Transcript Non-Renewable Mineral Resources

Chapter 16
Geology and
Nonrenewable Mineral Resources
Section 16-1 & 16-2
Geologic Processes
Plate Tectonics
GEOLOGIC PROCESSES
 The
earth is made up of a core, mantle, and
crust and is constantly changing as a result
of processes taking place on and below its
surface.
 The



earth’s interior consists of:
Core: innermost zone with solid inner core and
molten outer core that is extremely hot.
Mantle: solid rock with a rigid outer part
(asthenosphere) that is melted pliable rock.
Crust: Outermost zone which underlies the
continents.
GEOLOGIC PROCESSES
 Major
features of the earth’s crust and upper
mantle.
Figure 15-2
Spreading
center
Collision between
two continents
Subduction
zone
Continental
crust
Oceanic
crust
Ocean
trench
Oceanic
crust
Continental
crust
Material cools Cold dense
as it reaches material falls
the outer back through
mantle
mantle
Hot
Mantle
material
convection
rising
cell
through
the
mantle
Two plates move
towards each other.
One is subducted
back into the mantle
on a falling convection
current.
Mantle
Hot outer
core Inner
core
Fig. 15-3, p. 337
GEOLOGIC PROCESSES
 Huge
volumes of heated and molten rack
moving around the earth’s interior form
massive solid plates that move extremely
slowly across the earth’s surface.

Tectonic plates: huge rigid plates that are
moved with convection cells or currents by
floating on magma or molten rock.
The Earth’s Major Tectonic Plates
Figure 15-4
The Earth’s Major Tectonic Plates

The extremely slow movements of these plates
cause them to form boundaries
•Convergent plate boundaries grind into one another
•Divergent plate boundaries plates move apart
•Transform plate boundaries slide past each other
Figure 15-4
Boundaries
 Divergent – the plates move
apart in opposite directions.

•
•
•
Convergent – the plates push together
by internal forces.
At most convergent plate boundaries,
the oceanic lithosphere is carried
downward under the island or
continent.
Earthquakes are common here.
It also forms an ocean ridge or a
mountain range.
Boundaries (Continued)
– plates
slide next or past
each other in
opposite directions
along a fracture.
 Transform
 California
will not
fall into the ocean!
Fig. 15-4, p. 338
GEOLOGIC PROCESSES
 The
San
Andreas Fault is
an example of a
transform fault.
Figure 15-5
Pacific Plate
 The
Pacific plate is off the coast of California.
Lots of volcanoes and earthquakes occur
here.
 “California
will fall into the ocean” idea.
It is the largest plate and the location of the ring
of fire.
Wearing Down and Building Up the
Earth’s Surface
 Weathering
is an
external process
that wears the
earth’s surface
down.
Figure 15-6
Importance
 Plate
movement adds new land at
boundaries, produces mountains,
trenches, earthquakes and
volcanoes.
Section 16-3 & 16-4
Geologic Hazards
& Minerals, Rocks &
The Rock Cycle
MINERALS, ROCKS, AND THE
ROCK CYCLE
 The
earth’s crust consists of solid inorganic
elements and compounds called minerals
that can sometimes be used as resources.

Mineral resource: is a concentration of
naturally occurring material in or on the earth’s
crust that can be extracted and processed into
useful materials at an affordable cost.
General Classification of
Nonrenewable Mineral Resources
 The
U.S. Geological Survey classifies
mineral resources into four major categories:
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Identified: known location, quantity, and quality
or existence known based on direct evidence and
measurements.
Undiscovered: potential supplies that are
assumed to exist.
Reserves: identified resources that can be
extracted profitably.
Other: undiscovered or identified resources not
classified as reserves
General Classification of
Nonrenewable Mineral Resources
 Examples
are
fossil fuels (coal,
oil), metallic
minerals (copper,
iron), and
nonmetallic
minerals (sand,
gravel).
Figure 15-7
Rock Cycle
The Rock Cycle – the interaction of processes that change
rocks from one type to another
Rock Cycle
Figure 15-8
Steps
GEOLOGIC PROCESSES
 Deposits
of nonrenewable mineral resources
in the earth’s crust vary in their abundance
and distribution.
A
very slow chemical cycle recycles three
types of rock found in the earth’s crust:
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Sedimentary rock (sandstone, limestone).
Metamorphic rock (slate, marble, quartzite).
Igneous rock (granite, pumice, basalt).
Element Abundance
Oxygen: The most abundant element in Earth’s
crust
Nitrogen: The most abundant element in the
Earth’s atmosphere.
Iron: The most abundant element in the Earth’s
core.
Aluminum: The element commercially extracted
from bauxite
Rock Classification
Igneous Rock
– forms the bulk of the earth’s
crust. It is the main source of many non-fuel
mineral resources.
 Description
– Granite, Pumice, Basalt,
Diamond, Tourmaline, Garnet, Ruby,
Sapphire
 Examples
Sedimentary Rock
– rock formed from sediments.
Most form when rocks are weathered and
eroded into small pieces, transported, and
deposited in a body of surface water.
 Description
 Examples:
sandstone (sand stuck together),
Conglomerate (rounded & concrete-looking)
and Breccia (like conglomerate but w/ angular
pieces)
Metamorphic Rock
Description – when preexisting rock is subjected to
high temperatures (which may cause it to partially
melt), high pressures, chemically active fluids, or a
combination of these
 Location – deep within the earth


Ex. limestone under heat becomes marble through
crystallization

Limestone -> marble
sandstone -> quartzite
shale -> hornfelds (slate)
Section 16-5
Removing & Processing
Non-Renewable Mineral
Resources
Nonrenewable Resources
– things human use that have a
limited supply; they cannot be regrown or
replenished by man
 Definition
Dealing with Nonrenewable Resources
Conservation
– using less of a resource or
reusing a resource, ex. refilling plastic
laundry jugs, reusing plastic bags, etc.
 Definition
– this requires a change in our
lifestyle and some people will resist.
 Problems
Restoration
 Definition
– recycling our resources
– aluminum, glass, tin, steel,
plastics, etc.
 Examples
– recycling a resource often costs
more than using the raw material; we don’t
have the technology to recycle everything
 Problems
Sustainability
– prediction of how long specific
resources will last; ex. we have a 200 year
supply of coal in the U.S.
 Definition
 Knowing
this helps people make decisions in
resource use
– these are only predictions; they
may not be accurate
 Problems
Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources
Steps
Environmental effects
Mining
Disturbed land; mining
accidents; health hazards,
mine waste dumping, oil
spills and blowouts; noise;
ugliness; heat
Exploration,
extraction
Processing
Use
Solid wastes; radioactive
material; air, water, and
soil pollution; noise;
safety and health
hazards; ugliness; heat
Transportation or
transmission to
individual user,
eventual use, and
discarding
Noise; ugliness; thermal
water pollution; pollution
of air, water, and soil;
solid and radioactive
wastes; safety and health
hazards; heat
Transportation,
purification,
manufacturing
Fig. 15-10, p. 344
Harvesting Nonrenewable Resources
Costs

Ownership costs – equipment, labor, safety
(insurance), environmental costs (reclamation,
pollution control, air monitors, water treatment,
etc.), taxes

External costs – processing the resource,
transporting the resource

Marginal costs – research: finding new sources
of the resource and new ways to harvest it
Benefits
– money received for resources;
provides many jobs
 Direct
– land can be reclaimed
(brought back to original condition) and
sold for profit.
 Indirect
ENVIRONMENTAL EFFECTS OF
USING MINERAL RESOURCES
 Minerals
are removed through a variety of
methods that vary widely in their costs, safety
factors, and levels of environmental harm.
 A variety of methods are used based on
mineral depth.

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Surface mining: shallow deposits are removed.
Subsurface mining: deep deposits are removed.
Removal Methods
 Surface
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Mining
Description – if resource is <200 ft. from the
surface, the topsoil is removed (and saved),
explosives are used to break up the rocks and to
remove the resource, reclamation follows
Benefits – cheap, easy, efficient
Costs – tears up the land (temporarily),
byproducts produce an acid that can accumulate
in rivers and lakes
Removal Methods (Continued)
 Underground
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Mining
Description – digging a shaft down to the
resource, using machinery (and people) to
tear off and remove the resource
Benefits – can get to resources far
underground
Costs – more expensive, more timeconsuming, more dangerous
Removal Methods (Continued)
 Reclamation
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
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Description – returning the rock layer
(overburden) and the topsoil to a
surface mine, fertilizing and planting it
Benefits – restores land to good
condition
Costs – expensive, time-consuming
Open-pit Mining
 Machines
dig
holes and
remove ores,
sand, gravel,
and stone.
 Toxic
groundwater can
accumulate at
the bottom.
Figure 15-11
Area Strip Mining
 Earth
movers
strips away
overburden, and
giant shovels
removes mineral
deposit.
 Often leaves highly
erodible hills of
rubble called spoil
banks.
Figure 15-12
Contour Strip Mining
 Used
on hilly or
mountainous
terrain.
 Unless the land is
restored, a wall of
dirt is left in front
of a highly
erodible bank
called a highwall.
Figure 15-13
Mountaintop Removal
 Machinery
removes the tops
of mountains to
expose coal.
 The resulting
waste rock and dirt
are dumped into
the streams and
valleys below.
Figure 15-14
Section 16-6
Environmental Effects
of Using
Mineral Resources
ENVIRONMENTAL EFFECTS OF
USING MINERAL RESOURCES
 The
extraction, processing, and use of
mineral resources has a large environmental
impact.
Figure 15-9
Mining Impacts
 Metal
ores are
smelted or treated
with (potentially toxic)
chemicals to extract
the desired metal.
Figure 15-15
Section 16-7
Supplies of
Mineral Resources
SUPPLIES OF MINERAL RESOURCES
 The
future supply of a resource depends on
its affordable supply and how rapidly that
supply is used.
A
rising price for a scarce mineral resource
can increase supplies and encourage more
efficient use.
Specific Resources & Their Uses

Limestone – abundant locally, formed from layers
of seashells and organisms under pressure as
they were covered; used in sidewalks, fertilizers,
plastics, carpets, and more

Lead – used in batteries and cars

Clay – used to make books, magazines, bricks,
and linoleum
 Gold – besides being used as money and for
jewelry, gold is used in medicine (lasers,
cauterizing agents) and in electronics (circuits in
computers, etc.)
United States
 Central
– diamonds (Arkansas), bituminous
coal
– bituminous and subbituminous coal,
gold, silver, copper
 West
 East
– anthracite coal, bituminous coal
 South
– some gold (SC), bituminous coal
 North
– bituminous coal, some gold (SD, WI)
Alabama

Crushed stone, including limestone, dolomite, marble,
granite, sandstone, and quartzite, contributes to a thriving
mineral industry in the state.

Stone, along with sand, gravel, and clay, makes up a multimillion dollar nonfuel minerals industry in Alabama.

In 2007, the value of these produced minerals was $1.34
billion.

Approximately 9.1 metric tons of nonfuel minerals are
required every year for every person in the United States to
maintain the current standard of living.
http://www.gsa.state.al.us/gsa/minerals.html
SUPPLIES OF MINERAL
RESOURCES
 Depletion
curves
for a renewable
resource using
three sets of
assumptions.

Dashed vertical
lines represent
times when 80%
depletion occurs.
Figure 15-16
SUPPLIES OF MINERAL RESOURCES
 New
technologies can increase the mining of
low-grade ores at affordable prices, but
harmful environmental effects can limit this
approach.
 Most
minerals in seawater and on the deep
ocean floor cost too much to extract, and
there are squabbles over who owns them.
Getting More Minerals from the
Ocean
 Hydrothermal
deposits form when
mineral-rich
superheated water
shoots out of vents
in solidified magma
on the ocean floor.
Figure 15-17
USING MINERAL RESOURCES
MORE SUSTAINABLY
 Scientists
and engineers are developing new
types of materials as substitutes for many
metals.
 Recycling valuable and scarce metals saves
money and has a lower environmental impact
then mining and extracting them from their
ores.
Solutions
Sustainable Use of Nonrenewable Minerals
• Do not waste mineral resources.
• Recycle and reuse 60–80% of mineral resources.
• Include the harmful environmental costs of
mining and processing minerals in the prices
of items (full-cost pricing).
• Reduce subsidies for mining mineral resources.
• Increase subsidies for recycling, reuse, and
finding less environmentally harmful substitutes.
• Redesign manufacturing processes to use less
mineral resources and to produce less pollution
and waste.
• Have the mineral-based wastes of one
manufacturing process become the raw
materials for other processes.
• Sell services instead of things.
• Slow population growth.
Fig. 15-18, p. 351
Case Study:
The Ecoindustrial Revolution
 Growing
signs point to an ecoindustrial
revolution taking place over the next 50
years.
 The goal is to redesign industrial
manufacturing processes to mimic how
nature deals with wastes.

Industries can interact in complex resource
exchange webs in which wastes from
manufacturer become raw materials for another.
Case Study:
The Ecoindustrial Revolution
Figure 15-19
Sludge
Pharmaceutical plant
Sludge
Greenhouses
Waste
heat
Fish farming
Waste heat
Oil refinery
Surplus
sulfur
Local farmers
Surplus
Electric power
natural gas
plant
Waste
calcium
sulfate
Cement manufacturer
Sulfuric acid
producer
Wallboard factory
Area homes
Fig. 15-19, p. 352