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Hydrothermal mineral deposits are accumulations of valuable minerals which formed from hot waters circulating in Earth's crust through fractures. They eventually produce metallic -rich fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals.
The Oubasi orogenic gold deposit in Southern Ghana is host to mineral resources of over 70 Moz Au at a grade of 7.39g/t or higher, with a past production of 32 Moz Au. [9] The deposit is located in the Birimian orogen, where gold mining is known to have taken place back to the 17th century, but modern industrial-scale mining began in 1897 by ...
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.
Epithermal — mineral ore deposits formed at low temperatures (50–200 °C) near the Earth's surface (<1500 m), that fill veins, breccias, and stockworks. [2] Telethermal — mineral ore deposits formed at shallow depth and relatively low temperatures, with little or no wall-rock alteration, presumably far from the source of hydrothermal ...
Mineral associations may vary (1) in different mineralized structures, either syngenetic (namely, passive precipitation in chimneys, mounds and stratiform deposits) or epigenetic (structures that correspond to feeder channels, and replacements of host rocks or pre-existing massive sulfide bodies), or structural zonation, (2) from proximal to ...
The term "polymetallic ore" also includes nodules, principally Manganese nodules, that do not form as terrestrial deposits but as concretions on the ocean floor. [ 3 ] [ 4 ] Rocks containing polymetallic ores are often altered or formed by hydrothermal processes — chloritization , sericitization and silicification .
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Since these ore deposits frequently form massive sulfide lenses, they are also named sediment-hosted massive sulfide (SHMS) deposits, [1] [4] as opposed to volcanic-hosted massive sulfide (VHMS) deposits. The sedimentary appearance of the thin laminations led to early interpretations that the deposits formed exclusively or mainly by exhalative ...