1. Plate Boundaries

2. Essential Questions: What is plate tectonics?
What are the three types of plate boundaries?
What crustal features are formed at plate boundaries?

3. Quick Action – INB Template
Cut out the INB Template. Paste it into your notebook.
The next two pages will go on top of this page to make a 3 page flip book.
This Template is page 3.
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4. Quick Action – INB Template
Page 2
Page 1
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5. Plate Boundaries
Seven Continents today
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6. Continental Drift Theory Theory of Plate Tectonics
Plate Boundaries
Continental Drift Theory
Alfred Wegener developed the theory that the continents drift. At the time he did not know the mechanism that made this happen.
Sea-Floor Spreading
Harry Hess discovered that magma was rising on the sea floor causing it to spread. The hot magma rising in the mantle caused the spreading on the sea floor and the large pieces of crust (tectonic plates) to move.
Theory of Plate Tectonics
These two theories lead to the Theory of Plate Tectonics.
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7. Plate Boundaries
Plate Tectonics is the theory that Earth's outer crust (lithosphere) is divided into several plates that glide over the plastic-like and less ridged asthenosphere (upper mantle).
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8. Plate Boundaries Convection Currents
What is the engine that moves the plates?
Convection Currents
Transfers energy in the mantle
Causes the hotter magma in the mantle to rise
Causes the cooler magma in the mantle to sink
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9. Quick Action – INB Template
Type of Boundary
Sketch of Boundary
Direction of Movement
Description/Features of Plate Boundary
Examples
Divergent Plate
Boundary
Transform Plate Boundary
Convergent Plate Boundary
Collision
Subduction
Ocean-Ocean
Ocean-Continent
Complete the table as you move through the PowerPoint Presentation. Glue into your notebook as a reference.
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10. (neither destroys or creates crust)
Plate Boundaries
What happens at plate boundaries?
Plates do one of 3 things.
Converge (colliding or coming together)
Diverge (dividing or moving apart)
Transform (sliding past each other)
Converge
(destroys crust)
Diverge
(creates crust)
Transform
(neither destroys or creates crust)
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11. Quick Action – Plate Boundaries
Ready for a song? The melody is to the “Adam’s Family.”
Converging is colliding,
Diverging is dividing,
Transform is sliding,
We are the plate boundaries.
Dah na na na. <Snap, Snap>
Bet you can’t get that out of your head!
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12. Plate Boundaries Divergent boundaries – dividing or moving apart
Two oceanic crusts diverge and create a mid-ocean ridge (mountains under the ocean).
This process is call sea-floor spreading.
New crust is created.
The Mid-Atlantic Ridge actually comes above the ground in Iceland.
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13. Plate Boundaries Divergent boundaries – dividing or moving apart
Two continental crusts diverge and create a rift valley.
New crust is created.
Example is the Great Rift Valley in Africa
Over millions of years water will eventually fill the valley.
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14. Plate Boundaries Transform boundaries
Transform boundaries
Plates slip sideways past each other creating earthquakes.
Crust is neither created or destroyed.
Many of these boundaries are found on the sea floor.
The most famous transform boundary is the San Andreas fault in California.
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15. Plate Boundaries What happens when plates converge or collide?
Continental/Continental = folded mountains (Himalayas).
Continental/Oceanic = volcanoes form (Cascades in Oregon and Washington)
Oceanic/Oceanic = Volcanic arc of islands form(Aleutian Islands in Alaska)
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16. Plate Boundaries
Converging boundary -continental/continental boundary.
Two continental crusts collide and push against each other.
This pressure causes both plates to rise creating folded mountains.
Not a subduction zone
Himalaya Mountains
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17. Cascade Volcanoes in WA, OR and CA
Plate Boundaries
Converging boundary - continental/oceanic boundary
The ocean crusts goes below the continental crust because its more dense.
Volcanoes form on the continent.
A trench forms at the place when the plates collide.
Subduction zone
Cascade Volcanoes in WA, OR and CA
Old crust is destroyed
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18. Aleutian Islands in Alaska
Plate Boundaries
Converging boundary - oceanic/oceanic boundary
Two oceanic crusts collide and push against each other.
The older crust goes below the other one and creates a volcanic arc of islands.
Subduction zone
Old crust is destroyed
Aleutian Islands in Alaska
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19. Quick Action – INB Template
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20. Quick Action – Plate Boundaries
Let’s review the three types of plate boundaries.
On three slips of paper write down C, D, or T. Get with a partner
Decided which type of boundary you want to “act out.”
Demonstrate to the class your “boundary” and have the class determine which type of boundary you are representing by holding up the corresponding letter, which represents converging, diverging and transform boundaries.
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21. Plate Boundaries Ring of Fire
A long chain of volcanoes that surround the Pacific Ocean.
One of the most geologically active area on Earth.
Site of frequent earthquakes and volcanic eruptions.
Caused by plate boundaries converging, diverging and transforming.
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22. Quick Action – INB Template
Plate Boundaries
Glue this side to Notebook after creating pocket with tabs
Glue this side to Notebook after creating pocket with tabs
Make pocket tabs in your notebook.
Convergent
Divergent
Glue this side to Notebook after creating pocket with tabs
Transform
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23. Quick Action – INB Template
Cut out plate boundary cards and put them in the correct pocket in your notebook.
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24. Quick Action – INB Template
Plate Boundaries
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25. Check for Understanding
Can you…
Explain plate tectonics?
Name the three types of plate boundaries and describe their movement?
Relate plate boundaries to the formation of crustal features: such as mountains, trenches, volcanoes and ridges?
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