Presentation on theme: "Chapter 14 Geology and Nonrenewable Resources Post Reading Discussion."— Presentation transcript:
Chapter 14 Geology and Nonrenewable Resources Post Reading Discussion
Contents 1a, bb6aa, b, c, d, e, f, gbcde fg 2aa, b, c, d, e, fbcdef7aa, bb 3aa, bb8a 4aa, b, c, d, ebcde9aa, b, c, d, ebc de 5aa, b, c, d, e, f, gbcdefg10a
1b. Describe the environmental effects of gold mining. Tons of mining waste – Pollutes air and nearby surface water Cyanide heap leaching – Cyanide salts used to extract gold – Extremely toxic, interferes with cell metabolism – Holding ponds of can leak or overflow contaminating groundwater and nearby lakes and streams
Fig. 14-1, p. 344 Back to Contents
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.
Fig. 14-3, p. 346 Spreading center Ocean trench Plate movement Subduction zone Oceanic crust Continental crust Material cools as it reaches the outer mantle Cold dense material falls back through mantle Hot material rising through the mantle Mantle convection cell Two plates move towards each other. One is subducted back into the mantle on a falling convection current. Mantle Hot outer core Inner core Plate movement Back to Contents
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.
Fig. 14-4, p. 347 EURASIAN PLATE NORTH AMERICAN PLATE ANATOLIAN PLATE JUAN DE FUCA PLATE CARIBBEAN PLATE PHILIPPINE PLATE CHINA SUBPLATE AFRICAN PLATE ARABIAN PLATE INDIA PLATE PACIFIC PLATE COCOS PLATE SOUTH AMERICAN PLATE NAZCA PLATE AUSTRALIAN PLATE SOMALIAN SUBPLATE SCOTIA PLATE ANTARCTIC PLATE Transform faults Divergent plate boundaries Convergent plate boundaries
Fig. 14-5, p. 348 Back to Contents
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.
Fig. 14-6, p. 348 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) Particles of parent material Back to Contents
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, CO 2 and SO 2 ) Mt. Pinatubo, Mt. St. Helens, 1980 Benefits? Created mountains, highly fertile soils.
Fig. 14-7, p. 349 Back to Contents
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 ground Can cause damage to building and infrastructure and represents a life hazard to people living in areas prone to earthquakes.
Fig. 14-8, p. 350 Liquefaction of recent sediments causes buildings to sink Two adjoining plates move laterally along the fault line Earth movements cause flooding in low-lying areas Landslides may occur on hilly ground Shock waves Epicenter Focus Back to Contents
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 shore – Largest loss occurred in December magnitude earthquake in the Indian Ocean Generated waves 100 ft Killed an estimated people.
Fig , p. 352 Earthquake in seafloor swiftly pushes water upwards, and starts a series of waves Waves 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 fault Upward wave Bangladesh India Thailand Sri Lanka Malaysia Earthquake Sumatra Indonesia December 26, 2004, tsunami Burma
Fig a, p. 352
Fig b, p. 352 Back to Contents
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
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.
Fig , p. 354 Back to Contents
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
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
4c. What are reserves? A reserve is an identified resource from which a mineral can be extracted profitably at current prices. – Change as Reserves are used New reserves are found New technology makes it profitable to tap mineral deposits previously too expensive to mine. Back to Contents
4d. Describe the life cycle of a metal resource. Back to Contents Fig , p. 355 Surface mining Metal oreSeparation of ore from gangue Smelting Melting metal Conversion to product Discarding of product Recycling
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.)
Fig , p. 356 NATURAL CAPITAL DEGRADATION Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources StepsEnvironmental Effects Mining Disturbed land; mining accidents; health hazards; mine waste dumping; oil spills and blowouts; noise; ugliness; heat Exploration, extraction Processing Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat Transportation, purification, manufacturing Use Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat Transportation or transmission to individual user, eventual use, and discarding Back to Contents
5a. Distinguish between surface mining and subsurface mining. Depends on mineral deposits. Are they shallow or deep underground? Back to Contents
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.
Fig , p. 356 Back to Contents
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
Fig , p. 357
Fig , p. 358 Back to Contents
5d. Describe the harmful environmental effects of mining. Long-term harm to environment Scarring and disruption of land surface Spoil banks – Spoils and tailing susceptible to chemical weathering and erosion by water and wind. – Re-growth of vegetation is slow because not topsoil Mountaintop removal – Waste 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 Appalachia – 470 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 areas Subsurface mining: health and life hazards, subsidence Lost of solid waste Major pollution of water and air – E.g., acid mine drainage (caused by aerobic bacteria act on iron sulfide producing H 2 SO 4 ) to nearby streams.
Fig , p. 357
Fig , p. 358 Back to Contents
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 effects – Process emits huge amounts of pollutants including SO 2, 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.
Fig , p. 360 Back to Contents
5f. What five nations supply most of the world’s nonrenewable mineral resources Mineral deposits are not distributed evenly. Some minerals are particularly scarce: – Examples: Mn, Cr, Co, and Pt Five countries that supply the most nonrenewable mineral resources used by modern societies: – U.S.A., Canada, Russia, South Africa, and Australia Back to Contents
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
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
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 supplies – Waste less – Use less – Find a substitute – Do without Back to Contents
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).
Fig , p. 361 Back to Contents
6d. Describe the conventional view of the relationship between the supply of a mineral resource and its market price. Standard economic theory – In 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 deposits Development of better mining technologies Mining of lower-grade ore, as this become more profitable. Search for substitutes Resource conservation In developed countries, such price effect may no longer apply. Why? Back to Contents
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
6f. Describe the benefits and possible drawbacks of nanotechnology. See answer to 6a.6a Back to Contents
6g. Discuss the pros and cons of the U.S. General Mining Law of Pros Encouraged mineral exploration and hard rock mineral mining. Cons Provides 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. citizens Back to Contents 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)
7a. Describe the opportunities and limitations of increasing mineral supplies by mining lower-grade ores. Opportunities New earth-moving equipment, techniques for removing impurities, and other technologies in extraction and processing. Lower grade ores are currently being used – Example: in 1900 copper ore was 5% by weight, now it is 0.5%. Limitations Increased cost of mining and processing Limited freshwater needed to mine and process, esp. in arid areas Environmental impact of increased land disruption, waster material, and pollution Back to Contents
7b. What are the advantages and disadvantages of biomining? Advantages Microbes can extract a desired metal from ore while leaving the surrounding environment undisturbed. Reduces air pollution from smelting Reduces water pollution, e.g. from cyanide heap leaching for Au Disadvantages Process is slow and currently only feasible for low-grade ores in which conventional techniques are too expensive. Back to Contents
8a. Describe the opportunities and limitations of getting more minerals from the ocean. Opportunities In seawater: Mg, Br, and NaCl In sediments of continental shelf and near shore: sand, gravel, phosphates, S, Sn, Cu, Fe, W, Ag, Ti, Pt, and diamonds Near hydrothermal vents: when magma solidifies particles of metal compounds precipitate out including sulfides, Ag, Zn, and Cu. Manganese nodules of the Pacific Ocean floor. Limitations Cost for mining some mineral may be too expensive, specially those of low concentration in sea water Who owns these minerals in open ocean Effects of mining on ocean floor ecosystem/food webs Back to Contents
9a. Describe the opportunities and limitations of finding substitutes for scarce mineral resources and recycling and reusing valuable metals. Opportunities Ceramics and plastics being used as replacements for metals. Nanotechnology may lead to development of substitutes. Grancrete: Styrofoam and ceramic. Plastic for pipes Plastic and composite materials for automobile and aerospace industry Plastic and gels for superinsulation Plastics from plant materials Limitations Plastics 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
9b. Describe ways of using nonrenewable mineral resources more sustainably. Recycle and reuse – Besides 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.
Fig , p. 366 Back to Contents
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 processes – Used fewer hazardous raw materials – Identified toxic chemical outputs and recycled or sold them as raw materials to other companies – Began making more nonpolluting products By 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
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
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.
Fig , p. 367 Back to Contents
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