Theory of Plate Tectonics Poster

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The Story of the Discovery of Plate Tectonics
The same fossils were found on different
continents
All Continents had been joined together in a
supercontinent, Pangaea and has since drifted
apart
This plant fossil Glossopteris was found on 5
different continents
In 1915 a German scientist named Alfred Wegener
proposed hypothesis called CONTINENTAL DRIFT
The same mountains were found on different
continents
Circle is where mountains split, half are found
in East US, the other half in Europe
Three Pieces of Evidence
Scratches from ice were found in deserts in
India and Africa
Scratches left by ice show that India and africa
were much farther South on Globe
WEGENERS HYPOTHESIS WAS REJECTED BECAUSE HE
COULDNT PROVE WHY CONTINENTS MOVED!
During World War II scientists began to use sonar
to map the ocean floor
With Sonar Scientists Discovered
Mid-Ocean Ridges Or Underwater volcanic mountain
ranges
Other Observations
Deep Ocean Trenches Or Deep holes where plates
slide under eachother
1 Youngest Rock was Found at the ridge and
oldest the farthest away from the ridge
2 Basalt rock was found at the mid-ocean ridge,
it comes from Volcanoes and makes the ocean floor
of every ocean
In 1963 Harry Hess created the idea of Sea-Floor
Spreading
3 Ocean floor was found to be sinking below
continents or other crust at the trenches this
process was named subduction
This lead to a new theory!
New ocean floor forms at the mid-ocean ridges,
slowly spreads out to form new ocean basins
before sinking below lighter plates
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WarmUp (3-19-13)

• What is going to happen to all of our continents
  within the next 250 million years?
• They will collide to form another supercontinent

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WarmUp (3-20-13)

• Who developed the concept of Continental Drift
  and what was his evidence to support it?
• Alfred Wegener same fossils on different
  continents, and same rocks from mountains, and
  how continents fit together like a puzzle

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WarmUp (3-21-13)

• Describe the process of sea-floor spreading.

• Agenda
• WarmUp
• How Its Made
• Finish Poster
• Watch Video

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WarmUp (3-25-13)

• Name the three different types of plate
  boundaries.
• Convergent boundary (plates collide with each
  other)
• Divergent boundary (plates move away from each
  other)
• Transform boundary (plates slide past each other)

• Agenda
• WarmUp
• How Its Made
• Plate Tectonic Activity

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(No Transcript)