Plate%20Tectonic%20Notes

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Plate Tectonic Notes
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I. Continental Drift Theory A. proposed by
Alfred Wegener in 1912 B. states that all
continents were once one supercontinent (Pangaea)
and have since floated apart over time

• C. Evidence to support theory
• 1. fossil records are similar on different
  continents
• 2. land forms such as mt. ranges and mineral
  deposits line up
• 3. coastlines of current continents appear to
  fit together like a puzzle

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• II. Theory of Plate Tectonics
• A. states that the earths crust is broken into
  large moving pieces (plates) to which the
  continents are attached.
• B. Why Change the Theory?
• 1. new technology allows
• scientists to discover new
• information
• a) sonar
• b) SCUBA
• c) submarine improvements
• C. New Evidence
• 1. sea-floor spreading
• 2. earthquakes and volcanoes
• 3. actual recorded movement

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• C. 16 plates ( means major plate)
• 1. N. American 6. Arabian 11.
  Indo-Australia
• 2. Eurasian 7. Phillippine 12. Fiji
• 3. Juan De Fuca 8. S. American 13. Nazca
• 4. Caribbean 9. Caroline 14. Pacific
• 5. Cocos 10. African 15. Scotia
• 16. Antarctic

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• III. Plate Boundaries
• A. locations where two plates meet
• B. where the forces that shape the earths
  surface occur
• 1. Constructive forces create landforms
• 2. Destructive forces destroy landforms
• C. three different types

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• 1. Divergent
• a) plates move away from each other
• b) sea-floor spreading ridges
• c) new crust is formed at this boundary type
• d) mid-Atlantic Ridge in Atlantic Ocean
• 2. Convergent
• a) plate move toward one another
• b) subduction- one plate forced underneath
  another
• gt deep trenches, coastal mt. ranges, volcanoes
• gt Andes Mts on west coast of S. America
• c) collision both plates push upward
• gt large mt ranges, earthquakes
• gt Himalaya mt range in northern India
• 3. Transform
• a) plates move past one another in different
  directions
• b) faults visible at surface, large earthquakes
• c) San Andres Fault in California

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Boundary Movement Picture Landform(s) Examples
Divergent Plates move AWAY from one another Landforms Mid-ocean ridges rift valleys Example Mid-Atlantic Ridge
Convergent Collision Plates move TOWARD each other and BOTH push upwards Landforms Large mountain ranges w/ lots of earthquakes Example Himalayan Mts in India
Convergent Subduction Plates move TOWARD each other and one plate gets pushed under the other Landforms Deep ocean trenches, coastal mt. ranges volcanoes Example Andes Mts in South America
Transform Plates move past one another in opposite directions Landforms Faults that are visible on land Example San Andres Fault in California
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• divergent boundary
• transform boundary
• convergent / subduction
• boundary
• convergent / collision
• boundary