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Vein (geology) White veins in dark rock at Imperia, Italy. In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation. [1]
Hydrothermal vein ore deposits consist of discrete veins or groups of closely spaced veins. Veins are believed to be precipitated by hydrothermal solutions travelling along discontinuities in a rockmass. [10] They are commonly epithermal in origin, that is to say they form at relatively high crustal levels and moderate to low temperatures.
Quartz reef mining. Quartz reef mining is a type of gold mining in "reefs" ( veins [ 1]) of quartz . Quartz is one of the most common minerals in the Earth's crust, and most quartz veins do not carry gold, but those that have gold are avidly hunted by prospectors. In the shallow, oxidized zones of quartz reef deposits, the gold occurs in its ...
Hushing. Sketch map of the development of the Dolaucothi Gold Mines in Carmarthenshire, south Wales, showing hushing fed by aqueducts. Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. [ 1][ 2] The method was applied in several ways, both in prospecting for ores, and for their exploitation.
By the 19th century coal mining had become an important local industry with many farmers operating mines or carting as a supplement to their income. By 1865 the coalfield was employing nearly 1,000 people. Decline began in the 19th century, with many collieries closing after 1900, but others retained a strong link between mining and agriculture.
An adit (from Latin aditus, entrance) [ 1] or stulm[ 2] is a horizontal or nearly horizontal passage to an underground mine. [ 3] Miners can use adits for access, drainage, [ 4] ventilation, and extracting minerals at the lowest convenient level. [ 1] Adits are also used to explore for mineral veins. [ 1]
Ore shoot. An ore shoot is a hypogenic mass that is deposited in veins within a planar channel or lode, found in a shear or fault zone, fissure or lithologic boundary. [1] The ore shoot is the area of concentration which contains a primary ore along the veins present in the rock, and consists of the most valuable part of the deposit.
Amendments. The General Mining Act of 1872 is a United States federal law that authorizes and governs prospecting and mining for economic minerals, such as gold, platinum, and silver, on federal public lands. This law, approved on May 10, 1872, codified the informal system of acquiring and protecting mining claims on public land, formed by ...