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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 ...
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
The hydrothermal fluid leaches metals as it descends and precipitates minerals as it rises. Sedimentary exhalative deposits, also called sedex deposits, are lead-zinc sulfide deposits formed in intracratonic sedimentary basins by the submarine venting of hydrothermal fluids. These deposits are typically hosted in shale.
VMS deposits are a major source of zinc (Zn), copper (Cu), lead (Pb), silver (Ag), and gold (Au). [33] Gold ore (size: 7.5 × 6.1 × 4.1 cm) Sedimentary exhalative sulphide deposits (SEDEX) are a copper sulphide ore which form in the same manor as VMS from metal rich brine but are hosted within sedimentary rocks and are not directly related to ...
Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite, dolomite, quartz, rhodochrosite, and fluorite. [6] German geologist Ernst Friedrich ...
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 ...
The key criteria for BHT ore deposits are; [11] Association with major sedimentary packages of sandstone and siltstone protoliths sequences in highly disturbed metamorphic terranes. A Proterozoic age is considered important, as no other major SEDEX lead-zinc deposits of this style are known from the Phanerozoic or Archean.
An evaporite (/ ɪ ˈ v æ p ə ˌ r aɪ t /) is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. [1] There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of ...