Classification of Ore Deposits
Ore deposits are usually classified by ore formation processes and geological setting. For example, SEDEX deposits, literally meaning "sedimentary exhalative" 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.
Ore deposits rarely fit snugly into the boxes in which geologists wish to place them. Many may be formed by one or more of the basic genesis processes above, creating ambiguous classifications and much argument and conjecture. Often ore deposits are classified after examples of their type, for instance Broken Hill type lead-zinc-silver deposits or Carlin–type gold deposits.
Classification of hydrothermal ore deposits is also achieved by classifying according to the temperature of formation, which roughly also correlates with particular mineralising fluids, mineral associations and structural styles. This scheme, proposed by Waldemar Lindgren (1933) classified hydrothermal deposits as hypothermal, mesothermal, epithermal and telethermal.
Read more about this topic: Ore Genesis
Famous quotes containing the word deposits:
“Were all the worshippers of the gold calf to memorialize me and request a restoration of the deposits I would cut my right hand from my body before I would do such an act. The gold calf may be worshipped by others but as for myself I serve the Lord.”
—Andrew Jackson (1767–1845)