Embed Size (px)
Citation preview
4000 2000 0 2000
BCE Time (years) CE
Stone Age Bronze age Iron Age
The ages of civilization and Metal Consumption
Mineral Resource Consumption
Copper
Lead
Iron
Aluminium
Zinc
Metal consumption – resources
Life expectancies of resources of selected commodities based on crustal abundance
Metal Recycling
Rates Metal Recycling
Metallic Mineral Exploration – Looking for the proverbial needle in the haystack
Black Smokers and Massive Sulphide Ore Deposits
350 oC
CuCl
ZnCl2
PbCl2
Chalcopyrite
Sphalerite
Pyrite(FeS2)
(CuFeS2)
(ZnS)
Black SmokersFluids precipitate sulphide minerals on the walls of the chimneys (Pyrite, FeS2; Chalcopyrite, CuFeS2; Sphalerite ZnS).
Massive Sulphide Ore Formation
Black Smokers and Massive Sulphide Ore Deposits
Sphalerite
Pyrite
Pyrite and sphalerite
Sphalerite
Pyrite
Chalcopyrite
Sphalerite
Pyrrhotite
Massive Sulphide Ores
Hydrothermal vein deposits
1 cm
Hot water dissolves metals as complex molecules, e.g. H2WO4 or Hg(HS)2. Quartz and metallic minerals precipitate in fractures in response to cooling or changes in water chemistry
Cinnabar (HgS)
m10 cm
Hg-bearing quartz vein
Fluid inclusionWolframite
(Fe,Mn)WO4)
Porphyry Copper deposits
1 cm
Porphyry ore Brine (NaCl-H2O) exsolves from cooling diorite intrusion
Cu dissolved as CuCl2, Fe as FeCl2Reaction with H2S on cooling to form chalcopyrite (CuFeS2)
Open pit mine
Au(HS)2- + H+ + 0.5 H2O
= Au + 0.25O2 + 2H2S
Removed by boiling
Native gold
Formation of an epithermal gold deposit
Gold-bearing quartz veins
Native gold
Alluvial depositsGold panning
Gold nugget
Witwatersrand Goldfields
Gold- bearing conglomerate
(Produces 35% of world’s gold)
Understanding Planet EarthThe Earth as a System
