I.
Outline Miller Chapter 14 Review
Chapter 14: Nonrenewable Mineral Resources
a. 14-1: What Are the Earth’s Major Geological Processes and What Are Mineral Resources?
i. Geology – the science devoted to the study of dynamic processes taking place on the
Earth’s surface and in its interior
1. Three major concentric zones:
a. Core – the earth’s innermost zone
b. Mantle – a zone made mostly of solid rock that can be soft and pliable
i. Asthenosphere – a volume of hot, partly melted rock that flows
ii. Convection Cells (currents) – that slowly move large volumes
of rock and heat in loops within the mantle like gigantic
conveyor belts
iii. The combination of the crust and the rigid, outermost part of
the mantle is called
1. We find the mineral resources on which we depend
c. Crust – the outermost and thinnest zone of solid material
i. Continental Crust – which underlies the continents (including
the continental shelves extending into the oceans)
ii. Oceanic Crust – underlies the ocean basins
ii. Mineral – a naturally occurring chemical element or inorganic compound that exists
as a solid with a regularly repeating internal arrangement of its atoms or ions (a
crystalline solid)
1. Mineral Resource – a concentration of one or more minerals in the earth’s
crust that we can extract and process into raw materials and useful products
at an affordable cost
2. Are classified as nonrenewable resources, and their supplies can be depleted
3. Metallic Minerals – made of single elements, such as Aluminum, Gold, and the
rare earths (used for technology), and those made of compounds such as rare
earth oxides
4. Nonmetallic Minerals – sand and limestone – made of nonmetallic elements
and compounds
iii. Rock – a solid combination of one or more minerals found in the earth’s crust
1. Sedimentary Rock – made of sediments – dead plant and animal remains and
tiny particles of weathered and eroded rock – deposited in layers that
accumulate over time
2. Igneous Rock – forms below or on the earth’s surface under intense heat and
pressure when magma wells up from the earth’s mantle and then cools and
hardens
a. Igneous rock forms the bulk of the earth’s crust but is usually covered
by sedimentary rock
3. Metamorphic Rock – forms when an existing rock is subjected to high
temperatures, high pressure, chemically active fluids, or a combination of
these agents
iv. Rock Cycle – the interaction of physical and chemical processes that change the
earth’s rocks from one type to another --- this is the slowest of the earth’s cyclic
processes
1. Three processes:
a. Erosion
b. Melting
c. Metamorphism
v. High-Grade Ore – contains a large concentration of the desired mineral
vi. Low-Grade Ore – contains smaller concentrations of the desired mineral
vii. Phosphates Salts – used to make inorganic fertilizer and certain detergents
b. 14-2: How Long Might Supplies of Nonrenewable Mineral Resources Last?
i. Reserves – supply, identified deposits from which we can extract the mineral
profitably at current prices
1. The future supply of any nonrenewable mineral resources depends on the
actual or potential supply of the mineral and the rate at which we use it
2. Mineral becomes economically depleted when it costs more than it is worth
to find, extract, transport, and process the remaining deposits
a. Recycle or reuses existing supplies
b. Waste less – use less
c. Find a substitute
d. Do without
3. The US, Canada, Russia, South Africa, and Australia – supply most of the
nonrenewable mineral resources used by modern societies
ii. Depletion Time – the time it takes to use up a certain proportion – usually 80% - of
the reserves of a mineral at a given rate of use
1. The shortest depletion-time estimate assumes no recycling or reuse and no
increase in reserves (Curve A)
2. Longer depletion-time estimate assumes that recycling will stretch existing
reserves and that better mining technology, higher prices, or new discovers
will increase reserves (Curve B)
3. Longest depletion-time estimate makes the same assumptions and A and B,
but also includes reused and reduced consumption to further expand
reserves (Curve C)
iii. Most US imports of metallic mineral resources come from reliable and politically
stable countries --- HOWEVER --- there are serious concerns about access to
adequate supplies of four major metal resources – manganese, cobalt, chromium,
and platinum
1. The US has little to no reserves of these metals
iv. Rare-earth elements are not actually rare, for the most part, but they are hard to
find in concentrations high enough to extract and process at an affordable price
1. China produces about 97% of the world’s rare-earth metals and oxides --partly because China does not strictly regulate the environmentally
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viii.
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disruptive mining and processing of rare earth (lower cost to consumer as
well)
2. A large rare-earth mine in California – the only one in the US – used to be the
world’s largest supplier of rare-earth metals ---HOWEVER --- it closed down
because of the expense of meeting pollution regulations, and because China
had driven the prices of rare-earth metals down to a point where the mine
was too costly to operate
3. China’s growing use of these resources means that it will use most of the rare
earths it produces and may soon need to important some types of rare earths
from other countries to meet its industrial needs
a. The transition from developing to developed
Geological processes determine the quantity and location of a nonrenewable
mineral resource in the earth’s crust, but economics determines what part of the
known supply is extracted and used
Standard Economic theory – in a competitive market system when a resource
becomes scarce, its price rises (can encourage growth)
1. Stimulate development of better mining technology and make it profitable to
min lower-grade ores
2. This price effect may no longer apply very well in most of the moredeveloped countries
a. Governments in such countries often use subsidies, tax breaks, and
import tariffs to control the supply, demand, and prices of key mineral
resources to such an extent that a truly competitive free market does
not exist
i. US – mining, companies get various types of government
subsidies, including depletion allowances
ii. Mining company representatives insist low taxes to keep the
prices of minerals low for consumers without the subsidies their companies might move their operations to other
countries – would not have to deal with strict mining and
pollution control regulations (aka: outsourcing jobs)
Increase supplies of some minerals by extracting them from lower-grade ores
1. Development of new earth-moving equipment, improved techniques for
removing impurities from ores, and other technological advances in mineral
extraction and processing that can make lower-grade ores accessible
Several factors can limit the mining of lower grade ores
1. Requires mining and processing larger volumes of ore – which takes more
energy and cost more
2. Dwindling supplies of freshwater needed for the mining and processing of
some minerals
3. The growing environmental impacts of land disruption
4. Waste material and pollution produced during mining and processing
The growing environmental impacts of land disruption, along with waste material
and pollution produced during mining and processing
Biomining - biological approach – miners use natural or genetically engineered
bacteria to remove desired metals from ores through wells bored into the deposits
1. Is slow and can take decades
2. Feasible only with low-grade ores for which conventional techniques are too
expensive
Because of the rapidly rising prices of many of these metals, there is growing
interest in deep-sea mining
1. The UN International Seabed Authority – established to manage seafloor
mining in international waters, began issuing mining permits in 2011
a. Marine biologist are concerned that the sediment stirred up by such
mining could harm or kill organism
b. Proponents of mining say that the number of potential mining sites is
quite small and that many of these organisms can live elsewhere
2. Obtaining minerals from the ocean bottom has been hindered by high costs
involved, the potential threat to marine ecosystems, and arguments over
rights to these minerals in deep-ocean areas that belong to no one country
c. 14-3: What Are the Environmental Effects of Using Nonrenewable Mineral Resources?
i. Life Cycle – that includes mining the mineral, processing it, manufacturing the
product, and disposal or recycling of the product
1. Large amounts of energy and water, and results in pollution and waste
ii. Environmental impacts of mining a metal ore are determined by the ore’s
percentage of metal content, or grade
iii. Surface Mining – overlying a mineral deposit are cleared away
1. Overburden – usually deposited in piles of waste material (aka: spoils)
2. Types of surface mining used depends on two factors:
a. The resource being sought
b. Local topography
iv. Open-pit mining – very large holes
v. Strip mining – large horizontal beds close to the earth’s surface
vi. Area strip mining – the terrain is fairly flat
vii. Contour strip mining – on hilly or mountainous terrain
viii. Unless the land is restored, what is left are a series of spoils banks and highly
erodible bank of soil and rock (highwall)
ix. Mountaintop removal – this destroys forests, buries mountain streams, and
increases the risk of flooding – wastewater and toxic sludge, produced when the
coal is processed are often stored behind dams in these valleys – which can overflow
or collapse and release toxic substances such as arsenic and mercury
1. Commonly used in the Appalachian Mountains of the US
2. Sites can be cleaned up and restored but it is costly and is rarely done even
when required by law
x. Subsurface Mining – disturbs less than one-tenth as much land as surface mining,
and it usually produces less waste material
1. Creates hazards such as cave-ins, explosions, and fires
2. Subsidence – the collapse of land above some underground mines
xi. Surface and subsurface mining operations also produce large amounts of solid
waste and cause major water and air pollution
1. Acid mine drainage – carries sulfuric acid (H2SO4)
xii. Ore extracted has two components:
1. Ore Mineral
2. Waste Material
a. Produces tailings that are left in piles or put into tailings ponds where
they settle out
i. Tailing ponds can also leak and contaminate surface water and
groundwater
b. Smelting – heating ores to release metals – emit sulfur dioxide and
suspended toxic particles, which damage vegetation and acidify soils
in the surrounding area
i. Cause water pollution and produce liquid and solid hazardous
wastes that require safe disposal
1. Lead smelting is the world’s second most toxic industry
after the recycling of lead-acid batteries
d. 14-4: How Can We Use Mineral Resources More Sustainably?
i. Materials Revolution – which silicon and other materials are replacing some metals
for common use
ii. Resource substitution is not a cure-all
iii. Several ways to use mineral resources more sustainably – focus on recycling and
reuse of nonrenewable mineral resources
iv. Recycling has a much lower environmental impact than that of mining and
processing metals from ores
1. Example: cleaning up and reusing items instead of recycling them has an
even lower environmental impact
e. 14-5: What Are the Earth’s Major Geological Hazards?
i. Tectonic Plates – which move extremely slowly atop the asthenosphere
1. Much of the geological activity at the earth’s surface takes place at the
boundaries between tectonic plates as they separate, collide, or grind along
against each other
ii. Volcano – occurs where magma rising in a plume through the lithosphere reaches
the earth’s surface through a central vent or a long crack (fissure)
1. Magma that reaches earth’s surface is called lava
2. Volcanoes form when one plate slides under or moves away from another
plate
3. Do provide some benefits in the formation of majestic mountains and lakes
such as Crater Lake – contribute to fertile soil – forms islands that have
become favorable for human settlement
iii. Earthquake – energy that has accumulated over time is released in the forms of
vibrations (seismic waves) that move in all directions through the surrounding rock
1. Fault – a fracture in earth’s crust
2. Seismic waves move upward and outward from the earthquake’s focus
3. Measure the severity of an earthquake by the magnitude of its seismic waves
a. Measure of ground motion (shaking) caused by the earthquake –
indicated by amplitude – Richter Scale
4. Primary Effects of the seismic waves – include shaking and sometimes a
permanent vertical or horizontal displacement of a part of the crust
iv. Tsunami – a series of large waves generated when part of the ocean floor suddenly
rises or drops
1. Most faults in the ocean floor move up or down
2. As a tsunami approaches a coast with its shallow waters, it slows down, its
wave crests squeeze closer together, and their heights grow rapidly