Figure 1.2. Growth of the world s population through history. Notice the sharp drop due to the Black Death that struck Europe in 1348, and the sharp

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2 Figure 1.2. Growth of the world s population through history. Notice the sharp drop due to the Black Death that struck Europe in 1348, and the sharp rise that occurred in the nineteenth and twentieth centuries. From Craig, J.R., Vaughan, D.J., and Skinner, B.J., 2001, Resources of the Earth Origin, Use, and Environmental Impact, 3 rd Edition. Prentice-Hall, 520p.

10 The periodic table

12 Silicates Classification of Minerals Most important mineral group Comprise most of the rock-forming minerals Very abundant due to large amounts of silicon and oxygen in Earth s crust Basic building block is the silicon-oxygen tetrahedron molecule Four oxygen ions surrounding a much smaller silicon ion

14 Classification of Minerals Important nonsilicate minerals Several major groups exist including Oxides Sulfides Sulfates Native Elements Carbonates Halides Phosphates

15 Mineral resources The endowment of useful minerals ultimately available commercially Mineral resources include Reserves already identified deposits (proven) Known deposits that are not yet economically or technologically recoverable (speculative)

16 Ore Mineral resources A useful metallic mineral that can be mined at a profit Must be concentrated above its average crustal abundance Profitability may change because of economic changes

17 Table 3-3. List of the common ore minerals. From Jensen, M.L., and Bateman, A.M., 1981, Economic Mineral Deposits, 3 rd Edition, Revised Printing. John Wiley & Sons, New York, 593p.

18 HYDROSPHERE BIOGENIC SEDIMENTS DIAGENESIS BIOSPHERE SEDIMENTS WEATHERING AND TRANSPORTATION ATMOSPHERE IGNEOUS ROCKS REMELTING CRYSTALLIZATION MAGMA ANATEXIS THE GEOCHEMICAL CYCLE SEDIMENTARY ROCKS METAMORPHISM METAMORPHIC ROCKS

19 Table 8.1 The geochemically scarce metals. From Craig, J.R., Vaughan, D.J., and Skinner, B.J., 2001, Resources of the Earth Origin, Use, and Environmental Impact, 3 rd Edition. Prentice- Hall, 520p.

20 Figure 3.10 Traditional stages in mine development, metal production, and imports in industrial countries. Curve A, representing the number of working mines, rises rapidly as a new country is prospected, but it declines when the rate of mine exhaustion exceeds the discovery rate. Curve B, representing metals produced, also rises and falls as mines are worked and eventually exhausted. Curve C, representing metals imported, rises exponentially and expresses the increasing inability of a country to meet its own needs. With traditional development, each country moves along the time axis from left to right.

21 From Cameron, E.N., 1986, At the Crossroads. The Mineral Problems of the United States. Wiley Interscience Pub., John Wiley & Sons, New York, 320p.

22 From Cameron, E.N., 1982, Non-fuel mineral problems of the United States. Resources and Conservation, v. 9, pp

24 The periodic table

26 HYDROSPHERE BIOGENIC SEDIMENTS DIAGENESIS BIOSPHERE SEDIMENTS WEATHERING AND TRANSPORTATION ATMOSPHERE IGNEOUS ROCKS REMELTING CRYSTALLIZATION MAGMA ANATEXIS THE GEOCHEMICAL CYCLE SEDIMENTARY ROCKS METAMORPHISM METAMORPHIC ROCKS

29 Mineral resources and igneous processes Examples of igneous mineral resources Magmatic segregation Separation of heavy minerals that crystallize early or enrichment of rare elements in the residual melt Diamonds Originate at great depths Crystals are disseminated in ultramafic rock called kimberlite

30 Mineral resources and igneous processes Hydrothermal solutions Among the best known and important ore deposits Majority originate from hot, metal rich fluids that are remnants of late-stage magmatic processes Move along fractures, cools, and precipitates the metallic ions to produce vein deposits

31 Hydrothermal deposits often occur with igneous rocks Figure 21.21

32 Mineral resources and metamorphic rocks Many of the most important metamorphic ore deposits are produced by contact metamorphism Sphalerite (zinc) Galena (lead) Chalcopyrite (copper)

33 Mineral resources and metamorphic rocks Regional metamorphism can also generate useful deposits Talc Graphite

34 Weathering and ore deposits Secondary enrichment - concentrating metals into economically valuable concentrations Bauxite Principal ore of aluminum Forms in rainy tropical climates from chemical weathering and the removal of undesirable elements by leaching

35 Bauxite the principal ore of aluminum Figure 21.26

36 Weathering and ore deposits Other deposits, such as many copper and silver deposits, result when weathering concentrates metals that are deposited through a low-grade primary ore

37 Placer deposits Placer deposits Placers deposits formed when heavy metals are mechanically concentrated by currents Involve heavy and durable minerals Examples include Gold Platinum Diamonds

38 Fig. 88 Diagram showing development of eluvial and stream placers. From Lindgren, W., 1932, Mineral Deposits, 4 th Edition. McGraw-Hill Book Co., New York, 930p.

39 Fig. 89 Plan of quartz vein and placers below it, illustrating the development of pay streaks. From Lindgren, W., 1932, Mineral Deposits, 4th Edition. McGraw-Hill Book Co., New York, 930p.

40 Figure 19. Succession of compounds precipitating from seawater. CaCO 3 is precipitated first. When evaporation reduces the volume to 19 percent of the original volume, CaSO 4 begins to precipitate; at 9.5 percent, NaCl; and so on. Sizes of triangles represent relative proportions of the dissolved salts. From Skinner, B.J., 1986, Earth Resources, 3 rd Edition. The Prentice-Hall Foundations of Earth Science Series, 184p.

41 HYDROSPHERE BIOGENIC SEDIMENTS DIAGENESIS BIOSPHERE SEDIMENTS WEATHERING AND TRANSPORTATION ATMOSPHERE IGNEOUS ROCKS REMELTING CRYSTALLIZATION MAGMA ANATEXIS THE GEOCHEMICAL CYCLE SEDIMENTARY ROCKS METAMORPHISM METAMORPHIC ROCKS

Real-Life Applications: Economic Mineral Deposits

Real-Life Applications: Economic Mineral Deposits Economic Minerals Economic minerals are minerals that can be extracted, processed and marketed for a profit. Various factors determine if a mineral is