The Geosphere

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The Geosphere
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What is the GEOSPHERE?

• All solid parts of Earth
• Rocks, soils, minerals, sediments, magma

The Grand Canyon, AZ
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Layers of the Earth

• Geologists classify Earths layers two ways
  chemically and physically
• Chemical by composition
• Physical- by structure

Chemical Layers of the Earth

1. Crust- O, Si, Al
2. Mantle- O, Si, Mg, Fe
3. Core- Fe, Ni

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Remember

• CruManCo
• Chemical Company

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Physical Layers of the Earth

• Lithosphere
• Crust and upper mantle combined
• Broken in chunks called tectonic plates
• Oceanic plates are thinner and denser than
  continental plates
• Asthenosphere
• Layer of Jello-like magma in the mantle
• Tectonic plates move due to convection currents
  in the asthenosphere

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Physical Layers, cont.

• Mesosphere
• The rest of the mantle molten rock
• Outer Core
• Liquid metal
• Surrounds inner core
• Inner Core
• Densest layer
• Solid metal

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Remember

• LAMOI,
• The physical trainer

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Theory of Plate Tectonics

• Lithosphere (upper mantle and crust) is divided
  into pieces called tectonic plates.
• These plates glide across the underlying
  asthenosphere like ice drifts across a pond.
• Continents are located on tectonic plates and
  move around with them

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Plate Boundaries

• The area where two plates meet is called a plate
  boundary.
• Most earthquakes and volcanoes occur at or near
  plate boundaries
• Three main types of plate boundaries
• Divergent- separating
• Convergent- colliding
• Transform- scraping past

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Tectonic Plates
Earthquakes Worldwide
Active Volcanoes
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Transform Boundaries

• 2 plates slide past each other
• This sliding is not smooth. Plates lock and
  build up tension. After too much tension builds,
  the plates snap and move against each.
• Causes earthquakes

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Divergent Boundaries

• When two plates separate
• Most common on ocean floor
• Creates Mid-Atlantic Ridge which is visible on
  land in Iceland

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Divergence Forms New Ocean Floor
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Convergent Boundaries

• Three Main Types
• Continental Oceanic- causes deep ocean trench
  and land
• volcanoes Ex Andes Mountains
• 2. Oceanic Oceanic- causes deep ocean trench
  and island arc
• (chain of volcanic mountains) Ex Mariana
  islands and Mariana
• trench
• 3. Continental Continental- causes
• large land mountain ranges
• Ex Himalayan Mountains

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Subduction Zone Continental Oceanic Crust
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Subduction ZoneOceanic Oceanic Crust
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Subduction Zone Oceanic Oceanic Crust (another
view)
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Continental Continental Crust
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Some videos for your viewing pleasure

• Plate Movement
• http//www.youtube.com/watch?vryrXAGY1dmEfeature
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• San Andreas Fault
• http//www.youtube.com/watch?NR1vZxPTLmg0ZCwfe
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