Large Basin (America)

The Grand Basin ( Great Basin in English) is an area of mountains, basins sedimentary and high plateaus of the west of the the United States and north of the Mexico. The area offers a large variety of landscapes: those of the National park of the Large Basin are protected. It is also about an arid desert and little populated.

Geography

The area of the Large Basin is in the east of the Sierra Nevada and in the west of the Plateau of Colorado and the Montagnes Wasatch. It is bordered in north by the Plateau of Columbia. It takes the appearance of a succession of mountainous wrinkles located between 2000 and 3000 meters of altitude. These mountains frame basins of longitudinal orientation filled by Alluvion S on several thousands of meters thickness, with the Miocène. One finds also Graben S and Horst S delimited by Faille S typical normals in a Zone of distension.

History

The history of the human settlement in the Large Basin goes back at least to 12.000 years. At the time of the arrival of Europeans, the area was inhabited by a great Amerindian group of tribes born from the group of the Uto-Aztecan known collectively under the name of the tribes of the Large Basin . There were for example the Shoshone S, Utes and Paiutes. The European first to arrive in the area were the first Spanish explorers , in south-west, at the end of the 18th century. Hunters of fur of Hudson Bay Company explored the high area of the basin at the beginning of the 19th century. The first comprehensible and precise chart of the area was carried out by John Charles Frémont during his explorations of the Années 1840 of the zone.

The the United States acquérirent the complete control of the area with the Traité of Oregon of 1846 and the Treaty of Guadalupe Hidalgo of 1848. The first true colony was that of the first Mormon pioneers of the end of the Années 1840 in the zones surrounding Salt Lake City and the Vallée of Mask. They established a provisional government quickly and proposed the creation of a new state, named the State de Deseret , which would include/understand the Large Basin in its entirety, as well as the coast of the California of the south. This idea disappeared since the area was successively organized manner different with creation from the Territoire from Oregon in 1848, the admission of the California as a state of the Union in 1850, and the creation of the Territoire of Utah in 1850. The discovery of gold in California in 1848 made flow of many emigrants in the Large Basin, along the Piste of California, which according to the Humboldt river in the Nevada.

In 1986 the National park of the Large Basin was established by the federal government, thus protecting 122 km ² from grounds in the Nevada, close to the border with the Utah. In the Années 1950 the area in the North-East of Las Vegas was the ground of test of many tests of atomic bombs to the free air, then in basement in the Années 1960.

Flora and fauna

Most of the Large Basin makes up of a desert of altitude, with differences in mediums between the tops with more than 2000 meters and the basins. The landscapes marked by the aridity are generally covered with shrubs adapted to the climatic constraints: the Atriplex dominates with the lowest altitudes; it is replaced by the Armoise ( Artemisia tridentata ) in altitude. On the mountainous slopes, the most common trees are the Genévrier ( Juniperus osteosperma ), the pine ( Pinus monophylla ), the Cercocarpus . The flexible Pine and the Pin of Bristlecone (Nevada, Utah) are sometimes present in top of the chains. The poplar ( Populus Aegiros ) and trembles it ( Populus tremuloides ) appear in the least dry places.

The most widespread mammals are the Lièvre S and the Lapin S ( Sylvilagus audubonii , Lepus californicus ) as well as the Coyote S and the squirrel S. the Neotoma and the Dipodomys are relatively frequent rodents, but they leave only during the night. The large mammals are the Puma, the Pronghorn, the Cerf hémione, but they are more difficult with observes. Lastly, the Wapiti and the Canadian Mouflon much rarer and are threatened.

In the basins, the small lizards (Lizard of the palisades, Gambelia wislizenii , Phrynosoma ) are numerous. The Crotale and the Pituophis catenifer are also present. Among the principal birds which nest in the Large Basin, one finds the Phalarope and the Courlis close to the stretches of water; the sad Turtle-dove, the Sturnelle of the West, the Black and white with black nozzle of America, the Large corbel; the Pélican of America lives on banks of the Pyramid Lake in Nevada. The Golden eagle is well represented.

Two fish species live only in Pyramid Lake and are threatened of extinction: the Chasmistes cujus and the Oncorhynchus clarki henshawi .

The invertebrates are represented by the Tarentule S and the Anabrus simplex (cricket).

The species which were introduced into the Large Basin are the Perdrix choukar, the gray Perdrix, the mustang, the wild ass and the Brome of the roofs.

See too

Laramide Orogenesis, Orogenesis névadienne
Big lake Salted
National park of the Large Basin

External bonds