Transcript Geology and Nonrenewable Mineral Resources G. Tyler Miller`s

Geology and Nonrenewable Mineral Resources
G. Tyler Miller’s
Living in the Environment
14th Edition
Chapter 16
Key Concepts
 Major geologic processes
 Earthquakes and volcanoes
 Minerals,
rocks, and the
rock cycle
 Finding and
extracting mineral
resources
 Non-renewable mineral resources
Geologic Processes:
Structure of the Earth
Geology is the study of dynamic processes
occurring on the earth’s surface and in its
interior.
The surface of the earth is composed of a
series of gigantic plates that move very
slowly across the earth’s surface.
The surface features of the earth change due
to the effects of water and earth
movements.
Earthquakes and volcanic action are violent
and disruptive actions of the earth.
Three major zones of the earth are the core, mantle, and crust.
The crust is soil and rock that floats on a mantle of partly melted and solid rock.
The core is intensely hot. It has a solid inner part surrounded by a liquid core of molten or
semisolid material.
The mantle is a thick, solid zone. It is mostly solid rock, but an area called the asthenosphere
is very hot, partly melted rock about the consistency of soft plastic.
The crust is thin and is divided into the continental crust and the oceanic crust.
Features of the Crust and Upper Mantle
There are three types of boundaries for lithospheric plates.
The boundaries are divergent plate boundaries, where
plates move apart in opposite directions, and
convergent plate boundaries,
where plates are pushed together by internal forces and
one plate rides up over the other. A trench generally
occurs at the subduction zone.
The third type of boundary is a transform fault and occurs
where plates slide/grind past one another.
The Dynamic Earth – Internal Processes
Geologic changes from
the earth’s interior generally
build up the earth’s surface.
Heat and gravity play a role
in these processes.
Heat from the core causes
much of the mantle to
deform and flow slowly like
heated plastic.
Two kinds of movement
seem to occur in the mantle.
Convection currents move
large volumes of rock and
heat in loops within the
mantle. Mantle plumes flow
slowly upward, and when it
reaches the top of the
plume, it radiates out like
the top of an open umbrella.
Earth’s Major Tectonic Plates
Measurement of the magnitude of an
earthquake is done using the Richter
scale, where each higher number is
10 times greater than the next lower
number.
Insignificant is less than 4.0 on the
Richter scale, minor is 4.0–4.9,
damaging is 5.0–5.9, destructive is
6.0–6.9, major is 7.0–7.9, and great is
over 8.0.
Plate Movement
Earthquakes
An earthquake occurs at a fracture line or
causes a fracture and shift in the earth’s
crust.
Earthquakes
Foreshocks may occur prior to the
main shock and aftershocks
occur up to several months after
the main shock.
Primary effects include shaking and
temporary to permanent
displacement of the ground.
Secondary effects include rockslides,
fires, and flooding due to
subsidence of the land.
Examination of an area for faults
prior to building can help save
lives and destruction of property
Expected Earthquake Damage
Fig. 16-7 p. 337
Seismic Waves
P – primary (compression waves)
S – Secondary wave (sheer waves)
Surface Waves
Impact of waves
Building Collapse
Building Collapse retrofit
Expected Earthquakes
Natural Hazards: Volcanic Eruptions
An active volcano releases magma onto the
earth’s surface. This release may be
violent or quiet.
1.
Volcanic activity is generally concentrated
in the same areas as seismic activity.
2.
Ash and gases may be ejected along with
magma.
3.
Gases such as sulfur dioxide may remain
in the atmosphere and cause acid rain.
4.
Particulate matter may remain in the
atmosphere for up to 3 years and cause
cooling of the atmosphere.
5.
Fertile soils are produced from the
weathering of lava flows.
6.
Scientists are studying phenomena that
precede an eruption to better predict their
occurrence.
External Earth Processes
 Erosion
 Mechanical (Physical)
weathering
 Frost wedging
 Chemical weathering
 Biological weathering
Minerals and Rocks
 Mineral (diamond, quartz)
Rock Types
 Igneous (granite, basalt)
 Sedimentary (limestone, sandstone)
 Metamorphic (marble, slate)
Breaker and whoosh
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

Metallic
Silver, Copper, Aluminum,
Gold

Non-metallic
Phosphates -Fertilizers

Energy resources
Coal, Oil and Natural Gas

Ores
Extracting Nonrenewable
Mineral Resources:
 Open-pit (surface mining)
 Dredging (surface mining)
 Area strip (surface mining)
 Contour strip
(surface mining)

Room-and-pillar
(subsurface mining)

Longwall
(subsurface mining)
Nonrenewable Mineral
Resources: Categories




Identified
Undiscovered
Reserves
Other
Finding Nonrenewable Mineral Resources






Satellite and air imagery
Radiation detectors
Magnetometers
Gravity differences
Seismic surveys
Chemical analyses
Processing Mineral Resources




Ore mineral
Gangue
Tailings
Smelting
Fig. 16-10 p. 340
Smelting
Separation
of ore from
gangue
Melting
metal
Metal ore
Conversion
to product
Recycling
Discarding
of product
Surface
mining
Scattered in environment
Mining Laws
Mining Act of 1872
What is the impact of the
1872 Law?
The Hardrock Mining and
Reclamation Act of 2009
(S.796)
Surface Mining Control
and Reclamation Act
 Established 1977
 Mine lands must be
restored to pre-mining conditions
 Taxes on mining companies
to restore pre-1977 sites
 Limited success
Environmental Effects of Mining Mineral Resources
Fig. 16-14 p. 344
 Disruption of land surface
 Subsidence
 Erosion of solid mining waste
 Acid mine drainage
 Air pollution
 Storage and leakage of
liquid mining waste
More Environmental Impacts of Nonrenewable Mineral Resources
Subsurface mining
Surface mining

Overburden


Spoil
Dredging


Open-pit
Strip mining

Room and pillar

Longwall
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