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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]
An orogenic gold deposit is a type of hydrothermal mineral deposit. More than 75% of the gold recovered by humans through history belongs to the class of orogenic gold deposits. [1] Rock structure is the primary control of orogenic gold mineralization at all scales, as it controls both the transport and deposition processes of the mineralized ...
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.
The epithermal vein deposit (EVP) is a type of mineral deposit that forms in the shallow subsurface, typically at depths of less than 1,500 meters below the Earth's surface. [1] These deposits are formed by hot, mineral-rich fluids that circulate through fractures and cracks in rocks. As the fluids cool, they deposit minerals, such as gold ...
Ore genesis. High-grade gold ore from the Harvard Mine, Jamestown, California, a wide quartz -gold vein in California's Mother Lode. Specimen is 3.2 cm (1.3 in) wide. Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada (then western Utah Territory), which was the first major discovery of silver ore in the United States and named after American miner Henry Comstock.
Carlin–type gold deposits are sediment -hosted disseminated gold deposits. These deposits are characterized by invisible (typically microscopic and/or dissolved) gold in arsenic rich pyrite and arsenopyrite. [2] This dissolved kind of gold is called "invisible gold", as it can only be found through chemical analysis. [3]
Paragenesis. Paragenesis is a petrologic concept meaning an equilibrium sequence of mineral phases. [1] It is used in studies of igneous and metamorphic rock genesis and importantly in studies of the hydrothermal deposition of ore minerals and the rock alteration (vein metasomatism) associated with ore mineral deposits.