Environmental Science

15C H A P T E R Review

Using Key Terms 13. Which of the following is not one the six
most produced foods worldwide each year?
Use each of the following terms in a separate a. potatoes
sentence. b. beef
c. rice
1. overharvesting d. wheat
2. erosion
3. livestock 14. Which of the following statements about
4. yield human diets in all parts of the world is true?
5. genetic engineering a. Most people eat pork.
For each pair of terms, explain how the meanings b. An adequate diet includes carbohydrates,
of the terms differ. proteins, and fats.
6. pesticide and biological pest control c. Most people do not have protein in their
7. arable land and topsoil diets.
8. livestock and ruminant d. Most people are obese.
9. malnutrition and famine
10. salinization and desertification 15. Malnutrition is largely a result of
a. war.
STUDY TIP b. soil erosion.
c. poverty.
Making It a Habit Many people find that devel- d. salinization.
oping a routine helps them to study more effec-
tively. Decide which time of day you feel most alert, 16. Which of the following is not found in fertile
and set it aside for studying. Make sure that any soil?
distractions around you will be minimal. When you a. rock particles
regularly follow through with your study plan, you b. worms
may find that you begin to learn more in less time. c. high concentrations of salts
d. high concentrations of organic matter
Understanding Key Ideas
17. Which of the following is not a soil conser-
11. Malnutrition can be caused by vation method?
a. a lack of enough Calories. a. contour plowing
b. a lack of carbohydrates. b. salinization
c. a lack of essential amino acids. c. no-till farming
d. All of the above d. terracing

12. Humans need which of the following 18. Which of the following statements is a disad-
nutrients? vantage of using chemical pesticides?
a. carbohydrates and minerals a. Pesticides can pollute waterways.
b. lipids and vitamins b. Pests evolve resistance to pesticides.
c. proteins c. Pesticides kill beneficial insects.
d. all of the above d. all of the above

19. How do pesticides that are growth regula-
tors work?
a. They kill fleas.
b. They disrupt the pest’s life cycle.
c. They attract predators of the pest.
d. They prevent the pest from attacking the
plant by poisoning its nervous system.

Chapter 15 Review 429

15C H A P T E R Review

Short Answer Concept Mapping ?
??
20. Why does it cost more to produce a kilo-
gram of meat than to produce a kilogram 28. Use the following terms to create a concept
of plants? map: contour plowing, no-till farming,
organic farming, careful irrigation, soil ero-
21. How does plowing soil increase soil erosion? sion, nutrient depletion, and salinization.

22. Why are biological controls for killing pests Critical Thinking
sometimes more effective than chemical pes-
ticides are? 29. Making Predictions Reread the text under
the heading “World Food Problems.” Write
23. Why are ruminants valuable livestock? a paragraph to predict how increasing the
productivity of the world’s subsistence
24. Explain how soil degradation leads to loss of farmers would affect poverty and food
arable land. production. WRITING SKILLS

Interpreting Graphics 30. Analyzing Ideas What incentives to conserve
soil do farmers in developed nations have?
Use the graph below to answer questions 25–27.
31. Inferring Relationships Read the text in this
25. In which year was the most corn planted? In chapter under the heading, “Disrupting Insect
which year was the least corn harvested? Breeding.” Are pheromones a type of pesti-
cide? Explain your reasoning. READING SKILLS
26. How many acres were planted with corn in
1991? Cross-Disciplinary Connection

27. According to the graph, more acres of 32. Social Studies Thousands of tons of dead
corn are planted than are harvested each fish are shoveled back into the ocean each
year. Why? year from fishing vessels because the fish are
species that consumers do not want to buy.
90 Identify some ways that humans might be
able to reuse this protein.
Corn (in millions of acres) 85
33. Economics Hundreds of thousands of people
Planted starve to death every year. How is this prob-
80 lem related to the problem of poverty?
Explain your answer.
75

70

65

60 Portfolio Project
Harvested
34. Prepare a Report Environmental degrada-
55 tion caused by farming is not a new prob-
lem. The Dust Bowl of the 1930s is an
50 1985 1989 1993 1997 2001 example of an environmental disaster caused
1981 by farming practices that we would now
consider to be damaging. Investigate the
Year Dust Bowl, and write a report about it.
Include information about the farming prac-
Source: U.S. Department of Agriculture. tices, laws, and regulations that were intro-
duced in the United States as a result of the
lessons learned during the 1930s.

WRITING SKILLS

430 Chapter 15 Review

MATH SKILLS READING SKILLS

Use the table below to answer questions 35–38. Read the passage below, and then answer
the questions that follow.
World Food Production (in millions of tons)
A large amount of energy is needed to pro-
Food 1990 1995 1999 duce food. In all parts of the world, the energy
used to process, distribute, and cook food is
Total grains 1,700 1,800 1,900 greater than the energy used to grow it. In the
Wheat 590 540 590 United States, it is estimated that every Calorie
Rice 350 370 400 of food on our dinner tables has required 9
Legumes 58 55 59 Calories of energy to get there. Half a Calorie
Poultry 37 51 58 accounts for the energy used on the farm. The
Milk 441 381 387 other 8.5 Calories account for the energy used
to process, package, distribute, and cook the
35. Analyzing Data Which foods had increased food. In rural India, twice as much energy goes
production in 1995 and 1999? into cooking a kilogram of rice as was invested
in producing it. Energy shortages, such as a
36. Analyzing Data Which foods had lower pro- shortage of wood for cooking, have caused
duction in 1995 than in 1990? environmental problems such as deforestation.
In poor countries, cooking may require more
37. Analyzing Data Taking into account the energy than is used by transportation, heating,
1999 data, can you think of any possible and all other energy uses combined.
reasons for the answer to question 36?
1. According to the passage, which of the
38. Analyzing Data The human population of following statements about food is true?
the world grew by 15 percent between 1990 a. Most of the energy invested in food
and 1999. By what percentage did total production goes into distributing
grain production increase during this time? the food.
b. More energy is used to grow food on
WRITING SKILLS the farm than is used to cook the food.
c. Most energy used to produce food
39. Communicating Ideas Explain how the way goes into processing, distributing, and
in which insects reproduce allows them to cooking the food.
evolve pesticide resistance very rapidly. d. In developing countries only, cooking
food requires more energy than grow-
40. Analyzing Ideas Explain why the pesticide ing food does.
DDT can still be detected in the environment
even though its use was banned decades ago. 2. Which of the following points is not dis-
cussed in this passage?
a. Packaging is the least costly part of
preparing food for sale to the customer.
b. It takes more energy to cook a kilogram
of rice than to grow a kilogram of rice.
c. In some countries, cooking requires
more energy than all other processes
that use energy combined.
d. Gathering sufficient wood to cook
food has led to deforestation.

Chapter 15 Review 431

15C H A P T E R Standardized Test Prep

Understanding Concepts Reading Skills

Directions (1–4): For each question, write on a Directions (7–8): Read the passage below. Then
separate sheet of paper the letter of the correct answer the questions.
answer.
Plant breeding has been used since
1 Which of the following is a major cause of agriculture began. Farmers select the plants
that have the most desirable characteristics.
malnutrition in the world today? They save seeds from these plants to use in
A. food efficiency planting the next crop. The selected seeds are
B. improved yield more likely to contain the genes for the desired
C. poverty traits. The same result is achieved with genetic
D. no-till farming engineering, the technology in which genetic
material in a living cell is modified for medical
2 What is the main difference between fertile or industrial use.

and infertile soil? Genetic engineering involves isolating genes
F. Fertile soil supports plant life; infertile from one organism and implanting them into
another. The plants that result from genetic
soil cannot. engineering are called genetically modified
G. Infertile soil supports plant life; fertile plants. Sometimes genes introduced into plants
are not plant genes. An insecticide gene from a
soil cannot. bacterium that produces a chemical that kills
H. Fertile soil supports insect life; infertile plant-eating caterpillars can be implanted into
crop plants. Hundreds of gene transfers have
soil cannot. now been performed to create many geneti-
I. Infertile soil supports insect life; fertile cally modified crops. In the United States, we
now eat and use genetically engineered agricul-
soil cannot. tural products every day.

3 What is the eventual result of land 7 What impact has the technology of genetic

degradation? engineering had on the agricultural
A. desertification community?
B. fertilization A. The technology of genetic engineering
C. integration
D. salinization has increased the efficiency of the
agricultural community.
4 Which of the following is an effect of soil B. The technoIogy of genetic engineering
has decreased the efficiency of the
erosion? agricultural community.
F. increased crop yields C. The technology of genetic engineering
G. increase in land fertility has increased cultivation within the
H. decrease in desertification agricultural community.
I. decrease in the amount of topsoil D. The technology of genetic engineering
has decreased cultivation within the
Directions (5–6): For each question, write a short agricultural community.
response.
8 What effect could introducing insecticide
5 Over time, controlling pests with pesticides
genes into crops have on insecticide
can make a pest problem worse if pest resistance?
populations develop resistance. Resistance
is the ability to survive exposure to a par-
ticular pesticide. Why are subsequent gener-
ations of resistant pest populations more
likely to be resistant?

6 Evaluate the practice of biological pest

control.

432 Chapter 15 Standardized Test Prep

Interpreting Graphics

Directions (9–11): For each question below, record the correct answer on a
separate sheet of paper.

The graph below shows world grain production over a 55-year period. Use
this graph to answer questions 9 through 11.

2,500 World Grain Production, 1950–2005 400
2,000 350
1,500 Grain per person 300
Grain production1,000 250
(in millions of metric tons) 200
500 150
Grain per person (kg)0100
1950 Grain production 50
0
1960 1970 1980 1990 2000

Year

9 In what year did the total amount of grain production equal the Test

average amount of grain per person? Slow, deep breathing
F. 1980 may help you relax. If
G. 1983 you suffer from test
H. 2003 anxiety, focus on your
I. The two amounts were never equal. breathing in order to
calm down.
0 What is the main reason that, while total grain production has

increased each year, the amount of grain per person has been
relatively steady?
A. Much of the grain produced could not be distributed efficiently.
B. The world’s population has grown faster than grain production.
C. The world’s population has remained roughly the same for the last

35 years.
D. Much of the grain produced in the world was used to feed livestock

or as seed.

q If the trend that was in place from 1990–1995 continued through

2005, what would have been the average amount of grain available
per person in 2005?
F. 200 kg
G. 250 kg
H. 300 kg
I. 350 kg

Chapter 15 Standardized Test Prep 433

15C H A P T E R Inquiry Lab: MODELING

Objectives Managing the Moisture in Garden Soil

̈ USING SCIENTIFIC METHODS You work as a soil specialist with the Smith County Soil
Conservation District. You are trying to help Mrs. Latisha
Hypothesize how to reduce the Norton, a local resident, solve an agricultural problem. Mrs.
amount of water a garden needs. Norton has found that she must water her vegetable garden very
often to keep it healthy. As a result, her family’s water bills have
̈ Compare the amount of water skyrocketed! Mrs. Norton and her family may have to give up
different soil samples can hold. their garden project because of the added expense.

̈ Explain how adding materials to a You realize that the water is probably draining out of the
soil sample can help increase the garden soil too quickly. To solve this problem, you need to find
sample’s ability to hold water. out how much water the soil can hold. You visit her garden
and collect several soil samples. (Your teacher will provide you
Materials with soil samples.)

beaker, 250 mL Procedure
compost, 5 g
crucible (or other heat-safe 1. Dry your soil sample without burning any of the organic
matter. To do this, place about 50 g of soil in a crucible or
container) other heat-safe container. Using tongs, gently heat the sample
dry chopped grass clippings, 5 g over a hot plate or put the sample in an oven. Stir the sample
eyedropper occasionally with a stirring rod to ensure that the sample
filter paper becomes completely dry.
funnel
heat source (hot plate or oven) 2. After the sample is completely dry, weigh about 10 g of dry
metric balance soil. Record the mass in a data table.
sawdust, 5 g
soil sample, 50 g 3. Dampen a circle of filter paper until it is thoroughly moist,
stirring rod but not dripping. Weigh the moist filter paper, and record its
tongs mass in a data table.
watch (or clock)
water 4. As shown below, fold the moist filter paper into quarters.
Next, open the filter paper to form a cup that fits in a fun-
nel. Place the cup-shaped filter paper in the funnel.

5. Place the dry soil sample on the filter paper in the funnel.
Place the funnel in the beaker.

6. Add water to the soil sample one drop at a time until all of
the soil is moist and water begins to drip out of the funnel.
Stop adding water, and let the funnel sit for 5 min.

̈ Step 4 Fold the moist filter paper
into quarters, and then open it to
form a cup that fits in a funnel.

434 Chapter 15 Inquiry Lab

7. After 5 min, remove the filter paper and moist soil from the ̈ Step 6 When adding water to the
funnel, and weigh the paper and soil together. Record their soil sample, add one drop at a time
mass in a data table. until all of the soil is moist and water
begins to drip out of the funnel.
8. Calculate the mass of the moistened soil sample by subtract-
ing the mass of the damp filter paper from the mass of the
completely moistened sample and the filter paper. Record the
mass in a data table.

9. Calculate the amount of water that your soil sample can hold
by subtracting the mass of the dry soil sample from the mass
of the moistened soil sample. Record the result in a data table.

10. Calculate the percentage of water that your sample held.
Divide the mass of water the soil held by the mass of the
moistened soil sample, and multiply by 100. The higher the
percentage is, the more water the soil can hold. Record the
percentage in a data table.

11. Divide the remaining dry soil sample into three 5 g portions.
To the first soil sample, add 5 g of dry compost. To the sec-
ond soil sample, add 5 g of dry chopped grass clippings. To
the third soil sample, add 5 g of dry sawdust. Weigh each
mixed soil sample, and record the masses of the three sam-
ples in a data table.

12. Perform steps 3–10 for each of your mixed soil samples.
Record your results in a data table.

Analysis

1. Organizing Data Compare your results with the results of your
classmates. Which soil samples held water the best? Why?

2. Analyzing Data Which of the additional materials improved
the soil’s ability to hold water?

Conclusions

3. Evaluating Methods Based on your results as well as your
research, what could you recommend to Mrs. Norton to
reduce the amount of water her garden needs?

Extension

1. Designing Experiments With the help of your teacher,
choose one more material in addition to the three materials
you used in step 11. Combine two of these materials, and
mix them with a soil sample. Combine the remaining two
materials with another soil sample. Perform steps 3–10 for
these two mixed soil samples. Compare your results with
the results you gathered earlier in the lab. Which combina-
tion of materials in the soil samples held water the best?

Chapter 15 Inquiry Lab 435

GENETICALLY ENGINEERED FOODS

Genetically engineered foods are shelves longer before becoming ̈ A scientist examines experimental
now on sale in the world’s super- soft and overripe. Biotechnologists samples of genetically modified
markets, and we do not recognize developed the tomato by altering fruit trees.
them because they are not labeled the gene that causes ripe tomatoes
as such. to soften. The Food and Drug Biotechnologists say that their
Administration (FDA) said it was new products are as safe for con-
As the world’s population con- as safe as other tomatoes and sumers as plants developed
tinues to increase, food production cleared it for sale. Here are two through crossbreeding. Why
must try to keep pace with the points of view on genetically engi- shouldn’t genetically engineered
increase. Genetic engineering pro- neered foods. foods sit beside other foods on
vides one way to develop new grocery store shelves?
foods. Biotechnologists develop The Benefits Outweigh
desirable characteristics in an the Risks The benefits of creating geneti-
organism by altering its genes or by cally engineered fruits and vegeta-
inserting new genes into the organ- Scientists who support the devel- bles include keeping produce fresh
ism’s cells. For example, a gene opment of genetically engineered longer, adding nutrients, and creat-
that makes one plant species resist- foods view the process as simply ing more-successful crops. For
ant to pests might be transferred to an extension of previous plant- example, by inserting a gene that
another plant species. The second breeding techniques. Traditionally, gives virus resistance to squash
plant species would then have the farmers altered the genetic makeup plants, scientists could boost the
same resistance to pests. of plants by crossbreeding different plants’ resistance to viral infection.
strains to combine the best traits These resistant squash could pro-
In 1994, the first genetically of both plants. However, the direct duce five times the amount of
modified food was offered for manipulation of genes makes it squash per harvest as other squash
sale. It was a tomato called the possible to control genetic changes do. Or scientists could increase the
Flavr Savr™ which softens slowly, more precisely and efficiently. amino acids in a food product to
so it can remain on grocery give it more nutritional value.

̈ The corn plants in this field have been genetically engineered to resist Crops could be developed to
the effects of herbicides. grow faster and have higher yields.
To combat world hunger, scientists
may be able to develop seeds that
can grow well in areas that have
poor soil or poor water conditions.
For more immediate relief, geneti-
cally engineered foods that would
not spoil as quickly could be
shipped to needy nations.

436 Chapter 15 Points of View

The Risks Outweigh
the Benefits

Critics of genetically engineered ̈ This farmer from Oaxaca, Mexico, holds up ears of traditional corn vari-
foods believe that these products eties. Some people fear that genes from genetically engineered varieties
are significantly different from could accidentally be introduced into native varieties.
foods developed through tradi-
tional methods. Genetic engineer- religions prohibit eating pork and Some scientists are concerned
ing allows genes from any living other foods. People may object to that genetically engineered plant
organism, including genes from the insertion of genes from pigs or species may be accidentally intro-
animals or bacteria, to be placed other prohibited foods into foods duced into the wild. Genetic engi-
into crops. Opponents are con- they normally eat. Similarly, veg- neering may give a new species an
cerned about the safety of foods etarians might object to eating advantage over an existing wild
that contain these “foreign” genes. foods containing animal genes. species. If the new species thrives at
the expense of the wild species, the
Another safety concern is the wild species could become extinct.
possibility of allergic reactions.
Some foods, such as peanuts and
shellfish, cause allergic reactions
in many people. If genes from
these foods are placed in entirely
different products, people who eat
these new products and do not
know that the new products con-
tain the foreign genes may have
allergic reactions.

Other critics object because of
religious or ethical reasons. Certain

̈ These people in Montreal, Quebec, are protesting the importation of
genetically modified organisms (GMOs). Many countries have not
accepted genetically engineered crops as much as the United States has.

What Do You Think?

Some people propose that
genetically engineered foods
should have labels that iden-
tify them as such. Could such
a measure decrease criticism
about the safety of genetically
engineered foods? Based on
what you have read, decide
whether you would buy
genetically engineered foods
at the grocery store. Explain
your reasoning.

Chapter 15 Points of View 437

MINERAL AND ENERGY RESOURCES

438

5U N I T

CHAPTER 16

Mining and Mineral
Resources

CHAPTER 17

Nonrenewable Energy

CHAPTER 18

Renewable Energy

CHAPTER 19

Waste

This pit in Brazil is one of the
world's largest iron ore mines.
Mineral and energy resources are
essential to human societies, but
extracting and using these resources
has environmental consequences.

439

16Mining and Mineral Resources CHAPTER

1 Minerals and Mineral

Resources

2 Mineral Exploration

and Mining

3 Mining Regulations and

Mine Reclamation

PRE-READING ACTIVITY

Three-Panel
Flip Chart
Before you
read this
chapter, create the
FoldNote entitled “Three-
Panel Flip Chart” described
in the Reading and Study
Skills section of the Appen-
dix. Label the flaps of the
chart with “Mineral
Resources,” “Mining,” and
“Mining Regulations and
Reclamation.” As you read
the chapter, write informa-
tion you learn about each
category
under the
appropri-
ate panel.

Obtaining the minerals humans
need requires removing large
amounts of rock at mines like this
open-pit copper mine in Arizona.
The challenge is to satisfy the
increasing demand for mineral
resources while minimizing the
cost to the environment.

440 Chapter 16 Mining and Mineral Resources

SECTION 1

Minerals and Mineral Resources

EARTH SCIENCE CONNECTION

Take a look at the human-made objects that surround you. Almost Objectives
every solid object you see is made of minerals. As shown in Figure 1,
we depend on the use of mineral resources in almost every aspect of ̈ Define the term mineral.
our daily lives. The current challenge is to obtain minerals at mini- ̈ Explain the difference between a
mal cost to the environment. In this chapter you will learn about
minerals and the environmental effects of mining. metal and a nonmetal, and give
two examples of each.
What Is a Mineral? ̈ Describe three processes by which
ore minerals form.
A mineral is a naturally occurring, usually inorganic solid that has
a characteristic chemical composition, an orderly internal structure, Key Terms
and a characteristic set of physical properties. Minerals are made up
of atoms of a single element, or of compounds—atoms of two or mineral
more elements chemically bonded together. The atoms that make up ore mineral
minerals are arranged in regular, repeating geometric patterns. The
arrangement of the atoms, along with the strength of the chemical FIELD ACTIVITY
bonds between them, determine the physical properties of minerals.
Identifying Objects Made of
The elements gold, silver, and copper are considered minerals. Minerals Take a walk around
These types of minerals are called native elements. However, most your neighborhood or through
minerals are compounds. For example, the mineral quartz is made your home with a notebook and
up of silica, a compound consisting of one silicon atom and two pencil. Pick an object such as a
oxygen atoms. When combined with other elements, silica forms car, an appliance, or a computer.
most of the minerals that make up Earth’s crust. List as many materials that make
up that object as you can. Be as
■✓● Reading Check List three characteristics of all minerals. (See the specific as possible. Repeat the
procedure for several other
Appendix for answers to Reading Checks.) objects. Which of these objects
do you think are made from min-
Aluminum erals? Write to the company that
made one of your objects, and
Copper ask what materials are used to
make the object. Record your
Iron ore observations, along with the com-
pany’s response, in your EcoLog.
Lead

Zinc

Clays

Phosphate 50 55 60 Figure 1 ̈ Mineral consumption is
greatest in developed countries, such
Salt as the United States. This graph
shows the average amount of miner-
Other metals als a person in the U.S. will consume
over his or her lifetime.
0 5 10 15 20 25 30 35 40 45
Amount of metals and minerals
(in thousands of pounds)

Source: Mineral Information Institute.

Section 1 Minerals and Mineral Resources 441

Table 1 ̄

Selected Elements and Their Ore Minerals

Element Important ore minerals

Figure 2 ̈ Certain minerals are mined Aluminum (Al) gibbsite, boehmite, diaspore (bauxite)
because of the valuable metals they Beryllium (Be) beryl
contain, as shown in the table. Wulfe- Chromium (Cr) chromite
nite (above) is a minor ore of lead. Copper (Cu) bornite, cuprite, chalcocite, chalcopyrite
Nice specimens of wulfenite are much Iron (Fe) goethite, hematite, magnetite, siderite
sought after by mineral collectors. Lead (Pb) galena
Manganese (Mn) psilomelane, pyrolusite
www.scilinks.org Mercury (Hg) cinnabar
Molybdenum (Mo) molybdenite
Topic: Minerals Nickel (Ni) pentlandite
Code: HE80966 Silver (Ag) acanthite
Tin (Sn) cassiterite
Titanium (Ti) ilmenite, rutile
Uranium (U) carnotite, uraninite
Zinc (Zn) sphalerite

Ore Minerals

Minerals that are valuable and economical to extract are known as
ore minerals. As shown in Table 1, ore minerals contain elements,
many of which are economically valuable. During the mining pro-
cess, ore minerals, along with minerals that have no commercial
value, or gangue (GANG) minerals, are extracted from the host
rock. After extraction, mining companies use various methods to
separate ore minerals from the gangue minerals. The ore minerals
are then further refined to extract the valuable elements they con-
tain. For mining to be profitable, the price of the final product
must be greater than the costs of extraction and refining.

Metallic Minerals Ore minerals are either metallic or nonmetal-
lic. Metals conduct electricity, have shiny surfaces, and are
opaque. Many valuable metallic minerals are native elements
such as gold, shown in Figure 3. Silver and copper are also
important native elements. Other important ore minerals are
compounds in which metallic elements combine with nonmetallic
elements, such as sulfur or oxygen.

Figure 3 ̈ Gold is one of the most Nonmetallic Minerals Nonmetals tend to be good insulators,
economically important metallic may have shiny or dull surfaces, and may allow light to pass
minerals. through them. Nonmetallic minerals can also be native elements
or compounds.

442 Chapter 16 Mining and Mineral Resources

How Do Ore Minerals Form? Geofact

As shown in Figure 4, economically important ore deposits Bauxite The major ore of alu-
form in a variety of ways. The types of minerals that form minum is a rock called bauxite.
depend on the environment in which they form. For example, Bauxite is a mixture of three alu-
metallic minerals form below ground when magma cools and minum oxide minerals. It forms in
hardens. The metallic minerals tend to form early in the cool- humid, tropical climates by the
ing process and sink to the lower part of the magma body weathering of rocks or soil that
because they are denser. This process concentrates important contain aluminum. Deposits of
ore minerals that can be extracted economically. bauxite are called aluminum lat-
erites. Australia, Guinea, and
Hydrothermal Solutions Hot, subsurface waters that contain dis- Jamaica are the major world
solved minerals are called hydrothermal solutions. As hydrothermal sources of bauxite.
solutions flow through cracks in rocks, they dissolve minerals they
come in contact with. New minerals crystallize out of these solu- Figure 4 ̈ Mineral Environments
tions and then fill fractures to form ore deposits called veins. Ore deposits form in different ways
upon and beneath Earth’s surface, and
Evaporites As rivers and streams wash over land surfaces, they at the bottom of lakes and oceans.
dissolve salts and carry them into the sea or inland lakes. When
the water in these seas or lakes evaporates, deposits of these salts,
called evaporites, are left behind. Evaporites form in arid regions
where rates of evaporation are high. Important evaporite minerals
include halite (rock salt) and gypsum.

■✓● Reading Check How do evaporites form?

Section 1 Minerals and Mineral Resources 443

Table 2 ̄ Mineral Resources and Their Uses

Uses of Important Metallic Certain metals are of major economic and industrial importance,
and Nonmetallic Elements as shown in Table 2. Some metals can be pounded or pressed into
various shapes or stretched very thinly without breaking. Other
Aluminum: cans, foil; windows, metals are good conductors of heat and electricity, or are prized
doors, siding; appliances, cooking for their durability and resistance to corrosion. Often, two or
utensils; automobiles, aircraft more metals are combined to form alloys. Alloys are important
because they often combine the most desirable properties of the
Copper: cables, wires; electrical metals used to make them. As shown in Figure 5, many new tech-
and electronic products; plumb- nologies depend on the mining of metallic minerals.
ing, heating; alloys; coinage
Nonmetals are among the most widely used minerals in the
Gold: computers; communica- world. For example, gypsum has many applications in the con-
tions equipment; spacecraft; den- struction industry. It is used to make Sheetrock™, or wallboard,
tistry, medicine; jewelry for homes and commercial buildings. It is also a major compo-
nent of concrete, which is used to build roads, buildings, and
Iron: steel making other structures. Industrial sand and gravel have uses that range
from glassmaking to the manufacture of com-
Lead: batteries; ammunition; puter chips. Some nonmetallic minerals,
glass; ceramics called gemstones, are prized purely for
their beauty, rarity, or durability.
Silicon: computer chips; glass; Important gemstones include diamond,
ceramics ruby, sapphire, emerald, aquamarine,
topaz, and tourmaline.
Silver: photography; electrical
and electronic products; mirrors;
chemistry

Sulfur: sulfuric acid; gunpowder;
rubber; fungicides

Titanium: jet engines, aircraft
bodies, spacecraft, missiles; pig-
ments

Zinc: coatings on steel; brass;
chemical compounds in rubber
and paints

Figure 5 ̈ The mineral ilmenite
(inset) is an important source of tita-
nium. Because titanium is both
strong and lightweight, it is used in
aircraft such as this stealth fighter.

S E C T I O N 1 Review

1. Define the term mineral. CRITICAL THINKING
2. Explain the difference between a metal and a non-
5. Analyzing Relationships A mineral is a naturally
metal, and give examples of each. occurring substance. Are synthetic minerals produced
3. Describe three processes by which minerals form. in laboratories minerals? Explain your answer.
4. List five properties that make metals economically
6. Making Comparisons Unlike metals, nonmetals
and industrially important. are not good conductors of heat and electricity. How
might these properties influence the use of nonmetals
444 Chapter 16 Mining and Mineral Resources in industry? Write a paragraph to explain your
answer. WRITING SKILLS

SECTION 2

Mineral Exploration and Mining

EARTH SCIENCE CONNECTION

The rate of technological change in the mining industry is Objectives
increasing rapidly. Computers are commonly used to make
models that show the location of ore within a deposit. Mineral ̈ Describe the manner in which
exploration data are now obtained from orbiting satellites or mining companies explore for new
from airplanes that carry sophisticated instruments. These mineral deposits.
instruments help scientists find new ore deposits.
̈ Describe three methods of subsur-
Mineral Exploration face mining.

Through mineral exploration, mining companies can identify areas ̈ Describe two methods of surface
where there is a high likelihood of finding valuable mineral resources mining.
in quantities that are worth mining. Usually, a mineral deposit has
100 to 1,000 times the concentration of the mineral than ordinary ̈ Define placer deposit, and explain
rocks do and enough material to justify opening a mine. how placer deposits form.

Exploring rock for mineralization is the first step in finding ̈ Describe the steps that take place
an ore deposit. Planes carrying instruments that identify patterns in smelting an ore.
in gravity, magnetism, or radioactivity fly over and collect these
data, as well as images and photographs of an area. When used Key Terms
with satellite images, these data and aerial photographs can be
used to create a geological map of the surface. As shown in subsurface mining
Figure 6, rock samples are then taken from the area. The sam- surface mining
ples are analyzed to determine ore grade — the metal content of placer deposit
an ore. If the ore grade is high enough, the companies will drill smelting
test holes that help them estimate the three-dimensional extent of
the ore. If the ore grade is high enough and the deposit extensive Figure 6 ̈ A geologist takes ore
enough, the cost to open a mine may be warranted. samples across the freshly blasted
tunnel of a Canadian gold mine.
■✓● Reading Check How are planes used to find rich ore deposits?

Section 2 445

Figure 7 ̈ This photo shows a
room-and-pillar salt mine in
Germany. A bucket wheel excavator
is used to remove the salt.

www.scilinks.org

Topic: Mining Minerals
Code: HE80968

Figure 8 ̈ Heavy equipment, like the Subsurface Mining
rotating shearer of the longwall min-
ing system shown here, is used to Ore deposits that are usually found 50 m or more beneath Earth’s
remove coal in subsurface mines. surface are mined by using subsurface mining methods. A com-
mon method of subsurface mining that is used to extract coal and
salt is known as room-and-pillar mining. In coal mines, a net-
work of entries, called rooms, are cut into a seam, a horizontal
layer of coal. Between the rooms, pillars of coal are left standing
to support the roof. When the mining of rooms is completed, the
pillars are then removed, beginning with pillars at the farthest
point in the mine. A room in a German salt mine, along with
mining equipment, is shown in Figure 7.

Longwall Mining A more efficient way to remove coal from a
subsurface seam is to use a method called longwall mining. In
longwall mining, a machine called a shearer moves back and forth
across the face of a coal seam. A shearer that is used in longwall

mining is shown in Figure 8. The wall of the seam,
called the longwall, may be more than 300 m long.
As coal is sheared from the face, it falls onto a con-
veyor. The conveyor transports the coal out of the
mine. A row of hydraulic roof supports protects
the miners and the equipment. As the shearer
advances forward through the coal seam, the mine
roof behind the hydraulic supports collapses.

Solution Mining For underground deposits of
soluble mineral ores such as potash, salt, and sul-
fur, solution mining is an economical mining
method. In solution mining, hot water is injected
into the ore and dissolves it. Compressed air is
then pumped into the dissolved ore, and air bub-
bles lift it to the surface.

446 Chapter 16 Mining and Mineral Resources

Surface Mining Figure 9 ̈ Cyanide heap leaching is
being used to extract gold from ore
Surface mining methods are used when at this open-pit mine in Idaho.
ore deposits are located close to
Earth’s surface. Open-pit mining is a Connection to Chemistry
method that is often used to mine large
quantities of near-surface ore. Coal and Cyanide Heap Leaching
metals such as copper are mined using Sodium cyanide, NaCN, has been
the open-pit method. used to extract gold from low-
grade ore deposits since the
In an open-pit mine, the ore is mined cyanide heap-leaching process
downward, layer by layer. First, explo- was pioneered in the United
sives are used, if needed, to break up the States in the early 1970s.
ore. Then, the ore is loaded into haul Crushed ore from a mine is
trucks. The haul trucks transport the ore placed on pads that have bot-
from the mine. Some ores, such as gold toms of asphalt or on impervious
ore, are taken to heap leaching pads, such as the pads shown in plastic sheets. A solution of dilute
Figure 9. There, the gold is extracted from the ore using chemicals. cyanide is sprayed on the ore.
The cyanide percolates down
Surface Coal Mining In the 19th-century American Midwest, through the ore for several weeks
horse- or mule-drawn plows were used to remove the rock, called to months and leaches out the
overburden, that covered near-surface coal seams. Today, some of gold. The gold, which is now in
the largest machines in the world are used to strip the overburden solution, drains off the pad into a
that covers shallow coal deposits. pond. From the pond, the gold-
bearing solution is pumped to a
The first step in surface coal mining is to remove and set aside recovery plant, where the gold is
the soil that covers the area to be mined. Next, the overburden is removed from solution.
removed by heavy equipment in cuts that may be up to 50 m
wide and over a kilometer long. The overburden is piled along-
side the cut. Loaders enter the pit and remove the exposed coal
seam. Once the coal is taken out, the pit is refilled with the over-
burden and contoured. The soil that has been set aside is now
laid on top of the overburden.

Quarrying Building stones such as granite and marble are mined
in quarries like the one shown in Figure 10. Sand, gravel, and
crushed rock, known as aggregates, are the main products of
quarrying. Quarries also produce clay, gypsum, and talc.

■✓● Reading Check Describe what happens to the overburden once all

the coal has been taken out of a surface coal mine.

Figure 10 ̈ Open pits called
quarries are used to mine near-
surface materials such as building
stone, crushed rock, sand, and gravel.

Section 2 447

Figure 11 ̈ This is an aerial view of Solar Evaporation The solar evaporation process consists of
solar evaporation ponds that are placing sea water, which is about 2.7 percent sodium chloride,
used to produce salt on San into enormous, shallow ponds. The sun evaporates the sea water,
Francisco Bay. which causes the sodium chloride concentration to increase.
When the concentration of sodium chloride in the sea water
reaches a little over 25 percent, salt crystals begin to form. With
further evaporation, layers of crystalline salt, or halite, build up.
When these layers reach the desired thickness, the salt is har-
vested. Salt harvesting generally occurs once a year.

Solar evaporation is a method of salt production that is used in
areas that receive little rainfall and that have high evaporation rates.
Along the Mediterranean Sea, on San Francisco Bay, and particu-
larly in Australia, solar evaporation is practical because evaporation
far exceeds rainfall. Steady prevailing winds, which increase the rate
of evaporation, are also important to solar evaporation. Figure 11
shows solar evaporation ponds on San Francisco Bay.

The solar evaporation process has been used to produce salt
for thousands of years. Today, solar evaporation is used largely in
developing countries. About 30 percent of the world’s salt comes
from the solar evaporation process.

EARTH SCIENCE CONNECTION

Hydraulic Mining in the
California Goldfields

About 50 million years ago, rivers ̈ By 1874, giant water monitors worked 24 hours a day, 7 days a week,
bearing gold flowed across present- at the Malakoff mine and processed about 50,000 tons of gravel a day.
day northern California. Over time, The resulting canyon was more than 2,000 m long, 900 m wide, and
the geologic processes that formed 180 m deep.
the Sierra Nevada Mountains buried
the gold-bearing river gravels
beneath as much as 60 m of soil. A
method was needed to remove this
soil and recover the gold from the
gravels of the ancient riverbeds.

The technology to perform this
task, called hydraulic mining, was
developed in the early 1850s.
Hydraulic miners used huge 4 to
5.5 m long water cannons, called
monitors, to send high-pressure
streams of water into the Sierra
Nevada mountainsides. The sedi-
ments that were blasted from the
mountainsides mixed with the water
to form a slurry, which was washed
through a series of long, inclined

448 Chapter 16 Mining and Mineral Resources

Placer Mining Figure 12 ̈ This dredge is mining
gold from placer deposits along a
When rock weathers and disintegrates, minerals within the river on New Zealand’s South Island.
rock are released. These minerals are concentrated by wind
and water into surface deposits called placer deposits. The
most important placer deposits are stream placers. Streams
transport mineral grains to a point where they fall to the
streambed and are concentrated. Concentration occurs at
places where currents are weak and the dense mineral grains
can no longer be carried in the water. These stream placers
often occur at bends in rivers, where the current slows.

Placer deposits may form along coastlines from heavy
minerals that wash down to the ocean in streams. These
heavy minerals are concentrated by wave action.

Placer gold, diamonds, and other heavy minerals are
mined by dredging. As shown in Figure 12, a dredge consists
of a floating barge on which buckets fixed on a conveyor are
used to excavate sediments in front of the dredge. Gold, dia-
monds, or heavy minerals are separated from the sediments
within the dredge housing. The processed sediments are dis-
charged via a conveyor that is located behind the dredge.

̈ To this day, the mountainsides
in the Sierra Nevada bear the
scars of hydraulic mining.

troughs called sluices. The sluices River overflowed its banks. But the CRITICAL THINKING
were lined with a series of devices farmers fought back. In January
known as riffles to catch the gold. 1884, Judge Lorenzo Sawyer ruled 1. Making Inferences What do
Mercury was also added to the rif- that mine tailings could no longer be you think were other environmental
fles to help capture the gold. The discharged into the rivers. The effects of hydraulic mining that
muddy water and processed sedi- Sawyer decision was the first environ- were not mentioned in this article?
ments were then discharged into mental ruling to be handed down in
adjacent rivers. the United States. This ruling closed 2. Analyzing Relationships Write
the door on hydraulic mining in the a paragraph about how the mer-
Hydraulic mining proved to be Sierra Nevada goldfields, where 2 bil- cury that was lost during hydraulic
an environmental disaster. Muddy lion cubic meters of soil and rocks mining may still be affecting the
water and sediments polluted rivers had been carved from the mountain- environment today. WRITING SKILLS
and caused them to fill with silt. The sides in slightly over 30 years.
silt from the hydraulic mines traveled
as far downstream as San Francisco
and into the Pacific Ocean. As much
as 1.4 to 3.6 million kilograms of
mercury may have been released
downstream, which poisoned fish,
amphibians, and invertebrates.
Farmers in California’s central valley
sustained millions of dollars in dam-
age as their fields were flooded when
the sediment-choked Sacramento

Section 2 Mineral Exploration and Mining 449

Figure 13 ̈ At a smelter, such as
this aluminum smelter in Venezuela,
ore is melted at high temperatures in
a furnace to obtain a desired metal.

QuickLAB Smelting

Surface Coal In the process called smelting, crushed ore is melted at high tem-
Mining peratures in furnaces to separate impurities from molten metal. In
the furnace, material called a flux bonds with impurities and
Procedure separates them from the molten metal. The molten metal, which
1. Cut off the top part of a 2 L is desired, falls to the bottom of the furnace and is recovered. The
flux and impurities, which are less dense, form a layer called slag
plastic soda bottle to make a on top of the molten metal. Gases such as sulfur dioxide form
container that has an open end. within the furnace and are captured, so they do not enter the
2. Spread a 5 cm layer of soil on environment. Figure 13 shows a smelter in Venezuela.
the bottom of the bottle.
3. Spread a 0.75 cm layer of rice Undersea Mining
on top of the soil to represent a
coal seam. The ocean floor contains significant mineral resources, which
4. Spread a 12.5 cm layer of soil include diamonds, precious metals such as gold and silver, mineral
on top of the coal. ores, and sand and gravel. Since the late 1950s, several attempts
5. To excavate the coal, dig out have been made to mine the ocean. These attempts met with vary-
the top layer of soil with a ing degrees of success. Competition with land-based companies
spoon, and place it in a bowl. that can mine minerals more cheaply and the great water depths
Measure the volume of this soil at which some mineral deposits are found are two of the reasons
by using a graduated cylinder. undersea mining has been largely unsuccessful to date.
Record the volume.
6. Dig out the layer of coal, and
place it in a second bowl.
Measure and record the volume.
Analysis
1. What is the ratio of overburden
to coal?
2. What are some factors that you
would need to consider if you
were going to surface-mine
coal economically?

S E C T I O N 2 Review

1. List the steps in mineral exploration. CRITICAL THINKING
2. Describe three methods of subsurface mining. 6. Making Comparisons Read about surface and
3. Describe two methods of surface mining.
4. Describe the steps involved in smelting ore. subsurface mining techniques. What are some of the
5. Define the term placer deposit, and explain how advantages and disadvantages of each technique?

placer deposits form. READING SKILLS

450 Chapter 16 Mining and Mineral Resources 7. Understanding Relationships If a mining com-
pany were exploring a river for potential placer
deposits, where are some likely places they would
focus their exploration?

SECTION 3 CONNECTION

Mining Regulations and Mine Reclamation

EARTH SCIENCE

With an increase in U.S. energy requirements, particularly the Objectives
demand for coal to fuel power plants that produce electricity, the
scale of surface mining has grown. So, too, have the potential ̈ Describe seven important potential
environmental effects of mining. For example, surface coal min- environmental consequences of
ing requires the removal of enormous amounts of soil and rock to mining.
reach near-surface coal seams.
̈ Name four federal laws that relate
Because of the environmental impacts of mining on such a to mining and reclaiming mined
large scale, mining has become one of the most heavily regulated land.
industries in the United States. Mining companies now spend
large amounts of money to preserve the environment. Reclaiming ̈ Define the term reclamation.
the land, or returning the land to its original condition after min- ̈ Describe two ways in which state
ing is completed, is part of every surface coal mining operation.
Before mining, companies develop a plan to reclaim the land. governments regulate mining.
Even before mining is complete, this plan is put into action. With
environmental preservation now a clear goal of mining compa- Key Terms
nies, future generations of Americans will not have to view scars
in the Earth, such as the one shown in Figure 14. subsidence
reclamation

The Environmental Impacts of Mining

There are many environmental impacts of mining. In the United
States, the federal and state governments and mining companies are
spending billions of dollars to clean up abandoned mines. Much of
this legacy has been left to U.S. citizens from a time when there was
little regulation of mining and mineral processing.

Figure 14 ̈ At 215 m deep and
1.6 km in circumference, the “Big
Hole” at the Kimberley Mine in South
Africa is the largest hand-dug excava-
tion in the world. By the time the
mine closed in 1914, 22.5 million
tons of rock had yielded almost
3,000 kg of diamonds.

Section 3 Mining Regulations and Mine Reclamation 451

www.scilinks.org Air and Noise Pollution Surface mining can cause both air
pollution and noise pollution. At surface coal mines, removing,
Topic: Mining loading, hauling, and dumping soil and overburden produce
Reclamation dust. Winds that blow across unreclaimed soil and overburden
storage areas also produce dust. Loading, hauling, and unload-
Code: HE80969 ing ore create dust emissions at open-pit mines. As well, dust is
created in open-pit mines when the ore is blasted apart.
Figure 15 ̈ Copper mines have pol-
luted the Queen River in Tasmania Noise is created by the equipment that is used in a mine as
with acid mine drainage. This photo well as by blasting. Whereas equipment noise may be a nuisance,
shows the river flowing past residen- blasting can cause physical damage to nearby structures.
tial housing.
Because of air and noise pollution, most surface mines are not
located near urban populations. More important, regulations in
the U.S. forbid mining operations to allow dust or noise to exit
the area that is being mined.

Water Contamination Water resources can be negatively
impacted by mining. Water that seeps into mines or through piles
of excess rock can pick up or dissolve toxic substances like
arsenic. These contaminants can wash into streams, where they
can harm or kill aquatic life.

Coal or minerals that contain a lot of sulfur can cause a
similar problem. When these materials react with oxygen and
water, they form dilute sulfuric acid. This acid can dissolve
toxic minerals that remain in mines and excess rock. The con-
taminated water that results from this process is known as acid
mine drainage, or AMD. An example of AMD is shown in
Figure 15. Mining regulation in the U.S. requires companies to
dispose of acid-producing rock in such a way that water is not
contaminated.

Displacement of Wildlife Removing soil
from a surface mine site strips away all plant
life. With their natural habitat removed, ani-
mals will leave the area. In addition, when
mining is completed and the soil is returned
to the mine site, different plants and animals
may establish themselves, which creates an
entirely new ecosystem. However, a good
development plan to reclaim a mine site can
ensure that the displacement of wildlife is
merely temporary.

Dredging can negatively affect aquatic
ecosystems and physically change the bot-
toms of rivers. Dredging disturbs river
bottoms and destroys aquatic plant life in
the dredged portion of the river. The dis-
turbance of a riverbed can cause sediments
to contaminate a river for up to 10 km.

■✓● Reading Check Why does surface mining

cause animals to leave an area?

452 Chapter 16 Mining and Mineral Resources

Erosion and Sedimentation Excess rock from mines is some- MATHPRACTICE
times dumped into large piles called dumps. Running water
erodes unprotected dumps and transports sediments into nearby Volume Soil and over-
streams. The sediments may harm water quality and aquatic life. burden must be removed
to reach a coal seam that is 10 m
Soil Degradation Soil at a mine site is removed from the upper- below Earth’s surface. The exposed
most layer downward. When this soil is stored for later reuse, seam will be 1 km in length and
care must be taken to ensure that the upper soil layers are not 50 m wide. What is the total vol-
buried beneath soil layers that were originally below them. In this ume of soil and overburden that
way, the soil layers that are richest in important nutrients are not will have to be moved and stored?
covered. If soil is not removed and stored in separate layers, the If the coal seam is 5 m thick, what
soil may be nutrient poor when it is reclaimed. is the volume of coal that will be
removed? (Hint: The answers
Minerals that contain sulfur may be found in deeper soil lay- should be in m3.) What is the ratio
ers. If these minerals are exposed to water and oxygen in the of overburden to coal?
atmosphere, chemical reactions result in the release of acid, which
then acidifies the soil. When the acidified soil is returned to the Figure 16 ̈ A hole created by the
mine site, it may be difficult for plants to grow. subsidence of a gold mine has swal-
lowed this house in New Zealand.
Subsidence The sinking of regions of the ground with little or
no horizontal movement is called subsidence (suhb SIED’ns).
Subsidence occurs when pillars that have been left standing in
mines collapse or the mine roof or floor fails.

Buildings, houses, roads, bridges, underground pipelines, and
utilities that are built over abandoned mines could be damaged if
the ground below them subsides. In November and December
2000, underground limestone mines that were several hundred
years old collapsed in Edinburgh, Scotland. The collapse caused
property damage and forced people to evacuate their homes.
Figure 16 shows the potential effects of mine subsidence.

■✓● Reading Check How might exposing deep soil layers to the air

prevent plants from growing?

Figure 17 ̈ This photo shows a
coal seam that is on fire in a surface
coal mine in China.

Ecofact Underground Mine Fires Fires that start in underground coal
seams are one of the most serious environmental consequences of
Bats and Mines Over the past coal mining. Lightning, forest fires, and burning trash can all
century, human disturbance of tra- cause coal-seam fires. In addition, fires can start by themselves
ditional bat roosting sites, such as when minerals in the coal that contain sulfur are exposed to oxy-
caves and trees, has caused bats to gen. These fires are hard to put out and are often left to burn
move into abandoned mines. At themselves out, which may take decades or even centuries. For
present, 30 of the 45 species of example, a fire that has been burning through an underground
bats in the United States live in coal seam in an Australian mountain is estimated to be 2,000
mines. Some of the largest popula- years old! Underground fires that burn their way to the surface
tions of endangered bat species release smoke and gases that can cause respiratory problems. A
now live in abandoned mines. fire in a coal seam is shown in Figure 17.

Spider Map Mining Regulation and Reclamation
Create the
Graphic Organizer entitled Mines on land in the United States are regulated by federal and
“Spider Map” described in the state laws. To ensure that contaminants from mines do not
Appendix. Label the circle threaten water quality, mining companies must comply with regu-
“Mining Regulations.” Create a lations of the Clean Water Act and the Safe Drinking Water Act.
leg for each type of mining regu- The release of hazardous substances into the air, soil, and water
lation. Then, fill in the by mining is regulated by the Comprehensive Response
map with details Compensation and Liability Act. In addition, all mining opera-
about each type of tions must comply with the Endangered Species Act. This act
mining regulation. ensures that mining activities will not affect threatened or endan-
gered species and their habitats.

Reclamation The process of returning land to its original or better
condition after mining is completed is called reclamation. The
Surface Mining Control and Reclamation Act of 1977 (SMCRA)
created a program for the regulation of surface coal mining on
public and private land. The act set standards that would minimize
the surface effects of coal mining on the environment. SMCRA
also established a fund that is administered by the federal govern-
ment and is used to reclaim land and water resources that have
been adversely affected by past coal-mining activities.

454 Chapter 16 Mining and Mineral Resources

State Regulation of Mining States have created programs to Connection to History
regulate mining on state and private lands. Mining companies must
obtain permits from state environmental agencies before mining a Jihlava Jihlava is an ancient town
site. These permits specify certain standards for mine design and in the Czech Republic. In the
reclamation. In addition, some states have bond forfeiture pro- 1200s, silver was discovered in
grams. In a bond forfeiture program, a mining company must post Jihlava. The rush that followed
funds, called a bond, before a mining project begins. If the com- brought miners, merchants, and
pany does not mine and reclaim a site according to the standards traders from all over Europe. As a
required by its permits, the company must give these funds to the result, Jihlava became very pros-
state. The state then uses the funds to reclaim the site. A reclaimed perous. In addition to creating
surface coal mine is shown in Figure 18. municipal laws, the town passed
its own mining laws. Jihlava’s
State agencies are also responsible for inspecting mines to ensure mining laws served as an exam-
compliance with environmental regulations. Agencies issue viola- ple for other mining towns in
tions to companies that do not comply with environmental regula- central Europe.
tions and assess fines for noncompliance. In addition, states such as
Pennsylvania have begun large projects to reclaim abandoned mine Figure 18 ̈ Reclamation often
lands. Acid mine drainage, mine fires, mine subsidence, and hazards includes seeding, planting, and
related to open shafts and abandoned mining structures are all irrigating to return the land to its
problems that these projects will attempt to correct. original state.

S E C T I O N 3 Review

1. List seven potential environmental impacts of mining. CRITICAL THINKING

2. Name four federal laws that regulate mining activities 5. Making Decisions Give examples of environmental
in the United States. concerns that would be taken into account by a min-
ing company when it created a reclamation plan for a
3. Define the term reclamation. mine site.

4. Describe two ways in which state governments 6. Making Decisions Read about how topsoil is
regulate mining. removed and stored for later reclamation under the
heading “Soil Degradation.” How can this process
be implemented to keep soils from degrading?

READING SKILLS

Section 3 Mining Regulations and Mine Reclamation 455

16C H A P T E R Highlights

1 Minerals and Mineral Key Terms Main Ideas
Resources
mineral, 441 ̈ A mineral is a naturally occurring, usually
2 Mineral Exploration and ore mineral, 442 inorganic solid that has a characteristic chemi-
Mining cal composition, an orderly physical structure,
and a characteristic set of physical properties.
3 Mining Regulations and
Mine Reclamation ̈ Minerals that are valuable and economical to
extract are known as ore minerals.
456 Chapter 16 Highlights
̈ Ore minerals may form from the cooling of
magma, the circulation of hot-water solutions
through rocks, and the evaporation of water
that contains salts.

̈ Metals are important economically because
of their electrical and thermal conductivity,
durability, and heat and corrosion resistance.

subsurface mining, ̈ Mining companies conduct mineral explo-
446 ration to identify areas where there is a high
likelihood of finding valuable mineral resources
surface mining, 447 in quantities worth mining.
placer deposit, 449
smelting, 450 ̈ Room-and-pillar mining, longwall mining, and
solution mining are subsurface mining methods.

̈ Open-pit mining, surface coal mining, quar-
rying, and solar evaporation are surface-mining
methods.

̈ Minerals are concentrated by wind and water
into surface deposits called placer deposits.

̈ Smelting is the process in which ore is melted
at high temperatures to separate impurities
from the molten metal.

subsidence, 453 ̈ Some of the environmental consequences of
reclamation, 454 mining may include air and noise pollution,
water contamination, displacement of wildlife,
erosion and sedimentation, soil degradation,
subsidence, and underground mine fires.

̈ The U.S. government has enacted legislation
that regulates mining and attempts to minimize
the impact of mining on the environment.

̈ Federal and state agencies issue permits to
mining companies, issue violations and assess
penalties when mining companies do not comply
with standards set by their permits, and ensure
that abandoned mine lands are reclaimed.

16C H A P T E R Review

Using Key Terms 12. Ore deposits form from
a. the cooling of magma.
Use each of the following terms in a separate b. the evaporation of water that contains
sentence. salts.
c. the circulation of hot-water solutions in
1. mineral rocks.
2. placer deposit d. All of the above
3. smelting
4. subsidence 13. Which of the following economically impor-
5. reclamation tant elements is not a metal?
For each pair of terms, explain how the meanings a. zinc
of the terms differ. b. titanium
6. element and mineral c. copper
7. ore mineral and gangue mineral d. sulfur
8. placer deposit and dredging
9. subsurface mining and surface mining 14. Which of the following methods is not a
subsurface mining method?
STUDY TIP a. quarrying
b. solution mining
Using Terms Work together with a study partner. c. longwall mining
Learn the definitions of both the boldfaced and d. room-and-pillar mining
italicized words that appear in this chapter. When
both you and your partner feel confident in hav- 15. Which of the following mining methods
ing learned the meanings of these terms, take out would most likely be used to mine salt?
a piece of paper. On this paper, you and your a. solution mining
partner will each write a one-page essay in which b. open-pit mining
you use as many of these terms as possible. When c. solar evaporation
you both are finished, exchange essays and review d. both (a) and (c)
them for accuracy.
16. Dredging would not be used to mine
Understanding Key Ideas a. diamonds.
b. salt.
10. Which of the following statements does not c. heavy minerals.
correctly describe a mineral? d. gold.
a. A mineral is a naturally occurring sub-
stance. 17. Which of the following elements in minerals
b. A mineral is an organic substance. causes soil to become acidified?
c. A mineral is a solid substance. a. potassium
d. A mineral has a characteristic chemical b. calcium
composition. c. sulfur
d. barium
11. Gold, silver, and copper are
a. nonmetallic minerals. 18. Which of the following pieces of federal leg-
b. native elements. islation established a program for regulating
c. compounds. coal mining on public and private lands?
d. gangue minerals. a. the Comprehensive Response and Liability
Act
b. the Clean Air Act
c. the Clean Water Act
d. the Surface Mining Control and
Reclamation Act of 1977

Chapter 16 Review 457

16C H A P T E R Review

Short Answer Concept Mapping ?
??
19. What is the difference between native ele-
ments and compounds? 27. Use the following terms to create a concept
map: subsurface mining, surface mining,
20. Describe the solar evaporation process. room-and-pillar mining, longwall mining,
solution mining, open-pit mining, surface
21. What are the surface and subsurface methods coal mining, and quarrying.
by which coal is commonly mined?
Critical Thinking
22. Explain why undersea mining has been
largely unsuccessful to date. 28. Analyzing Relationships Read about the
technological changes in the mining industry
23. Describe how reclaimed soil may become that are discussed in the introduction to
degraded. Section 2. What method or methods of min-
ing seem well suited for automation, particu-
24. Explain the purpose of a state bond forfei- larly robotics? READING SKILLS
ture program.
29. Making Decisions Mining companies use com-
Interpreting Graphics puter models to show them where high- and
low-grade ores are located in the deposit that
The graph below shows total U.S. mineral pro- they are mining. If the price of the ore mineral
duction from 1995 to 1999. Use the graph to that a company is mining suddenly increases,
answer questions 25–26. how would computer modeling help the com-
pany economically exploit the mineral deposit
25. In 1995, metals accounted for $14 billion of to take advantage of the increase in price?
the $39 billion total U.S. production of min-
erals. Metals accounted for what percentage Cross-Disciplinary Connection
of the total U.S. production of minerals?
30. Social Studies Fifteen to 20 miles southwest
26. In 1999, metals accounted for only of Santa Fe, New Mexico, are a series of low
$10 billion of the $39 billion total U.S. hills known as Los Cerrillos. Native
production of minerals. Metals accounted Americans mined the blue-green gemstone
for what percentage of the total U.S. pro- turquoise from narrow veins in rock from
duction of minerals? these hills for more than 1,000 years,
beginning in about the year 875. Research
U.S. mineral production Changes in U.S. Mineral Production Native American mining at Los Cerrillos,
(in billions of dollars) 1995–1999 New Mexico. Write a short report about
your findings. WRITING SKILLS
50

45 Metals
Industrial minerals

40

35 Portfolio Project

30 31. Debate A mining company has applied for
permits to establish a surface mine on land
25 that is located near a stretch of river in
which an endangered species of fish lives.
20 Assume that the ore to be mined is rare and
has important new applications in cancer
15 treatment. Weighing both sides of the argu-
ment, would you issue the permits? Make
10 your case for or against issuing the mining
permits in a debate with your classmates.
5

0 1996 1997 1998 1999
1995

Source: U.S. Geological Survey.

458 Chapter 16 Review

MATH SKILLS READING SKILLS

32. Making Calculations Some low-grade gold Read the passage below, and then answer
ores that have been mined economically aver- the questions that follow.
age about 0.1 oz of gold per ton of ore. Five
tons of rock must be removed to obtain one One of the only two rocks in which diamonds
ton of ore. How many tons of rock must be have been found is called kimberlite. Kimber-
mined to obtain 1 oz of gold? How many lite is an uncommon kind of rock that forms
pounds of ore must be processed to obtain cylindrical subsurface bodies called kimberlite
1 oz of gold? pipes. Kimberlite pipes look very much like
the vents that bring lava to the surface in vol-
WRITING SKILLS canoes. Diamonds form deep in the Earth’s
mantle under enormous temperatures and
33. Communicating Main Ideas One of the pressures. Diamonds are believed to be carried
main ideas of this chapter is that the human to the surface in kimberlite pipes in very rapid,
need for minerals requires mining companies explosive events. However, not all kimberlite
to continually find new deposits of minerals pipes contain diamonds.
that can be extracted inexpensively.
Extraction must be done in such a way that Kimberlite is a soft, black, blue, or green
the environment is not severely affected. rock that weathers rapidly when it reaches
Using surface coal mining or open-pit mining Earth’s surface. Because kimberlite decom-
as an example, explain why it is difficult to poses rapidly, it does not form rock outcrops.
mine large ore deposits without affecting the Instead, it forms circular depressions several
environment. feet below the surface of the ground. These
depressions may be covered with a bluish
34. Writing Persuasively A mining company is kimberlite soil called blue ground. Iron-
applying for permits to establish an open-pit stained soils may also cover depressions.
mine near your home. Do research to deter- These soils are referred to as yellow ground.
mine what impact, if any, the operation will
have on your quality of life, the environ- 1. Which of the following statements about
ment, and the economics of your community. kimberlite is not true?
Summarize your findings in a concise one- a. Diamonds are found in kimberlite.
page paper. b. All kimberlite contains diamonds.
c. Kimberlite weathers rapidly at Earth’s
35. Outlining Topics You are an exploration surface.
geologist who works for a mining company. d. Kimberlite is an uncommon kind
You are searching for a new deposit of an ore of rock.
mineral. Outline the steps you would take to
find a deposit and to determine whether that 2. If you were an exploration geologist
deposit would be economical to mine. searching for a deposit of diamonds,
which of the following would not be a
good surface indicator of the existence of
a kimberlite pipe?
a. a circular depression
b. a bluish soil that fills a depression
c. an iron-stained soil that fills a
depression
d. a large rock outcrop

Chapter 16 Review 459

16C H A P T E R Standardized Test Prep

Understanding Concepts Reading Skills

Directions (1–4): For each question, write on a Directions (7–9): Read the passage below. Then
separate sheet of paper the letter of the correct answer the questions.
answer.
The process of returning land to its original
1 Which of the following statements is true? or better condition after mining is completed is
called reclamation. In the United States billions
A. Minerals are found both on and beneath of dollars are spent to clean up abandoned
Earth’s surface. mines. The Surface Mining Control and
Reclamation Act of 1977 (SMCRA) created a
B. Minerals are metallic compounds of program for the regulation of surface coal
economic importance. mining on public and private lands. The act set
standards that would minimize the surface
C. Minerals are limited resources easily effects of coal mining on the environment.
extracted from the ground. SMCRA also established a fund that is used to
reclaim land and water resources that have
D. Minerals are unlimited resources been adversely affected by past coal-mining
extracted from the ground at little cost. activities.

2 Which of these nonmetallic minerals has States also have programs to regulate
mining activities. Mining companies must
many uses in the construction industry? obtain permits from state environmental
F. gypsum agencies before mining a site.
G. quartz
H. silicon 7 Reclamation is
I. tourmaline
A. a program for the regulation of surface
3 Salt is mined underground using what coal mining on public and private lands.

technique? B. a program to regulate mining activities.
A. longwall mining C. the process of returning land to its origi-
B. open-pit mining
C. solution mining nal or better condition before mining.
D. surface mining D. the process of returning land to its origi-

4 What distinguishes native elements from nal or better condition after mining.

most other minerals? 8 What is the focus of the SMCRA?
F. Native elements are not compounds.
G. Native elements are always non-metallic. F. maximizing profits from surface coal
H. Native elements are mined by solar mines

evaporation. G. decreasing air pollution from surface
I. Native elements are essentially the coal mines

minerals that make up Earth’s crust. H. minimizing harm to the environment
caused by surface coal mining
Directions (5–6): For each question, write a short
response. I. ensuring safe conditions for people
who work in coal mines
5 Excess rock from mines is sometimes
9 Before mining a site, coal-mining compa-
dumped into large piles. Running water
erodes these unprotected dumps, nies must
transporting the rocks and sediment into A. reclaim land and water resources.
nearby streams. What effect does the B. return land to its original or better
resulting sedimentation have on a stream’s
ecosystem? condition.
C. obtain permits from state environmental
6 The ocean floor contains significant mineral
agencies.
resources. Assess the environmental impact D. set standards to minimize the effects of
of mining on the ocean floor.
mining on the environment.

460 Chapter 16 Standardized Test Prep

Interpreting Graphics

Directions (10–13): For each question below, record the correct answer on
a separate sheet of paper.

The table below shows the properties for some minerals. Use this table to
answer questions 10 through 12.

Properties of Selected Minerals

Mineral Luster Color Streak Hardness Specific
Gravity
Bauxite varies brownish yel- varies varies varies
(a mixture of low, brown, red,
several gray 2.6–2.8
minerals) 4.5–4.8
vitreous blue, green, white 721ᎏ – 8 8.0–8.2
Beryl yellow, pink
(Be Al Si O ) 5.8–6.1
metallic to sub- black to brown- dark brown 521ᎏ
3 2 6 18
metallic ish black
Chromite
(FeCr O ) adamantine scarlet red to vermillion 2–221ᎏ
(diamond-like) brownish red
24 (vivid red to red

Cinnabar orange)

Cuprite adamantine or red, sometimes brownish red 312ᎏ – 4
(Cu O)
submetallic very dark red
2

0 If a mineral sample has an adamantine luster, what test could be used Test

to most accurately identify the specific mineral? Take time to read
F. color each question com-
G. hardness pletely, including all
H. specific gravity of the answer
I. streak choices. Consider
each answer choice
q Using the table, what conclusion can be reached about beryl? before determining
which one is correct.
A. It is a soft mineral.
B. Its color varies greatly.
C. It has a metallic luster.
D. It is seven times heavier than water.

w What properties can a scientist observe most easily in the field?

F. color and luster
G. hardness and streak
H. specific gravity and hardness
I. streak and specific gravity

e Bauxite is the major ore mineral of what element?

A. aluminum
B. copper
C. manganese
D. titanium

Chapter 16 Standardized Test Prep 461

16C H A P T E R Skills Practice Lab: OBSERVATION

Objectives Extraction of Copper from Its Ore

̈ Extract copper from copper car- Most metals are combined with other elements in the Earth’s crust.
bonate in much the same way A material in the crust that is a profitable source of an element is
that copper is extracted from called an ore. Malachite (MAL uh KIET) is the basic carbonate of
malachite ore. copper. The green corrosion that forms on copper because of
weathering has the same composition that malachite does. The
̈ USING SCIENTIFIC METHODS reactions of malachite are similar to those of copper carbonate.

Hypothesize how this process In this investigation, you will extract copper from copper car-
can be applied to extract other bonate using heat and dilute sulfuric acid. The process you will
metallic elements from ores. be using will be similar to the process in which copper is
extracted from malachite ore.
Materials
Procedure
Bunsen burner
copper (cupric) carbonate 1. CAUTION: Wear your laboratory apron, gloves, and safety
funnel goggles throughout the investigation. Fill one of the test
iron filings tubes about one-fourth full of copper carbonate. Record the
sulfuric acid, dilute color of the copper carbonate.
test-tube holder
test-tube rack 2. Light the Bunsen burner, and adjust the flame.
test tubes, 13 mm x 100 mm (2)
water 3. Heat the copper carbonate by holding the tube over the
flame with a test-tube holder, as shown in the figure on the
next page. CAUTION: When heating a test tube, point it
away from yourself and other students. To prevent the test
tube from breaking, heat it slowly by gently moving the test
tube over the flame. As you heat the copper carbonate,
observe any changes in color.

4. Continue heating the tube over the flame for 5 min.

5. Allow the test tube to cool. Observe any change in the vol-
ume of the material in the test tube. Then, place the test tube
in the test-tube rack. Insert a funnel in the test tube, and add

̈ Copper Ore Malachite is a car-
bonate of copper that commonly
forms in copper deposits. It is some-
times used as an ore of copper.

462 Chapter 16 Skills Practice Lab

dilute sulfuric acid until the test tube is three-fourths full. ̈ Step 3 To heat the copper car-
CAUTION: Avoid touching the sides of the test tube, which bonate, hold the tube over the flame
may be hot. If any of the acid gets on your skin or clothing, with a test-tube holder. Point the test
rinse immediately with cool water and alert your teacher. tube away from yourself and other
students.
6. Allow the test tube to stand until some of the substance at
the bottom of the test tube dissolves. After the sulfuric acid
has dissolved some of the solid substance, note the color of
the solution.

7. Use a second test tube to add more sulfuric acid to the
first test tube until the first test tube is nearly full.
Allow the first test tube to stand until more of the sub-
stance at the bottom of the test tube dissolves. Pour
this solution (copper sulfate) into the second test tube.

8. Add a small number of iron filings to the second test
tube. Observe what happens.

9. Clean all of the laboratory equipment, and dispose of
the sulfuric acid as directed by your teacher.

Analysis

1. Explaining Events Disregard-
ing any condensed water
on the test-tube walls, what
do you call the substance
formed in the first test tube?
Explain any change in the
volume of the new substance
relative to the volume of the copper carbonate.

2. Explaining Events When the iron filings were added to the
second test tube, what indicated that a chemical reaction was
taking place? Explain any change to the iron filings. Explain
any change in the solution.

Conclusions

3. Drawing Conclusions Why was sulfuric acid used to extract
copper from copper carbonate?

Extension

1. Analyzing Data Suppose that a certain deposit of copper
ore contains a minimum of 1 percent copper by mass and
that copper sells for $0.30 per kilogram. Approximately
how much could you spend to mine and process the copper
from 100 kg of copper ore and remain profitable?

2. Making Comparisons How is the process used in this
experiment similar to the cyanide heap-leaching process
used to extract gold from low-grade ore?

Chapter 16 Skills Practice Lab 463

EARTH SCIENCE CONNECTION

MINERAL PRODUCTION IN THE UNITED STATES

MAP SKILLS

In 1999, the top 10 mineral commodities pro- 2. Evaluating Data Gold, copper, iron ore, and zinc
duced in the United States had a total value of are metals in the top 10 mineral commodities pro-
about $31.6 billion. Over half of this production duced in 1999. What percentage of total 1999 pro-
value came from the top three commodities: duction value do these metals represent? Which
stone, cement, and sand and gravel. The map states were the producers of these metals in 1999?
above shows the distribution of the production
of these commodities by state. Use the map 3. Evaluating Data Stone, sand, and gravel are col-
above to answer the following questions. lectively known as aggregates. What percentage of
total 1999 production value do aggregates represent?
1. Using a Key Find your state on the map of mineral Which states were the major producers of aggregates
production. Which of the top 10 mineral commodi- in 1999?
ties, if any, were produced in your state in 1999?
4. Using a Key Which states produced salt in 1999?
464 Chapter 16 Maps in Action

EARTH SCIENCE CONNECTION

COLTAN AND THE WAR IN THE CONGO

If you purchase a mobile phone, out in the DRC. Two years later, ̈ Cell phones are just one of the
pager, or laptop computer, you may neighbors Rwanda and Uganda electronic products in common use
not be aware of the connection entered the conflict and backed two today that require tantalum in their
between these devices and politics in Congolese rebel movements. Shortly production.
central Africa. Each of these prod- thereafter, Angola, Namibia, and
ucts requires tantalum in its manu- Zimbabwe lent their support to the DRC. Government and rebel
facture. Tantalum is a heat-resistant government of the DRC. Today, the forces have attacked, killed, and
metal that can hold a high electric Rwandan- and Ugandan-backed tortured innocent civilians to
charge. Tantalum is ideal for the rebels have primary control of the maintain their rule. Almost half of
production of capacitors, which are coltan ore in the eastern DRC. the population of the DRC lacks
used to regulate voltage in many of safe drinking water. Access to
the electronic products in use today. The war in the DRC is as much health care is limited, and an esti-
an economic war as an ethnic war. mated 2 million people suffer from
The main ore of tantalum is The price of coltan has reached HIV/AIDS.
columbite-tantalite, which is often prices as high as $400 per kilogram.
shortened to coltan. Eighty percent Forces from neighboring Rwanda, Meanwhile, coltan mining has
of the world’s coltan reserves are Uganda, and Burundi have been moved into coltan-rich national
found in the mountains of the east- accused of smuggling coltan out of parks and reserves. Wildlife is
ern part of the Democratic Republic the DRC and making enormous being lost at an alarming rate as
of the Congo (DRC). From the profits. This money is being used to miners kill animals for food and
DRC, coltan makes its way into the help finance the continuing war elephants for ivory.
world market, much of it illegally. efforts of these countries.

The 1996 Civil War The Consequences of Civil War

In 1996, hostilities between ethnic Since 1998, almost 2.5 million peo-
peoples caused civil war to break ple have died in the fighting in the

̈ Columbite-tantalite miners in the Democratic Republic of the Congo
can earn from $10 to $50 a week, whereas the average Congolese worker
earns around $10 a month.

What Do You Think?

Many electronics companies
have stopped buying
columbite-tantalite ore from
central African countries. What
effect, if any, do you think this
action will have on present
conditions in the DRC?

Chapter 16 Society and the Environment 465

Nonrenewable Energy 17C H A P T E R

1 Energy Resources and

Fossil Fuels

2 Nuclear Energy

PRE-READING ACTIVITY

Booklet
Before you
read this chap-
ter, create the
FoldNote entitled “Booklet”
described in the Reading and
Study Skills section of the
Appendix. Label each page of
the booklet with a main idea
from the chapter. As you
read the chapter, write what
you learn about
each main idea
on the appropri-
ate page of the
booklet.

At this petroleum refinery in
Germany, crude oil pumped from the
Earth is changed into fuels, such as
gasoline, and other products.

466

SECTION 1 EARTH SCIENCE CONNECTION

Energy Resources and Fossil Fuels Objectives

How does a sunny day 200 million years ago relate to your life ̈ List five factors that influence the
today? Chances are that if you traveled to school today or used a value of a fuel.
product made of plastic, you used some of the energy from sun-
light that fell on Earth several hundred million years ago. Life as ̈ Explain how fuels are used to gen-
we know it would be very different without the fuels or products erate electricity in an electric
formed from plants and animals that lived alongside the dinosaurs. power plant.

The fuels we use to run cars, ships, planes, and factories and to ̈ Identify patterns of energy con-
produce electricity are natural resources. Most of the energy we sumption and production in the
use comes from a group of natural resources called fossil fuels. world and in the United States.
Fossil fuels are the remains of ancient organisms that changed into
coal, oil, or natural gas. Fossil fuels are central to life in modern ̈ Explain how fossil fuels form and
societies, yet there are two main problems with fossil fuels. First, how they are used.
the supply of fossil fuels is limited. Second, obtaining and using
them causes environmental problems. In the 21st century, societies ̈ Compare the advantages and dis-
will continue to explore alternatives to fossil fuels but will also advantages of fossil-fuel use.
focus on developing more-efficient ways to use these fuels.
̈ List three factors that influence pre-
Fuels for Different Uses dictions of fossil-fuel production.

Fuels are used for five main purposes: for cooking, transportation, Key Terms
manufacturing, heating and cooling buildings, and generating elec-
tricity to run machines and appliances. The suitability of a fuel for fossil fuels
each application depends on the fuel’s energy content, cost, avail- electric generator
ability, and safety, and the byproducts of the fuel’s use. For exam- petroleum
ple, it is hard to imagine an airplane, such as the one shown in oil reserves
Figure 1, running on coal. Although coal is readily available and
inexpensive, to power an airplane using coal would require hun- Figure 1 ̈ Different Fuels,
dreds of tons of coal. Likewise, the people shown around the Different Purposes The airplane
campfire are not warming themselves by burning airplane fuel, (left) is being refueled with a highly
they are burning wood, which is a perfect fuel for their needs. refined liquid fuel. Airplane fuel must
have a high ratio of energy to
weight. The campers (below) are
keeping warm by burning wood in
an open fire.

Section 1 467

Figure 2 ̈ These pylons and wires Electricity—Power on Demand
are part of an electricity distribution
grid in upstate New York. The energy in fuels is often converted into electrical energy in
order to power machines, because electricity is more convenient
to use. Computers, for example, run on electricity rather than oil.
Electricity can be transported quickly across great distances, such
as an entire state, or across tiny distances, such as inside a com-
puter chip. The electricity that powers the lights in your school
was generated in a power plant and then carried to users through
a distribution grid like the one shown in Figure 2. Two disadvan-
tages of electricity are that it is difficult to store and other energy
sources have to be used to generate it.

How Is Electricity Generated? An electric generator is a
machine that converts mechanical energy, or motion, into electri-
cal energy. Generators produce electrical energy by moving an
electrically conductive material within a magnetic field. Most
commercial electric generators convert the movement of a turbine
into electrical energy, as shown in Figure 3. A turbine is a wheel
that changes the force of a moving gas or liquid into energy that
can do work. In most power plants, water is boiled to produce
the steam that turns the turbine. The water is heated by burning
a fuel in coal-fired and gas-fired plants or is heated from the
fission of uranium in nuclear plants. The turbine spins a genera-
tor to produce electricity.

Figure 3 ̈ How a Coal-Fired Power Plant Works

468 Chapter 17 Nonrenewable Energy

Energy consumption per person Energy Consumption per Person by Country, 1990 and 2003 Figure 4 ̈ During this fourteen-year
(in millions of Btu) 450 period, energy use per person stayed
about the same in Switzerland and in
400 1990 the United States. Energy use per
2003 person in South Korea increased by
almost 50 percent.
350

300

250
200

150

100 QuickLAB

50 Generating
Electricity
0 South Argen- Indo-
Canada United Switzer- Japan Korea tina nesia Procedure
States land 1. Tightly wrap 100 cm of fine-

Source: U.S. Department of Energy. gauge copper wire around a
small cardboard tube.
Energy Use 2. Attach a galvanometer or a
battery tester to the ends of
Every product requires energy to produce. And the price of most the wire.
products and services that you use reflects the cost of energy. 3. Pass a bar magnet through the
Buying a plane ticket, for example, includes the cost of the fuel. cardboard tube, and observe
the galvanometer.
World Patterns People in developed societies use much more Analysis
energy than people in developing countries do. However, energy 1. What did you observe?
use in some developing countries is growing rapidly. Even within 2. How could you increase the
the developed world there are striking differences in energy use. current you detected?
For example, Figure 4 shows that a person in Canada or the 3. How does this lab model an
United States uses more than twice as much energy as a person in electric power plant?
Japan or Switzerland does. Yet personal income in Japan and
Switzerland is higher than personal income in Canada and the How Energy Is Used
United States. One reason for this difference lies in how energy in the United States
is generated and used in those countries.
Residential Industrial
Energy Use in the United States The United States uses more 19% 38%
energy per person than any other country in the world except
Canada and the United Arab Emirates. Part of the reason that the Commercial
United States uses so much energy is that, as Figure 5 shows, the 16%
United States uses more than 25 percent of its energy resources to
transport goods and people, mainly by trucks and personal vehicles. Transportation
In contrast, Japan and Switzerland have extensive rail systems and 27%
they are relatively small, compact countries. The availability and
cost of fuels also influence fuel use. Residents of the United States Source: International Energy Agency.
and Canada enjoy some of the lowest gasoline taxes in the world.
There is little incentive to conserve gasoline when its cost is so low. Figure 5 ̈ This graph shows the
Japan and Switzerland, which have minimal fossil-fuel resources, percentages of total energy use in the
supplement a greater percentage of their energy needs with other United States for different purposes.
energy sources, such as hydroelectric or nuclear power.

■✓● Reading Check Give two reasons why the United States uses more

energy per person compared with most other countries. (See the

Appendix for answers to Reading Checks.)

Section 1 Energy Resources and Fossil Fuels 469

www.scilinks.org How Fossil-Fuel Deposits Form

Topic: Fossil Fuels Fossil fuels are not distributed evenly, as shown in Figure 6. For
Code: HE80614 example, why is there an abundance of oil in Texas and Alaska
but very little in Maine? Why does the eastern United States
Chain-of- produce so much coal? The answers to these questions lie in the
Events Chart geologic history of the areas.
Create the Graphic Organizer
entitled “Chain-of-Events Chart” Coal Formation Coal forms from the remains of plants that lived
described in the Appen- in swamps hundreds of millions of years ago. Much of the coal in
dix. Then, fill in the chart the eastern United States formed about 320 million to 300 million
with details about each years ago, when vast areas of swampland covered the eastern
step of the formation of United States. As ocean levels rose and fell, these swamps were
fossil fuels. repeatedly covered with sediment. Layers of sediment compressed
the plant remains, and heat and pressure within the Earth’s crust
Figure 6 ̈ This map shows coal, oil, caused coal to form. Coal deposits in the western United States
and natural gas deposits in the also formed from ancient swamps, but those deposits are much
United States. younger. The abundant coal deposits in states such as Wyoming
formed between 100 million and 40 million years ago.

Oil and Natural Gas Formation Oil and natural gas result from
the decay of tiny marine organisms that accumulated on the bot-
tom of the ocean millions of years ago. After these remains were
buried by sediments, they were heated until they became com-
plex energy-rich carbon-based molecules. Over time, the mole-
cules migrated into the porous rocks that now contain them.
Much of the oil and natural gas in the United States is located in
Alaska, Texas, California, and the Gulf of Mexico.

470 Chapter 17 Nonrenewable Energy

Energy Production by Source Figure 7 ̈ The

1.2 Middle East pro-

Energy equivalent duces the majority
(in billions of metric tons of oil) Coal of the world’s oil.
1.0 Oil Asia, however,

Natural gas produces the

Nuclear most coal.

0.8 Renewable

0.6

0.4

0.2

0 Europe Middle North South Africa
Asia East America America

Source: International Energy Agency.

Coal Figure 8 ̈ About half of the
electricity generated in the United
Most of the world’s fossil-fuel reserves are made up of coal. Asia States comes from burning coal.
and North America are particularly rich in coal deposits, as shown This power plant (bottom) in West
in Figure 7. Two major advantages of coal are that it is relatively Virginia is located close to the
inexpensive and that it needs little refining after it has been mined. abundant coal deposits in that state.
About half of the electricity generated in the United States comes
from coal-fired power plants, as shown in Figure 8. How Electricity Is Generated
in the United States

Coal Mining and the Environment The environmental effects of Hydroelectricity 7%
coal mining vary. Underground mines can have a minimal effect
on the environment at the surface. However, surface coal-mining Natural gas 18% Oil 3%
operations sometimes remove the top of an entire mountain to
reach the coal deposit. In addition, if waste rock from coal mines Other 2%
is not properly contained, toxic chemicals can leach into nearby
streams. A lot of research focuses on developing better methods Nuclear Coal
of locating the most productive, clean-burning coal deposits and 20% 50%
developing less damaging methods of mining coal.

Air Pollution The quality of coal varies. Higher-
grade coals, such as bituminous coal, produce more
heat and less pollution than a lower-grade coal, such
as lignite. Sulfur, which is found in all grades of coal,
can be a major source of pollution when coal is
burned. When high-sulfur, low-grade coal is burned,
it releases much more pollution than a low-sulfur
bituminous coal does. The air pollution and acid pre-
cipitation that result from burning high-sulfur coal
without adequate pollution controls are serious prob-
lems in countries such as China. However, clean-
burning coal technology has dramatically reduced air
pollution in countries such as the United States.

Section 1 Energy Resources and Fossil Fuels 471

Connection to Chemistry Petroleum

Catalytic Converters Catalytic Oil that is pumped from the ground is also known as crude oil, or
converters are one of the most petroleum. Anything that is made from crude oil, such as fuels,
important emission-control fea- chemicals, and plastics, is called a petroleum product. Much of the
tures on cars. These devices use world’s energy needs are met by petroleum products. In fact, petro-
two separate catalysts—a reduc- leum accounts for 45 percent of the world’s commercial energy use.
tion catalyst and an oxidation
catalyst. The reduction catalyst Locating Oil Deposits Oil is found in and around major geologic
uses platinum and rhodium to features, such as folds, faults, and salt domes, that tend to trap
separate nitrous oxides, forming oil as it moves in the Earth’s crust. These features are bound by
nitrogen and oxygen molecules. impermeable layers of rock, which prevent the oil from escaping.
The oxidation catalyst uses plat- Most of the world’s oil reserves are in the Middle East. Large oil
inum and palladium to burn—or deposits also exist in the United States, Venezuela, the North Sea,
oxidize—hydrocarbons and car- Siberia, and Nigeria. When geologists have gathered all of the
bon monoxide, forming carbon data that they can from the Earth’s surface, exploration wells are
dioxide, which is less harmful. drilled to determine the volume and availability of the oil deposit.
If oil can be extracted at a profitable rate, wells are drilled and
the oil is pumped or flows to the surface. After the oil is removed
from a well, it is transported to a refinery to be converted into
fuels and other petroleum products.

■✓● Reading Check What is the purpose of drilling exploration wells

for oil?

Methane Hydrates—
Fossil Fuel of the Future?

Deep under the waves in the Gulf drilling for oil in Siberia. Today, the Carolinas and in the Gulf of
of Mexico lies an untapped resource huge deposits of this “solid” natural Mexico. If we could recover just one
that could be the fuel of the future. gas have been discovered around percent of the methane hydrates
It looks like ice, but it burns with a the edges of most continents. The around the United States we could
bright fire. This strange compound deposits are often several hundred more than double our supply of
is called methane hydrate. meters thick. natural gas, a clean-burning fuel
that produces little pollution except
A methane hydrate is a cagelike Methane hydrates form in geo- for carbon dioxide.
lattice of ice that contains trapped logic situations in which tempera-
molecules of methane. Methane is a tures are stable and low and Natural gas is in increasing
natural gas made up of carbon and pressure is high. In places such as demand for use in new electric
hydrogen. The methane in methane Siberia and Alaska, methane power stations. These power sta-
hydrates results from the bacterial hydrates form below the tundra tions are cheaper to build than
decomposition of organic matter. where permafrost extends down other power stations and produce
into shallow sediments. They also little air pollution. Natural gas is also
Methane hydrates have been form under the ocean in water that used to fuel low-pollution vehicles.
known to exist since 1890. How- is deeper than 500 m. In the United
ever, nobody knew that the States, there are deposits of Natural gas will become an
hydrates formed in nature until methane hydrates off the shores of increasingly important substitute for
1964, when a large deposit was dis- Alaska, Washington, California, and coal and petroleum as countries limit
covered by a Soviet crew that was their emissions of the greenhouse

472 Chapter 17 Nonrenewable Energy

The Environmental Effects of Using Oil When petroleum fuels Figure 9 ̈ This ship is attempting to
are burned, they release pollutants. Internal combustion engines contain the oil spilled from the Sea
in vehicles that burn gasoline pollute the air in many cities. These Empress in 1996.
pollutants contribute to the formation of smog and cause health
problems. Emissions regulations and technology such as catalytic
converters have reduced air pollution in many areas. However, in
developing countries, cars are generally older, and the gasoline
that they burn contains significantly more sulfur, a pollutant that
contributes to acid precipitation. As well, the carbon dioxide
released from burning petroleum fuels may contribute to global
warming.

Oil spills, such as the one shown in Figure 9, are another
potential environmental problem of oil use. In recent years, new
measures have been taken to prevent oil spills from tankers.
These measures include requiring that new tankers be double-
hulled so that puncturing the outer hull does not allow the oil
to leak out. Also, response times to clean up oil spills have
improved. While oil spills are dramatic, much more oil pollution
comes from everyday sources, such as leaking cars. However,
measures to reduce everyday contamination of our waterways
from oil lag far behind the efforts made to prevent large spills.

EARTH SCIENCE CONNECTION

̈ A researcher holds a chunk of
burning methane hydrate (far left).
A methane hydrate mound in the
Gulf of Mexico (left).

gas carbon dioxide to reduce global So far, we have no technology CRITICAL THINKING
warming. The use of fuel-cell tech- to recover or use this strange mix-
nology in vehicles will also increase. ture of ice and methane. One 1. Applying Processes What are
Fuel cells need hydrogen as a power potential idea is to pump heated the differences between the geo-
source, and natural gas is a conven- water into a methane hydrate logic processes by which petroleum
ient source of hydrogen. The first deposit to melt the ice and release and natural gas form and the way
fuel-cell vehicles will probably be the methane gas. The gas would methane hydrates form?
fueled at a gas station that also has a then have to be pumped to a pro-
natural gas pump. cessing plant. 2. Analyzing Relationships
Methane is a very effective green-
house gas. How might this factor
into the extraction or use of
methane hydrates in the future?

Section 1 Energy Resources and Fossil Fuels 473

Figure 10 ̈ Except when it is refuel- Natural Gas About 20 percent of the world’s nonrenewable
ing, a vehicle that runs on natural gas energy comes from natural gas. Natural gas, or methane (CH4), is
looks like one that runs on gasoline. a good example of how advances in technology can make a fuel
more common. In the past, when natural gas was encountered in
MATHPRACTICE an oil well, it was burned off because it was considered a nui-
sance. As technology improved, transporting natural gas in
World Energy Use pipelines and storing it compressed in tanks became more practi-
In 1980, worldwide cal. Now, many more oil wells recover natural gas. Because burn-
production of petroleum ing natural gas produces fewer pollutants than burning other
was 59.6 million barrels per day. fossil fuels, vehicles that run on natural gas, such as the one in
In 1998, petroleum production Figure 10, require fewer pollution controls. Electric power plants
was 66.9 million barrels a day. can also use this clean-burning fuel.
Calculate the percent increase in
oil production during this period. Fossil Fuels and the Future

Today, fossil fuels supply about 90 percent of the energy used in
developed countries. Some projections suggest that by 2050
world energy demand will have doubled, mainly as a result of
increased population and industry in developing countries. As the
demand for energy resources increases, the cost of fossil fuels will
likely increase enough to make other energy sources more attrac-
tive. Planning now for the energy we will use in the future is
important because it takes many years for a new source of energy
to make a significant contribution to our energy supply.

Predicting Oil Production Oil production is still increasing, but
it is increasing much more slowly than it has in the past, as
shown in Figure 11. Many different factors must be considered
when predicting oil production. Oil reserves are oil deposits that
can be extracted profitably at current prices using current tech-
nology. In contrast, some oil deposits are yet to be discovered or
to become commercial. Predictions must also take into account
changes in technology that would allow more oil to be extracted
in the future.

Figure 11 ̈ This graph shows past Past and Predicted Oil Production
oil production and one prediction for 30
the future.
25
474 Chapter 17 Nonrenewable Energy
Oil production 20
(in billions of barrels)
15

10

5

0 1950 1970 1990 2010 2030 2050
1930 Year

Source: Petroconsultants S.A.

Finally, all predictions of future oil production are guided by an Connection to Astronomy
important principle: the relative cost of obtaining fuels influences
the amount of fossil fuels that we extract from the Earth. For exam- Cosmic Oil Some scientists sup-
ple, as the supply of readily available oil decreases, we may begin to port a controversial hypothesis
rely less on oil reserves and focus on using oil more selectively. At that some oil and natural gas
that time, oil will begin to be used more for applications in which it deposits did not come from the
is essential. Cars and power plants, which can be powered in many remains of ancient life but were
ways, will begin to rely on other energy sources. incorporated into the Earth dur-
ing its formation from the solar
Future Oil Reserves No large oil reserves have been discovered nebula 4.5 billion years ago.
in the past decade, and geologists predict that oil production Hydrocarbons are some of the
from fields accessible from land will peak in about 2010. most common compounds in the
Additional oil reserves are under the ocean, but extracting oil universe and large amounts of
from beneath the ocean floor is much more expensive. Currently, them could have been incorpo-
oil platforms can be built to drill for oil at depths greater than rated in the Earth as it formed. If
1,800 m, but much of the oil in the deep ocean is currently inac- this theory is correct, the Earth
cessible. Deep-ocean reserves may be tapped in the future, but could contain vast reserves of
unless oil-drilling technology improves, oil from the deep ocean “cosmic fossil fuels” that are not
will be much more expensive than oil produced on land. yet discovered.

Figure 12 ̈ This offshore oil rig is
extracting petroleum from beneath
the ocean floor.

S E C T I O N 1 Review

1. Describe five factors that influence the value of CRITICAL THINKING
a fuel. 4. Analyzing Relationships What is the relationship

2. Describe how fossil fuels are used to produce elec- between natural gas and petroleum?
tricity, and explain how an electric generator works.
5. Making Comparisons Read the description of how
3. Describe how coal, oil, and natural gas form, how fossil-fuel deposits form. Are fossil fuels produced
these fuels are used, and how using each fuel affects today by the same geologic processes as in the past?
the environment.
READING SKILLS

6. Making Inferences Examine Figure 11. What do
you think accounts for the dramatic increase in the
worldwide production of oil after 1950?

Section 1 Energy Resources and Fossil Fuels 475

SECTION 2 EARTH SCIENCE CONNECTION

Nuclear Energy In the 1950s and 1960s, nuclear power plants were seen as the
power source of the future because the fuel they use is clean and
Objectives plentiful. It was predicted that a nationwide network of nuclear
power plants would provide electricity that was “too cheap to
̈ Describe nuclear fission. meter.” But in the 1970s and 1980s, almost 120 planned nuclear
̈ Describe how a nuclear power power plants were canceled, and about 40 partially constructed
nuclear plants were abandoned. What happened? In this section,
plant works. you will learn how nuclear power works and why about 17 per-
̈ List three advantages and three cent of the world’s electricity comes from nuclear power today.

disadvantages of nuclear energy. Fission: Splitting Atoms

Key Terms Nuclear power plants get their power from nuclear energy, the
energy within the nucleus of an atom. The forces that hold
nuclear energy together the nucleus of an atom are more than 1 million times
nuclear fission stronger than the chemical bonds between atoms. In nuclear
nuclear fusion power plants, atoms of the element uranium are used as the fuel.

www.scilinks.org The nuclei of uranium atoms are bombarded with atomic par-
ticles called neutrons. These collisions cause the nuclei to split in
Topic: Nuclear Energy a process called nuclear fission. A fission reaction is shown in
Code: HE81047 Figure 13. Nuclear fission releases a tremendous amount of
energy and more neutrons, which in turn collide with more ura-
Figure 13 ̈ Neutrons are released nium nuclei. If a fission reaction is allowed to continue, this chain
from the fission, or the splitting, of a reaction will escalate quickly. One example of an uncontrolled
uranium atom’s nucleus. Some of fission reaction is the explosion of an atomic bomb. In contrast,
these neutrons then cause other nuclear power stations are designed so that the chain reaction
atoms to undergo nuclear fission in a produces a controllable level of energy.
process called a chain reaction.

476 Chapter 17 Nonrenewable Energy

How Nuclear Energy Works Figure 14 ̈ Every year, the Diablo
Canyon nuclear plant generates
A nuclear reactor is surrounded by a thick pressure enough energy for 2 million
vessel that is filled with a cooling fluid. The pres- Californian households—the energy
sure vessel is designed to contain the fission prod- equivalent of burning 20 million
ucts in case of an accident. Thick concrete walls barrels of oil.
also surround reactors as shown in Figure 14.

Inside a reactor, shown in Figure 15, metal fuel
rods that contain solid uranium pellets are bom-
barded with neutrons. The chain reaction that
results releases energy and produces more neutrons.
The reactor core contains control rods that control
the rate of fission in the reactor. They do this by
absorbing neutrons, which prevents the neutrons
from causing fission reactions in the uranium fuel.

The heat released during nuclear reactions is
used to generate electricity in the same way that
power plants burn fossil fuels to generate electric-
ity. In a nuclear power plant, energy released from the fission
reactions heats a closed loop of water that heats another body of
water. As the water boils, it produces steam that drives a steam
turbine, which is used to generate electricity.

■✓● Reading Check What is the function of the pressure vessel of a

nuclear reactor?

Figure 15 ̈ How a Typical Nuclear Power Plant Works

Section 2 Nuclear Energy 477

The Advantages of Nuclear Energy

Nuclear energy has many advantages. Nuclear fuel is a very con-
centrated energy source, as shown in Figure 16. Furthermore,
nuclear power plants do not produce greenhouse gases. When
operated properly, nuclear plants release less radioactivity than
coal-fired power plants do. Many countries with limited fossil-
fuel reserves rely heavily on nuclear plants to supply electricity.
France, for example, generates about three-fourths of its electric-
ity from nuclear power. France produces less than one-fifth of the
air pollutants per person than does the United States, which relies
on fossil fuels for almost 70 percent of its electricity needs.

Figure 16 ̈ Uranium is a very com- Why Aren’t We Using More Nuclear Energy?
pact fuel. The uranium pellets (above)
can generate as much electricity as Building and maintaining a safe reactor is very expensive. The
the trainload full of coal does. last 20 nuclear reactors built in the United States cost more than
$3,000 per kilowatt of electrical capacity. In contrast, wind
Geofact power is being installed at less than $1,000 per kilowatt. This
cost will decrease as construction costs decrease. Natural gas
Radon Uranium occurs naturally power plants are also less expensive to build than nuclear power
in rock and soil. When uranium plants, costing less than $600 per kilowatt.
undergoes radioactive decay, it
gives off a number of products, Storing Waste The difficulty of finding a safe place to store
including an invisible and odorless nuclear wastes is one of the greatest disadvantages of nuclear
radioactive gas called radon. Radon power. The fuel cycle of uranium produces fission products that
can seep into buildings from the remain dangerously radioactive for thousands of years. Uranium
surrounding rock and soil, and if mining and fuel development produce radioactive wastes. In addi-
buildings are not ventilated prop- tion, the used fuel, liquids, and equipment from a reactor core are
erly, dangerous levels of radon can also considered hazardous wastes. Storage sites for nuclear wastes
build up. It is estimated that radon must be located in areas that are geologically stable for tens of
causes 5,000 to 20,000 people in thousands of years. The United States has spent over two decades
the United States to die from lung studying a site called Yucca Mountain in southern Nevada as a
cancer each year. place to store nuclear waste. Scientists are also researching a
process called transmutation, which would recycle the radioactive
elements in nuclear fuel.

Safety Concerns In a poorly designed nuclear plant, the fission
process can potentially get out of control. This is what happened
during the world’s worst nuclear reactor accident, which occurred
at Chernobyl in the Ukraine in 1986. Engineers turned off most
of the reactor’s safety devices to conduct an unauthorized test.
This test caused explosions that destroyed the reactor and
released large amounts of radioactive materials into the air. Areas
of northern Europe and the Ukraine are still contaminated. The
Chernobyl reactor was an old design that, for safety reasons, is
not used in the United States. The nuclear reactor had no con-
tainment building. In addition, the engineers at Chernobyl vio-
lated basic safety guidelines.

■✓● Reading Check Why is it so difficult to find a place that can be used

to store nuclear waste safely?

478 Chapter 17 Nonrenewable Energy