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Explore the dynamic processes that shape the Earth's surface and the environmental effects of extracting and using nonrenewable mineral resources.
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13e ENVIRONMENTALSCIENCE CHAPTER 12:Geology and Nonrenewable Mineral
Core Case Study: The Real Cost of Gold • Two wedding rings = 6 tons of mining waste • Gold mining pollutes air and water • Toxic cyanide used to mine gold • Gold mining harms wildlife
12-1 What Are the Earth’s Major Geological Processes and Hazards? • Concept 12-1 Dynamic processes move matter within the earth and on its surface and can cause volcanic eruptions, tsunamis, and earthquakes.
The Earth Is a Dynamic Planet • What is geology? • Earth’s internal structure • Core • Mantle • Asthenosphere • Crust • Lithosphere
Plate Tectonics • Tectonic plates • Divergent plate boundaries • Convergent boundaries • Transform fault boundaries
Folded mountain belt Volcanoes Oceanic ridge Trench Abyssal floor Abyssal floor Craton Abyssal hills Abyssal plain Oceanic crust (lithosphere) Abyssal plain Continental shelf Continental slope Continental rise Continental crust (lithosphere) Mantle (lithosphere) Mantle (lithosphere) Mantle (asthenosphere) Fig. 12-2, p. 275
Spreading center Ocean trench Oceanic tectonic plate Oceanic tectonic plate Collision between two continents Plate movement Plate movement Subduction zone Tectonic plate Oceanic crust Oceanic crust Continental crust Continental crust Cold dense material falls back through mantle Material cools as it reaches the outer mantle Hot material rising through the mantle Mantle convection cell Mantle Two plates move towards each other. One is subducted back into the mantle on a falling convection current. Hot outer core Inner core Fig. 12-3, p. 275
EURASIAN PLATE NORTH AMERICAN PLATE ANATOLIAN PLATE CHINA SUBPLATE JUAN DE FUCA PLATE CARIBBEAN PLATE PHILIPPINE PLATE AFRICAN PLATE ARABIAN PLATE PACIFIC PLATE SOUTH AMERICAN PLATE NAZCA PLATE INDIA-AUSTRALIAN PLATE SOMALIAN SUBPLATE ANTARCTIC PLATE Divergent plate boundaries Convergent plate boundaries Transform faults Fig. 12-4, p. 276
Volcanoes • Magma • Lava • Eruptions • Lava rock • Hot ash • Liquid lava • Gases
Extinct volcanoes Eruption cloud Ash Acid rain Ash flow Lava flow Mud flow Central vent Landslide Magma conduit Magma reservoir Solid lithosphere Upwelling magma Partially molten asthenosphere Fig. 12-6, p. 277
Earthquakes • Stressed rocks shift or break • Seismic waves • Seismographs • Richter scale to measure amplitude • Tsunami
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 Focus Epicenter Fig. 12-7, p. 278
Waves head inland causing damage in their path. 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. Undersea thrust fault Upward wave Bangladesh India Burma Thailand Malaysia Sri Lanka Earthquake Sumatra Indonesia December 26, 2004, tsunami Fig. 12-10, p. 280
12-2 How Are Earth’s Rocks Recycled? • Concept 12-2 The three major types of rock found in the earth’s crust are recycled very slowly by physical and chemical processes.
Rocks and Minerals • Minerals • Rock • Igneous • Sedimentary • Metamorphic • Rock cycle
Sedimentary Rocks • Sediments • Tiny particles of eroded rocks • Dead plant and animal remains • Transported by water, wind, or gravity • Pressure converts into rock • Sandstone • Shale • Coal – some types
Igneous Rocks • Forms from magma • Can cool beneath earth’s surface • Granite • Can cool above earth’s surface • Lava rocks • Most of earth’s crust
Metamorphic Rocks • From preexisting rocks • Pressure • Heat • Chemically active fluids • Slate from shale • Marble from limestone
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 Fig. 12-12, p. 282
12-3 What Are Mineral Resources and What Are the Environmental Effects of Using Them? • Concept 12-3 Some minerals in the earth’s crust can be made into useful products, but extracting and using these resources can disturb the land, erode soils, produce large amounts of solid waste, and pollute the air, water, and soil.
Nonrenewable Mineral Resources (1) • Minerals • Mineral resources • Fossil fuels • Metallic • Nonmetallic • Reserves
Nonrenewable Mineral Resources (2) • Ore • High-grade ore • Low-grade ore • Examples of mineral resources • Aluminum • Iron – used for steel • Copper • Gold • Sand and gravel
Smelting Surface mining Melting metal Metal ore Separation of ore from gangue Conversion to product Discarding of product Recycling Fig. 12-13, p. 283
Conversion to product Surface mining Melting metal Metal ore Separation of ore from gangue Discarding of product Smelting Recycling Stepped Art Fig. 12-13, p. 283
Extracting Mineral Deposits (1) • Surface mining • Overburden • Spoils • Open-pit mining
Extracting Mineral Deposits (2) • Strip mining • Area strip mining • Contour strip mining • Mountaintop removal • Subsurface mining
Undisturbed land Overburden Highwall Coal seam Overburden Pit Bench Coal seam Spoil banks Fig. 12-16, p. 285
Harmful Environmental Effects of Mining • Disruption of land surface • Damage to forests and watersheds • Biodiversity harmed • Subsidence • Toxic-laced mining wastes • Acid mine drainage
Harmful Environmental Effects of Removing Metals from Ores • Ore mineral – desired metal • Gangue – waste material • Smelting • Air pollution • Water pollution • Acidified nearby soils • Liquid and solid hazardous wastes
12-4 How Long Will Supplies of Nonrenewable Mineral Resources Last? • Concept 12-4 Raising the price of a scarce mineral resource can lead to an increase in its supply, but there are environmental limits to this effect.
Uneven Distribution of Mineral Resources • Abundant minerals • Scarce minerals • Exporters and importers • Strategic metal resources • Economic and military strength • U.S. dependency on importing four critical minerals
Supplies of Mineral Resources • Available supply and use • Economic depletion • Five choices after depletion • Recycle or reuse • Waste less • Use less • Find a substitute • Do without