 |
Business | Industries | Finance | Tax |
| Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|||||
| First Prev [ 1 2 3 4 ] Next Last |
The canyon, created by the Colorado River cutting a channel over millions of years, is about 277 mile (446 km) long, ranges in width from 4 to 18 miles (6 to 29 kilometers) and attains a depth of more than a mile (1,600 m). Nearly 2000 million years of the Earth's history has been exposed as the Colorado River and its tributaries cut through layer after layer of sediment as the Colorado Plateaus have uplifted.
The Grand Canyon was first seen by a European in 1540, García López de Cárdenas from Spain. The first scientific expedition to the canyon was led by U.S. Major John Wesely Powell in the late 1870Events January 6 The inauguration of the Musikverein ( Vienna). January 10 John D. Rockefeller incorporates Standard Oil January 15 A political cartoon for the first time symbolizes the United States Democratic Party with a donkey ("A Live Jackass Kickings. Powell referred to the sedimentary rockshale overlaid by limestone. Cumberland Plateau, Tennessee. Sedimentary rock is one of the three main rock groups (along with igneous and metamorphic rocks) and is formed in three main ways—by the deposition of the weathered remains of other rocks (known units exposed in the canyon as "leaves in a great story book." Long before that however the area was inhabited by Native AmericanNative Americans (also Indians Aboriginal Peoples American Indians First Nations Alaskan Natives or Indigenous Peoples of America are the indigenous inhabitants of Americas prior to the European colonization, and their modern descendants. This term compris who built settlements in the canyon walls.
The Grand Canyon is a deep - in places a mile deep - 277 mile (446 km) long cut in the Colorado Plateaus that exposes uplifted Proteozoic and Paleozoic strata. The exposed strata are gradually revealed by the gentle incline beginning at Lees Ferry and continuing to Phantom Ranch. At the point where the river crosses the Grand Wash Fault (near Lake Mead) the Canyon ends.
Uplift associated with plate tectonics20th century. Plate tectonics (from the Greek word for "one who constructs", τεκτων tekton ) is a theory of geology developed to explain the phenomenon of continental drift. In the theory of plate tectonics the outermost par-caused mountainThis article is about the landform. For other meanings, see Mountain (disambiguation). Mount Cook, a mountain in New Zealand A mountain is a landform that extends above the surrounding terrain in a limited area. A mountain is generally much higher and ste building events later moved these sediments thousands of feet upward and created the Colorado Plateaus. The higher elevation has also resulted in greater precipitation in the Colorado River drainage area, but not enough to change the Grand Canyon area from being semi-arid. Landslides and other mass wasting events then caused headward erosion and stream capture - all of which tend to increase the depth and width of canyons in arid environments.
The uplift of the Colorado Plateaus is uneven, resulting in the North Rim of the Grand Canyon being over a thousand feet (about 300 meters) higher than the South Rim. The fact that the Colorado River flows closer to the South Rim is also explained by this asymmetrical uplift. Almost all runoff from the plateau behind the North Rim (which also gets more rain and snow) flows toward the Grand Canyon, while much of the runoff on the plateau behind the South Rim flows away from the canyon (following the general tilt). The result is much greater erosion and thus faster widening of the canyon and its tributary canyons north of the Colorado River.
Temperatures on the North Rim are generally lower that the South Rim because of the greater elevation (8000 feet/2438 m above sea level). Heavy snowfall is common during the winter months. Views from the North Rim tend to give a better impression of the expanse of the canyon rather than the views down which characterise the South Rim.
The Havasupai Indian Reservation is in a large tributary canyon on the south side of the Colorado River, it is administered by the Havasupai Indian Tribe.
| Politics | Business | Finance |
 |
 |
 |
|