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Hydrothermal deposits of economically valuable and recoverable minerals are generally considered scarce, meaning such deposits are very small relative to the total area of earth's surface. [ 2 ] Each of these deposit types is usually considered to represent a distinctive deposit group with common features and in a similar four-dimensional ...
Volcanogenic massive sulfide ore deposits, also known as VMS ore deposits, are a type of metal sulfide ore deposit, mainly copper-zinc which are associated with and produced by volcanic-associated hydrothermal events in submarine environments. [2] [3] [4] These deposits are also sometimes called volcanic-hosted massive sulfide (VHMS) deposits
Massive sulfide deposits are ore deposits that have significant stratiform ore bodies consisting mainly of sulfide minerals.Most massive sulfide ore deposits have other portions that are not massive, including stringer or feeder zones beneath the massive parts that mostly consist of crosscutting veins and veinlets of sulfides in a matrix of pervasively altered host rock and gangue.
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 ore fluids of MVT deposits are typically low temperature (100 °C–150 °C) and have the composition of basinal brines (10–30 wt.% NaCl equivalent) with pH's of 4.5–5 (buffered by host carbonates). This hydrothermal fluid may or may not carry the required sulfur to form sulfide minerals.
Main ore minerals in SEDEX deposits are fine-grained sphalerite and galena, chalcopyrite is significant in some deposits; silver-bearing sulfosalts are frequent minor constituents; pyrite is always present and can be a minor component or the dominant sulfide, as it is the case in massive sulfide bodies; barite content is common to absent ...
The reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is particularly noted in copper ore deposits where the copper sulfide minerals chalcocite (Cu 2 S), covellite (CuS), digenite (Cu 18 S 10), and djurleite (Cu 31 S 16) are deposited by the descending surface waters. [1]