TABLE 3.1
Occurrences of Metallic Minerals
Metal
Principal Ores
Geological Occurrences
Aluminum
Bauxite
Residual product of weathering
Chromium
Chromite
Magmatic segregation
Copper
Chalcopyrite
Hydrothermal deposits; contact metamorphism; enrichment by weathering processes
Bornite
Chalcocite
Gold
Native gold
Hydrothermal deposits; placers
Iron
Hematite
Banded sedimentary formations; magmatic segregation
Magnetite
Limonite
Lead
Galena
Hydrothermal deposits
Magnesium
Magnesite
Hydrothermal deposits
Dolomite
Manganese
Pyrolusite
Residual product of weathering
Mercury
Cinnabar
Hydrothermal deposits
Molybdenum
Molybdenite
Hydrothermal deposits
Nickel
Pentlandite
Magmatic segregation
Platinum
Native platinum
Magmatic segregation; placers
Silver
Native silver
Hydrothermal deposits; enrichment by weathering processes
Argentite
Tin
Cassiterite
Hydrothermal deposits; placers
Titanium
Ilmenite
Magmatic segregation; placers
Tungsten
Wolframite
Pegmatites; contact metamorphic deposits; placers
Uranium
Uraninite (pitchblende)
Pegmatites; sedimentary deposits
Zinc
Sphalerite
Hydrothermal deposits
85
Mineral Resources and Igneous Processes
Geyser
Fault
Pegmatite
deposits
Hydrothermal
disseminated
deposits
Hydrothermal
vein
deposits
Parent igneous body
(pluton)
FIGURE 3.31 Illustration of the relationship between a
parent igneous body and the associated pegmatite and
hydrothermal deposits. Inset photo shows light-colored vein
deposits emplaced along a series of fractures in dark-colored
metamorphic rock. (Photo by James E. Patterson)