How to Make a Mountain

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How to Make a Mountain

• Using a sandbox to Model mountain building

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Part 1 SOAR-High Collaborators
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Dr. Michele Cooke

• Dr. Mario Del Castello

Department of Geosciences, University of
Massachusetts
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Part 2Structure of the Earth
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The Earth

• Crust
• Continents
• Ocean Floor
• Core
• Lithosphere
• aethenosphere

• Picture of Earth cross- section here

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Earths Crust is made of plates

• A large rigid slab of solid rock
• 15 km under oceans
• 200 under continents
• Billion years old
• Largest plates are under the Pacific ocean, and
  Antarctica.

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Earths Crust

• The plates are cracked
• The cracks are called faults
• The edge of a plate is called a boundary

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Earths crust

• The plates are always in motion!
• Changes require much more time than humans can
  live!

• Fastest movement is 2 to 3 cm/yr
• Most geologic changes require a 100 million
  years.
• Humans live 80 years

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Part 3Kinds of Faults
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Faults can be large and small

• A Large scale fault

• Small scale faults

The San Andreas Fault in California stretches
1000 km!
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Part 4The plates move!
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What happens when Plates Move?

• A Geologic Rule
• A broken plate may move apart, and it always uses
  faults to move around blocks of crust and will
  always fill up the space between

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Two kinds of movement

• Extension
• lt gt
• Pull apart force is called TENSION
• Creates a RIFT

• Contraction
• gt lt
• Push together force is called SHORTENING
• Creates a SUBDUCTION

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Extension Contraction

• Drawing of extension situation

• Drawing of contraction
• situation

Combine pictures with vocab on next slide ( 1
slide)
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Rifts vs Subduction

• (Contraction)
• Plates are Colliding
• gt lt
• Involves a
• thrust fault

• (Extension)
• Plates are Stretching
• lt gt
• Involves an
• extensional fault

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Part 5studying mountains
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Lets study mountains!

• Go out for a hike
• You can see the real thing
• Can make measurements drawings
• -- You cant see underground
• -- cant change anything!

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Or we can Make a model

• you can test variables (different
  situations)
• you can measure and draw
• you can see underground (cross sections)
• -- Is it really the same?
• -- Do real mountains follow the same patterns?

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The Sandbox is a model of mountains

• Mountains are LARGE scale.
• Sand is very small scale.
• 1 cm deep sand 1 km of crust

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What we can measure

• Strike a faults orientation
• (north/south, east/west, or parallel, or
  whatever to tell how it looks.)
• Dip How steep or shallow the fault is its
  angle.

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Part 6 Set up the Sandbox
Carefully observe what happens in the sandbox.
Make small sketches of the results frequently
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Part 7Thinking and Understanding
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SynthesisLabel your drawings - Show your
understanding

• Label a fault
• Is it an extensional or thrust fault?
• Show the force.
• Is the force Tension or Shortening?
• Measure the angles

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SynthesisThe big picture

• View the sandbox from above, looking down. Make
  a sketch.
• Draw the plate (use the whole sand area)
• Label the boundary (the edges of the sand area)
• show the strike of the fault or faults
• How does the surface look?

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Part 8Compare with the real world
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Back in the real world - How do mountains look?
Young mountains
Old mountains
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SynthesisWhat do you see in the real world?

• How does the surface look after millions of
  years?
• How did it change?
• Erosion by wind
• Erosion by water
• Erosion by temperature changes

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• More mountain pictures. Identify types of
  faults? Old/new, other vocabulary.

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Web sites

• http//www.pbs.org/wgbh/nova/everest/earth/birthmo
  untains.html
• http//www.open.ac.uk/science/discover/structure/b
  lock3.htm
• http//www.edu.pe.ca/southernkings/earthcrust.htm
• http//www.thinkquest.org/library/site_sum.html?tn
  ame17701url17701/high/pangaea/