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27-495: Toter Mann (German for "dead man") may refer to: a German mining expression for an unproductive mineral vein ( Mann ) Erdanker Toter Mann , a fixing technology in firn and snow Toter Mann , German for the ball of coke that forms in the centre of a blast furnace Toter Mann , German for "back floating" a form of survival when swimming Places [ edit ] Toter Mann (Warscheneck Group) (2,137 m), subpeak of

54-457: A fiercely fought-over hill in the Battle of Verdun Other uses [ edit ] Toter Mann (film) , 2001 German TV thriller by Christian Petzold a 1989 crime story by Yaak Karsunke See also [ edit ] Todtmann , Todter Mann Dead man (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

81-445: A plane of extension within the rock mass. In all cases except brecciation, therefore, a vein measures the plane of extension within the rock mass, give or take a sizeable bit of error. Measurement of enough veins will statistically form a plane of principal extension. In ductilely deforming compressional regimes, this can in turn give information on the stresses active at the time of vein formation. In extensionally deforming regimes,

108-544: Is a primary cause of mineral deposit formation and a cornerstone of most theories on ore genesis . During the early 1900s, various geologists worked to classify hydrothermal ore deposits that they assumed formed from upward-flowing aqueous solutions. Waldemar Lindgren (1860–1939) developed a classification based on interpreted decreasing temperature and pressure conditions of the depositing fluid. His terms: "hypothermal", "mesothermal", "epithermal" and "teleothermal", expressed decreasing temperature and increasing distance from

135-544: Is invisible to the naked eye. In these cases, veining is the subordinate host to mineralisation and may only be an indicator of the presence of metasomatism of the wall-rocks which contains the low-grade mineralisation. For this reason, veins within hydrothermal gold deposits are no longer the exclusive target of mining, and in some cases gold mineralisation is restricted entirely to the altered wall rocks within which entirely barren quartz veins are hosted. Epithermal Hydrothermal circulation in its most general sense

162-482: Is not limited to ocean ridge environments. Hydrothermal circulating convection cells can exist in any place an anomalous source of heat, such as an intruding magma or volcanic vent, comes into contact with the groundwater system where permeability allows flow. This convection can manifest as hydrothermal explosions , geysers , and hot springs , although this is not always the case.   Hydrothermal circulation above magma bodies has been intensively studied in

189-405: Is plenty of fluid flow and open space to deposit ore minerals. Ores related to hydrothermal mineralisation, which are associated with vein material, may be composed of vein material and/or the rock in which the vein is hosted. In many gold mines exploited during the gold rushes of the 19th century, vein material alone was typically sought as ore material. In most of today's mines, ore material

216-469: Is possible to construct on a Mohr diagram the shear fracture envelope that separates stable from unstable states of stresses. The shear fracture envelope is approximated by a pair of lines that are symmetric across the σ n axis. As soon as the Mohr circle touches the lines of the fracture envelope that represent a critical state of stress, a fracture will be generated. The point of the circle that first touches

243-402: Is primarily composed of the veins and some component of the wall rocks which surrounds the veins. The difference between 19th-century and 21st-century mining techniques and the type of ore sought is based on the grade of material being mined and the methods of mining which are used. Historically, hand-mining of gold ores permitted the miners to pick out the lode quartz or reef quartz, allowing

270-597: Is the circulation of hot water ( Ancient Greek ὕδωρ, water , and θέρμη, heat ). Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's crust . In general, this occurs near volcanic activity, but can occur in the shallow to mid crust along deeply penetrating fault irregularities or in the deep crust related to the intrusion of granite , or as the result of orogeny or metamorphism . Hydrothermal circulation often results in hydrothermal mineral deposits . Hydrothermal circulation in

297-424: Is the hallmark of epithermal vein systems, such as a stockwork , in greisens or in certain skarn environments. For open space filling to take effect, the confining pressure is generally considered to be below 0.5 GPa , or less than 3–5 km (2–3 mi). Veins formed in this way may exhibit a colloform , agate -like habit, of sequential selvages of minerals which radiate out from nucleation points on

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324-635: The Warscheneck on the Pyhrn Pass in Upper Austria Toter Mann (Berchtesgaden Alps) (1,392 m), mountain near Berchtesgaden, Bavaria Toter Mann (Black Forest) (1,321 m), mountain in the municipality of Oberried im Breisgau, well known mountain run Toter Mann (Kolomansberg) , 874 m, mountain with Bildbaum am Kolomansberg, Salzburg state Toter Mann (Seulingswald) , 480 m, hill near Friedewald, Hessen Le Mort Homme ,

351-417: The oceans is the passage of the water through mid-oceanic ridge systems. The term includes both the circulation of the well-known, high-temperature vent waters near the ridge crests, and the much-lower-temperature, diffuse flow of water through sediments and buried basalts further from the ridge crests. The former circulation type is sometimes termed "active", and the latter "passive". In both cases,

378-530: The context of geothermal projects where many deep wells are drilled into the system to produce and subsequently re-inject the hydrothermal fluids. The detailed data sets available from this work show the long term persistence of these systems, the development of fluid circulation patterns, histories that can be influenced by renewed magmatism, fault movement, or changes associated with hydrothermal brecciation and eruption sometimes followed by massive cold water invasion. Less direct but as intensive study has focused on

405-472: The crystal growth occurring normal to the walls of the cavity, and the crystal protruding into open space. This certainly is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock, especially several kilometers below the surface. Thus, there are two main mechanisms considered likely for the formation of veins: open-space filling and crack-seal growth . Open space filling

432-633: The envelope represents the plane along which a fracture forms. A newly formed fracture leads to changes in the stress field and tensile strength of the fractured rock and causes a drop in stress magnitude. If a stress increases again, a new fracture will most likely be generated along the same fracture plane. This process is known as the crack-seal mechanism Crack-seal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained; generally

459-403: The highest-grade portions of the lodes to be worked, without dilution from the unmineralised wall rocks. Today's mining, which uses larger machinery and equipment, forces the miners to take low-grade waste rock in with the ore material, resulting in dilution of the grade. However, today's mining and assaying allows the delineation of lower-grade bulk tonnage mineralisation, within which the gold

486-490: The macroscopic scale, the formation of veins is controlled by fracture mechanics, providing the space for minerals to precipitate. Failure modes are classified as (1) shear fractures, (2) extensional fractures, and (3) hybrid fractures, and can be described by the Mohr-Griffith-Coulomb fracture criterion. The fracture criterion defines both the stress required for fracturing and the fracture orientation, as it

513-545: The minerals deposited especially in the upper parts of hydrothermal circulation systems. Understanding volcanic and magma-related hydrothermal circulation means studying hydrothermal explosions, geysers, hot springs, and other related systems and their interactions with associated surface water and groundwater bodies. A good environment to observe this phenomenon is in volcanogenic lakes where hot springs and geysers are commonly present. The convection systems in these lakes work through cold lake water percolating downward through

540-443: The permeable lake bed, mixing with groundwater heated by magma or residual heat, and rising to form thermal springs at discharge points. The existence of hydrothermal convection cells and hot springs or geysers in these environments depends not only on the presence of a colder water body and geothermal heat but also strongly depends on a no-flow boundary at the water table. These systems can develop their own boundaries. For example

567-428: The principle is the same: Cold, dense seawater sinks into the basalt of the seafloor and is heated at depth whereupon it rises back to the rock-ocean water interface due to its lesser density. The heat source for the active vents is the newly formed basalt, and, for the highest temperature vents, the underlying magma chamber. The heat source for the passive vents is the still-cooling older basalts. Heat flow studies of

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594-413: The seafloor suggest that basalts within the oceanic crust take millions of years to completely cool as they continue to support passive hydrothermal circulation systems. Hydrothermal vents are locations on the seafloor where hydrothermal fluids mix into the overlying ocean. Perhaps the best-known vent forms are the naturally occurring chimneys referred to as black smokers . Hydrothermal circulation

621-409: The space is in the order of millimeters or micrometers . Veins grow in thickness by reopening of the vein fracture and progressive deposition of minerals on the growth surface as well as being decomposable . Veins generally need either hydraulic pressure in excess of hydrostatic pressure (to form hydraulic fractures or hydrofracture breccias) or they need open spaces or fractures, which requires

648-530: The title Toter Mann . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Toter_Mann&oldid=757329786 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Vein (geology) Veins are classically thought of as being planar fractures in rocks, with

675-564: The vein walls and appear to fill up the available open space. Often evidence of fluid boiling is present. Vugs , cavities and geodes are all examples of open-space filling phenomena in hydrothermal systems. Alternatively, hydraulic fracturing may create a breccia which is filled with vein material. Such breccia vein systems may be quite extensive, and can form the shape of tabular dipping sheets, diatremes or laterally extensive mantos controlled by boundaries such as thrust faults , competent sedimentary layers , or cap rocks . On

702-422: The veins occur roughly normal to the axis of extension. Veins are common features in rocks and are evidence of fluid flow in fracture systems. Veins provide information on stress, strain, pressure, temperature, fluid origin and fluid composition during their formation. Typical examples include gold lodes , as well as skarn mineralisation. Hydrofracture breccias are classic targets for ore exploration as there

729-411: The water level represents a fluid pressure condition that leads to gas exsolution or boiling that in turn causes intense mineralization that can seal cracks. Hydrothermal also refers to the transport and circulation of water within the deep crust, in general from areas of hot rocks to areas of cooler rocks. The causes for this convection can be: Hydrothermal circulation, in particular in the deep crust,

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