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28-529: The Steens Mountain Wilderness ranges in elevation from 4,200 to 9,733 feet (1,280 to 2,967 m) at the summit of Steens Mountain . The reserve features a variety of vegetative zones, from the arid sagebrush zone in the Alvord Desert , through the western juniper , mountain mahogany , mountain big sagebrush , quaking aspen , subalpine meadow, and subalpine grassland, to the snow cover zone. Steens Mountain

56-501: A dwarf blue lupine , and Cusick's buckwheat ( Eriogonum cusickii ). Steens Mountain is distinctive in its absence of conifers , especially Ponderosa Pine and Douglas Fir , at elevations in which they would normally be found – from 5,500–8,000 feet (1,700–2,400 meters) above sea level. Although other mountains of the Great Basin also lack conifers, Steens Mountain is the largest mountain area without conifers. One possible cause of

84-463: A dwarf blue lupine , and Cusick's buckwheat ( Eriogonum cusickii ). Steens Mountain is home to a variety of wildlife, including bighorn sheep , Rocky Mountain elk , mule deer , pronghorn , sage grouse , coyotes, and the Great Basin redband trout . Cattle can be found in the wilderness as well, though they are excluded from grazing 98,859 acres (40,007 ha) on top of Steens Mountain. The area

112-438: A stratum , is the smallest formal unit in the hierarchy of sedimentary lithostratigraphic units and is lithologically distinguishable from other layers above and below. Customarily, only distinctive beds, i.e. key beds , marker beds , that are particularly useful for stratigraphic purposes are given proper names and considered formal lithostratigraphic units. In case of volcanic rocks, the lithostratigraphic unit equivalent to

140-401: A 425,000-acre (1,720 km ) area. This law protects 1,200,000 acres (1,870 sq mi; 4,860 km ) from mining, and 100,000 acres (156 sq mi; 405 km ) from cattle grazing. The west slope of Steens Mountain is traversed by a 52-mile (84 km) loop road, which is suitable for passenger vehicles. The road reaches an elevation of 9,700 feet (2,960 m), making it

168-415: A bed can be defined by thickness where a bed is a coherent layer of sedimentary rock, sediment, or pyroclastic material greater than 1 cm thick and a lamina is a coherent layer of sedimentary rock, sediment, or pyroclastic material less than 1 cm thick. This method of defining bed versus lamina is frequently used in textbooks, e.g., Collinson & Mountney or Miall. Both definitions have merit and

196-526: A bed is a flow . A flow is “...a discrete, extrusive, volcanic rock body distinguishable by texture, composition, order of superposition, paleomagnetism, or other objective criteria.” A flow is a part of a member as a bed of sedimentary rock is a part of a member. In geotechnical engineering a bedding surface often forms a discontinuity that may have a large influence on the mechanical behaviour (strength, deformation, etc.) of soil and rock masses in tunnel , foundation , or slope construction. These are

224-509: A combination of local deposition on the inclined surfaces of ripples or dunes , and local erosion . Graded beds show a gradual change in grain or clast sizes from one side of the bed to the other. A normal grading occurs where there are larger grain sizes on the older side, while an inverse grading occurs where there are smaller grain sizes on the older side. Bed thickness is a basic and important characteristic of beds. Besides mapping stratigraphic units and interpreting sedimentary facies,

252-442: A result of changes in environmental conditions. As a result, a bed is typically, but not always, interpreted to represent a single period of time when sediments or pyroclastic material accumulated during uniform and steady paleoenvironmental conditions. However, some bedding surfaces may be postdepositional features either formed or enhanced by diagenetic processes or weathering . The relationship between bedding surfaces controls

280-465: A skull was unearthed in nearby Malheur Lake . In the 1970s, a wolverine was trapped and released on Steens Mountain. 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

308-519: Is also home to mustang herds, including Kiger mustangs . Steens Mountain Steens Mountain is a large fault-block mountain in the northwest United States , located in Harney County , Oregon . Stretching some fifty miles (80 km) north to south, on its west side it rises from the Alvord Desert at an elevation of about 4,200 feet (1,280 m) to 9,738 feet (2,968 m) at

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336-571: Is the largest fault-block mountain in North America. Pressure under the Earth's surface thrust the block upward approximately 20 million years ago, resulting in a steep eastern face with a more gentle slope on the western side of the mountain. During the Ice Age , glaciers carved several deep gorges into the peak and created depressions where Lily, Fish, and Wildhorse lakes now stand. Vegetation in

364-498: Is the remnant of a long shield volcano . The east face of Steens Mountain is composed mainly of basalts stacked one upon another. Lava flows several hundreds of feet thick inundated the region between 17 and 14 million years ago. Chemical data from magma deposits from the area reveal three distinct stages of volcanism. Layers of clay and volcanic dust show over forty lava flows on Steens Mountain. Most lava layers reach to 3,000 feet (910 m) thick or more in some areas. As

392-568: The Steens Mountain Wilderness varies greatly according to elevation. Common plants include sagebrush , juniper , various species of bunchgrass , mountain mahogany , aspen , mountain meadow knotweed , and false hellebore . Other vegetation endemic to Steens Mountain includes Steens paintbrush ( Castilleja pilosa var. steenensis ), moss gentian ( Gentiana fremontii ), Steens Mountain penstemon ( Penstemon davidsonii var. praeteritus ), Steens Mountain thistle ( Cirsium peckii ),

420-497: The Steens Mountain Wilderness varies greatly according to elevation. Common plants include sagebrush , juniper , various species of bunchgrass , mountain mahogany , aspen , mountain meadow knotweed , and false hellebore . Other vegetation endemic to Steens Mountain includes Steens paintbrush ( Castilleja pilosa var. steenensis ), moss gentian ( Gentiana fremontii ), Steens Mountain penstemon ( Penstemon davidsonii var. praeteritus ), Steens Mountain thistle ( Cirsium peckii ),

448-642: The Steens Mountain, particularly Big Indian Gorge. On October 24, 2000, President Bill Clinton approved the Steens Mountain Cooperative Management and Protective Act. The act was created by local landowners in cooperation with local and national government representatives in response to a proposed National Monument . This act created the Steens Mountain BLM Cooperative Management and Protection Area,

476-429: The absence of conifers is the isolation of Steens Mountain, although lack of seed dispersal by bird species such as Clark's Nutcracker may also be a factor. It is also possible that prehistoric fires, including fires used by Native Americans , eradicated the conifer population. Home to a wide variety of animals, the area is primarily known for birding , hunting, and fishing. Birds here include Golden eagles , owls, and

504-533: The analysis of bed thickness can be used to recognize breaks in sedimentation, cyclic sedimentation patterns, and gradual environmental changes. Such sedimentological studies are typically based on the hypothesis that the thicknesses of stratigraphic units follows a log-normal distribution . Differing nomenclatures for the bed and laminae thickness have been proposed by various authors, including McKee and Weir, Ingram, and Reineck and Singh. However, none of them have been universally accepted by Earth scientists. In

532-418: The base of Steens Mountain, including Alvord Hot Springs . Far from city lights, stargazing is also popular. Bed (geology) In geology , a bed is a layer of sediment , sedimentary rock , or volcanic rock "bounded above and below by more or less well-defined bedding surfaces". A bedding surface is three-dimensional surface , planar or curved, that visibly separates each successive bed (of

560-422: The choice of which one to use will depend on the focus of the specific study on a case by case basis. Typically, but not always, bedding surfaces record changes in either the rate or type of accumulating sediment that created the underlying bed. Typically, they represent either a period of nondeposition, erosional truncation, shift in flow or sediment regime, abrupt change in composition, or combination of these as

588-530: The gross geometry of a bed. Most commonly, the bottom and top surfaces of beds are subparallel to parallel to each other. However, some bedding surfaces of a bed are nonparallel, e.g., wavy, or curved. Differing combinations of nonparallel bedding surfaces results in beds of widely varying geometric shapes such as uniform-tabular, tabular-lenticular, curved-tabular, wedge-shaped, and irregular beds. Types of beds include cross-beds and graded beds . Cross-beds, or "sets," are not layered horizontally and are formed by

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616-529: The highest road in Oregon. It is possible to drive nearly to the summit of the mountain and to other viewpoints such as Kiger Gorge. Steens Mountain is also host to Steens Mountain High Altitude Running Camp. Other recreational activities enjoyed on and around Steens Mountain are camping, picknicking, bicycling, hiking, hunting, sightseeing, soaring, and exploring. There are numerous hot springs along

644-710: The practice of engineering geology, a standardized nomenclature is used for describing bed thickness in Australia, the European Union, and the United Kingdom. Examples of widely used bed thickness classifications include Tucker (1982) and McKee and Weir (1953). According to both the North American Stratigraphic Code and International Stratigraphic Guide, a bed is the smallest formal lithostratigraphic unit that can be used for sedimentary rocks. A bed,

672-468: The protected sage grouse . Other animals found in the area include rattlesnakes , scorpions, elk , bighorn sheep , pronghorn antelope , and cougars . The area is home to wild horses . Drawing much controversy, the Bureau of Land Management engages in wild horse roundups every few years, employing helicopters to herd the horses. Historically, Steens Mountain Wilderness was once home to grizzly bears ;

700-489: The same or different lithology ) from the preceding or following bed. Where bedding surfaces occur as cross-sections, e.g., in a 2-dimensional vertical cliff face of horizontal strata, are often referred to as bedding contacts . Within conformable successions, each bedding surface acted as the depositional surface for the accumulation of younger sediment. Specifically in sedimentology , a bed can be defined in one of two major ways. First, Campbell and Reineck and Singh use

728-410: The summit. Steens Mountain is not part of a mountain range but is properly a single mountain, the largest of Oregon's fault-block mountains. The Steens Mountain Wilderness encompasses 170,166 acres (265.9 sq mi; 688.6 km ) of Steens Mountain. 98,859 acres (154.5 sq mi; 400.1 km ) of the Wilderness are protected from grazing and free of cattle . Steens Mountain

756-446: The surface cracked, peaks and valleys were formed. Erosion and landfalls continue to modify the faces of the cliffs along the mountain. The sediment bedding is roughly horizontal, evidence to the absence of compressional forces . The white sediments consist primarily of stratified acidic tuffs. While rain hasn't been a main contributor to erosion , ice and snow melt are the main sources of erosion on Steens Mountain. Vegetation in

784-403: The term bed to refer to a thickness-independent layer comprising a coherent layer of sedimentary rock, sediment, or pyroclastic material bounded above and below by surfaces known as bedding planes. By this definition of bed, laminae are small beds that constitute the smallest (visible) layers of a hierarchical succession and often, but not always, internally comprise a bed. Alternatively,

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