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The 'Teton Range' is a mountain range of the Rocky Mountains in North America. A north-south range, it is on the Wyoming side of the state's border with Idaho, just south of Yellowstone National Park. The two principal summits are the Grand Teton at 13,772 ft (4198 m) and Mount Moran at 12,605 ft (3842 m); most of the range is within the Grand Teton National Park. Early French voyageurs gave the name "les Trois Tetons" (the three breasts) ^[1].
Between six and nine million years ago, stretching and thinning of the Earth's crust caused movement along the Teton fault. The west block along the fault line was pushed upwards to form the Teton Range, thereby creating the youngest range of the Rocky Mountains. The fault's east block fell downwards to form the valley called Jackson Hole. While many of the central peaks of the range are comprised of granite, the geological processes that lead to the current composition began about 2.5 billion years ago. At that time, sand and volcanic debris settled into an ancient ocean. Additional sediment was deposited for several million years and eventually heat and pressure metamorphosed the sediment into gneiss, which comprises the major mass of the range. Subsequently, magma was forced up through the cracks and weaknesses in the gneiss to form granite, anywhere from inches to hundreds of feet thick. This ancient magma has manifested itself as noticeable black dikes of diabase rock, visible on the southwest face of Mount Moran and on the Grand Teton. Erosion and uplift have exposed the granite now visible today.
One reason the Tetons are famous is because of their great elevation above their base. Unlike most mountain ranges the Tetons lack foothills, or lower peaks which can obscure the view. As such, the Tetons rise sharply from 5,000 to nearly 7,000 feet above the surrounding terrain; the view is especially dramatic from Jackson Hole. Jackson Hole and the Tetons have been the setting for a number of prominent films, most notably ''Shane'', a 1953 Western.

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Pictures of the area

References

Pictures of the area

:''Main article: Geology of the Grand Teton area''

References

1. http://www.nps.gov/history/history/online_books/grte/grte_geology/sec1.htm


★ America's Volcanic Past - Wyoming