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38-740: The massif encompasses a number of mittelgebirges and consists of crystalline rocks, which are older than the Permian (more than 300 million years old) and therefore deformed during the Variscan Orogeny . Parts of the Sudetes within the Bohemian Massif, Giant Mountains in particular, stand out from the ordinary mittelgebirge pattern by having up to four distinct levels of altitudinal zonation , glacial cirques , small periglacial landforms and an elevation significantly above

76-458: A centimeter over several million years. The average diameter of a polymetallic nodule is between 3 and 10 cm (1 and 4 in) in diameter and are characterized by enrichment in iron, manganese, heavy metals , and rare earth element content when compared to the Earth's crust and surrounding sediment. The proposed mining of these nodules via remotely operated ocean floor trawling robots has raised

114-421: A direct result of metamorphism. These are the leading source of copper ore. Porphyry copper deposits form along convergent boundaries and are thought to originate from the partial melting of subducted oceanic plates and subsequent concentration of Cu, driven by oxidation. These are large, round, disseminated deposits containing on average 0.8% copper by weight. Hydrothermal Hydrothermal deposits are

152-449: A large source of ore. They form as a result of the precipitation of dissolved ore constituents out of fluids. Laterites form from the weathering of highly mafic rock near the equator. They can form in as little as one million years and are a source of iron (Fe), manganese (Mn), and aluminum (Al). They may also be a source of nickel and cobalt when the parent rock is enriched in these elements. Banded iron formations (BIFs) are

190-644: A number of ecological concerns. The extraction of ore deposits generally follows these steps. Progression from stages 1–3 will see a continuous disqualification of potential ore bodies as more information is obtained on their viability: With rates of ore discovery in a steady decline since the mid 20th century, it is thought that most surface level, easily accessible sources have been exhausted. This means progressively lower grade deposits must be turned to, and new methods of extraction must be developed. Some ores contain heavy metals , toxins, radioactive isotopes and other potentially negative compounds which may pose

228-824: A risk to the environment or health. The exact effects an ore and its tailings have is dependent on the minerals present. Tailings of particular concern are those of older mines, as containment and remediation methods in the past were next to non-existent, leading to high levels of leaching into the surrounding environment. Mercury and arsenic are two ore related elements of particular concern. Additional elements found in ore which may have adverse health affects in organisms include iron, lead, uranium, zinc, silicon, titanium, sulfur, nitrogen, platinum, and chromium. Exposure to these elements may result in respiratory and cardiovascular problems and neurological issues. These are of particular danger to aquatic life if dissolved in water. Ores such as those of sulphide minerals may severely increase

266-513: A single mineral, but it is mixed with other valuable minerals and with unwanted or valueless rocks and minerals. The part of an ore that is not economically desirable and that cannot be avoided in mining is known as gangue . The valuable ore minerals are separated from the gangue minerals by froth flotation , gravity concentration, electric or magnetic methods, and other operations known collectively as mineral processing or ore dressing . Mineral processing consists of first liberation, to free

304-552: A sizeable portion of international trade in raw materials both in value and volume. This is because the worldwide distribution of ores is unequal and dislocated from locations of peak demand and from smelting infrastructure. Most base metals (copper, lead, zinc, nickel) are traded internationally on the London Metal Exchange , with smaller stockpiles and metals exchanges monitored by the COMEX and NYMEX exchanges in

342-486: A variety of geological processes generally referred to as ore genesis and can be classified based on their deposit type. Ore is extracted from the earth through mining and treated or refined , often via smelting , to extract the valuable metals or minerals. Some ores, depending on their composition, may pose threats to health or surrounding ecosystems. The word ore is of Anglo-Saxon origin, meaning lump of metal . In most cases, an ore does not consist entirely of

380-483: Is a mineral deposit occurring in high enough concentration to be economically viable. An ore deposit is one occurrence of a particular ore type. Most ore deposits are named according to their location, or after a discoverer (e.g. the Kambalda nickel shoots are named after drillers), or after some whimsy, a historical figure, a prominent person, a city or town from which the owner came, something from mythology (such as

418-519: Is a type of relatively low mountain range or highland area typical of the geography of central Europe, especially central and southern Germany; it refers to something between rolling low hill country or Hügelland and a proper mountain range (German: Gebirge or Hochgebirge ) like the High Alps . The term is not precise, but typically refers to topography where the peaks rise at least 200 metres (660 ft) to 500 metres (1,600 ft) above

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456-410: Is considered alluvial if formed via river, colluvial if by gravity, and eluvial when close to their parent rock. Polymetallic nodules , also called manganese nodules, are mineral concretions on the sea floor formed of concentric layers of iron and manganese hydroxides around a core. They are formed by a combination of diagenetic and sedimentary precipitation at the estimated rate of about

494-1089: Is marked by the Mittelgebirge threshold ( Mittelgebirgsschwelle ), running from the Belgian Ardennes in the west along the Rhenish Massif , the Rhön and Harz Mountains, the Thuringian Forest and the Fichtel Mountains to the Bohemian Massif on the Czech border, including the Bavarian Forest and the Ore Mountains , leading to the Bohemian Forest and to the Sudetes in the east. In

532-1089: The Apennine Mountains running from the Maritime Alps down to the Strait of Messina are shaped by its Mittelgebirge character, though in Abruzzo peaks are up to 2,912 metres (9,554 ft) high. In Britain well-known examples include the pikes of the Lake District , the Pennines , the Scottish Highlands and the Snowdon Massif , in Ireland the MacGillycuddy's Reeks , in the United States some ranges of

570-536: The Appalachians , such as the Green Mountains (Vermont). [REDACTED] The dictionary definition of Mittelgebirge at Wiktionary Ore Ore is natural rock or sediment that contains one or more valuable minerals , typically including metals , concentrated above background levels, and that is economically viable to mine and process. The grade of ore refers to the concentration of

608-606: The Rhenohercynian Zone , have more ore deposits. On the other hand, the Bohemian massif has many quarries where granite , granodiorite and diorite are won for use as decorative building stone. 50°08′N 14°59′E  /  50.133°N 14.983°E  / 50.133; 14.983 Mittelgebirge A Mittelgebirge ( pronounced [ˈmɪtl̩ɡəˌbɪʁɡə] ; German: Mittel , "middle or mid"; Gebirge , "mountains or mountainous area")

646-825: The Transdanubian Mountains form an extended Mittelgebirge range within the Pannonian Basin . Stretching from Lake Balaton to north of Budapest , marked by the Danube Bend , it separates the Little and Great Hungarian Plain . In France, the Massif Central , located between the western Alps and the Pyrenees , rises to 1,886 metres (6,188 ft) but does not reach the tree line due to its Mediterranean climate . In Italy, most parts of

684-481: The timber line . The Bohemian Massif is a province within the Hercynian Forest subsystem. It borders with four provinces: Western Carpathians on the east, Eastern Alps on the south, North European Plain on the north, and Central Uplands on the west. The Bohemian Massif is further divided into six subprovinces: The landscapes in the Bohemian Massif are mostly dominated by rolling hills. North of

722-473: The Bohemian Massif was formed during the Variscan Orogeny . The Variscan Orogeny was a phase of mountain building and accretion of terranes that resulted from the closing of the Rheic Ocean when the two paleocontinents Gondwana (in the south) and Laurussia (in the north) collided. Most of the Bohemian Massif is often supposed to belong to a terrane called Cadomia or Armorica , which also included

760-835: The Swiss-French border run the Jura Mountains , a fold mountain range reaching up to 1,718 metres (5,636 ft), separated from the western Alps by the Swiss Plateau . Though located within the Alpine foothills , the Jura Mountains are usually considered a separate Mittelgebirge range, while the Karst Plateau , leading to the Dinarides , geologically forms a part of the southern Alps . In Hungary,

798-689: The United States and the Shanghai Futures Exchange in China. The global Chromium market is currently dominated by the United States and China. Iron ore is traded between customer and producer, though various benchmark prices are set quarterly between the major mining conglomerates and the major consumers, and this sets the stage for smaller participants. Other, lesser, commodities do not have international clearing houses and benchmark prices, with most prices negotiated between suppliers and customers one-on-one. This generally makes determining

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836-553: The acidity of their immediate surroundings and of water, with numerous, long lasting impacts on ecosystems. When water becomes contaminated it may transport these compounds far from the tailings site, greatly increasing the affected range. Uranium ores and those containing other radioactive elements may pose a significant threat if leaving occurs and isotope concentration increases above background levels. Radiation can have severe, long lasting environmental impacts and cause irreversible damage to living organisms. Metallurgy began with

874-452: The desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining and is therefore considered an ore. A complex ore is one containing more than one valuable mineral. Minerals of interest are generally oxides , sulfides , silicates , or native metals such as copper or gold . Ore bodies are formed by

912-417: The direct working of native metals such as gold, lead and copper. Placer deposits, for example, would have been the first source of native gold. The first exploited ores were copper oxides such as malachite and azurite, over 7000 years ago at Çatalhöyük . These were the easiest to work, with relatively limited mining and basic requirements for smelting. It is believed they were once much more abundant on

950-676: The exception of Variscan massifs like the Bohemian Massif. The basement rocks and terranes of the Bohemian Massif are tectonically part of three main structural zones, which differ in metamorphic degrees, lithologies and tectonic styles. This tectonic subdivision was formed during the Variscan Orogeny. Unlike other Variscan massifs in Central Europe the Bohemian Massif is not very rich in ores . The Harz Mountains further north in Germany, which are geologically part of

988-458: The highest concentration of any single metal available. They are composed of chert beds alternating between high and low iron concentrations. Their deposition occurred early in Earth's history when the atmospheric composition was significantly different from today. Iron rich water is thought to have upwelled where it oxidized to Fe (III) in the presence of early photosynthetic plankton producing oxygen. This iron then precipitated out and deposited on

1026-626: The main tin source, began. Some 3000 years ago, the smelting of iron ores began in Mesopotamia . Iron oxide is quite abundant on the surface and forms from a variety of processes. Until the 18th century gold, copper, lead, iron, silver, tin, arsenic and mercury were the only metals mined and used. In recent decades, Rare Earth Elements have been increasingly exploited for various high-tech applications. This has led to an ever-growing search for REE ore and novel ways of extracting said elements. Ores (metals) are traded internationally and comprise

1064-526: The name of a god or goddess) or the code name of the resource company which found it (e.g. MKD-5 was the in-house name for the Mount Keith nickel sulphide deposit ). Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis . The following is a general categorization of the main ore deposit types: Magmatic deposits are ones who originate directly from magma These are ore deposits which form as

1102-582: The ocean floor. The banding is thought to be a result of changing plankton population. Sediment Hosted Copper forms from the precipitation of a copper rich oxidized brine into sedimentary rocks. These are a source of copper primarily in the form of copper-sulfide minerals. Placer deposits are the result of weathering, transport, and subsequent concentration of a valuable mineral via water or wind. They are typically sources of gold (Au), platinum group elements (PGE), sulfide minerals , tin (Sn), tungsten (W), and rare-earth elements (REEs). A placer deposit

1140-403: The ore from the gangue, and concentration to separate the desired mineral(s) from it. Once processed, the gangue is known as tailings , which are useless but potentially harmful materials produced in great quantity, especially from lower grade deposits. An ore deposit is an economically significant accumulation of minerals within a host rock. This is distinct from a mineral resource in that it

1178-729: The other Variscan mittelgebirges of Central Europe, the valleys are more irregular and less pronounced as in the relatively young fold and thrust belt of the Alps . The plateaus are orographically more similar in morphology. Water gaps in the Bohemian Massif are the Wachau , the Strudengau and the valley of the Danube from Vilshofen over Passau and the Schlögener Schlinge till Aschach . The internal tectonic structure of

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1216-735: The plural, die Mittelgebirge (as opposed to the singular, das Mittelgebirge ), sometimes qualified as die deutschen Mittelgebirge , usually refers to the Central Uplands of Germany which is a belt of low mountain ranges or hills between the Northern Lowland and the Bavarian Alpine Foreland . The ranges stretch from the North German Plain up to the Alps in the south. The northern limitation

1254-431: The price of ores of this nature opaque and difficult. Such metals include lithium , niobium - tantalum , bismuth , antimony and rare earths . Most of these commodities are also dominated by one or two major suppliers with >60% of the world's reserves. China is currently leading in world production of Rare Earth Elements. The World Bank reports that China was the top importer of ores and metals in 2005 followed by

1292-578: The river Danube the topography is characterized by gentle valleys and broad, flat ridges and hilltops. The highest peaks on the Czech-Austrian borderline are the Plöckenstein (Plechý, 1,378 m) and Sternstein (1,125 m). The bedrock of acid gneiss and granite is weathered to brown soil ( cambisols ). In flat areas and valleys the groundwater had more influence on soil formation ; in such places gley soils may be found too. As in

1330-1164: The southwest, the Upper Rhine Plain stretches up to the Swiss border at Basel , accompanied by the South German Scarplands including the Odenwald range and the Black Forest , as well as the Swabian Jura and its eastern continuation, the Franconian Jura . Left of the Upper Rhine , the North French Scarplands reach from the Palatinate and the Vosges Mountains down to the Paris Basin . Along

1368-471: The surface than today. After this, copper sulphides would have been turned to as oxide resources depleted and the Bronze Age progressed. Lead production from galena smelting may have been occurring at this time as well. The smelting of arsenic-copper sulphides would have produced the first bronze alloys. The majority of bronze creation however required tin, and thus the exploitation of cassiterite,

1406-440: The surrounding terrain (as opposed to above sea level). The summits usually do not reach the tree line and were not glaciated after the last glacial period . In contrast, Hochgebirge is used to refer to mountain ranges rising above approximately 1,500 metres (4,900 ft) to 1,800 metres (5,900 ft). The delineation corresponds with the differentation between Montane and Alpine level according to altitudinal zonation . In

1444-546: The terranes of the Armorican Massif in western France. This supposedly formed a microcontinent that became sandwiched between the large continental masses north and south. The result of the Variscan Orogeny was that almost all continental mass became united in a supercontinent called Pangaea . From the Permian period onward the Variscan mountain belt eroded and became partly covered by younger sediments , with

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