Presentation on theme: "Chapter 14 Geology and Nonrenewable Resources"— Presentation transcript:
1 Chapter 14 Geology and Nonrenewable Resources Post Reading Discussion
2 Contents 1 a, b 6 a, b, c, d, e, f, g 2 a, b, c, d, e, f 7 3 8 a 4 9510
3 1b. Describe the environmental effects of gold mining. Tons of mining wastePollutes air and nearby surface waterCyanide heap leachingCyanide salts used to extract goldExtremely toxic, interferes with cell metabolismHolding ponds of can leak or overflow contaminating groundwater and nearby lakes and streams
4 Back to Contents Figure 14.1 Gold mine with cyanide leach piles and ponds in the Black Hills of the U.S. state of South Dakota.Back to ContentsFig. 14-1, p. 344
5 2a. Define geology, core, mantle, crust, tectonic plate, and lithosphere. Science of studying the dynamic processes occurring on the earth’s surface and its interior.Earth’s inner most zone; extremely hot solid inner core surrounded by liquid core.Surround the core, thick zone, mostly solid rock, but lower part—the asthenosphere—is hot and partly melted rock that flows.Outermost and thinnest zone.The broken sections of crust that move atop of flowing mantle.Continental and oceanic crusts and upper part of mantle.
6 Mantle (asthenosphere) VolcanoesFolded mountain beltAbyssal floorOceanic ridgeAbyssal floorAbyssal hillsTrenchCratonAbyssal plainOceanic crust (lithosphere)Abyssal plainContinental shelfContinental slopeContinental riseMantle (lithosphere)Continental crust (lithosphere)Mantle (lithosphere)Figure 14.2Major features of the earth’s crust and upper mantle. The lithosphere, composed of the crust and outermost mantle, is rigid and brittle. The asthenosphere, a zone in the mantle, can be deformed by heat and pressure.Mantle (asthenosphere)Fig. 14-2, p. 346
7 Back to Contents Spreading center Ocean trench Oceanic tectonic plateOceanic tectonic platePlate movementCollision between two continentsPlate movementTectonic plateSubduction zoneOceanic crustOceanic crustContinental crustContinental crustCold dense material falls back through mantleMaterial cools as it reaches the outer mantleMantle convection cellHot material rising through the mantleFigure 14.3The earth’s crust is made up of a mosaic of huge rigid plates, called tectonic plates, which move very slowly across the asthenosphere in response to forces in the mantle. See an animation based on this figure at CengageNOW™.Two plates move towards each other. One is subducted back into the mantle on a falling convection current.MantleHot outer coreInner coreBack to ContentsFig. 14-3, p. 346
8 2b. What is a transform fault? Boundary between tectonic plates where the plates slide and grind past one another along the fracture (fault) in the lithosphere.
9 Divergent plate boundaries Convergent plate boundaries EURASIAN PLATENORTH AMERICAN PLATEANATOLIAN PLATEJUAN DE FUCA PLATECHINA SUBPLATECARIBBEAN PLATEPHILIPPINE PLATEARABIAN PLATEAFRICAN PLATEINDIA PLATEPACIFIC PLATEPACIFIC PLATECOCOS PLATESOUTH AMERICAN PLATENAZCA PLATEAUSTRALIAN PLATESOMALIAN SUBPLATEFigure 14.4The earth’s major tectonic plates. See an animation based on this figure at CengageNOW. Question: What plate are you riding on?SCOTIA PLATEANTARCTIC PLATEDivergent plate boundariesConvergent plate boundariesTransform faultsFig. 14-4, p. 347
10 Back to Contents Figure 14.5 The San Andreas Fault as it crosses part of the Carrizo plain between San Francisco and Los Angeles, California (USA). This fault, which runs along almost the full length of California, is responsible for earthquakes of various magnitudes. Question: Is there a transform fault near where you live or go to school? (See Figure 14-4.)Back to ContentsFig. 14-5, p. 348
11 2c. What is weathering and why is it important? There are internal and external geologic processes.Weathering is an external geologic process that is the physical, chemical and biological breakdown of rocks.Helps build soil—important for sustaining terrestrial ecosystems.
12 Parent material (rock) Biological weathering(tree roots and lichens)Chemical weathering (water, acids, and gases)Physical weathering(wind, rain, thermal expansion and contraction, water freezing)Figure 14.6Weathering: Biological, chemical, and physical processes weather or convert rock into smaller fragments and particles. It is the first step in soil formation.Back to ContentsParticles of parent materialFig. 14-6, p. 348
13 2d. Define volcano and describe the nature and effects of a volcanic eruption. Volcano occurs when magma reaches the earth’s surface though a central vent or long crack called a fissure; occur at tectonic plate boundaries.Rocks, lava, hot ash, gases (water, CO2 and SO2)Mt. Pinatubo, Mt. St. Helens, 1980Benefits? Created mountains, highly fertile soils.
14 Back to Contents Figure 14.7 A volcano is created when magma in the partially molten asthenosphere rises in a plume through the lithosphere to erupt on the surface as lava, which builds a cone. Sometimes, internal pressure is high enough to cause lava, ash, and gases to be ejected into the atmosphere or to flow over land, causing considerable damage (Concept 14-1B). Chains of islands have been created by volcanoes that erupted and then became inactive.Back to ContentsFig. 14-7, p. 349
15 2e. Define and describe the nature and effects of an earthquake. Earthquakes occur when a fault forms or there is an abrupt movement of an existing fault releasing energy that has accumulated over time in the form of seismic waves.Severity is related to magnitude of seismic waves measure by the Richter scale (a log base 10 scale)Primary effects: Shaking and sometime permanent vertical or horizontal displacement of the groundCan cause damage to building and infrastructure and represents a life hazard to people living in areas prone to earthquakes.
16 Liquefaction of recent sediments causes buildings to sink Two adjoining plates move laterally along the fault lineEarth movements cause flooding in low-lying areasLandslides may occur on hilly groundFigure 14.8Major features and effects of an earthquake, one of nature’s most powerful events.Shock wavesFocusEpicenterBack to ContentsFig. 14-8, p. 350
17 2f. What is a tsunami and what are its effects? Tsunami is a series of large waves generated when part of the ocean floor suddenly rises or drops—caused by thrust faults in the ocean floor.Kill people and destroy property when the wave reaches shoreLargest loss occurred in December 20049.15 magnitude earthquake in the Indian OceanGenerated waves 100 ftKilled an estimated people.
18 Undersea thrust fault Upward wave Bangladesh India Burma Thailand Earthquake in seafloor swiftly pushes water upwards, and starts a series of wavesWaves move rapidly in deep ocean reaching speeds of up to 890 kilometers per hour.As the waves near land they slow to about 45 kilometers per hour but are squeezed upwards and increased in height.Waves head inland causing damage in their path.Undersea thrust faultUpward waveBangladeshIndiaBurmaFigure 14.11Formation of a tsunami and map of area affected by a large tsunami in December 2004.ThailandMalaysiaSri LankaEarthquakeIndonesiaSumatraDecember 26, 2004, tsunamiFig , p. 352
19 Figure 14.12In December 2004, a great earthquake with a magnitude of 9.15 on the seafloor of the Pacific Ocean created a large tsunami that killed 168,000 people in Indonesia. These photos show the Banda Aceh Shore near Gleebruk in Indonesia on June 23, 2004 before the tsunami (left) and on December 28, 2004 after it was stuck by the tsunami (right) (Concept 14-1B).Fig a, p. 352
20 Back to Contents Figure 14.12 In December 2004, a great earthquake with a magnitude of 9.15 on the seafloor of the Pacific Ocean created a large tsunami that killed 168,000 people in Indonesia. These photos show the Banda Aceh Shore near Gleebruk in Indonesia on June 23, 2004 before the tsunami (left) and on December 28, 2004 after it was stuck by the tsunami (right) (Concept 14-1B).Back to ContentsFig b, p. 352
21 3a. Define mineral, rock, sedimentary rock, igneous rock, and metamorphic rock and give and example of each.A mineral is an element or inorganic compound that occurs naturally in the earth’s crust as a solid with a regular crystalline structure.A rock is a solid combination of one or more minerals found in the earth’s crust.Sedimentary rocks are made of sediments—dead plant and animal remains and weathered rocks.Examples: Sandstone and shale (from sand), dolomite and limestone (from compacted shells, skeletons, and other remains of dead organisms, lignite and bituminous coal (derived from plant material)Igneous rocks form below the earth’s surface when magma wells up from the earth’s upper mantle or deep crust and then cools and hardens.Examples: Granite (formed underground) and lava (for above ground)Metamorphic rocks form when a preexisting rock is subjected to high temperatures and/or pressures, and/or chemically active fluids causing a change in the crystalline structure, physical properties and appearance.Examples: anthracite (from coal), slate (from shale or mudstone) and marble (from limestone).Back to Contents
22 3b. Describe the nature and importance of the rock cycle. Physical and chemical processes that change rocks from one form to another; recycle earth’s three types of rocks over millions of years.Concentrates the planet’s nonrenewable mineral resources on which our life processes and economies depend.
23 Back to Contents Figure 14.13 Natural capital: the rock cycle is the slowest of the earth’s cyclic processes. Rocks are recycled over millions of years by three processes: erosion, melting, and metamorphism, which produce sedimentary, igneous, and metamorphic rocks. Rock from any of these classes can be converted to rock of either of the other two classes, or can be recycled within its own class (Concept 14-2). Question: What are three ways in which the rock cycle benefits your lifestyle?Back to ContentsFig , p. 354
24 4a. Define mineral resource and list three types of such resources. Mineral resource is a concentration of naturally occurring material from the earth’s crust that can be extracted and processed into useful products and raw materials at an affordable cost.Three types:Fossil fuels (such as coal)Metallic minerals (e.g., Al, Fe, Cu)Nonmetallic minerals (e.g., sand, gravel, limestone)Back to Contents
25 4b. Define ore and distinguish between high-grade and low-grade ore. Ore is rock that contains a large enough concentration of a particular mineral—often a metal—to make it profitable for mining and processing.High-grade ore contains fairly large amounts of the desired nonrenewable mineral resource.Low-grade ore contains a lesser concentration of the desired mineral resource.More costly both financially and environmentally to mine.Back to Contents
26 4c. What are reserves?A reserve is an identified resource from which a mineral can be extracted profitably at current prices.Change asReserves are usedNew reserves are foundNew technology makes it profitable to tap mineral deposits previously too expensive to mine.Back to Contents
27 4d. Describe the life cycle of a metal resource. Surface miningMetal oreSeparation of ore from gangueSmeltingMelting metalConversion to productDiscarding of productRecyclingBack to ContentsFig , p. 355
28 4e. Describe the major harmful effects of extracting, processing, and using nonrenewable resources. Takes tremendous amounts of energy and disturbs land, erodes soil, produces solid waste, and pollutes the air, water and soil.Are there benefits for such activities? (See p. 355, right column, first paragraph.)
29 NATURAL CAPITAL DEGRADATION Extracting, Processing, and Using Nonrenewable Mineral and Energy ResourcesStepsEnvironmental EffectsMiningDisturbed land; mining accidents; health hazards; mine waste dumping; oil spills and blowouts; noise; ugliness; heatExploration, extractionProcessingSolid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heatTransportation, purification, manufacturingFigure 14.15Some harmful environmental effects of extracting, processing, and using nonrenewable mineral and energy resources (Concept 14-3B). Providing the energy required to carry out each step causes additional pollution and environmental degradation. Question: What are three mineral resources that you used today? Which of these harmful environmental effects might have resulted from obtaining and using these resources?UseNoise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heatTransportation or transmission to individual user, eventual use, and discardingBack to ContentsFig , p. 356
30 5a. Distinguish between surface mining and subsurface mining. Depends on mineral deposits. Are they shallow or deep underground?Back to Contents
31 5b. Define overburden, spoils, and open-pit mining. Overburden is the soil and rock overlying useful mineral deposits.Spoils – discarded overburden.When deposits are dredged from streams, the unused materials or tailings are usually left on land.Open-pit mining is a type of surface mining in which machines dig holes and remove ores.
32 Back to Contents Figure 14.16 Natural capital degradation: This open-pit mine, located near the city of Kalgoolie in the outback of western Australia, is the world’s largest gold mine. Question: Should governments require mining companies to fill in and restore such sites once their ore is depleted? Explain.Back to ContentsFig , p. 356
33 Area strip mining used where topography is fairly flat. 5c. Define strip mining and distinguish among area strip mining, contour strip mining, and mountaintop removal.Strip mining is a type of surface mining in which bulldozers, power shovels, or stripping wheels remove large chunks of the earth’s surface in strips; useful and economical when deposits lie close to surface in large horizontal beds.Area strip mining used where topography is fairly flat.Contour strip mining used mostly to mine on hilly or mountainous terrain.Mountaintop removal
34 Figure 14.17Natural capital degradation: contour strip mining of coal used in hilly or mountainous terrain.Fig , p. 357
35 Back to Contents Figure 14.19 Natural capital degradation: mountaintop coal mining operation in the U.S. state of West Virginia. The large amount of resulting debris is deposited in the valleys and streams below. Mountaintop removal for coal is also occurring in the U.S. states of Virginia, Tennessee, Kentucky, and Pennsylvania. See other mining sites at Question: Are you for or against mountaintop coal mining? Explain.Back to ContentsFig , p. 358
36 5d. Describe the harmful environmental effects of mining. Long-term harm to environmentScarring and disruption of land surfaceSpoil banksSpoils and tailing susceptible to chemical weathering and erosion by water and wind.Re-growth of vegetation is slow because not topsoilMountaintop removalWaste rock and dirt pushed into valleys, destroying forests, burying streams, and increasing flood hazards.Toxic wastewater from coal processing, stored in valleys behind coal waster sludge dams; contain toxic selenium, arsenic, and mercury.EPA: 1200 mi or rivers and streams buried in Appalachia470 of largest mountain have disappeared.In 2007, U.S. DOI allowed this mining to continue w/ expanded easier dumping into streams.Hydraulic mining for AU in tropical forest and other tropical areasSubsurface mining: health and life hazards, subsidenceLost of solid wasteMajor pollution of water and airE.g., acid mine drainage (caused by aerobic bacteria act on iron sulfide producing H2SO4) to nearby streams.
37 Figure 14.18Natural capital degradation: banks of waste or spoils created by area strip mining of coal on an unrestored, mostly flat area near Mulla, Colorado (USA). Government laws require at least partial restoration of newly strip-mined areas in the United States. Nevertheless, many previously mined sites have not been restored and restoration is not possible in some arid areas. Question: Should the government require mining companies to restore such sites as fully as possible? Explain.Fig , p. 357
38 Back to Contents Figure 14.20 Illegal gold mine in the Brazilian Amazon. Such mines degrade terrestrial biodiversity when numerous areas of tropical rain forest are cleared for mining sites.Back to ContentsFig , p. 358
39 5e. What is smelting and what are its major harmful environmental effects? Smelting is the use of heat and/or chemical solvents to extract metals from ores.Harmful environmental effectsProcess emits huge amounts of pollutants including SO2, which damages vegetation and acidifies the soil.Water pollution and liquid and solid and solid hazardous wastes that need safe (or is it safer?) disposal.
40 Back to Contents Figure 14.22 Natural capital degradation: the Summitville gold mining site near Alamosa, Colorado (USA), became a toxic waste site after the Canadian company that owned it declared bankruptcy and abandoned it rather than cleaning up the acids and toxic metals that leaked from this site into the nearby Alamosa River. Cleanup by the EPA will cost U.S. taxpayers about $120 million.Back to ContentsFig , p. 360
41 Mineral deposits are not distributed evenly. 5f. What five nations supply most of the world’s nonrenewable mineral resourcesMineral deposits are not distributed evenly.Some minerals are particularly scarce:Examples: Mn, Cr, Co, and PtFive countries that supply the most nonrenewable mineral resources used by modern societies:U.S.A., Canada, Russia, South Africa, and AustraliaBack to Contents
42 5g. How dependent is the United States on other countries for important nonrenewable mineral resources?Has been a sharp rise in the total per capita use of nonrenewable mineral resources in the United States.Depleted once rich deposits including Pb, Al, and Fe.Depends on imports of 50% or more of 24 of its most important nonrenewable minerals.Experts concerned over four strategic metal resources—Mn, Co, Cr, and Pt—essential for economic and military strength.Back to Contents
43 6a. Describe the advantages and disadvantages of the nanotechnology revolution. R&D possibilities, limitless; manufacturing with little environmental harm w/o depleting nonrenewable resources, and w/ many potential environmental benefits.Mining and processing of most mineral resources could become obsolete businesses eliminating the harmful effects of mining and processing mineral resources.As with any technology, unintended consequences.Potential health effect of nanoparticles; small particles, more toxic and more reactive.Loss of businesses and jobs causing severe social and economic stress as entire industries disappear.Back to Contents
44 6b. What are five possible solutions when a mineral becomes economically depleted? Two factors determine future supply of a mineral: actual potential supply and the rate at which we use it.When a mineral become economically depleted—What does this mean?—there are five solutions:Recycle or reuse existing suppliesWaste lessUse lessFind a substituteDo withoutBack to Contents
45 6c. Define depletion time and describe three types of depletion curves for a mineral resource. Depletion time it the time it takes to use up a certain proportion—usually 80%—of the reserves of a mineral at a given rate of use.Depletion curves are used to estimate the depletion time. Three types depend different sets of assumptions (Figure 14-23).
46 Back to Contents Figure 14.23 Natural capital depletion: depletion curves for a nonrenewable resource (such as aluminum or copper) using three sets of assumptions. Dashed vertical lines represent times when 80% depletion occurs.Back to ContentsFig , p. 361
47 6d. Describe the conventional view of the relationship between the supply of a mineral resource and its market price.Standard economic theoryIn a competitive market, a plentiful mineral resource is cheap when supply exceeds demand.When the resource become scarce, prices go up. Encourages:Exploration for new depositsDevelopment of better mining technologiesMining of lower-grade ore, as this become more profitable.Search for substitutesResource conservationIn developed countries, such price effect may no longer apply. Why?Back to Contents
48 6e. What factors can influence the market interaction between mineral resource supply and market price.Subsidies, taxes, regulations and import tariffs are used to control supplies, demands, and prices.Government subsidies keep mineral prices artificially low which can promote development of domestic mineral resources to help economic growth national security.However, Such subsidies are hidden cost to taxpayers that promote environmental degradation, due to extraction and processing, and waste.If these hidden cost were included in the market prices, this would encourage recycling and reusing and the search for substitutes. Would also reduce pollution.The mining industry insists that they need taxpayer subsidies and low taxes to keep prices of minerals low for consumers.Back to Contents
49 6f. Describe the benefits and possible drawbacks of nanotechnology. See answer to 6a.Back to Contents
50 6g. Discuss the pros and cons of the U.S. General Mining Law of 1872. Under this law, a person or corporation could:File a claim or assume legal ownership of pieces of U.S. public lands, except national parks and wilderness.$500 for a claim plus $120 per year to maintain claim.Buy for $6-12 per hectare ($ per acre)Encouraged mineral exploration and hard rock mineral mining.ConsProvides very little accountability for mining co’s for cleanup and restoration of mined areas.Some companies have purchased land worth millions of dollars for a few hundred dollars. A “license to steal” from U.S. citizensBack to Contents
51 7a. Describe the opportunities and limitations of increasing mineral supplies by mining lower-grade ores.OpportunitiesLimitationsNew earth-moving equipment, techniques for removing impurities, and other technologies in extraction and processing.Lower grade ores are currently being usedExample: in 1900 copper ore was 5% by weight, now it is 0.5%.Increased cost of mining and processingLimited freshwater needed to mine and process, esp. in arid areasEnvironmental impact of increased land disruption, waster material, and pollutionBack to Contents
52 7b. What are the advantages and disadvantages of biomining? Microbes can extract a desired metal from ore while leaving the surrounding environment undisturbed.Reduces air pollution from smeltingReduces water pollution, e.g. from cyanide heap leaching for AuProcess is slow and currently only feasible for low-grade ores in which conventional techniques are too expensive.Back to Contents
53 8a. Describe the opportunities and limitations of getting more minerals from the ocean. In seawater: Mg, Br, and NaClIn sediments of continental shelf and near shore: sand, gravel, phosphates, S, Sn, Cu, Fe, W, Ag, Ti, Pt, and diamondsNear hydrothermal vents: when magma solidifies particles of metal compounds precipitate out including sulfides, Ag, Zn, and Cu.Manganese nodules of the Pacific Ocean floor.Cost for mining some mineral may be too expensive, specially those of low concentration in sea waterWho owns these minerals in open oceanEffects of mining on ocean floor ecosystem/food websBack to Contents
54 9a. Describe the opportunities and limitations of finding substitutes for scarce mineral resources and recycling and reusing valuable metals.OpportunitiesLimitationsCeramics and plastics being used as replacements for metals.Nanotechnology may lead to development of substitutes.Grancrete: Styrofoam and ceramic.Plastic for pipesPlastic and composite materials for automobile and aerospace industryPlastic and gels for superinsulationPlastics from plant materialsPlastics require the use of fossil fuels, which are nonrenewable and have their own environmental impacts.Substitutes for scare materials may not always be possible: e.g., Pt as an industrial catalyst and Cr in stainless steel.Back to Contents
55 9b. Describe ways of using nonrenewable mineral resources more sustainably. Recycle and reuseBesides being sustainable practices for mineral use, has much lower environmental impact.Example: Recycling Al produces 95% less air pollution, 97% less water pollution, and uses 95% less energy than mining and processing Al ore.
56 Back to Contents Figure 14.24 Ways to achieve more sustainable use of nonrenewable mineral resources (Concept 14-5). Question: Which two of these solutions do you think are the most important? Why?Back to ContentsFig , p. 366
57 9c. Describe the Pollution Prevention Pays program of the Minnesota Mining and Manufacturing Company.In answer the question, how can we reduce use and waste, 3M developed the 3P program.Redesigned equipment and processesUsed fewer hazardous raw materialsIdentified toxic chemical outputs and recycled or sold them as raw materials to other companiesBegan making more nonpolluting productsBy 1998, waste production was down by 1/3, air pollution per unit of production was down 70%, and 3M saved $750 million in waste disposal and material costs.Back to Contents
58 9d. What is an industrial ecosystem? Making industrial manufacturing cleaner and more sustainable by redesigning them to mimic how nature deals with wastes.Might include recycling and reusing most minerals and chemicals instead of dumping them into the environment.Resource exchange webs – waste of one manufacturer become the raw materials of another, similar to a food web in nature.Back to Contents
59 9e. Describe the industrial ecosystem operating in Kalundborg, Denmark. Collaboration between an electric power plant and nearby industries, farms, and homes to save money and reduce outputs of waste and pollution.Reduces the flow of nonrenewable mineral and energy resources through their economy.
60 Back to Contents Figure 14.25 Solutions: an industrial ecosystem in Kalundborg, Denmark, reduces waste production by mimicking a food web in natural ecosystems. The wastes of one business become the raw materials for another. Question: Is there an industrial ecosystem near where you live or go to school? If not, think about where and how such a system could be set up.Back to ContentsFig , p. 367
61 See p. 367, Revisiting: Gold Mining and Sustainability. 10a. Describe the relationship between gold mining and the four scientific principles of sustainability.See p. 367, Revisiting: Gold Mining and Sustainability.Back to Contents