How are MVT deposits formed?
MVT ore deposits commonly occur in carbonate rock around the edges or margins of intracratonic basins. This is due to the migration of H2S from hydrocarbon basins into structural and stratigraphic traps along the basin margins.
What are MVT deposits?
MVT deposits are part of a larger family of Carbonate-hosted deposits, all of which contain zinc. The MVT style of zinc and lead deposits formed at relatively low temperatures, from 90°C to 150°C. Other carbonate-hosted deposits can form at higher temperatures and commonly contain silver.
Where are lead deposits found?
Lead deposits form from hot, aqueous (or hydrothermal) fluids generated within the earth. These fluids flow along sub-surface fractures, where galena and other minerals may be deposited to form vein deposits.
What is secondary enrichment?
supergene sulfide enrichment, also called Secondary Enrichment, in geology, natural upgrading of buried sulfide deposits by the secondary or subsequent deposition of metals that are dissolved as sulfates in waters percolating through the oxidized mineral zone near the surface.
How are porphyry copper deposits formed?
Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name.
How do lead zinc deposits form?
Commonly MVT deposits form by the combination of hydrocarbon pyrolysis liberating zinc-lead ions and sulfur to form an acidic solution which dissolves the host carbonate formation and replaces it with massive sulfide accumulations.
Which mineral is found together with lead deposits?
The great majority of zinc deposits contain the lead mineral, galena, and both the lead and zinc minerals are mined together. Other metals that are found with zinc are silver and copper.
What is the most common ore of lead?
galena
The most important lead ore is galena (PbS), with other less important minerals being cerrusite (PbCO3) and anglesite (PbSO4).
Where are stratiform deposits found?
Stratiform chromite deposits are found throughout the world, but the chromitite seams of the Bushveld Complex, South Africa, are the largest and most intensely researched.
What are supergene minerals?
Supergene minerals such as sulfides, clays, hydroxides and sulfates are formed in the supergene zone as secondary minerals by the alteration of primary sulfide minerals from the oxidized zone above the water table. Supergene sulfide enrichment is the most common use for the term supergene.
Where are copper porphyry deposits?
Porphyry copper deposits form in continental magmatic arcs along convergent plate-margin boundaries or in island-arc environments. The deposits are associated with subduction-related volcanic centers, although in some examples, they are thought to be associated with postcollisional volcanism.
Where are porphyry copper deposits found?
Large porphyry copper deposits are worked in the southwestern United States (where molybdenum is produced as a by-product), the Solomon Islands, Canada, Peru, Chile, Mexico, and other parts of the world.