Volcanic deposit

Volcanic Deposits. Uranium deposits of volcanic deposits type are strata-bound and stmcture-bound concentrations in acid volcanic rocks. Uranium is commonly associated with molybdenum, fluorine, etc. Examples are the uranium deposits in Michelin, Canada Nopal I in Chihualiua, Mexico Macusani in Pern and numerous deposits in China and the CIS (16). 

Sulfur for commercial purposes is derived mainly from native elemental sulfur mined by the Frasch process. Large quantities of sulfur are also recovered from the roasting of metal sulfides and the refining of crude oil, i.e., from the sulfur by-products of purified sour natural gas and petroleum (the designation sour is generally associated with high-sulfur petroleum products). Reserves of elemental sulfur in evaporite and volcanic deposits and of sulfur associated with natural gas,... 

Volcanic Deposits Michelin in Canada, Nopal I in Chichuahua, Mexico, Macusani in Peru and many deposits in China and the CIS. 

Volcanic deposits, mining Weathering of geologic materials, hydrothermal, mining smelter emissions Mining... 

In the subsurface, arsenic may readily accumulate in coal. Specifically, groundwater percolating through volcanic deposits may leach arsenic and transfer it to underlying coal beds during or after coalification. Contact metamorphism and any associated hydrothermal fluids are other processes that sometimes locally enrich arsenic in coal seams. At a site in British Columbia, a Cretaceous bituminous coal seam was contact metamorphosed by a mafic dike. The contact temperatures were about 700-900 °C, which could volatilize arsenic and/or dissolve it into associated hydrothermal fluids. The arsenic was then transported and deposited into cooler sections of the seam (Yudovich and Ketris, 2005), 163. 

Schist Pramerkogel Formation (metamorphosed volcanic deposits) Eastern Alps, Austria 6 - 2,000 4000 near veins Bojar et al. (2001)... 

Indonesia West Java Ciwidey River Volcanic deposits... 

Inceptisol L. inceptum, beginning Soils with only slight horizon development. Tundra soils, soils on new volcanic deposits, recently deglaciated areas, and so on... 

Cyclooctasulfur exists as three main crystalline forms (allotropes) the most stable allotrope at 25°C is orthorhombic sulfur (Sa) (m.p. 112.8°C), found as large yellow crystals in volcanic deposits. When Sa is heated slowly to 95.5°C, it is converted to the high temperature monoclinic form (Sp) (m.p. 119.5°C), which also contains S8 rings but differently arranged. Another monoclinic form of sulfur (Sy) (m.p. 106.8°C) can be prepared by the slow crystallisation of sulfur from ammonium polysulfide. When sulfur... 

SP1/BAD] Spiridonov, E. M., Badalov, A. S., New sulfurselentellurides and sulfoselenides of bismuth from volcanic deposit Kiragach (East Uzbekistan), Uzb. Geol. Zh, 6, (1983), 82-84, in Russian. Cited on page 637. 

Imogolite is a natural hydrated aluminum silicate first discovered in 1962 in the clay fraction of Japanese volcanic ash and it is found widely distributed in recent volcanic deposits. Since 1977, it is possible to synthesize it in the laboratory from dilute aqueous solutions of hydroxyaluminum cations and orthosilicic acid [25] or, by reaction of tetraethylorthosilicate with an aluminum source (aluminum chloride or aluminum sec-butoxide) [26,27], at temperatures ranging from 25 to 100 °C. 

Houghton BF, Smith RT (1993) Recycling of magmatic clasts during explosive emptions Estimating the tme juvenile content of phreatomagmatic volcanic deposits. Bull Volcanol 55 414 20... 

Delmas RJ, Briat M, Legrand M (1982) Chemistry of south polar snow. J Geophys Res 87 4314-4318 Delmas RJ, Legrand M, Aristarain AL, Zanolini F (1985) Volcanic deposits in Antarctic snow and ice. J Geophys Res 90 12901-12920... 

Native sulfur or brimstone, sulfur naturally occurring in the elemental form, is found in several geologic environments. During volcanic activity sulfur may be sublimated directly around volcanic vents. Although sulfur production from volcanic deposits is generally limited, considerable tonnages have been produced in Japan from such deposits. 

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