Plate Tectonics

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Plate Tectonics

• The Earths Crust in Motion

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The Theory
In 1910 Alfred begins to wonder
Whats the relationship? Perhaps all these
pieces used to be connected. Continental
driftslow movement over Earths surface 300
million years ago
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Supercontinent

• Pangea all lands
• Reptiles and insects
• Tropical forrests
• -coal deposits

?Tens of Millions of years!
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Structure of the Earths Interior
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How does it work?
Plates pieces of the lithosphere Plates fit
closely together along cracks called Plate
Boundaries Convection Currents ? movement
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Earths Puzzle

• What plate do we live on?
• What plates do we border?
• USGS Earths Plates
• How far do we move every year?

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Types of Boundaries

• Divergent
• Convergent
• Transform

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Your Task...Get Organized

• Get into teams of three
• Each person will focus on one type of boundary
• divergent (Column A)
• convergent (Column B)
• transform (Column C)
• Look only at your column
• Make a concept map

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A Divergent B Convergent C Transform

• plates are moving apart
• new crust is created
• Magma is coming to the surface

• plates are coming together
• crust is returning to the mantle

• plates are slipping past each other
• crust is not created or destroyed

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A Divergent B Convergent C Transform
Continental crust ? rift valley Oceanic crust ? mid-ocean ridge 2 continental plates ? mountain range Plates move against each other Stress builds up Stress is released ?earthquake
2 oceanic plates or oceanic continental
?subduction
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The Big Picture
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Key Terms for Map

• convergent boundary
• divergent boundary
• transform boundary
• subduction
• rift valley
• mid-ocean ridge
• continental crust
• oceanic crust
• mountain range
• earthquake