FSU GEO1330 Environmental Science Final Exam Guide Chapter 9 Geology and mining Lithosphere and Mantel Smelting minerals o Geology the study of Earth s physical features processes and history o Core solid iron in the center Molten iron in the outer core o Mantle less dense elastic rock Asthenosphere semi fluid o Lithosphere harder rock that contains the mantle and crust o Crust the thin brittle low density layer of rock o Plate tectonics movement of lithospheric plates Pangaea all landmass joined into one supercontinent 225 million years ago o Different types of plate boundaries Divergent rising magma pushes plates apart Transform two plates meet slipping and grinding Fault a fracture in the crust Convergent plates collide Subduction one plate slides beneath another Himalaya and Appalachian Mountains o Rock cycle the heating melting cooling breaking and reassembling of rocks and Magma molten liquid rock Lava magma released by a volcano Igneous rock formed when magma cools Sediments rock particles formed by physical erosion or chemically from precipitation of substances Sedimentary rock formed as sediments are pressed together and bound by dissolved materials Metamorphic rock rock deep underground is subjected togreat heat or pressure changing its form o Geologic and natural hazards Circum Pacific belt the ring of fire An arc of subduction zones and fault systems Earthquake a release of pressure along plate boundaries and faults Volcano molten rock hot gas or ash erupts through Earth s surface Pyroclastic flow fast moving cloud of gas ash and rock Landslide severe sudden mass wasting Mass wasting the downslope movement of soil and rock due to gravity Mudslides soil rock and water movement caused by saturated soil from heavy rains Lahars extremely dangerous mudslides Surface mining surface Tsunamis huge volumes of water are displaced by earthquakes volcanoes landslides o Mining extraction of any nonrenewable resource o Metal an element that is lustrous opaque and malleable and can conduct heat and o Ore a mineral or grouping of minerals from which we extract metals o Alloy metal mixed melted or fused with another metal or nonmetal substance o Smelting heating ore beyond its melting point then combining it with other metals or electricity chemicals Modifies strength malleability etc o Processing minerals has environmental costs Most methods are water and energy intensive Chemical reactions and heating to extract metals from ores emit air pollution and toxic wastes o Tailings ore left over after metals have been extracted Pollute soil and water Contain heavy metals or chemicals o Surface impoundments store slurries of tailings o Strip mining removal of layers of soil and rock to expose the resource just below the Overburden soil and rock that is removed by heavy machinery Destroys natural communities over large areas and triggers erosion After extraction each strip is refilled with the overburden o Subsurface mining underground work Dynamite blasts collapsed tunnels sinkholes toxic fumes and coal dust o Open pit mining creates immense holes Used with evenly distributed minerals Terraced so men and machines can move about Huge amounts of rock are removed to get small amounts of minerals Habitat loss aesthetic degradation acid drainage Abandoned pits fill with water Acid drainage forms if sulfur is present o Placer mining uses running water Using running water miners shift through material in riverbeds Used for gold gems Debris washes into streams They become uninhabitable for wildlife Disturbs stream banks Causes erosion Harms plant communities o Solution mining dissolves resources Solution mining resources in a deep deposit are dissolved in a liquid and sucked out Water acid or other liquids are injected into holes Used for salt lithium boron bromine magnesium potash copper uranium Less environmental impact than other methods Less surface area is distributed Acids heavy metals uranium can accidentally leak or leach out of rocks and contaminate groundwater o Ocean mining We extract minerals magnesium from seawater Minerals are dredged from the ocean floor Manganese nodules small ball shaped ores scattered across the ocean floor These reserves may exceed all terrestrial reserves Logistical difficulties in mining have kept extractions limited so far o Restoring mined sites only partly works Governments in developed countries require companies to reclaim surface mined sites Reclamation aims to bring a site to a condition similar to its pre mining condition Remove structures replace overburden replant vegetation The U S Surface Mining Control and Reclamation Act 1977 mandates restoration Companies must post bonds to cover restoration costs Mountain removal o Mountaintop removal reshapes ridges Entire mountaintops are blasted off Valley filling dumping rock and debris into valleys For coal in the Appalachian Mountains Degrades and destroys vast areas Pollutes streams deforests areas causes erosion mudslides flash floods biodiversity loss o Mountaintop removal is devastating Mine blasting cracks foundations and walls Floods and rock slides affect properties Coal dust and contaminated water cause illness Lung cancer heart and kidney disease pulmonary disorders hypertension death The poor people of Appalachia suffer while we benefit from coal produced electricity Critics argue that valley filling violates the Clean Water Act In 2010 the EPA introduced rules to limit damage The U S General Mining Act of 1872 o Encourages metal and mineral mining on federal land Any citizen or company can stake a claim on or buy for 5 per acre any public land open to mining The public gets no payment for any minerals found o Supporters say it encourages a domestic industry that is risky and requires investment to locate vital resources o Critics say it give valuable public land basically free to private interests o Efforts to amend that act have failed in Congress Acid drainage o Sulfide in newly exposed rock reacts with oxygen and rainwater Produces sulfuric acid Sulfuric acid leaches toxic materials from rock Flows into streams killing fish and other organisms Pollutes groundwater used for drinking and irrigation Chapter 10 water crisis and air pollution Upwelling and downwelling o Currents vast riverlike flows in the upper 1 300 feet Driven by wind heating cooling gravity density differences and the Coriolis effect o Upwelling the rising of cold deep water to the surface Rick in nutrients High primary