Terrestrial Earth

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Terrestrial Earth

• Plate Tectonics, Minerals, Rocks Mining

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Plate tectonics shapes the Earth

• Plate tectonics process that underlies
  earthquakes and volcanoes and that determines the
  geography of the Earths surface
• Crust lightweight thin component of Earths
  surface
• Mantle malleable layer on which the crust
  floats
• Core molten heavy center of Earth made mostly
  of iron

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Pangaea the supercontinent

• Pangaea at least twice in Earths history, all
  landmasses were joined in one supercontinent

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Earths crust is constantly created and destroyed

• Divergent plate boundaries magma surging upward
  to the surface divides plates and pushes them
  apart, creating new crust as it cools and spreads
  
• Transform plate boundary two plates meet,
  slipping and grinding alongside one another
• Friction spawns earthquakes along slip-strike
  faults

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Tectonic plates can collide

• Convergent plate boundaries where plates
  collide
• Subduction one plate of crust may slide beneath
  another
• Magma erupts through the surface in volcanoes
• Two colliding plates of continental crust may
  lift material from both plates
• Resulted in the Himalaya and Appalachian mountains

Boundary Interactive Boundary Animations
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The Earth has 15 major tectonic plates
Movement of these plates influences climate and
evolution
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Minerals and Rocks

• What is a mineral?
• naturally occurring, inorganic, solid element or
  compound with a definite chemical composition and
  a regular internal crystal structure
• What is rock?
• solid, cohesive, aggregate of one or more
  minerals
• Each rock type has a characteristic mixture of
  minerals
• What is an Ore?
• Rock with large concentration of a particular
  maineral to make it profitable
• High and low grade ores
• NON- Metalic Mineral
• Sand, gravel, limestone
• Metalic
• Aluminum, Steel, manganese, cobalt, chromium,
  Copper, Gold

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Minerals
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Rock Cycle
Heat, Pressure
Heat, Pressure
Igneous Rock Granite, Pumice, Basalt
Magma (Molten Rock)
Fig. 16-9 p. 339
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Mining Extract Ore from Ground

• Types of Mining
• Surface Mining Scoop ore off surface or earth.
  
• cheap.
• safe for miners.
• large environmental destruction.
• Sub-Surface or Underground Mining Use of
  shafts to reach deeply buried ores.
• expensive.
• hazardous for miners.
• less environmental damage.

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Surface Mining

• open pit mining
• circular hole in ground, with ramp circling down
  along sides, allows deeper ore to be reached.

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Surface Mining- Strip Mining

• strip-mining scoop off rock overburden, and
  then scoop off ore material.
• Economics of strip mining depend on stripping
  ratio
• Large land area can be involved, especially for
  coal and bauxite.

Results of Mining utube
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Bauxite Mine
In the Earth's Crust, in every million atoms,
around 82 000 of them are Aluminum, (82 000
ppm1), by weight. This is around 8 or almost
one in every 12 atoms. This places aluminum
amongst the world's most abundant elements.
Despite being present of Earth in such
incredibly vast quantities on Earth, the metal
never occurs on it's own in nature. Instead of
existing free like Gold and Silver, due to its
higher level of reactivity, it is always
chemically bonded in compounds when it normally
occurs. The most common of these compounds is
Bauxite, or Aluminum Ore which contains large
quantities of Aluminum Oxide.
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Mountain Top Removal
Removing Overburden
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spoils
Overburden Coal seem bedrock
Appalachian Voices http//www.youtube.com/watch?v
aiSzOiGFa-0
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Gold in Quartz
https//www.youtube.com/watch?vohrrE1rjzLo

• A large quartz boulder with a lot of visible
  gold. Usually, the gold is much finer and hard
  to see.

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Placer Deposition

• Panning for gold in a placer deposit

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Aeolian Placers

• The "diamond crawl" in a deflation basin, Diamond
  Area No 1, Namibia
• Diamond concentrations were increased by wind
  erosion

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Environmental Impact of Mining
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Waste water/sludge dams
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• Underground Mining
• A technology originating in antiquity.
• A variety of configurations, depending upon
  conditions

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Acid Mine Drainage
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Environmental Impact of Mining

• Scaring the land surface- result spoils banks
• Soil poor, windblown .. Primary succession slow
• Toxic wastewater stored in sludge dams.
• Toxins include slenium, arsenic, and mercury

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Cassiterite

• tin oxide ore mineral, SnO2. It is generally
  opaque but is translucent in thin crystals. Its
  luster and multiple crystal faces produce a
  desirable gem. Cassiterite has been the chief tin
  ore throughout ancient history and remains the
  most important source of tin today

TinSoldiers
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Non-renewable Mineral Resource Depletion Curves
Source Miller, G. Tyler, Living In The
Environment. (2000) Wadsworth Publishing. New
York.
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Non-renewable Mineral Resource Depletion Curves
Source Miller, G. Tyler, Living In The
Environment. (2000) Wadsworth Publishing. New
York.
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US Non-renewable Resource Reserves
Source Miller, G. Tyler, Living In The
Environment. (2000) Wadsworth Publishing. New
York.
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Mining is an Economic Activity

• The decision to mine (or not to mine) a
  particular ore deposit depends upon
• an analysis of costs, benefits and risks
• tangible (i.e. dollar profit)
• intangible (i.e. hopes of stimulating the
  economy, fears of environmental damage)

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Gradual shift toward surface mining
Surface mining
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Minining Law http//www.youtube.com/watch?vofN1a
LMwcUI Mining around the world Hungarys
disaster Chinas rare earth minerals US rare
earth mineral info ad Proposal for New Massive
Mine in Romania Goldmining Mining ore Bauxite
mining Mountaintop removal
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Mining Issues Mine Safety In U.S., stringent
mining regulations have lead to a reduction in
fatalities, both in terms of total deaths per
year, deaths per person-hour worked, and deaths
per ton mined.
surface
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Acid Mine Drainage
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Health Problems

• collapse of mine.
• fire (methane, coal dust, etc.).
• asphyxiation (methane, carbon monoxide, etc.).
• pneumoconiosis (from inhaling coal dust).
• asbestosis (from inhaling asbestos fibers).
• silicosis (from inhaling silicate dust).
• heavy metal poisoning (e.g. mercury).
• radiation exposure (in uranium mining).

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• Environmental Damage
• Gaping holes in ground (old open pit mines).
• Piles of mine tailings (non-ore removed from
  mines).
• Accidental draining of rivers and lakes.
• Disruption of ground water flow patterns.
• Loss of topsoil in strip-mined regions (350 to
  2,700 km2 in US alone).
• Contamination from sulfuric acid (H2SO4)
  produced through weathering of iron sulfide
  (FeS2, pyrite) in tailings.
• 4FeS2 14H2O 4Fe(OH)3 8H2SO4
• Contamination from heavy metals (e.g. arsenic,
  mercury) in mine tailings.

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Smelting and Refining Environmental Problems

1. Production of huge piles of slag.
2. Emission of CO2, a greenhouse gas, into the
   atmosphere.
3. Pollution associated with the generation of
   electricity needed in anode furnaces (especially
   aluminum).
4. Sulfur dioxide emissions from the refining of
   sulfide ores are a major source of air pollution.
   The sulfur dioxide combines with water to produce
   sulfuric acid.
5. Release of heavy metals (As, Cd, Hg), present in
   trace quantities in sulfide ores, into the
   atmosphere.

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Cost Trends

• Amount of commodities mined per year has
  generally increased.
• Commodity prices can take big swings, but average
  prices during the last century often declined or
  remained constant.

Cents per pound
copper
Ore grades have all decreased as milling
technology has improved