Transcript Chapter 16

Geology and Nonrenewable Mineral
Resources
G. Tyler Miller’s
Living in the Environment
14th Edition
Chapter 16
Chapter Key Concepts
 Major geologic processes
 Earthquakes and volcanoes
 Minerals, rocks, and the rock cycle
 Finding and extracting mineral resources
 Non-renewable mineral resources
Sections 1 and 2 Key Concepts
• What are the major geological processes
that occur within the earth and its
surface?
• What is the Plate Tectonic Theory?
• What types of plate boundaries occur as
the plates move around the surface?
• What is erosion and weathering?
Earth A Dynamic Planet
Has the Earth always
looked the same as
it looks today?
Geology: the subject that
is devoted to studying
the dynamic processes
occurring on the earth’s
surface and the interior.
Earth A Dynamic Planet
Sometimes the changes on
earth’s surface occur
quickly, other times they
take a LONG time.
Earth A Dynamic Planet
Our planet is
constantly
changing
due to
forces at
play within
the earth.
Geologic Processes: Structure of
the Earth
The three
major zones:
CRUST
MANTLE
CORE
Internal Geological Processes
Features of the Crust and Upper
Mantle
Fig. 16-2 p. 333
Plate Tectonic Theory
Earth’s surface is
broken into about 15
huge rigid plates that
are moving very
slowly across the earth
surface.
• Lithosphere Plates
UNIFYING THEORY
OF GEOLOGY
Plate Tectonic Theory
Plate Tectonics
Divergent boundary
Convergent boundary
Subduction zone
Transform fault
Refer to Fig. 16-3 p. 334
Earth’s Major Tectonic Plates
Fig. 16-4, p. 335
Tectonic Theory Helps Explain
Mountain “building” occurs mainly along
plate boundaries
Tectonic Theory Helps Explain
Most
volcanoes
are found at
divergent
and
convergent
plate
boundaries
Tectonic Theory Helps Explain
Most
earthquakes
occur near
plate
boundaries.
External Earth Processes
Erosion: the process by
which material such as
rocks, sand and soil are
dissolved, loosened, or
worn away from one part
of the earth’s surface and
deposited elsewhere.
 Water causes most
erosion on earth
External Earth Processes
 Mechanical
weathering:
large rock pieces
are broken into
smaller
fragments.
 Water is main
agent
Glacial
erosion
versus
stream
erosion
External Earth Processes
Frost wedging: water
collects in the pores
and cracks of rocks
and expands when
frozen, then splits the
rock.
Causes street potholes to
expand.
External Earth Processes
Chemical
weathering:
process by which
chemicals naturally
break down rocks
and soil.
Examples: rusting,
acid rain
External Earth Processes
Biological
weathering: the
conversion of rocks
or minerals into
smaller particles by
living organisms.
Example: roots
breaking into
cracks of rocks.
Sections 1 and 2 Review
• What are the major geological processes
that occur within the earth and its
surface?
• What is the Plate Tectonic Theory?
• What types of plate boundaries occur as
the plates move around the surface?
• What is erosion and weathering?
Sections 3 and 4 Key Concepts
• What are earthquakes? Where do they
occur most frequently?
• What are volcanoes? Where do they
occur most frequently?
• What are minerals and rocks? What is the
rock cycle?
• What are nonrenewable mineral
resources?
Natural Hazards: Earthquakes
Earthquakes occur
when part of the
crust suddenly
fractures along a
fault to relieve stress
and gives off energy
as shockwaves that
travel through the
earth
Fig. 16-6 p. 337
Natural Hazards: Earthquakes
http://earthquake.usgs.gov/
Natural Hazards: Earthquakes
Richter Scale: the scale
used to measure the
intensity of an
earthquake.
< 4 insignificant
4-5 minor
5-6 damaging
6-7 destructive
7-8 major
> 8 great
Natural Hazards: Earthquakes
Primary Impacts
• Ground shaking
IMPACTS:
Buildings, highway
overpasses, dams,
pipelines, bridges,
etc.
Natural Hazards: Earthquakes
Secondary Impacts
• Fires
• Flooding
• Subsidence
• Tsunamis
Expected Earthquake Damage
No damage expected
Minimal damage
Canada
Moderate damage
Severe damage
United States
Fig. 16-7 p. 337
Natural Hazards: Volcanic Eruptions
extinct
volcanoes
central
vent
magma
conduit
magma
reservoir
Solid
lithosphere
Upwelling
magma
Partially molten
asthenosphere
Fig. 16-8 p. 338
Natural Hazards: Volcanic Eruptions
Volcanoes occur where
magma reaches the
earth’s surface through
a crack in the
crust…usually near
divergent or
convergent plate
boundaries.
Natural Hazards: Volcanic Eruptions
Impacts:
• Ejects – hot ash, hot
gases, lava, chunks of
rocks.
• Mudflows
• Acid Rain
• Earthquakes
Some eruptions violent,
others not so violent
Minerals and Rocks
The earth’s crust consists of
solid inorganic elements
and compounds called
minerals and masses of 1
or more mineral we call
rocks
Mineral: an element or
inorganic compound that
occurs naturally, is solid,
and in fixed crystal
structure. (gold, sulfur,
copper)
Minerals and Rocks
Igneous Rocks: formed
from cooled and
hardened magma or
lava.
Source a many non-fuel
mineral resources.
Examples: granite,
basalt.
Minerals and Rocks
Sedimentary Rocks:
formed from
compressed and
hardened sediment such
as sand and clay.
When sediment is eroded and
carried away by rivers and
streams it often build up in
layers.
Examples: sandstone,
limestone, shale.
Minerals and Rocks
Metamorphic Rocks:
produced by existing
rocks are subjected to
enormous heat and
pressure.
Usually occurs deep in
the earth.
Examples: marble, slate
Minerals and Rocks
Rock Cycle: the
interaction of physical
and chemical changes
that change rocks from
one form to another.
Happens very slowly over
long periods of time.
Transport
Erosion
Deposition
Shale, Sandstone,
Limestone
Rock
Cycle
Weathering
Igneous Rock
Granite, Pumice,
Basalt
Sedimentary Rock
Heat,
Pressure
Heat,
Metamorphic Rock
Pressure
Slate, Quartzite,
Marble
Magma
(Molten Rock)
Fig. 16-9 p. 339
Nonrenewable Mineral Resources
Nonrenewable Mineral
Resource: is a
concentration of
naturally occurring
material that can be
extracted and used at a
reasonable cost.
It takes the earth so long
to produce so we
consider them
nonrenewable.
Nonrenewable Mineral Resources
Metallic: iron, copper,
aluminum are examples
of some metallic
nonrenewable mineral
resources.
Copper mine
Nonrenewable Mineral Resources
Non-Metallic: sand,
salt, clay, soil.
Sand mine
Nonrenewable Mineral Resources
Energy Sources: coal,
oil, natural gas,
uranium.
Nonrenewable Mineral Resources
Ores: is rock
containing enough or
one or more metallic
minerals to be mined
profitably.
Gold ore
We use more than 40
metals extracted
from ores for
everyday items.
Nonrenewable Mineral Resources:
Categories
Identified: known
location, quantity and
quality.
Undiscovered: potential
supply assumed to exist based
upon theory.
Reserves: identified
sources from which can be
extracted at current prices.
Other: undiscovered and
unidentified.
Fig. 16-10 p. 340
Sections 3 and 4 Review
• What are earthquakes? Where do they
occur most frequently?
• What are volcanoes? Where do they
occur most frequently?
• What are minerals and rocks? What is the
rock cycle?
• What are nonrenewable mineral
resources?
Sections 5, 6 and 7 Key Concepts
• How are buried mineral deposits found? How
are they then removed?
• What are some environmental impacts of using
nonrenewable mineral resources?
• What is a typical life cycle of a nonrenewable
metal resource?
• Do we have enough nonrenewable mineral
resources?
Finding Nonrenewable Mineral
Resources
Promising underground deposits of minerals are
located using various techniques.
Finding Nonrenewable Mineral
Resources
Satellite and air
imagery:
ariel photos and images
from space
help locate outcrops.
Radiation
detectors:
To find radioactive
minerals like
uranium.
Finding Nonrenewable Mineral
Resources
Magnetometers:
measures changes in
earth’s magnetic field
caused by minerals
like iron
Seismic surveys:
detonating explosives
to see how sound
waves travel through
ground.
Finding Nonrenewable Mineral
Resources
Extracting Nonrenewable Mineral
Resources:
Open-pit
(surface mining):
machines dig holes and
remove ores (common for
iron, copper, limestone,
sand)
Dredging (surface
mining): chain
buckets scrape the
bottom underwater
Extracting Nonrenewable Mineral
Resources:
Area strip (surface
mining): big machine
move strips away to
reach ore.
Contour strip (surface
mining): used in hilly
areas to remove tops of
mountains.
Extracting Nonrenewable Mineral
Resources:
Subsurface mining
impacts much less
land, but…
• Leaves some
resource behind
• Is more dangerous
• Is more expensive
Extracting, processing and using mineral
resources has environmental impacts.
Environmental Effects of Mining
Mineral Resources
Disruption of land surface
Subsidence
Erosion of solid mining waste
Acid mine drainage
Air pollution
Storage and leakage of liquid mining
waste
Environmental Effects of Mining
Mineral Resources
Fig. 16-14 p. 344
More Environmental Impacts of
Nonrenewable Mineral Resources
Surface mining
Subsurface mining
Overburden
Room and pillar
Spoil
Longwall
Open-pit
Dredging
Strip mining
Refer to Figs. 15-4 and
15-5, p. 341 and 342
Acid mine
drainage.
Processing Mineral Resources
Ore mineral
Gangue
Tailings
Smelting
Supplies of Mineral Resources
 Economic depletion
 Depletion time
 Foreign sources
 Environmental concerns
 Economics
 New technologies
 Mining the ocean
 Finding substitutes
Fig. 16-16 p. 346
Sections 5,6,7 Review
• How are buried mineral deposits found? How
are they then removed?
• What are some environmental impacts of using
nonrenewable mineral resources?
• What is a typical life cycle of a nonrenewable
metal resource?
• Do we have enough nonrenewable mineral
resources?