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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 ...
For example, sedimentary exhalative deposits (SEDEX), are a class of ore deposit formed on the sea floor (sedimentary) by exhalation of brines into seawater (exhalative), causing chemical precipitation of ore minerals when the brine cools, mixes with sea water, and loses its metal carrying capacity.
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.
Sedimentary exhalative (SEDEX) deposits account for 40% of total world zinc production, 60% of lead and a significant proportion of silver. Despite their economic importance however, sedex deposits are relatively rare. A worldwide compilation of sedex deposits indicates that about 70 are known, of which 24 have been or are being mined.
A sulfide deposit is an ore body or rock containing a great deal of sulfide minerals. Articles on this topic include: Seafloor massive sulfide deposits; Sedimentary exhalative deposits; Volcanogenic massive sulfide ore deposit; Massive sulfide deposits
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.
Sphalerite is a sulfide mineral with the chemical formula (Zn, Fe)S. [5] It is the most important ore of zinc.Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits.
VMS deposits have a wide variety of morphologies, with mound shaped and bowl shaped deposits most typical. The bowl-shaped formations formed due to venting of hydrothermal solutions into submarine depressions – in many cases, this type of deposit can be confused with sedimentary exhalative deposits. The mound-shaped deposits formed in a way ...