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Vermilion Range (Minnesota)
The Vermilion Range exists between Tower, Minnesota and Ely, Minnesota, and contains significant deposits of iron ore. Together with the Mesabi and Cuyuna Ranges, these three constitute the Iron Ranges of northern Minnesota. While the Mesabi Range had iron ore close enough to the surface to enable pit mining, mines had to be dug deep underground to reach the ore of the Vermilion and Cuyuna ranges. The Soudan mine was nearly 1/2 mile underground and required blasting of Precambrian sedimentary bedrock.Jackson, Judy"Notes from Underground" ''Ferminews'', July 19, 2002. The banded iron formation in the range consists of a "interbedded sequence" of chert, magnetite and hematite. Eleven mines operated in the range, with five in the Ely area. The Ely Trough, a synclinal fold, produced 70 million metric tons from the Chandler, Pioneer, Zenith, Sibley and Savoy mines. The largest mine in the range, Soudan, was closed in 1962, and the last mine in the Ely area closed in 1964. Despite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Ranges
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trough (geology)
In geology, a trough is a linear structural depression that extends laterally over a distance. Although it is less steep than a trench, a trough can be a narrow basin or a geologic rift. These features often form at the rim of tectonic plates. There are various oceanic troughs on the ocean floors. Examples of oceanic troughs * Benue Trough * Cayman Trough * Kings Trough * Hesperides Trough * Nankai Trough * Northumberland Trough * Okinawa Trough in the East China Sea * Rockall Trough and others along the rift of the mid-oceanic ridge * Salton Trough * South Shetland Trough * Suakin TroughDinwiddie, Robert et al. (2008) ''Ocean: The World's Last Wilderness Revealed'', London, Dorling Kindersley, page 452. in the Red Sea * Timor Trough See also * Walker Lane * Oceanic basin In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, ocean basins are large geologic basins that are below sea level. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Minnesota
The geology of Minnesota comprises the rock, minerals, and soils of the U.S. state of Minnesota, including their formation, development, distribution, and condition. The state's geologic history can be divided into three periods. The first period was a lengthy period of geologic instability from the origin of the planet until roughly 1,100 million years ago. During this time, the state's Precambrian bedrock was formed by volcanism and the deposition of sedimentary rock and then modified by processes such as faulting, folding and erosion. In the second period, many layers of sedimentary rock were formed by deposition and lithification of successive layers of sediment from runoff and repeated incursions of the sea. In the third and most recent period starting about 1.8 million years ago, glaciation eroded previous rock formations and deposited deep layers of glacial till over most of the state, and created the beds and valleys of modern lakes and rivers. Minnesota's geologic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marquette Iron Range
The Marquette Iron Range is a deposit of iron ore located in Marquette County, Michigan in the United States. The towns of Ishpeming and Negaunee developed as a result of mining this deposit. A smaller counterpart of Minnesota's Mesabi Range, this is one of two iron ranges in the Lake Superior basin that are in active production as of 2018. The iron ore of the Marquette Range has been mined continuously from 1847 until the present day. Marquette Iron Range is the deposit's popular and commercial name; it is also known to geologists as the Negaunee Iron Formation. History The geology of the district consists of middle Precambrian rocks in the Animikie Group, which form a westward plunging syncline long and wide. The principal iron ore is found in the Negaunee Iron formation. This formation is thick near Negaunee. This is a magnetite or hematite chert. Natural ore deposits are located in synclines and up against mafic dikes. Beneficiation commenced in 1954 and this concentration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gunflint Range
The Gunflint Range is an iron ore deposit in northern Minnesota in the United States and Northwestern Ontario, Canada. The range extends from the extreme northern portion of Cook County, Minnesota into the Thunder Bay District, Ontario. The Gunflint Iron Formation is a continuation of the Mesabi Range to the southwest. The two have been separated by the intrusion of the Duluth Gabbro complex. The iron deposit is a banded iron formation of the Early Proterozoic Animikie Group. The Gunflint Iron Formation is overlain by "brecciated and complexly deformed iron formations", which in turn is overlain by ejecta from the " Sudbury meteorite impact event." This Sudbury Impact Layer is overlain by the Rove Formation. Stromatolite structures are evident within the Gunflint Iron Formation. The cherts of the Gunflint (the Gunflint Chert) are noted for containing Precambrian microfossils. See also *Midcontinent Rift System * Paulson Mine * Cuyuna Range *Vermilion Range (Minnesota) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gogebic Range
The Gogebic Range is an elongated area of iron ore deposits located within a range of hills in northern Michigan and Wisconsin just south of Lake Superior. It extends from Lake Namakagon in Wisconsin eastward to Lake Gogebic in Michigan, or almost 80 miles. Though long, it is only about a half mile wide and forms a crescent concave to the southeast. The Gogebic Range includes the communities of Ironwood in Michigan, plus Mellen and Hurley in Wisconsin. The name Gogebic is Ojibwa for "where trout rising to the surface make rings in the water." "Range" is the term commonly used for such iron ore areas around Lake Superior. In Wisconsin, the Gogebic Range is often called the Penokee Range. The range is named after Lake Gogebic, a large lake near the east end of the range in Gogebic and Ontonagon Counties in Michigan. Located within the southern of two parallel prominent ridges, the Gogebic range iron formation name is often used interchangeably with the range of hills that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-pit Mining
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface. It is applied to ore or rocks found at the surface because the overburden is relatively thin or the material of interest is structurally unsuitable for tunnelling (as would be the case for cinder, sand, and gravel). In contrast, minerals that have been found underground but are difficult to retrieve due to hard rock, can be reached using a form of underground mining. To create an open-pit mine, the miners must determine the information of the ore that is underground. This is done through drilling of probe holes in the ground, then plotting ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of carbon, other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematite
Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . It has the same crystal structure as corundum () and ilmenite (). With this it forms a complete solid solution at temperatures above . Hematite naturally occurs in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include ''kidney ore'', ''martite'' (pseudomorphs after magnetite), ''iron rose'' and ''specularite'' (specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. Maghemite is a polymorph of hematite (γ-) with the same chemical formula, but with a spinel structure like magnetite. Large deposits of hematite are found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soudan Underground Mine State Park
The Lake Vermilion-Soudan Underground Mine State Park is a Minnesota state park at the site of the Soudan Underground Mine, on the south shore of Lake Vermilion, in the Vermilion Range (Minnesota). The mine is known as Minnesota's oldest, deepest, and richest iron mine, and now hosts the Soudan Underground Laboratory. As the Soudan Iron Mine, it has been designated a U.S. National Historic Landmark. History In the late 19th century, prospectors searching for gold in northern Minnesota discovered extremely rich veins of hematite at this site, often containing more than 65% iron. An open pit mine began operation in 1882, and moved to underground mining by 1900 for safety reasons. From 1901 until the end of active mining in 1962, the Soudan Mine was owned by the United States Steel Corporation's Oliver Iron Mining division. By 1912 the mine was at a depth of 1,250 feet (381 m). When the mine closed, level 27 was being developed at 2,341 feet (713.5 m) below the surface and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncline
In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed smaller folds. Synclines are typically a downward fold (synform), termed a synformal syncline (i.e. a trough), but synclines that point upwards can be found when strata have been overturned and folded (an antiformal syncline). Characteristics On a geologic map, synclines are recognized as a sequence of rock layers, with the youngest at the fold's center or ''hinge'' and with a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate, the structure is a basin. Folds typically form during crustal deformation as the result of compression that accompanies orogenic mountain building. Notable examples * Powder River Basin, Wyoming, US * Sideling Hill roadcut along Interstate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak. Small grains of magnetite are very common in igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite also occurs in sedimentary rocks, including banded iron formations and in lake and marine sediments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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