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Cartoon cross-section showing manto ore deposits (USGS) [1] A polymetallic replacement deposit, also known as carbonate replacement deposit or high-temperature carbonate-hosted Ag-Pb-Zn deposit, [2] is an orebody of metallic minerals formed by the replacement of sedimentary, usually carbonate rock, by metal-bearing solutions in the vicinity of igneous intrusions. [3]
World-wide distribution of MVT deposits (red), clastic sediment-hosted (green), and unclassified (blue) lead-zinc deposits. Source: USGS. Carbonate-hosted lead-zinc ore deposits are important and highly valuable concentrations of lead and zinc sulfide ores hosted within carbonate (limestone, marl, dolomite) formations and which share a common genetic origin.
The sedimentary appearance of the thin laminations led to early interpretations that the deposits formed exclusively or mainly by exhalative processes onto the seafloor, hence the term SEDEX. However, recent study of numerous deposits indicates that shallow subsurface replacement is also an important process, in several deposits the predominant ...
Lead and zinc deposits are formed by discharge of deep sedimentary brine onto the sea floor (termed sedimentary exhalative or SEDEX), or by replacement of limestone, in skarn deposits, some associated with submarine volcanoes (called volcanogenic massive sulfide ore deposits or VMS), or in the aureole of subvolcanic intrusions of granite.
Volcanogenic massive sulfide deposits are distinctive in that ore deposits are formed in close temporal association with submarine volcanism and are formed by hydrothermal circulation and exhalation of sulfides which are independent of sedimentary processes, which sets VMS deposits apart from sedimentary exhalative (SEDEX) deposits.
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. In some occurrences, minerals can be extracted ...
Citigroup disclosed Friday that it paid an average rate of 3.09% on its deposits, up from 0.05% a year earlier. JPMorgan Chase paid 2.24%, up from 0.20%. Wells Fargo’s rate was an average of 1. ...
The first of these is the ion-by-ion replacement in minerals, this can happen from the precipitation of new minerals at the same time as the dissolution of existing minerals. [6] The second feature used to identify metasomatism is that it is from the preservation of rocks in its solid state during replacement. [6]