Mountain range
From Wikipedia, the free encyclopedia
A mountain range is a chain of mountains bordered by lowlands or separated from other mountain ranges by passes or rivers. Individual mountains within the same mountain range do not necessarily have the same geology, though they often do; they may be a mix of different orogeny, for example volcanoes, uplifted mountains or fold mountains and may, therefore, be of different rock. The Andes is the world's longest mountain range. The Himalaya contains the world's highest mountains. The Arctic Cordillera is the world's northernmost mountain system and contains the highest point in eastern North America.
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[edit] Tectonic plate movement
A range of mountains (often elongated) may be caused by tectonic plate interactions. For example, the Himalaya in Asia are the result of the Indian plate hitting the Eurasian plate, causing a 'crumple zone' near the line of impact. Sometimes, one tectonic plate can become pushed beneath another. The top plate scrapes off the material which builds up to form mountains. This happens over millions of years. Volcanoes can arise for this reason. An example is Vesuvius.
[edit] Erosion
Uplifted regions or volcanic caps can undergo erosion, resulting in a range of mountains. An example is the English Lake District. Mountain streams carry eroded debris downhill and deposit it in alluvial plains or in deltas. This forms the classical geological chain of events, leading to one type of sedimentary rock formation: erosion, transportation, deposition and compaction.
[edit] Climate
The position of mountains influences climate, such as rainfall. When wind moves over the sea, the warm moist air rises and cools to form orographic rainfall, while cool dry air moves over the ridge to the leeward side.
Their location also affects temperature. If the sun is shining from the east, then the eastern side of the mountain will receive sunlight and warmth, while the other side will be shaded and cooled, so certain ecosystems maintain different biological clocks depending on the location of a mountain.
[edit] Sub-ranges
It should be noted that the mountain systems of the earth are characterized by a tree structure, that is, mountain ranges are defined as having sub-ranges within them. It can be thought of as a parent-child relationship. For example, the Appalachian Mountains are the parent range of other ranges comprising it, some of which include the White Mountains and the Blue Ridge Mountains. The White Mountains are a child of the Appalachians, and there are also children of the Whites, including the Sandwich Range and the Presidential Range. Further, the Presidential Range can be broken up into the Northern Presidential Range and Southern Presidential Range. For more information, see List of mountain ranges and Peakbagger Ranges Home Page.
