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Bronzitite
Bronzite is a member of the pyroxene group of minerals, belonging with enstatite and hypersthene to the orthorhombic series of the group. Rather than a distinct species, it is really a ferriferous variety of enstatite, which owing to partial alteration has acquired a bronze-like sub-metallic luster on the cleavage surfaces. Enstatite is magnesium silicate, MgSiO3, with the magnesium partly replaced by small amounts (up to about 12%) of Fe+2. In the bronzite variety, (Mg,Fe)SiO3, the iron(II) oxide ranges from about 12 to 30%, and with still more iron there is a passage to hypersthene.Klein, Cornelis and Cornelius Hurlbut, Jr. (1985) ''Manual of Mineralogy,'' Wiley, 20th ed., The ferriferous varieties are liable to a particular kind of alteration, known as schillerization, which results in the separation of the iron as very fine films of oxide and hydroxides along the cleavage cracks of the mineral. The cleavage surfaces therefore exhibit a metallic sheen or schiller, which is e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronzitite
Bronzite is a member of the pyroxene group of minerals, belonging with enstatite and hypersthene to the orthorhombic series of the group. Rather than a distinct species, it is really a ferriferous variety of enstatite, which owing to partial alteration has acquired a bronze-like sub-metallic luster on the cleavage surfaces. Enstatite is magnesium silicate, MgSiO3, with the magnesium partly replaced by small amounts (up to about 12%) of Fe+2. In the bronzite variety, (Mg,Fe)SiO3, the iron(II) oxide ranges from about 12 to 30%, and with still more iron there is a passage to hypersthene.Klein, Cornelis and Cornelius Hurlbut, Jr. (1985) ''Manual of Mineralogy,'' Wiley, 20th ed., The ferriferous varieties are liable to a particular kind of alteration, known as schillerization, which results in the separation of the iron as very fine films of oxide and hydroxides along the cleavage cracks of the mineral. The cleavage surfaces therefore exhibit a metallic sheen or schiller, which is e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stillwater Igneous Complex
The Stillwater igneous complex is a large layered mafic intrusion (LMI) located in southern Montana in Stillwater, Sweet Grass and Park Counties. The complex is exposed across 30 miles (48 km) of the north flank of the Beartooth Mountain Range. The complex has extensive reserves of chromium ore and has a history of being mined for chromium. More recent mining activity has produced palladium and other platinum group elements.The Stillwater Complex: A review of the geology by I. S. McCallum http://serc.carleton.edu/files/NAGTWorkshops/petrology03/McCallum.Stillwater.doc Geology The Stillwater complex is a large layered intrusion with many similarities to the Bushveld igneous complex of South Africa. The complex was intruded into existing gneisses during the Archean at about 2700 Ma. Host rocks on the northern side are Archean sedimentary rocks while the southern boundary includes Precambrian rocks of granite, granite gneiss and schist. The Precambrian rock on its southe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harz
The Harz () is a highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The name ''Harz'' derives from the Middle High German word ''Hardt'' or ''Hart'' (hill forest). The name ''Hercynia'' derives from a Celtic name and could refer to other mountain forests, but has also been applied to the geology of the Harz. The Brocken is the highest summit in the Harz with an elevation of above sea level. The Wurmberg () is the highest peak located entirely within the state of Lower Saxony. Geography Location and extent The Harz has a length of , stretching from the town of Seesen in the northwest to Eisleben in the east, and a width of . It occupies an area of , and is divided into the Upper Harz (''Oberharz'') in the northwest, which is up to 800 m high, apart from the 1,100 m high Brocken massif, and the Lower Harz (''Unterharz'') in the east which is up to aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styria
Styria (german: Steiermark ; Serbo-Croatian and sl, ; hu, Stájerország) is a state (''Bundesland'') in the southeast of Austria. With an area of , Styria is the second largest state of Austria, after Lower Austria. Styria is bordered to the south by Slovenia, and clockwise, from the southwest, by the Austrian states of Carinthia, Salzburg, Upper Austria, Lower Austria, and Burgenland. The state capital is Graz. Etymology The March of Styria derived its name from the original seat of its ruling Otakar dynasty: Steyr, in today's Upper Austria. In German, the area is still called "Steiermark" while in English the Latin name "Styria" is used. The ancient link between Steyr and Styria is also apparent in their nearly identical coats of arms, a white Panther on a green background. Geography * The term "Upper Styria" (german: Obersteiermark) refers to the northern and northwestern parts of the federal-state (districts Liezen, Murau, Murtal, Leoben, Bruck-Mürzzuschlag). * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fichtelgebirge
The Fichtel MountainsRandlesome, C. et al. (2011). ''Business Cultures in Europe'', 2nd ed., Routledge, Abingdon and New York, p. 52. . (german: Fichtelgebirge, cs, Smrčiny), form a small horseshoe-shaped mountain range in northeastern Bavaria, Germany. They extend from the valley of the Red Main River to the Czech border, a few foothills spilling over into the Czech Republic. They continue in a northeasterly direction as the Elster Mountains, and in a southeasterly direction as the Upper Palatine Forest. The Fichtel Mountains contain an important nature park, the Fichtel Mountain Nature Park, with an area of . Etymology The first person to write about the Fichtel Mountains, Matthias of Kemnath (actually Matthias Widmann, born 23 February 1429 in Kemnath) reported in 1476: ''Ein bergk, hoch, weitt, wolbekant ligt in Beiern, gnant der Fichtelberg'' ("A mountain, high, wide and well-known, lies in Bavaria, known as the Fichtelberg"). In descriptions of the border in 1499 and 15 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kupferberg
Kupferberg () is a municipality in the district of Kulmbach, in Bavaria, Germany. It is situated in the Frankenwald, 9 km northeast of Kulmbach. Notable people * Joseph Gabriel Findel Gottfried Joseph Gabriel Findel (born 21 October 1828 in Kupferberg, died 23 November 1905 in Leipzig) was a Masonic writer and publisher. Life Findel came from a poor family. He went to high school in Bamberg in 1848 and attended Ludwig Maximilian ... (1828-1905), freemason writer. * Peter Zeidler named Hofmann (1525-1593), merchant for jewels with extensive business connections. References Kulmbach (district) {{Kulmbach-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the fourth-largest state by area, the eighth-least populous state, and the third-least densely populated state. Its state capital is Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several unofficial ones, most notably "Big Sky Country", "The Treasure State", "Land of the Shining Mountains", and " The Last Best Place". The economy is primarily based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, gas, coal, mining, and lumber. The health ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumulate Rock
Cumulate rocks are igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Cumulate rocks are named according to their texture; cumulate texture is diagnostic of the conditions of formation of this group of igneous rocks. Cumulates can be deposited on top of other older cumulates of different composition and colour, typically giving the cumulate rock a layered or banded appearance. Formation Cumulate rocks are the typical product of precipitation of solid crystals from a fractionating magma chamber. These accumulations typically occur on the floor of the magma chamber, although they are possible on the roofs if anorthite plagioclase is able to float free of a denser mafic melt. Cumulates are typically found in ultramafic intrusions, in the base of large ultramafic lava tubes in komatiite and magnesium rich basalt flows and also in some granitic intrusions. Terminology Cumulates are named according to their dominant mineralogy and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroxenite
Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite, diopside, hypersthene, bronzite or enstatite. Pyroxenites are classified into clinopyroxenites, orthopyroxenites, and the websterites which contain both types of pyroxenes (see diagram below). Closely allied to this group are the hornblendites, consisting essentially of hornblende and other amphiboles. They are essentially of igneous origin, though some pyroxenites are included in the metamorphic Lewisian complex of Scotland. The pyroxene-rich rocks, which result from the type of contact metamorphism known as pyroxene-hornfels facies, have siliceous sediment or basaltic protoliths, and are respectively metapelites and metabasites. Intrusive and mantle pyroxenites Igneous pyroxenites are closely allied to gabbros and norites, from which they differ by the absence of feldspar, and to peridotites, which are distinguished from them by containing more than 40% olivine. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as micas, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schist''). Where the type of the original rock (the protolith) is discernible, the schist is us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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