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