Mineral Ore Deposits

Ores are minerals or rocks with concentrations of elements that can be economically extracted.

Hydrothermal Deposits

  1. Associated with igneous intrusions and metamorphic processes.
  2. Superheated water, often rich in salts, dissolves minerals.
  3. The fluids move through fractures and joints in rock.
  4. These transported minerals are deposited or precipitated in surrounding rock or within the rock voids (veins).
  5. Examples: pyrite (FeS2), galena (PbS), cinnabar (HgS), sphalerite (ZnS), covellite (CuS). Metals are often deposited as sulphides.
  6. Metamorphic examples: Marble external arrow

Igneous Ores

  1. As intrusions cool, minerals form at different rates and specific temperatures.
  2. Early forming minerals may sink within the intrusive body.
  3. Examples: Chromium and platinum deposits in South Africa.

Sedimentary Ores

  1. Minerals segregate due to chemical and physical sedimentary processes.
  2. Placer deposits: gold external arrow and titanium.
  3. Evaporate examples: gypsum (CaSO4 · 2H2O) and halite (NaCl)
  4. Precipitate examples: phosphate external arrow rock, limestone (CaCO3) and BIF external arrow

Astrobleme !

Ni, Cu and Fe deposits external arrow in Sudbury external arrow Ontario.