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High Desert (Oregon)
The Oregon high desert is a region of the U.S. state of Oregon located east of the Cascade Range and south of the Blue Mountains, in the central and eastern parts of the state. Divided into a southern region and a northern region, the desert covers most of five Oregon counties and averages above sea level. The southwest region is part of the Great Basin and the southeast is the lower Owyhee River watershed. The northern region is part of the Columbia Plateau, where higher levels of rainfall allow the largest industry on private land to be the cultivation of alfalfa and hay. Public land within the region is owned primarily by the Bureau of Land Management, which manages more than including five rivers designated as Wild and Scenic. While the high desert is somewhat dry, it is only arid relative to Western Oregon. The region averages of annual rainfall; the Alvord Desert, however, receives only of rain each year. Contrary to its name, most of the high desert is not dry en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frenchglen, Oregon
Frenchglen is an unincorporated small village in Harney County, Oregon, United States. It is south of Burns on Oregon Route 205 and its population is approximately 12. Frenchglen is near Steens Mountain and Malheur National Wildlife Refuge, and is home to the historic Frenchglen Hotel, an Oregon State Heritage Site built in 1917. In addition to the hotel, which includes a restaurant, the town has a K-8 school divided into two classes, a general store with gas pumps, and a county roads department base. The area is known as a haven for birdwatching. History The community is named after the French-Glenn Livestock Company, founded by Hugh J. Glenn and later joined by his son-in-law, Peter French. French-Glenn built its headquarters there in 1872. Education The zoned K-8 school is Frenchglen Elementary School (of Frenchglen School District 16). In the 1980-1981 school year there were two students, until one moved away, meaning that towards the end of the school year the school ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Land Management
The Bureau of Land Management (BLM) is an agency within the United States Department of the Interior responsible for administering federal lands. Headquartered in Washington DC, and with oversight over , it governs one eighth of the country's landmass. President Harry S. Truman created the BLM in 1946 by combining two existing agencies: the General Land Office and the Grazing Service. The agency manages the federal government's nearly of subsurface mineral estate located beneath federal, state and private lands severed from their surface rights by the Homestead Act of 1862. Most BLM public lands are located in these 12 western states: Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. The mission of the BLM is "to sustain the health, diversity, and productivity of the public lands for the use and enjoyment of present and future generations." Originally BLM holdings were described as "land nobody wanted" because home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American antelope, prong buck, pronghorn antelope and prairie antelope, because it closely resembles the antelopes of the Old World and fills a similar ecological niche due to parallel evolution. It is the only surviving member of the family Antilocapridae. During the Pleistocene epoch, about 11 other antilocaprid species existed in North America.Smithsonian Institution. North American MammalsPronghorn ''Antilocapra americana''/ref> Three other genera (''Capromeryx'', '' Stockoceros'' and ''Tetrameryx'') existed when humans entered North America but are now extinct. As a member of the superfamily Giraffoidea, the pronghorn's closest living relatives are the giraffe and okapi. See Fig. S10 in Supplementary Information. The Giraffoidea are in tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation. Individual pulses of cold climate within an ice age are termed ''glacial periods'' (or, alternatively, ''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, ''ice age'' implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basin And Range Topography
Basin and range topography is characterized by alternating parallel mountain ranges and valleys. It is a result of crustal extension due to mantle upwelling, gravitational collapse, crustal thickening, or relaxation of confining stresses. The extension results in the thinning and deformation of the upper crust, causing it to fracture and create a series of long parallel normal faults. This results in block faulting, where the blocks of rock between the normal faults either subside, uplift, or tilt. The movement of these blocks results in the alternating valleys and mountains. As the crust thins, it also allows heat from the mantle to more easily melt rock and form magma, resulting in increased volcanic activity. Types of faulting Symmetrical faulting: horst and graben With crustal extension, a series of normal faults which occur in groups, form in close proximity and dipping in opposite directions. As the crust extends it fractures in series of fault planes, some bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault-block Mountain
Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relatively uniform lithology. The largest of these fault blocks are called crustal blocks. Large crustal blocks broken off from tectonic plates are called terranes. Those terranes which are the full thickness of the lithosphere are called microplates. Continent-sized blocks are called variously ''microcontinents, continental ribbons, H-blocks, extensional allochthons and outer highs.'' Because most stresses relate to the tectonic activity of moving plates, most motion between blocks is horizontal, that is parallel to the Earth's crust by strike-slip faults. However vertical movement of blocks produces much more dramatic results. Landforms (mountains, hills, ridges, lakes, valleys, etc.) are sometimes formed when the faults have a large vert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steens Mountain
Steens Mountain is in the southeastern part of the U.S. state of Oregon, and is a large fault-block mountain. Located in Harney County, it stretches some north to south, and rises from the west side the Alvord Desert at elevation of about to a summit elevation of . Steens Mountain is not part of a mountain range but is properly a single mountain, the largest of Oregon's fault-block mountains.Conkling, C., Jackman, E. R., & Scharff, J. (1967)Steens Mountain in Oregon's high desert country Caxton Press. Retrieved April 25, 2022 The Steens Mountain Wilderness encompasses of Steens Mountain. of the Wilderness are protected from grazing and free of cattle. History The mountain was called the "Snowy Mountains" by John Work, one of the fur traders who were the first Europeans in the area. It was renamed in 1860 for United States Army Major Enoch Steen, who fought and drove members of the Paiute tribe off the mountain. American Indians used the Steens Mountain, particularly Big I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, savannas and shrublands biome A steppe may be semi-arid or covered with grass or with shrubs or with both, depending on the season and latitude. The term " steppe climate" denotes the climate encountered in regions too dry to support a forest but not dry enough to be a desert. Steppe soils are typically of the chernozem type. Steppes are usually characterized by a semi-arid or continental climate. Extremes can be recorded in the summer of up to and in winter, . Besides this major seasonal difference, fluctuations between day and night are also very great. In both the highlands of Mongolia and northern Nevada, can be reached during the day with sub-freezing readings at night. Mid-latitude steppes feature hot summers and cold wint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrubland
Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, Herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It may be the mature vegetation type in a particular region and remain stable over time, or a transitional community that occurs temporarily as the result of a disturbance, such as fire. A stable state may be maintained by regular natural disturbance such as fire or browsing (predation), browsing. Shrubland may be unsuitable for human habitation because of the danger of fire. The term was coined in 1903. Shrubland species generally show a wide range of adaptations to fire, such as heavy seed production, lignotubers, and fire-induced germination. Botanical structural form In botany and ecology a shrub is defined as a much-branched woody plant less than 8 m high and usually with many Plant stem, stems. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desert
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting fragments and rubble strewn over the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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