Presentation on theme: "Chapter 15 Geology and Nonrenewable Mineral Resources."— Presentation transcript:
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 do 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 to access InfoTrac articles. InfoTrac: Residents discuss towns' deaths. Daily Oklahoman (Oklahoma City, OK) August 2, 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: Little environmental harm: Does not use renewable resources.Does not use renewable resources. Potential biological concerns. Potential biological concerns. Can move through cell membranes: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. 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. Mantle: solid rock with a rigid outer part (asthenosphere) that is melted pliable rock. Crust: Outermost zone which underlies the continents. Crust: Outermost zone which underlies the continents.
GEOLOGIC PROCESSES Major features of the earth’s crust and upper mantle. Figure 15-2
Fig. 15-3, p. 337 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 Collision between two continents Tectonic plate Oceanic tectonic plate Oceanic crust
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. Tectonic plates: huge rigid plates that are moved with convection cells or currents by floating on magma or molten rock.
The Earth’s Major Tectonic Plates Figure 15-4
The Earth’s Major Tectonic Plates The extremely slow movements of these plates cause them to grind into one another at convergent plate boundaries, move apart at divergent plate boundaries and slide past at transform plate boundaries. Figure 15-4
Fig. 15-4, p. 338
Fig. 15-4a, p. 338 EURASIAN PLATE NORTH AMERICAN PLATE ANATOLIAN PLATE JUAN DE FUCA PLATE CHINA SUBPLATE CARIBBEAN PLATE PHILIPPINE PLATE ARABIAN PLATE AFRICAN PLATE PACIFIC PLATE SOUTH AMERICAN PLATE NAZCA PLATE INDIA- AUSTRALIAN PLATE SOMALIAN SUBPLATE ANTARCTIC PLATE Divergent plate boundaries Convergent plate boundaries Transform faults
Fig. 15-4b, p. 338 TrenchVolcanic island arcCraton Transform fault Lithosphere Subduction zone Lithosphere Asthenosphere Divergent plate boundariesConvergent plate boundariesTransform faults Rising magma
GEOLOGIC PROCESSES The San Andreas Fault is an example of a transform fault. Figure 15-5
Wearing Down and Building Up the Earth’s Surface Weathering is an external process that wears the earth’s surface down. Figure 15-6
Fig. 15-6, p. 340 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
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 of naturally occurring material in or on the earth’s crust that can be extracted and processed into useful materials at an affordable cost. Mineral resource: is a concentration of naturally occurring material in or on the earth’s crust that can be extracted 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. Identified: known location, quantity, and quality or existence known based on direct evidence and measurements. Undiscovered: potential supplies that are assumed to exist. Undiscovered: potential supplies that are assumed to exist. Reserves: identified resources that can be extracted profitably. Reserves: identified resources that can be extracted profitably. Other: undiscovered or identified resources not classified as reserves 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
Fig. 15-7, p. 341 UndiscoveredIdentified Reserves Economical Other resources Decreasing cost of extraction Not economical Decreasing certaintyKnown Existence
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). Sedimentary rock (sandstone, limestone). Metamorphic rock (slate, marble, quartzite). Metamorphic rock (slate, marble, quartzite). Igneous rock (granite, pumice, basalt). Igneous rock (granite, pumice, basalt).
Rock Cycle Figure 15-8
Fig. 15-8, p. 343 Erosion Transportation Weathering Deposition Igneous rock Granite, pumice, basalt Sedimentary rock Sandstone, limestone Heat, pressure Cooling Heat, pressure, stress Magma (molten rock) Melting Metamorphic rock Slate, marble, gneiss, quartzite
ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCES The extraction, processing, and use of mineral resources has a large environmental impact. Figure 15-9
Fig. 15-9, p. 344 Surface mining Metal oreSeparation of ore from gangue SmeltingMelting metal Conversion to product Discarding of product (scattered in environment) Recycling
Fig , p. 344 Natural 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 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
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 harm. A variety of methods are used based on mineral depth. Surface mining: shallow deposits are removed. Surface mining: shallow deposits are removed. Subsurface mining: deep 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 erodible hills of rubble called spoil banks. Figure 15-12
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
Fig , p. 346 Undisturbed land Overburden Highwall Coal seam Overburden Pit Bench Coal seam Spoil banks
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. Dashed vertical lines represent times when 80% depletion occurs. Figure 15-16
Fig , p. 348 AMine, use, throw away; no new discoveries; rising prices Recycle; increase reserves by improved mining technology, higher prices, and new discoveries B Production Recycle, reuse, reduce consumption; increase reserves by improved mining technology, higher prices, and new discoveries C PresentDepletion time A Depletion time B Depletion time C Time
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
Fig , p. 350 Black smoker White smoker Sulfide deposits Magma White clam White crab Tube worms
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.
Fig , p. 351 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.
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. 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
Fig , p. 352 Sludge Pharmaceutical plant Local farmers Sludge Greenhouses Waste heat Fish farming Oil refinery Surplus natural gas Electric power plant Fly ash Surplus sulfur Surplus natural gas Waste calcium sulfate Waste heat Cement manufacturer Sulfuric acid producer Wallboard factory Area homes