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Smuggler Mine
The Smuggler Mine is located on the slopes of Smuggler Mountain, on the north edge of Aspen, Colorado, United States. It is the oldest operating silver mine in the Aspen mining district, and one of the few still operating from Aspen's early boom years. In 1987 it was listed on the National Register of Historic Places. The largest silver nugget ever mined, weighing , came from Smuggler. At its peak the mine was responsible for nearly one-fifth of the world's total silver output. Its extensive tunnel system reaches more than a thousand feet (300 m) below the entrance, extending under the city of Aspen, although most of the lower tunnels are presently flooded. Smuggler was one of the few mines in the Aspen area to reopen after the 1893 repeal of the Sherman Silver Purchase Act. It continued producing ore until 1918, and was reopened in the 1970s. In 1984 it was designated a Superfund site after tests found high levels of lead and cadmium in the soil. It took the Environmental Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailings
In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. The extraction of minerals from ore can be done two ways: placer mining, which uses water and gravity to concentrate the valuable minerals, or hard rock mining, which pulverizes the rock containing the ore and then relies on chemical reactions to concentrate the sought-after material. In the latter, the extraction of minerals from ore requires comminution, i.e., grinding the ore into fine particles to facilitate extraction of the target element(s). Because of this comminution, tailings consist of a slurry of fine particles, ranging from the size of a grain of sand to a few micrometres. Mine tailings are usually produced from the mill in slurry form, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Independence Pass (Colorado)
Independence Pass, originally known as Hunter Pass, is a high mountain pass in central Colorado, United States. It is at elevation on the Continental Divide in the Sawatch Range of the Rocky Mountains. The pass is midway between Aspen and Twin Lakes, on the border between Pitkin and Lake counties. State Highway 82 traverses it, and after Cottonwood Pass to the south, is the second highest elevation of a paved Colorado state highway on a through road. State Highway 5, the highest paved road in North America, is a dead-end route reaching , just below the summit of Mount Evans. The recently paved Pikes Peak Highway is another dead-end road and is only slightly lower, with an elevation of on the summit of the mountain. Trail Ridge Road in Rocky Mountain National Park, part of U.S. Highway 34, reaches a maximum elevation of . It is also the second-highest pass with an improved road in the state, the fourth-highest paved road in the state and the second highest paved crossing of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Divide
A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not connected to the open sea. Every continent on earth except Antarctica (which has no known significant, definable free-flowing surface rivers) has at least one continental drainage divide; islands, even small ones like Killiniq Island on the Labrador Sea in Canada, may also host part of a continental divide or have their own island-spanning divide. The endpoints of a continental divide may be coastlines of gulfs, seas or oceans, the boundary of an endorheic basin, or another continental divide. One case, the Great Basin Divide, is a closed loop around an endoreic basin. The endpoints where a continental divide meets the coast are not always definite since the exact border between adjacent bodies of water is usually not clearly defined. The I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prospecting
Prospecting is the first stage of the geological analysis (followed by exploration) of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking. Traditionally prospecting relied on direct observation of mineralization in rock outcrops or in sediments. Modern prospecting also includes the use of geologic, geophysical, and geochemical tools to search for anomalies which can narrow the search area. Once an anomaly has been identified and interpreted to be a potential prospect direct observation can then be focused on this area. In some areas a prospector must also make claims, meaning they must erect posts with the appropriate placards on all four corners of a desired land they wish to prospect and register this claim before they may take samples. In other areas publicly held lands are open to prospecting without staking a mining claim. Historical methods The traditional methods of prospecting involved combi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panic Of 1893
The Panic of 1893 was an economic depression in the United States that began in 1893 and ended in 1897. It deeply affected every sector of the economy, and produced political upheaval that led to the political realignment of 1896 and the presidency of William McKinley. Causes The Panic of 1893 has been traced to many causes, one of those points to Argentina; investment was encouraged by the Argentine agent bank, Baring Brothers. However, the 1890 wheat crop failure and a failed coup in Buenos Aires ended further investments. In addition, speculations in South African and Australian properties also collapsed. Because European investors were concerned that these problems might spread, they started a run on gold in the U.S. Treasury. Specie was considered more valuable than paper money; when people were uncertain about the future, they hoarded specie and rejected paper notes.Nelson, Scott Reynolds. 2012. A Nation of Deadbeats. New York: Alfred Knopf, p. 189. During the Gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headframe
A headframe (also known as a gallows frame, winding tower, hoist frame,Ernst, Dr.-Ing. Richard (1989). ''Wörterbuch der Industriellen Technik'' (5th ed.). Wiesbaden: Oscar Brandstetter, 1989. pit frame, shafthead frame, headgear, headstock or poppethead) is the structural frame above an underground mine shaft so as to enable the hoisting of machinery, personnel, or materials. Design Modern headframes are built out of steel, concrete or a combination of both. Timber headframes are no longer used in industrialized countries, but are still used in developing nations. Conventionally steel headframes are used when a drum hoist is employed, and concrete headframes are built for friction hoists; however a steel headframe can be used with a friction hoist for shafts with a smaller capacity and depth. Steel headframes A steel headframe is less expensive than a concrete headframe; the tallest steel headframe measures 87 m. Steel headframes are more adaptable to modifications (mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundation (architecture)
In engineering, a foundation is the element of a structure which connects it to the ground, transferring loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics ( geotechnical engineering) in the design of foundation elements of structures. Purpose Foundations provide the structure's stability from the ground: * To distribute the weight of the structure over a large area in order to avoid overloading the underlying soil (possibly causing unequal settlement). * To anchor the structure against natural forces including earthquakes, floods, droughts, frost heaves, tornadoes and wind. * To provide a level surface for construction. * To anchor the structure deeply into the ground, increasing its stability and preventing overloading. * To prevent lateral movements of the supported structure (in some cases). Requirements of a good foundation The design and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chute (gravity)
A chute is a vertical or inclined plane, channel, or passage through which objects are moved by means of gravity. Landform A chute, also known as a race, flume, cat, or river canyon, is a steep-sided passage through which water flows rapidly. Akin to these, man-made chutes, such as the timber slide and log flume, were used in the logging industry to facilitate the downstream transportation of timber along rivers. These are no longer in common use. Man-made chutes may also be a feature of spillways on some dams. Some types of water supply and irrigation systems are gravity fed, hence chutes. These include aqueducts, puquios, and acequias. Building chute Chutes are in common use in tall buildings to allow the rapid transport of items from the upper floors to a central location on one of the lower floors or basement. Chutes may be round, square or rectangular at the top and/or the bottom. * Laundry chutes in hotels are placed on each floor to allow the expedient transfer and col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gable
A gable is the generally triangular portion of a wall between the edges of intersecting roof pitches. The shape of the gable and how it is detailed depends on the structural system used, which reflects climate, material availability, and aesthetic concerns. The term gable wall or gable end more commonly refers to the entire wall, including the gable and the wall below it. Some types of roof do not have a gable (for example hip roofs do not). One common type of roof with gables, the gable roof, is named after its prominent gables. A parapet made of a series of curves (Dutch gable) or horizontal steps (crow-stepped gable) may hide the diagonal lines of the roof. Gable ends of more recent buildings are often treated in the same way as the Classic pediment form. But unlike Classical structures, which operate through trabeation, the gable ends of many buildings are actually bearing-wall structures. Gable style is also used in the design of fabric structures, with varying degree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corrugated Metal
Corrugated galvanised iron or steel, colloquially corrugated iron (near universal), wriggly tin (taken from UK military slang), pailing (in Caribbean English), corrugated sheet metal (in North America) and occasionally abbreviated CGI is a building material composed of sheets of hot-dip galvanised mild steel, cold-rolled to produce a linear ridged pattern in them. Although it is still popularly called "iron" in the UK, the material used is actually steel (which is iron alloyed with carbon for strength, commonly 0.3% carbon), and only the surviving vintage sheets may actually be made up of 100% iron. The corrugations increase the bending strength of the sheet in the direction perpendicular to the corrugations, but not parallel to them, because the steel must be stretched to bend perpendicular to the corrugations. Normally each sheet is manufactured longer in its strong direction. CGI is lightweight and easily transported. It was and still is widely used especially in rural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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