Geology and Nonrenewable Mineral Resources Chapter 14 Geology and Nonrenewable Mineral Resources

14-1 What Are the Earth’s Major Geological Processes and Hazards?

The Earth Is a Dynamic Planet Geology? Study of the dynamic processes taking place on earth’s surface and in its interior Three major concentric zones of the earth Core Mantle Including the asthenosphere Crust Continental crust Oceanic crust: 71% of crust The Earth Is a Dynamic Planet

Major Features of the Earth’s Crust and Upper Mantle Figure 14.2: The earth’s crust and upper mantle have certain major features. The lithosphere, composed of the crust and outermost mantle, is rigid and brittle. The asthenosphere, a zone in the mantle, can be deformed by heat and pressure. Fig. 14-2, p. 348

The Earth Beneath Your Feet Is Moving Convection cells, or currents move large volumes and heat in loops within the mantle Lithosphere: earth’s crust and the outermost layer of mantle Scientists believe that the flow of heat/material broke up the lithosphere into large sections called Tectonic Plates Three types of boundaries between plates Divergent boundaries Magma Oceanic ridge Convergent boundaries Subduction zone Trench Transform boundaries: San Andreas fault The Earth Beneath Your Feet Is Moving

The Earth’s Crust Is Made Up of a Mosaic of Huge Rigid Plates Figure 14.3: The earth’s crust is made up of a mosaic of huge rigid plates, called tectonic plates, which move very slowly across the asthenosphere in response to forces in the mantle. See an animation based on this figure at CengageNOW. Fig. 14-3, p. 348

The Earth’s Major Tectonic Plates Figure 14.4: This map shows the earth’s major tectonic plates. See an animation based on this figure at CengageNOW. Question: Which plate are you riding on? Fig. 14-4, p. 349

The San Andreas Fault as It Crosses Part of the Carrizo Plain in California, U.S. Figure 14.5: This is the San Andreas Fault as it crosses part of the Carrizo plain between San Francisco and Los Angeles, California (USA). This fault, which runs almost the full length of California, is responsible for earthquakes of various magnitudes. Question: Is there a transform fault near where you live? Fig. 14-5, p. 350

Some Parts of the Earth’s Surface Build Up and Some Wear Down Internal geologic processes Generally build up the earth’s surface Push up continental and oceanic crusts Form mountains and volcanoes External geologic processes Generally break down the earth’s surface (Weathering) Physical, chemical, and biological Erosion Wind Flowing water Human activities Glaciers Some Parts of the Earth’s Surface Build Up and Some Wear Down

Volcanoes And Earthquakes Reshape the Earth’s Surface Volcanic activities release large amounts of molten rock which solidify into new land forms Earthquake activity moves huge masses of land around Both are responsible for mountain formation Volcanoes And Earthquakes Reshape the Earth’s Surface

Earthquake Risk in the United States Figure 16, Supplement 8

World Earthquake Risk Figure 17, Supplement 8

Earthquakes on the Ocean Floor Can Cause Waves Called Tsunamis Tsunami, tidal wave Travels several hundred miles per hour Detection of tsunamis Buoys in open ocean December 2004: Indian Ocean tsunami Magnitude 9.15 and 31-meter waves at shore Coral reefs and mangrove forests help absorb the force of the wave which reduces the death toll on land Earthquakes on the Ocean Floor Can Cause Waves Called Tsunamis

Indonesian Sunami of 2004: Map of Formation & Images of Coastal Change Figure 14.8: This diagram illustrates how a tsunami forms. The map shows the area affected by a large tsunami in December 2004. Fig. 14-8, p. 352

14-2 How Are the Earth’s Rocks Recycled?

There Are Three Major Types of Rocks Minerals Element or inorganic compound in earth’s crust Usually a crystalline solid Regular and repeating arrangement of atoms Rock Combination of one or more minerals

There Are Three Major Types of Rocks (2)

There Are Three Major Types of Rocks Sedimentary Made of sediments of dead plant/animal remains and particles of weathered/eroded rock Sandstone Shale Limestone Lignite and bituminous coal Igneous Forms below or at earth’s surface from magma Granite Lava rocks Metamorphic Pre-existing rock subjected to high pressures, high temperatures, and/or chemically active fluids Anthracitic coal Slate Marble There Are Three Major Types of Rocks

The Earth’s Rocks Are Recycled Very Slowly Rock cycle Slowest of the earth’s cyclic processes The Earth’s Rocks Are Recycled Very Slowly

14-3 What Are Mineral Resources, and What Are the Environmental Effects of Using Them?

We Use a Variety of Nonrenewable Mineral Resources Can be extracted from earth’s crust and processed into raw materials and products at an affordable cost Metallic minerals Nonmetallic minerals Ore Rock that contains profitable concentrations of a mineral High-grade ore Low-grade ore We Use a Variety of Nonrenewable Mineral Resources

We Use a Variety of Nonrenewable Mineral Resources Metallic mineral resources Aluminum Iron for steel Copper Nonmetallic mineral resources Sand, gravel, limestone Reserves: estimated supply of a mineral resource

The Life Cycle of a Metal Resource Figure 14.11: Each metal resource that we use has a life cycle. Each step in this process uses large amounts of energy and water, and produces some pollution and waste. Fig. 14-11, p. 355

Extracting, Processing, Using Nonrenewable Mineral and Energy Resources Figure 14.12: The extraction, processing, and use of any nonrenewable mineral or energy resource all contribute to a number of harmful environmental effects (Concept 14-3). Further, providing the energy required to carry out each step causes additional pollution and environmental degradation. Questions: What are three mineral resources that you used today? Which of these harmful environmental effects might have resulted from obtaining and using these resources? Fig. 14-12, p. 356

There Are Several Ways to Remove Mineral Deposits Surface mining – removing shallow deposits (90 % of non-fuel mineral resources and 60 % of the coal) Steps: Vegetation (including forests) is removed Overburden (soil and rock) removed and deposited in piles of waste called spoils Resource is removed Types: Open-pit mining Strip mining Contour Strip Mining Mountaintop Removal Subsurface mining Deep deposits removed through shafts, tunnels & chambers blasted in the ground There Are Several Ways to Remove Mineral Deposits

Open-Pit Mine in Arizona Figure 14.13: Natural capital degradation. This open-pit copper mine, which is located near the U.S. city of Bisbee, Arizona, has been abandoned since the mid-1970s. Question: Should governments require mining companies to fill in and restore such sites once their ore is depleted? Explain. Fig. 14-13, p. 357

Area Strip Mining in Wyoming Figure 14.14: This heavy piece of equipment with a large bucket is removing material from an area-strip-mining operation in the U.S. state of Wyoming. Fig. 14-14, p. 357

Contour Strip Mining Figure 14.15: Natural capital degradation. Contour strip mining is used in hilly or mountainous terrain to extract minerals such as coal. Fig. 14-15, p. 358

Spoils Banks in Germany from Area Strip Mining Figure 14.16: Natural capital degradation. Area strip mining of coal in Germany created these spoils banks. A coal-burning power plant is in the background. Question: Should governments require mining companies to restore such sites as fully as possible? Explain. Fig. 14-16, p. 358

Mountaintop Coal Mining in West Virginia Figure 14.17: Natural capital degradation. This is a mountaintop coal mining operation in the U.S. state of West Virginia, where coal is the state rock. The large amount of debris that results from this method is deposited in the valleys and streams below. Mountaintop removal for coal is also occurring in the U.S. states of Virginia, Tennessee, Kentucky, and Pennsylvania. See other sites at http://www.appvoices.org/. Question: Are you for or against mountaintop coal mining? Explain. Fig. 14-17, p. 359

Ecological Restoration of a Mining Site in Indonesia Figure 14.18: This mining site in Indonesia has been ecologically restored, but such restoration is rare. Fig. 14-18, p. 360

Removing Metals from Ores Has Harmful Environmental Effects Ore extracted by mining has 2 components: ore mineral and gangue (waste materials) The gangue is left at the mining site The ore is then heated (smelted) or treated with chemicals (such as cyanide salts) to extract the desired mineral These processes produce large quantities of highly toxic gases and particulate matter that require hazmat disposal procedures Air and water pollution are frequently the result of careless mining operations Removing Metals from Ores Has Harmful Environmental Effects

14-4 How Long Will Supplies of Nonrenewable Mineral Resources Last?

Mineral Resources Are Distributed Unevenly Most of the nonrenewable mineral resources used worldwide are supplied by United States Canada Russia South Africa Australia Sharp rise in per capita use in the U.S. especially of Strategic metal resources Manganese (Mn) Cobalt (Co) Chromium (Cr) Platinum (Pt) Mineral Resources Are Distributed Unevenly

Future supply depends on: Actual or potential supply of the mineral Rate at which it is used When it becomes economically depleted: Recycle or reuse existing supplies Waste less Use less Find a substitute Do without Depletion time: time to use a certain portion of reserves Supplies of Nonrenewable Mineral Resources Can Be Economically Depleted

Is Mining Lower-Grade Ores the Answer? Factors that limit the mining of lower-grade ores Increased cost of mining and processing larger volumes of ore Availability of freshwater Environmental impact Improve mining technology Use microorganisms, in situ Slow process What about genetic engineering of the microbes? Is Mining Lower-Grade Ores the Answer?

14-5 How Can We Use Mineral Resources More Sustainably?