Download Geology and Mining

Geology and Earth
Resources
Botkin Ch 27
Raven, p110-116, Ch 16
Warmup (Hwcheck)
8/21/13
Of the 1498 contaminated sites on
the US Superfund National Priorities
list in 2002, 846 sites were cleaned up
by 2006. What percent remains to be
cleaned up?
A.44%
B.56%
C.77%
D.82%
Key Terms
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Convection
Converge
Deposition
Diverge
Geologic time
Organic
Pangaea
Precipitate
Richter scale
Ring of Fire
Social Responsibility
Subduction
Objectives - KWL
• Explain basic geologic principles, including how tectonic plate
movements affect conditions for life on earth
• Explain how the three major rock types are formed and how
the rock cycle works
• Summarize economic mineralogy and strategic minerals
• Discuss the environmental effects of mining and mineral
processing
• Recognize the geologic hazards of earthquakes, volcanoes,
and tsunamis
Outline
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Dynamic Planet
Rocks and Minerals
Categories of Minerals
Environmental Effects of Resource Extraction
Conserving Geologic Resources
Geologic Hazards
A Dynamic Planet
The Earth consists of four layers
• InnerThe
core
– dense
very
iron
inner
and outer
corehot
form
Earth’s
• Outer
coremagnetic
– plasticfield
consistency
• Mantle – pliable and less dense
• Lighter elements include oxygen, silicon, magnesium
• Convection currents occur due to heat from the core
• Crust – lighter, brittle, and broken into pieces called plates,
which move
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Contain calcium, potassium, sodium, aluminum
Divergent boundaries – where plates separatae
Convergent boundaries – where plates come together
Transverse boundaries – where plates slide past each other
Earth’s formation - Theory
Formation of solar system bodies occurred with the Sun
EARTH’s FORMATION
• 4.54 billion years ago (bya) Solar nebula begins to collapse
• Partitions into separate volumes over 10 million years
Crust
Dynamics
• Divergent boundaries are driven
apart by convection in the mantle
• Magma is iron-rich (basalt)
• New crust is formed as it cools
• Plates push away from each other
• Convergent Boundaries: Subduction occurs as one plate collides
into its neighboring plate and slides downward into the mantle
• Deep ocean trenches at subduction zone
• Volcanoes arise as gases bubble up from the mantle
• Magma is silica-rich (granite)
• “Ring of Fire” – subduction zones in the Pacific Ocean Rim, where
most of the world’s earthquakes and volcanoes occur
• “Hot Spots” – continual stream of magma in one area, crust moves
over it creating a chain of volcanic mountains. Ex: Hawaii
Rocks and
Minerals
• Minerals: compounds of elements that occur in crystalline structure
• Rocks: aggregates of one or more minerals
• Rock Cycle: rocks form and are destroyed in a continual cycle of
crystallization, breaking down, heating, pressure, cooling
• Three types of rocks:
• Igneous – “formed of fire”, when magma rises to earth’s surface
• Metamorphic – modified by heat and pressure
• Sedimentary – formed by the “weathering” of other rock types that are
carried by wind and water, deposited, and compacted
Agenda: Monday, Aug 26
I. Discuss: How should government respond to Hazards? Write a
summary sentence based on your reading, then pass the paper on
to each team member.
II. Demonstrations : Density and Viscosity
III. Video Questions: Hot Spots – 1:28 start
https://www.youtube.com/watch?v=07b6ijzbT6A
1. How do volcanoes affect the atmosphere? biosphere?
2.What is a hot spot? What do Hawaii and Yellowstone have in common?
Video Question: How are the Himalayas formed?
https://www.youtube.com/watch?v=goszsQl0Bc0
QUIZ FRIDAY!!! OOPS! I forgot there is no school. What shall we do?
I want to test what you’ve learned so far. OK Quiz next Wednesday!!!!
STUDY!!
DEMONSTRATIONS
• How is density measured?
• How does silica affect viscosity?
DEFINITIONS:
Density – mass per unit volume (g / m3)
Silica – the mineral present in sand that is found in magma at
convergent boundaries
Viscosity – the property of a fluid that causes it to resist
movement, generally understood as thickness.
Should we revise mining laws?
20 minutes
CLOSE READING / DISCUSS:
1. Underline any words you do not know or cannot figure out.
2. Use context clues to guess at the meaning. (note in the
margin)
3. Look them up in the dictionary if you need to.
4. How many acres could I buy for $100 if I wanted to start a
business on public land when I retire?
5. What kind of profits are being made through the General
Mining Law? Provide examples.
6. List the pros and cons of this law.
7. What do you think?
Elements present in Earth’s structure
Create two different graphs, one for each set of percentages
of elements in the different parts of Earth’s structures.
What processes account for the differences?
Whole Earth
(core, mantle, crust)
Crust only
Iron
33.3
Oxygen
45.1
Oxygen
29.8
Silicon
27.2
Silicon
15.6
Aluminum
8.2
Magnesium
13.9
Iron
5.8
Nickel
2.0
Calcium
5.1
Aluminum
1.5
Sodium
2.3
Sodium
0.2
Potassium
1.7
Total
100%
Total
100%
Categories of Minerals
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Minerals, especially metals, are important to industry
Mining, processing, and distribution are commercial activities
Minerals found in abundance are worth extraction costs
Besides metals, sand, and gravel, minerals deposited through
evaporation can be mined and refined commercially
Metals
Non-metals
Evaporates
Aluminum, iron, lead,
nickel, gold, platinum,
silver copper,
chromium
Sand, gravel - construction
Silicates – high silica sand for
glass; gemstones, mica, talc,
asbestos
Soil
Limestone - construction
Halite - salts
Gypsum – plaster
Potash – fertilizer
Sulfur – batteries,
medicine
Important Metals and primary sources
Nickel
Nickel, Zinc,
Copper
Copper, Lead
Mercury
Aluminum
Copper,
Tin, Zinc,
Iron Ore
Aluminum ,Tin,
Mercury, Zinc, Lead,
Iron ore,
Aluminum,
Nickel, Tin
Aluminum
Lead
Zinc
Iron ore
Metals and their uses
Metal
Aluminum
Chromium
Copper
Iron
Manganese
Nickel
Platinum
Gold
Silver
Use
Environmental Effects of
Resource Extraction
• Mining disturbs the surface of the land (see next page)
• Air is polluted with dust and chemicals
• Smelting is the process of roasting ore to release metals; this
releases sulfur emissions
• Water is polluted by chemical and sediment runoff
• Piles of crushed ore are sprayed with alkaline-cyanide solution
• Chemicals leak into groundwater, surface waters are
contaminated
The 1977 Surface Mining Control and Reclamation Act requires
restoration of mined lands.
Mining
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Placer mining – water is used to disturb the surface; streams fill with sediment
Open pit mining – upper layers removed, polluted water accumulates in pits
Strip mining – layers are systematically removed and the spoils are dumped
Shaft mining – methane accumulates in tunnels; explosions and collapses occur
Mountaintop removal – tops of mountains are blasted away and the spoils
tumble into river valleys
Conserving Geologic Resources
• Recycling metals (aluminum, platinum) costs less than mining
for the metal ore
• Using new materials, new technologies helps reduce our need
for mining and extraction
• Polymers
• Alloys
• glass
Geologic Hazards
• Geologic forces have shaped the Earth for millions of years
• Massive events happen rarely and are called natural disasters
• Floods – take the most human lives
• Hurricanes and tornadoes cause greatest property damage
• Earthquakes cause the most damage in areas with poorly
constructed buildings
• Tsunamis, generated by earthquakes or volcanoes, cause flooding
in coastal areas
• Volcanoes release huge amounts of dust and gases into the
atmosphere  blocks sunlight, reduce temperature, produce
sulfuric acid rain, reduces stratospheric ozone
• Landslides cause property damage when people build homes and
roads on unstable ground