Geology and nonrenewable mineral resources

Chapter 15 Geology and Nonrenewable Mineral Resources Chapter Overview Questions  What major geologic processes occur within the earth and on its surface?  What are nonrenewable mineral resources and where are they found?  What are rocks, and how are they recycled by the rock cycle?  How we find and extract mineral resources from the earth’s crust, and what harmful environmental effects result from removing and using these minerals? Chapter Overview Questions (cont’d)  Will there be enough nonrenewable mineral resources for future generations?  Can we find substitutes for scarce nonrenewable mineral resources?  How can we shift to more sustainable use of nonrenewable mineral resources? Updates Online The latest references for topics covered in this section can be found at the book companion website Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles       InfoTrac: Residents discuss towns' deaths Daily Oklahoman (Oklahoma City, OK) August 2, 2006 InfoTrac: All that glitters: the demand for gold is soaring Jane Perlez, Kirk Johnson New York Times, May 8, 2006 v138 i14 p12(6) InfoTrac: In Old Mining Town, New Charges Over Asbestos Kirk Johnson The New York Times, April 22, 2006 pA1(L) Science Daily: Putting Coal Ash Back Into Mines A Viable Option For Disposal, But Risks Must Be Addressed National Park Service: Mining Operations Management Arizona Mining Association: From the Ground Up: Mining/Mineral Resource Development Core Case Study: The Nanotechnology Revolution  Nanotechnology uses science and engineering to create materials out of atoms and molecules at the scale of less than 100 nanometers  Little environmental harm: • Does not use renewable resources  Potential biological concerns • Can move through cell membranes: Figure 15-1 GEOLOGIC PROCESSES  The earth is made up of a core, mantle, and crust and is constantly changing as a result of processes taking place on and below its surface  The earth’s interior consists of:    Core: innermost zone with solid inner core and molten outer core that is extremely hot Mantle: solid rock with a rigid outer part (asthenosphere) that is melted pliable rock Crust: Outermost zone which underlies the continents GEOLOGIC PROCESSES  Major features of the earth’s crust and upper mantle Figure 15-2 Volcanoes Abyssal floor Trench Abyssal plain Craton lp lai n Abyssal hills Abyssal Oceanic floor ridge Folded mountain belt Ab ys sa Oceanic crust (lithosphere) Mantle (li thospher e) Continental shelf Continental slope Continental rise Continental crust (lithosphere) Mantle (lithosphere) Mantle (asthen o sphere) Fig 15-2, p 336 Te c pl toni at c e Collision between two continents to c tec i n a Oce plate nic Spreading Oceanic tecto nic center plate ement v o m Plate Subduction zone Continental crust Oceanic crust Plate mov em Ocean trench ent Oceanic crust Continental crust Material cools Cold dense as it reaches material falls the outer back through mantle mantle Hot Mantle material convection rising cell through the mantle Two plates move towards each other One is subducted back into the mantle on a falling convection current Mantle Hot outer core Inner core Fig 15-3, p 337 GEOLOGIC PROCESSES  Huge volumes of heated and molten rack moving around the earth’s interior form massive solid plates that move extremely slowly across the earth’s surface  Tectonic plates: huge rigid plates that are moved with convection cells or currents by floating on magma or molten rock Contour Strip Mining  Used on hilly or mountainous terrain  Unless the land is restored, a wall of dirt is left in front of a highly erodible bank called a highwall Figure 15-13 Undisturbed land Overburden Hig Pit hw a ll Coa l se am Ov e rb urd en Bench Co al s eam Spoil banks Fig 15-13, p 346 Mountaintop Removal  Machinery removes the tops of mountains to expose coal  The resulting waste rock and dirt are dumped into the streams and valleys below Figure 15-14 Mining Impacts  Metal ores are smelted or treated with (potentially toxic) chemicals to extract the desired metal Figure 15-15 SUPPLIES OF MINERAL RESOURCES  The future supply of a resource depends on its affordable supply and how rapidly that supply is used  A rising price for a scarce mineral resource can increase supplies and encourage more efficient use SUPPLIES OF MINERAL RESOURCES  Depletion curves for a renewable resource using three sets of assumptions  Dashed vertical lines represent times when 80% depletion occurs Figure 15-16 Production A Mine, use, throw away; no new discoveries; rising prices Recycle; increase reserves by improved mining technology, higher prices, and new discoveries B Recycle, reuse, reduce consumption; increase reserves by improved mining technology, higher prices, and new discoveries C Present Depletion Depletion Depletion time A time B time C Time Fig 15-16, p 348 SUPPLIES OF MINERAL RESOURCES  New technologies can increase the mining of low-grade ores at affordable prices, but harmful environmental effects can limit this approach  Most minerals in seawater and on the deep ocean floor cost too much to extract, and there are squabbles over who owns them Getting More Minerals from the Ocean  Hydrothermal deposits form when mineral-rich superheated water shoots out of vents in solidified magma on the ocean floor Figure 15-17 Black smoker White smoker Sulfide deposits Magma White crab White clam Tube worms Fig 15-17, p 350 USING MINERAL RESOURCES MORE SUSTAINABLY   Scientists and engineers are developing new types of materials as substitutes for many metals Recycling valuable and scarce metals saves money and has a lower environmental impact then mining and extracting them from their ores Solutions Sustainable Use of Nonrenewable Minerals • Do not waste mineral resources • Recycle and reuse 60–80% of mineral resources • Include the harmful environmental costs of mining and processing minerals in the prices of items (full-cost pricing) • Reduce subsidies for mining mineral resources • Increase subsidies for recycling, reuse, and finding less environmentally harmful substitutes • Redesign manufacturing processes to use less mineral resources and to produce less pollution and waste • Have the mineral-based wastes of one manufacturing process become the raw materials for other processes • Sell services instead of things • Slow population growth Fig 15-18, p 351 Case Study: The Ecoindustrial Revolution  Growing signs point to an ecoindustrial revolution taking place over the next 50 years  The goal is to redesign industrial manufacturing processes to mimic how nature deals with wastes  Industries can interact in complex resource exchange webs in which wastes from manufacturer become raw materials for another Case Study: The Ecoindustrial Revolution Figure 15-19 Sludge Pharmaceutical plant Greenhouses W as te Local farmers Sludge he at Waste heat eat h ste a W Fish farming Waste heat Fly ash Surplus Electric power Oil refinery plant Su natural gas W Surplus rp as Waste l te us sulfur calcium he na Cement manufacturer at sulfate tu lg as Sulfuric acid producer Wallboard factory Area homes Fig 15-19, p 352 [...]... Biological weathering (tree roots and lichens) Chemical weathering (water, acids, and gases) Particles of parent material Physical weathering (wind, rain, thermal expansion and contraction, water freezing) Fig 15-6, p 340 MINERALS, ROCKS, AND THE ROCK CYCLE  The earth’s crust consists of solid inorganic elements and compounds called minerals that can sometimes be used as resources  Mineral resource: is a concentration... and processed into useful materials at an affordable cost General Classification of Nonrenewable Mineral Resources  The U.S Geological Survey classifies mineral resources into four major categories:     Identified: known location, quantity, and quality or existence known based on direct evidence and measurements Undiscovered: potential supplies that are assumed to exist Reserves: identified resources. .. identified resources that can be extracted profitably Other: undiscovered or identified resources not classified as reserves General Classification of Nonrenewable Mineral Resources  Examples are fossil fuels (coal, oil), metallic minerals (copper, iron), and nonmetallic minerals (sand, gravel) Figure 15-7 Reserves Other resources Economical Identified Not economical Decreasing cost of extraction Undiscovered... Capital Degradation Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources Steps Environmental effects Mining Disturbed land; mining accidents; health hazards, mine waste dumping, oil spills and blowouts; noise; ugliness; heat Exploration, extraction Processing Use Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat Transportation... user, eventual use, and discarding Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat Transportation, purification, manufacturing Fig 15-10, p 344 ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCES  Minerals are removed through a variety of methods that vary widely in their costs, safety factors, and levels of environmental... Weathering Deposition Igneous rock Granite, pumice, basalt Sedimentar y rock Sandstone, limestone Heat, pressure Cooling Heat, pressure, stress Magma (molten rock) Melting Metamorphic rock Slate, marble, gneiss, quartzite Fig 15-8, p 343 ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCES  The extraction, processing, and use of mineral resources has a large environmental impact Figure 15-9 Surface mining Metal... variety of methods are used based on mineral depth   Surface mining: shallow deposits are removed Subsurface mining: deep deposits are removed Open-pit Mining  Machines dig holes and remove ores, sand, gravel, and stone  Toxic groundwater can accumulate at the bottom Figure 15-11 Area Strip Mining  Earth movers strips away overburden, and giant shovels removes mineral deposit  Often leaves highly... Undiscovered Decreasing certainty Existence Known Fig 15-7, p 341 GEOLOGIC PROCESSES  Deposits of nonrenewable mineral resources in the earth’s crust vary in their abundance and distribution  A very slow chemical cycle recycles three types of rock found in the earth’s crust:    Sedimentary rock (sandstone, limestone) Metamorphic rock (slate, marble, quartzite) Igneous rock (granite, pumice, basalt)... smelted or treated with (potentially toxic) chemicals to extract the desired metal Figure 15-15 SUPPLIES OF MINERAL RESOURCES  The future supply of a resource depends on its affordable supply and how rapidly that supply is used  A rising price for a scarce mineral resource can increase supplies and encourage more efficient use ... terrain  Unless the land is restored, a wall of dirt is left in front of a highly erodible bank called a highwall Figure 15-13 Undisturbed land Overburden Hig Pit hw a ll Coa l se am Ov e rb urd en Bench Co al s eam Spoil banks Fig 15-13, p 346 Mountaintop Removal  Machinery removes the tops of mountains to expose coal  The resulting waste rock and dirt are dumped into the streams and valleys below