Transcript 14.2 & 14.3 Notes

14-2 How Are the Earth’s Rocks Recycled?
• Concept 14-2 The three major types of rocks found
in the earth’s crust—sedimentary, igneous, and
metamorphic—are recycled very slowly by the
process of erosion, melting, and metamorphism.
There Are Three Major Types of Rocks (1)
• The earth’s crust consists mainly of rocks and
minerals…
• Minerals - ________________
or inorganic
element
compound
______________
in earth’s crust
• Usually a crystalline _______________,
which has
solid
regular and repeating arrangement of atoms
• Examples: gold, mercury, salt, quartz
• Rock - solid _________________
of one or more
combination
minerals
• Examples: limestone, quartzite, granite
There Are Three Major Types of Rocks (2)
sediments
1. Sedimentary rock – made of _________________
from dead plant and animal remains and tiny
particles of weathered and eroded rocks
layers
• Deposited in ________________
and compacted
• Increasing ______________
overtime converts them to
pressure
rock
• Examples…Sandstone, Shale, Dolomite, Limestone,
Lignite, Bituminous coal
Sedimentary Rock
Sandstone
limestone
There Are Three Major Types of Rocks (3)
2. Igneous rock - Forms below or at earth’s surface when
magma
______________
wells up, cools and hardens
• Form the ____________
of earth’s crust but are usually covered
bulk
by sedimentary rock
• Examples: Granite, Lava rocks
Igneous Rock
granite
pumice
basalt
3. Metamorphic rock – forms when
preexisting rock is subjected to high pressures,
______________
high temperatures, and/or chemically active fluids
• Examples: Anthracite, Slate, Marble
Metamorphic rock
Slate, marble,
gneiss, quartzite
The Earth’s Rocks Are Recycled
Very Slowly
• Rock cycle – The interaction of physical and chemical
change
processes that ____________
rocks from one type to
another
Slowest
• ______________
of the earth’s cyclic processes
• Plays a major role in forming concentrated deposits of
mineral
________________
resources
Erosion
Transportation
Weathering
Deposition
Igneous rock
Granite,
pumice,
basalt
Sedimentary rock
Sandstone,
limestone
Heat, pressure
Cooling
Heat, pressure, stress
Magma
(molten rock)
Melting
Metamorphic rock
Slate, marble,
gneiss, quartzite
Fig. 14-10, p. 354
14-3 What Are Mineral Resources, and
What Are their Environmental Effects?
• Concept 14-3 We can make some minerals in the
earth’s crust into useful products, but extracting and
using these resources can disturb the land, erode
soils, produce large amounts of solid waste, and
pollute the air, water, and soil.
We Use a Variety of Nonrenewable
Mineral Resources (1)
naturally
• A mineral resource is a concentration of _________________
occurring material from the earth’s crust that can be
___________________
from earth’s crust and processed into
extracted
_________
________________
raw
materials and products at an affordable
cost
• _________________
minerals – like gold and aluminum
Metallic
• ____________________
minerals – like sand and limestone
Nonmetallic
• Because minerals and rocks take so long to form, they are
nonrenewable
classified as _____________________
resources
We Use a Variety of Nonrenewable
Mineral Resources (1)
• An ____________
ore
is rock that contains a large enough
concentration of particular mineral – often a metal – to make
it ______________________
for mining and processing
profitable
• High-grade ore – contains a ________________
concentration
large
• Low-grade ore - contains a ______________
smaller concentration
We Use a Variety of Nonrenewable
Mineral Resources (2)
• Metallic mineral resources
• Aluminum (Al) – used for packaging and beverage
cans
________;
structural material in motor vehicles, aircrafts
and buildings
steel
• Iron (Fe) – essential for ______________;
buildings and
motor vehicles
wiring
• Copper (Cu) – electrical and communication ___________
electrical
• Gold (Au) – used in ________________
equipment, tooth
jewelry
fillings, ________________,
coins, and some medical
implants
We Use a Variety of Nonrenewable
Mineral Resources (2)
• Nonmetallic mineral resources
SiO2
glass
• Sand (mostly ______)
– used to make ____________,
bricks and concrete
roadbeds
• Gravel – used for _______________
and to make
concrete
CaCO3 – crushed to make
• Limestone (mostly _______)
cement
concrete and ______________
fertilizers
• Phosphate salts – used for inorganic ______________
and some detergents
We Use a Variety of Nonrenewable
Mineral Resources (2)
• The estimated supply of a mineral resource is called
reserve
a ________________
• Reserves can increase when…
found
• new deposits are _____________
technologies
• Improved mining _____________________
make it
more profitable to extract deposits
Some Environmental Impacts of Mineral
Use
• While we can produce many useful products from
mined resources, many disadvantages are related to
the entire _______________
of a metal
life cycle
Surface
mining
Metal ore
Separation
of ore from
gangue
Smelting
Melting
metal
Recycling
Conversion
to product
Discarding
of product
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
Transportation,
purification,
manufacturing
Use
Transportation or
transmission to
individual user,
eventual use, and
discarding
Solid wastes; radioactive
material; air, water, and soil
pollution; noise; safety and
health hazards; ugliness;
heat
Noise; ugliness; thermal water
pollution; pollution of air,
water, and soil; solid and
radioactive wastes; safety and
health hazards; heat
Fig. 14-12, p. 356
There Are Several Ways to Remove
Mineral Deposits (1)
• Surface mining
shallow
• Used to remove ________________
deposits
vegetation
• Begins with the removal of all __________________
covering the site
overburden is removed…
• Then the __________________
• soil and rock covering the useful mineral deposits
spoils
• Deposited in waste piles called _______________
There Are Several Ways to Remove
Mineral Deposits (2)
• Type of surface mining used depends on the ______________
resource
and local _____________________
topography
• Types of surface mining
Open-pit
• _________________
mining
• machines dig very larger holes
Strip
• __________
mining
• useful for deposits that lie in large _________________
horizontal beds
Area
• _________________
strip mining: flat surfaces
Contour
• _________________
strip: hilly or mountainous terrains
Mountaintop
• _______________________
removal
• Removes the tops of mountains
Natural Capital Degradation: Open-Pit Mine in
Arizona
Scarring and _______________________
degradation
of the land surface
Fig. 14-13, p. 357
Area Strip Mining in Wyoming
Fig. 14-14, p. 357
Spoils Banks in Germany from Area Strip
Mining
Fig. 14-16, p. 358
banks
• Strip mining often leaves spoil ___________
• Susceptible to erosion
• Regrowth of vegetation is slow due to the lack of
topsoil
Spoil banks
Mountaintop Coal Mining in West Virginia
Waste is deposited into ________________
valleys
below the mountaintops
buried
Streams are ______________;
waste water and toxic sludge are often
stored in _____________
in these valleys which can collapse and
dams
over flow
Daily blasting
exposes people
dust
to ____________
and can damage
groundwater
_______________
supplies
Fig. 14-17, p. 359
Individuals Matter: Maria Gunnoe
• Maria Gunnoe
• West Virginia environmental activist…national public
speaker
Goldman
• won a _________________
Environmental Prize in
2009 for her efforts to fight against mountaintop coal
mining
$150,000
• Cash prize of ________________
• Her home…
• Flooded _______
times
7
yard
• Toxic coal sludge in ______________
well
• Groundwater and ___________
was contaminated
Ecological Restoration of a Mining Site in
Indonesia
Surface mining
sites can be
restored but it is
costly
___________
U.S. Department
of the Interior,
DOI
_________,
estimates that
cleaning all U.S.
sites would cost
taxpayers
$ 70 billion
______________
Fig. 14-18, p. 360
Mining Has Harmful Environmental Effects
(2)
• Subsurface mining
deep
• Used to remove __________________
deposits through tunnels
and shafts
cave-ins
• Creates hazards such as _________________,
explosions, and
fires
• Miners often get _________________
black lung - caused by prolonged
inhalation of coal dust
• Subsidence - _________________
land can affect communities
sinking
above mines
Removing Metals from Ores Has Harmful
Environmental Effects (1)
• Ore extracted by mining typically has two components…
• Ore mineral containing the ________________
metal
desired
• waste material called ___________________
gangue
• The waste material is left in piles called _______________....toxic
tailings
particles can be blown by the wind or leached by rainfall
Removing Metals from Ores Has Harmful
Environmental Effects (1)
• Heat or chemical solvents must be used to extract metals
from ores
smelting
• Process called ________________________
• Without effective pollution control equipment, smelters emit
air
enormous amounts of __________
pollution
liquid
• Also produces ________________
and
solid
________________
hazardous wastes
Removing Metals from Ores Has Harmful
Environmental Effects (2)
• Core Case Study: highly toxic cyanide salt is used to
extract gold from its ore
• After extracting the gold from a mine, some mining
bankruptcy so
companies deliberately declare ______________
that they can avoid cleaning up their sites
Colorado
• Summitville gold mine: _________________,
U.S.
• Toxic waste site
• Cleanup by the EPA will cost U.S. taxpayers about
__________________
$120 million
Tropical Gold Mining
• Since the 1980s, millions of miners have streamed in
tropical rivers to search for gold
• Dig large ___________
and dredge
pits
________________
from rivers
sediment
• Some use _________________
hydraulic
mining (currently
cannons
outlawed in the U.S.) in which water _____________
wash entire hillsides into collection boxes
Mercury
• _______________
is also illegally used to separate
gold from stream sediment
• Nearby fish populations have dropped
• Nearby villages suffer from mercury poisoning
Review Questions!
• Identify the types of rock formed throughout the rock cycle…
Erosion
Transportation
Weathering
Deposition
igneous
sedimentary
Heat, pressure
Heat, pressure,
stress
metamorphic
Magma
Review Questions!
• What are some examples of…
• metallic mineral resources?
Aluminum, iron, copper, gold
• nonmetallic mineral resources?
Sand, limestone, gravel, phosphate salts
• After an ore is acquired, what must be done to get the
desired metal?
Separate ore from waste (gangue)
Heat or use chemicals (smelting) to get metal
Review Questions!
• Identify the types of surface mining shown below…
Open pit
mining
Strip mining
Mountain-top
removal