, sheep, pigs, or llamas turn the upland vegetation directly into food and industrial productswool, tallow, leather, and so on. But in order for farming and herding people to dwell in the mountains with any economic security, the population must remain low, to avoid using up all of the sparse resources.

Because of the difficulties mountains put in the way of making a living at agriculture, mountain regions usually cannot support a prosperous agricultural tax base. People of mountain cultures, therefore, are used to being left alone by governments. These peoples independent outlook is interchangeable around the world, whether they are Swiss, Papuan, Appalachian, or Jamaican Maroon. Language and customs from hundreds or thousands of years ago survive in remote mountains, preserved by the same geography that cut them off in the first place.

Unlike farmers, people of the worlds industrial civilization can find in the mountains a great bounty of the resources they cannot live without. Geologic formations of economically valuable minerals, called ore bodies, are left behind by the processes that make mountains. Mountain-building rearranges the formations that hold metal ores, coal, gemstones, asbestos, and other substances. These ore bodies come to rest near enough to the surface to be mined at a profit. Although many mining districts have been mined out, this only means that the minerals that could be mined for a profit have been removed. The worlds mountain ranges still contain vast amounts of economic minerals, out of sight under kilometers of rock. Present mining methods are too expensive to dig deep enough to process the great majority of them, however.

Broad, swift rivers drain mountains that receive large amounts of rain and snow. Dropping from the uplands, water rapidly accumulates kinetic energy (kinetic energy is the energy in a moving object). Hydroelectric power plants convert some of this energy into power, providing industries and cities with cheap, clean, and plentiful electric power. Mountainous Switzerlands hydroelectric power enabled it to become one of the worlds leading industrial countries.

Resources

BOOKS

Crump, D., ed. Mountain Worlds. Washington, DC: The National Geographic Society, 1988.

Keller, E.A. Introduction to Environmental Geology. 2nd ed. Upper Saddle River: Prentice Hall, 2002.

Press, F., and R. Siever. Understanding Earth. 3rd ed. New York: W.H Freeman and Company, 2001.

Mountains

views updated May 21 2018

Mountains

A mountain is a large-scale topographic feature that is set apart from the local landscape by being much higher in elevation (topographic means having to do with the shape of the land surface).


Relative size of mountains

Mountains are taller than hills, but the distinction between hills and mountains is decided entirely by the people that live near them.

Thus, distinguishing mountains from smaller topographic features is partly a matter of perception , rather than of scientific measurement and comparison to a known standard. Absolute elevation above sea level does not make a high point into a mountain nearly so much as local relief does (relief is the difference between topographic high spots and low spots). In a landscape with thousands of feet or more of local relief, a feature several hundred feet tall would be considered an insignificant hill, whereas in Holland, it would be considered a mountain of the first order. Mountains of 4,000 ft (1,219 m), 10,000 ft (3,048 m), and 16,000 ft (4,877 m) may look vastly different on a map , but look equally large when observed in their local environment.

Duration of mountains

Mountains, like every other thing in the natural world, go through a life cycle. They rise, from a variety of reasons, and wear down over time , at various rates. Although humans have always used mountains to represent eternity, individual mountains do not last very long in the powerfully erosive atmosphere of the earth . Mountains on the waterless worlds of Mars and the moon are billions of years old, but Earth's peaks begin to fracture and dissolve as soon as their rocks are exposed to air. The permanent part of a mountain range is not the shape taken by the rocks at the surface, but the huge folded shapes that the rocks were deformed into by the original orogenic event. (Orogeny is the process of mountain formation.) Throughout their almost four-billion year history, the continents have been criss-crossed by many immense ranges of mountains. Most of the mountain ranges in the planet's history rose and wore away at different times, a long time ago. Where did these mountains go?

A range of mountains may persist for hundreds of millions of years, like the Appalachians. At several different times, the warped, folded rocks of the Appalachians were brought up out of the continent's basement and raised thousands of feet by tectonic forces. In order to stand for any considerable length of geologic time , a mountain range must experience continuous uplift . A tectonically quiet mountain range will wear down from erosion in a few million years. In North America's geologic past, for example, eroded particles from its mountains were carried by streams and dumped into the continent's inland seas, some of which were as large as the present-day Mediterranean. Those rivers and seas are gone from the continent , but the sediments that filled them remain, like dirt in a bathtub when the water is drained. The roots of all the mountain ranges that have ever stood in North America still exist, and much of the sand and clay into which the mountains were transformed still exists also, as rock or soil formations. This is true of all the continents of Earth.


Plate tectonics, the force that builds mountains

Orogeny is the process of mountain formation. Plate tectonics is the main force of nature responsible for orogeny. This continent-building process may be simply explained:

The Earth is covered with a thin, brittle crust. Below the crust is the mantle, a region where solid rock below a certain depth stretches like rubber.

The crust floats on top of Earth's mantle like the crust of grease that forms on top of a pot of chili or chicken broth in the refrigerator.

The Earth's crust has been broken into pieces, called plates. The motion of a tireless heat engine that swirls and stirs within the earth's mantle, moves the plates.


Isostasy

The thicker parts of the continents float higher than the thinner parts, and any process that thickens the continental crust will bring about the uplift of the thickened portion. Continental crust "floats" in the mantle, and can be compared to the way an ice cube floats in water. An ice cube floats because it is lighter per unit volume than water—that is, ice is less dense than liquid water. The ice cube may weigh a few ounces, and rise a centimeter above the water's surface. An iceberg might weigh millions of tons, but float a hundred feet out of the water, because although it is vastly heavier than the ice cube, it is still less dense than water per unit volume—it floats. The more there is of it, the higher it floats. Similarly, any mass of continental crust, no matter how thick, is still less dense per unit volume than the mantle rock beneath it. Thus the edge of the continent begins rising to a higher elevation, and mountains begin to form.

Mountains are generated both at the edges of plates, and within plates. Other processes, such as sedimentation and erosion, modify the shape of the land that has been forged by plate tectonics .


Types of mountains

Island arcs

When the edge of a plate of Earth's crust runs over another plate, forcing the lower plate deep into Earth's elastic interior, a long, curved mountain chain of volcanos usually forms on the forward-moving edge of the upper plate. When this border between two plates forms in the middle of the ocean , the volcanic mountains form a string of islands, or archipelago, such as the Antilles and the Aleutians. This is called an island arc.


Continental arcs

When the upper plate is carrying a continent on its forward edge, a mountain chain, like the Cascades or the Andes, forms right on the forward edge. This edge, heavily populated with volcanos, is called a continental arc.


Collisional mountain belt

A continent or island arc runs into a continent, shattering and deforming the rocks of the collision area, and stacking up the pieces into a mountain range. This is how the Appalachians, Alps, and Himalayas were formed: the rocks of their continents were folded just as flat-lying cloth folds when pushed. Imagine how much taller your school would be if it were squeezed by bulldozers so it remained the same length east to west as it is now, but from north to south measured the width of a school bus. The result would be a tall wall of compressed material, and that is just what a collisional mountain belt is. Collisional mountain belts are one of three types of boundary between plates of the earth's crust, along with mid-ocean ridges and inter-plate strike-slip faults. Mountains rise relatively quickly, over a few million years, such as the Appalachians did more than 200 million years ago. As these mountains begin to erode, the topography continually changes and develops. Hard rock layers influence the development of streams, because they resist erosion and form the ridgetops in the mountain range.

One special type of orogeny that can happen during a continental collision is the rise of ophiolite mountains. On rare occasions the crust beneath the ocean floor fractures along the tectonically active coast of a continent, and oceanic crust is thrust up over the shore and forms mountains. This spectacular form of plate-tectonic back-fire is not supposed to happen, yet it does often enough to have its own name: obduction, meaning "over" (ob-) "leading" (-duction). A piece of oceanic crust, and the mantle rock beneath it, is heaved up onto the land to form mountains. The Taconic Mountains that rose in upstate New York 430 million years ago were an obducted ophiolite, as are the uplands around Troodos in Cyprus.

Fault block mountains: When a continent-sized "layer cake" of rock is pushed, the upper layers can be pushed more readily than the lower layers. The easy-to-push upper layers split from the deeper rocks, and a broad sheet of the upper crust, a few miles thick, begins to move across the continent. This thrust sheet floats on fluid pressure between the upper and lower sections of the crust. The horizontal split in the crust that separates the motionless lower crust from the floating upper layers is called a detachment fault in English, or a decollement in French.

Like a hydroplaning tractor trailer (viewed in very slow motion), the upper fault block glides until it runs into something. When the thrust sheet runs into something that resists its forward motion, the detachment fault turns into a ramp, leading up to the surface. The moving layer of upper crust is pushed up the ramp-like fault, and the front of the fault block rises out of the ground. The mountains thrown up where the thrust fault reaches the surface are one kind of fault block mountains. The mountains of Glacier National Park slid along a thrust fault over younger rocks, and out onto the Great Plains. Chief Mountain, a remarkable square mountain in Montana, moved to where it is now by sliding out onto the prairie on a thrust fault. The broad, flat fault block it belonged to, called a thrust sheet, has long since disappeared, leaving Chief Mountain standing alone.

Another kind of fault block mountain comes from stretching of Earth's crust. As the crust stretches, it pulls apart, making long faults that run perpendicular to the direction of pulling. These faults grow and connect with each other, isolating mountain-sized, wedge-shaped fault blocks. Some of these fault blocks begin slipping downward between more stable blocks that still rest on a firm foundation of deep rock. The stable blocks are called horsts, and the sinking blocks, that form valley floors, are called grabens.


Mid-ocean ridge

The longest mountain chain on Earth, the mid-ocean ridge system is entirely under water. Twisting down the center of the Atlantic Ocean, it continues through the Indian and Pacific oceans. It is one of three types of boundary between plates of the crust, along with inter-plate strike-slip faults and collisional mountain belts. Along this ridge, lava continuously erupts, releasing heat from the planet's interior and extruding new strips of ocean floor.


Stratovolcanos

Popocatepetl, Mt. Fuji, Vesuvius, and Mt. Ararat are all stratovolcanos. The prefix strato-refers to these moun tains' characteristic layers, the result of alternately erupting ash and lava. Spectacularly tall and pointed, stratovolcanos may grow to an elevation of 2-3 mi (3.2-4.8 km) before collapsing. It is not certain that every stratovolcano collapses into a crater of superheated steam and molten rock. But the continents are dotted with the remains of these mountains' self-annihilations, some of whose like has not been witnessed in human history.


Cinder cone

These volcanos build a pile of pyroclastic gravel and boulders (pyroclastic is derived from "fire" and "broken pieces") that forms a pointed or rounded cone. Because they are made of loose material, they quickly erode away unless further eruptions continue to build them.


Shield volcanos

Often solitary volcanic mountains form as a volcano piles up rock above the ocean floor over millions of years. Hawaii, Bermuda, and the Canary Islands are shield volcanos. These islands, and others like them, are the work of hot spots (hot spot is a volcanically active site heated from below by a concentrated flow of heat out of the earth's mantle). Iceland is a hot spot that sits astride the mid-ocean ridge system. Shield volcanos also occur on continents, particularly in rift valleys where a continent is being ripped in two. Kilimanjaro is the classic example of a continental shield volcano. Olympus Mons on Mars is another classic shield volcano, and is the largest known mountain in the solar system .

Volcanic necks

In a cinder cone, lava rises through a vertical pipe before it erupts. The mountain resembles a huge pile of gravel. After an old cinder cone becomes extinct, the underground pipes that brought it lava from below solidify, and the pile of erupted material begins to wear away. Solid lava, usually a very hard rock, often fills the extinct volcano's vent. In a cinder cone, the solidified lava will resist the forces of erosion far longer than the ash, cinders, and other loose material of which the volcanic pile is made. Thus, as rain, wind , and frost scrub the soft exterior of the volcano away from the hard interior, a columnar mountain emerges. Shiprock, in New Mexico, and Devil's Tower, in Wyoming, are classic examples of these mountains, called volcanic necks.


Exposed plutons

Plutons are masses of hard, visibly crystalline igneous rock that form deep in Earth's crust. Plutons rise through the earth's crust when they are molten, and freeze into solid rock far below the surface. Plutons can be as small as a highway roadcut, or as large as an entire mountain range. Mountains emerge from a landscape as erosive forces strip away the rocks that cover a pluton. A small pluton called a stock forms the granite core of Mount Ellsworth in southern Utah. The Sierra Nevada mountains are entirely made up of massed plutons, collectively called the Sierra Nevada batholith. The Yosemite Valley cuts into the solid granite interior of these mountains.


Unusual volcanos

A rare kind of mountain is the individual volcano with no known relationship to a volcanically active region. Solitary volcanos like these have erupted in tectonically quiet landscapes, such as east Texas of the Cretaceous period, and their cause remains a mystery.

Mesas are flat-topped mountains. They form when a solid sheet of hard rock sits on top of softer rock. The hard rock layer on top, called the "caprock," once covered a wide area. The caprock is cut up by the erosive action of streams. Where there is no more caprock, the softer rock beneath washes away relatively quickly. Mesas are left wherever a remnant of the caprock forms a roof over the softer rock below. A cuesta is a mesa that has been tilted, so the caprock forms a slope.


Inverted topography

When lava erupts from a volcano or fissure, it flows downhill like any other liquid, into low spots in the landscape. This is why a river valley makes a convenient path for a lava flow. When the lava has solidified in the lowest part of the valley, it may be harder than the rocks that form the valley's walls. So when water again can flow through the valley, it flows around both sides of the lava flow. Eventually the lava flow has two valleys on either side of it, getting deeper every year. After thousands of years, a mesa will have been created, for the lava flow has become a caprock. This form of mesa is called inverted topography, because the low places become high places.

Outliers and monadnocks: Another term for a mountain made from a plateau worn by erosion is outlier. Not necessarily flat-topped, an outlier can be any hill or mountain left standing as the plateau with which it was once joined erodes farther and farther away. The Tepuis of Venezuela are outliers of a once-widespread plateau. A hard-rock mountain left standing after an entire mountain range has eroded away around it is a monadnock.


Weather effects of mountains

Mountains make a barrier for moving air. The wind pushes air, and clouds in the air, up the mountain slopes. The atmosphere is cooler at high elevations, and there is less of it: lower pressure makes it hard for lowland animals to get enough air to breathe. Dense masses of warm, moist air that move up and over a mountain swell as the air pressure confining them drops away. The air becomes colder in the same way as a pressurized spray can's contents become colder when the can's pressure drops rapidly. (The phrase that describes this phenomenon is adiabatic expansion.) Water that existed as a gas under the high pressure and temperature of the flatlands now condenses into cool droplets, and clouds form over the mountain. As the cloud continues to rise, droplets grow and grow, eventually becoming too heavy to float in the air. The clouds dump rain, and snow, on the mountain slopes. After topping the crest, however, the clouds may have no more moisture to rain on the other side of the mountain, which becomes arid. This rain shadow is best illustrated in the Sierra Nevada mountains of California, where tall redwood forests cover the ocean-facing side of the mountains, and Death Valley lies in the rain shadow.

Mountains' effect on evolution

Sometimes mountains can become refuges for species endangered by the drying climate, or other radical ecological change, in the surrounding lowlands. In this way mountains can influence a species' chances to live and prosper. Climatic "islands" like this may isolate one population from the rest of its species. Entire uncatalogued species of large animals have been found in the 1990s living in the mountains of southeast Asia . As generation succeeds generation, the genetic pattern that defines a population can change during its separation from the rest of its species. An isolated population may even become a species unto itself, unable to reproduce with the population from which it was once separated. This evolutionary phenomenon is called speciation, and mountain topography provides barriers between populations that have made speciation happen.

When the Grand Canyon was cut, speciation occurred in the squirrels that inhabit the high-altitude ponderosa pine forest of the southwest Colorado Plateau. The canyon's steep cliffs and desert terrain contained nothing for a squirrel to eat, so individual squirrels did not enter it. The squirrels stayed at home on the south rim or the north rim, and the populations ceased to interbreed with each other. The eventual result has been speciation: the north rim's Kaibab squirrel and the south rim's Abert squirrel have become separate species.


Mountains and humans

Transportation and communication are more difficult in mountains. Even today, mountain weather sometimes makes flying into mountains risky, and radio signals are blocked by the masses of stone. U.S. interstate highways close down due to snow, ice, and even rockfalls. The difficulty of operating in the mountainous countries of Afghanistan and Vietnam certainly affected the outcomes of the wars fought in those countries.

The thin, stony soil of mountain slopes possesses minimal value as farmland. Mountain meadows and forests provide a good pasture for grazing animals, however, and mountain people often practice pastoral agriculture. Herds of goats , cows, sheep , pigs , or llamas turn the upland vegetation directly into food and industrial products—wool, tallow, leather, and so on. But in order for farming and herding people to dwell in the mountains with any economic security, the population must remain low, to avoid using up all of the sparse resources.

Because of the difficulties mountains put in the way of making a living at agriculture, mountain regions usually cannot support a prosperous agricultural tax base. People of mountain cultures, therefore, are used to being left alone by governments. These peoples' independent outlook is interchangeable around the world, whether they are Swiss, Papuan, Appalachian, or Jamaican Maroon. Language and customs from hundreds or thousands of years ago survive in remote mountains, preserved by the same geography that cut them off in the first place.

Unlike farmers, people of the world's industrial civilization can find in the mountains a great bounty of the resources they cannot live without. Geologic formations of economically valuable minerals , called ore bodies, are left behind by the processes that make mountains. Mountain-building rearranges the formations that hold metal ores, coal , gemstones, asbestos , and other substances. These ore bodies come to rest near enough to the surface to be mined at a profit. Although many mining districts have been "mined out," this only means that the minerals that could be mined for a profit have been removed. The world's mountain ranges still contain vast amounts of economic minerals, out of sight under kilometers of rock. Present mining methods are too expensive to dig deep enough to process the great majority of them, however.

Broad, swift rivers drain mountains that receive large amounts of rain and snow. Dropping from the uplands, water rapidly accumulates kinetic energy (kinetic energy is the energy in a moving object). Hydroelectric power plants convert some of this energy into power, providing industries and cities with cheap, clean, and plentiful electric power. Mountainous Switzerland's hydroelectric power enabled it to become one of the world's leading industrial countries.

Resources

books

Crump, D., ed. Mountain Worlds. Washington, DC: The National Geographic Society, 1988.

Keller, E.A. Introduction to Environmental Geology. 2nd ed. Upper Saddle River: Prentice Hall, 2002.

Press, F.,and R. Siever. Understanding Earth. 3rd ed. New York: W.H Freeman and Company, 2001.

periodicals

George, U. "Tepuis-Venezuela's Islands in Time." National Geographic 175 (May 1989): 526-561.

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Collisional mountain belt

—A mountain range that is built when two or more continents run into each other.

Fault block mountains

—A mountain range formed by horizontal forces that squeeze a continent, fracturing its crust and pushing some crustal blocks upward to form mountains while others drop down to form valleys.

Island arc

—A string of volcanic mountains that emerge from the sea as islands.

Obduction

—A geological "accident" wherein a piece of the oceanic crust gets put on top of the continental crust, as opposed to beneath it as usual.

Ore body

—A geological formation in which an economically valuable mineral is concentrated.

Plate

—One of the pieces into which Earth's crust is broken, which floats on top of the mantle, and is pushed around by tectonic forces.

Shield volcano

—A broad, low profile volcano consisting of layers of basaltic rock, typically formed in the middle of oceanic plates or on continental rifts.

Stratovolcano

—A large, steepsided volcanic mountain, often located in an island chain (island arc) or on land in a series of volcanos along a tectonically active coast (continental arc).

Tectonic

—Having to do with forces that fold and fracture the rocks of planets.

Thrust fault

—A low-angle reverse fault in which the dip of the fault plane is 45° or less and displacement is primarily horizontal.

Thrust sheet

—A slab of the crust that gets pushed up on top of a neighboring slab of crust.

Topography

—The detailed surface features of an area.

Uplift

—An episode in the history of a region when tectonic forces lift the region's crust to a higher elevation.

Volcanic neck

—A usually tall, steep mountain of lava rock that solidified in the volcano's throat, stopping up the volcano as it became extinct.

Volcano

—A mountain that forms around a vent from which lava, ash, or other igneous rock is erupted.

Mountain

views updated May 17 2018

Mountain

A mountain is any landmass on Earth's surface that rises to a great height in comparison to its surrounding landscape. Mountains usually have more-or-less steep sides meeting in a summit that is much narrower in width than the mountain's base.

Although single mountains exist, most occur as a group, called a mountain range. A group of ranges that share a common origin and form is known as a mountain system. A group of systems is called a mountain chain. Finally, a complex group of continental (land-based) ranges, systems, and chains is called a mountain belt or cordillera (pronounced kordee-YARE-ah).

The greatest mountain systems are the Alps of Europe, the Andes of South America, the Himalayas of Asia, and the Rockies of North America. Notable single peaks in these systems include Mont Blanc (Alps), Aconcagua (Andes), Everest (Himalayas), and Elbert (Rockies). The Himalayas is the world's highest mountain system, containing some 30 peaks rising to more than 25,000 feet (7,620 meters). Included among these peaks is the world's highest, Mount Everest, at 29,028 feet (8,848 meters) above sea level. North America's highest peak is Mount McKinley, part of the Alaska Range, which rises 20,320 feet (6,194 meters).

Mountains, like every other thing in the natural world, go through a life cycle. They rise from a variety of causes and wear down over time at various rates. Individual mountains do not last very long in the powerfully erosive atmosphere of Earth. Mountains on the waterless world of Mars are billions of years old, but Earth's peaks begin to fracture and dissolve as soon as their rocks are exposed to the weathering action of wind and rain. This is why young mountains are high and rugged, while older mountains are lower and smoother.

Words to Know

Belt: Complex group of continental mountain ranges, systems, and chains.

Chain: Group of mountain systems.

Crust: Thin layer of rock covering the planet.

Lithosphere: Rigid uppermost section of the mantle combined with the crust.

Orogeny: Mountain building.

Plate tectonics: Geological theory holding that Earth's surface is composed of rigid plates or sections that move about the surface in response to internal pressure, creating the major geographical features such as mountains.

Range: Group of mountains.

System: Group of mountain ranges that share a common origin and form.

Mountain building

Mountain building (a process known as orogeny [pronounced o-RA-je-nee]) occurs mainly as a result of movements in the surface of Earth. The thin shell of rock covering the globe is called the crust, which varies in depth from 5 to 25 miles (8 to 40 kilometers). Underneath the crust is the mantle, which extends to a depth of about 1,800 miles (2,900 kilometers) below the surface. The mantle has an upper rigid layer and a partially melted lower layer. The crust and the upper rigid layer of the mantle together make up the lithosphere. The lithosphere, broken up into various-sized plates or sections, "floats" on top of the heated, semiliquid layer underneath.

The heat energy carried from the core of the planet through the semi-liquid layer of the mantle causes the lithospheric plates to move back and forth. This motion is known as plate tectonics. Plates that move toward each other are called convergent plates; plates moving away from each other are divergent plates.

When continental plates converge, they shatter, fold, and compress the rocks of the collision area, thrusting the pieces up into a mountain range of great height. This is how the Appalachians, Alps, and Himalayas were formed: the rocks of their continents were folded just as a flat-lying piece of cloth folds when pushed.

When a continental plate and an oceanic plate converge, the oceanic plate subducts or sinks below the continental plate because it is more dense. As the oceanic plate sinks deeper and deeper into Earth, its leading edge of rock is melted by intense pressure and heat. The molten rock then rises to the surface where it lifts and deforms rock, resulting in the formation of volcanic mountains on the forward edge of the continental plate. The Andes and the Cascade Range in the western United States are examples of this type of plate convergence.

The longest mountain range on Earth is entirely underwater. The Mid-Atlantic Ridge is a submarine mountain range that extends about 10,000 miles (16,000 kilometers) from Iceland to near the Antarctic Circle. The ridge is formed by the divergence of two oceanic plates. As the plates move away from each other, magma (molten rock) from inside Earth rises and creates new ocean floor in a deep crevice known as a rift valley in the middle of the ridge. On either side of the rift lie tall volcanic mountains. The peaks of some of these mountains rise above the surface of the ocean to form islands, such as Iceland and the Azores.

Other mountains on the planet form as solitary volcanic mountains in rift valleys on land where two continental plates are diverging. Mount Kilimanjaro, the highest point in Africa, is an extinct volcano that stands along the Great Rift Valley in northeast Tanzania. The highest of its two peaks, Kibo, rises 19,340 feet (5,895 meters) above sea level.

The erosive power of water on plateaus can also create mountains. Mesas, flat-topped mountains common in the southwest United States, are such a case. They form when a solid sheet of hard rock sits on top of softer rock. The hard rock layer on top, called the caprock, once covered a wide area. The caprock is cut up by the erosive action of streams. Where there is no more caprock, the softer rock beneath washes away relatively quickly. Mesas are left wherever a remnant of the caprock forms a roof over the softer rock below. Mesa Verde in Colorado and the Enchanted Mesa in New Mexico are classic examples.

Mountains and weather

Mountains make a barrier for moving air, robbing it of any precipitation. The atmosphere at higher elevations is cooler and thinner. As dense masses of warm, moist air are pushed up a mountain slope by winds, the air pressure surrounding the mass drops away. As a result, the mass becomes cooler. The moisture contained in the mass then condenses into cool droplets, and clouds form over the mountain. As the clouds continue to rise into cooler, thinner air, the droplets increase in size until they become too heavy to float in the air. The clouds then dump rain or snow on the mountain slope. After topping the crest, however, the clouds often contain little moisture to rain on the lee side of the mountain, which becomes arid. This is best illustrated in the Sierra Nevada mountains of

California, where tall redwood forests cover the ocean-facing side of the mountains and Death Valley lies on the lee side.

[See also Plate tectonics; Volcano ]

mountain

views updated May 21 2018

moun·tain / ˈmountn/ • n. a large natural elevation of the earth's surface rising abruptly from the surrounding level; a large steep hill: the village is backed by awe-inspiring mountains we set off down the mountain | [as adj.] the ice and snow of a mountain peak. ∎  (mountains) a region where there are many such features, characterized by remoteness and inaccessibility: they sought refuge in the mountains | [as adj.] (mountain) his attempt to picture the mountain folk in ridiculous attire. ∎  (a mountain/mountains of) a large pile or quantity of something: a mountain of paperwork. ∎  a large surplus stock of a commodity: this farming produced huge food mountains.PHRASES: make a mountain out of a molehillsee molehill.move mountains1. achieve spectacular and apparently impossible results.2. make every possible effort: his fans move mountains to catch as many of his performances as possible.DERIVATIVES: moun·tain·y adj.

Mountains

views updated May 23 2018

283. Mountains

See also 178. GEOGRAPHY ; 202. HEIGHTS ; 411. VOLCANOES .

acrophilia
a love of high mountains and of heights. acrophile , n.
alpinism
the climbing of the Alps or any equally high mountain ranges. alpinist , n.
orogenesis
the process of the formation of mountains. Also called orogeny . orogenic , adj.
orography, oreography
Physical Geography. the study of mountains and mountain systems. orographic, oreographic, oreographical, orographical , adj.
orology, oreology
the scientific study of mountains. orologist, oreologist , n. orological, oreological , adj.
orometry
the measurement of mountains. orometric , adj.
orophilous
Botany. referring to orophytes, a class of plants growing on mountains below the timberline.

mountains

views updated Jun 08 2018

mountains Mountains of the Moon the type of a very remote place; further than one can imagine, the ends of the earth. The term is also used by Ptolemy as the supposed source of the Nile, and is thought there to designate the Ruwenzori mountain range in central Africa.
move mountains achieve spectacular and apparently impossible results; make every possible effort. Often referring to the saying faith will move mountains, ultimately with biblical allusion, as to Matthew 17:20.

See also mountain, old man of the mountains.

mountain

views updated Jun 27 2018

mountain in figurative use, something of great size.
make a mountain out of a molehill lay unnecessary stress on a small matter.
mountain in labour great effort expended on little outcome, an allusion to the words of the Roman poet Horace (65–8 bc) in his Ars Poetica, ‘Parturient montes, nascetur ridiculus mus [Mountains will go into labour, and a silly little mouse will be born].’
Mountain State an informal name for Vermont.

See also if the mountain will not come to Mahomet, mountains.

About this article

Mountains

All Sources -
Updated Aug 13 2018 About encyclopedia.com content Print Topic