Unit 10 part 2 Geology

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Unit 10 part 2 Geology
2013-04-10 10:20:19

part 2
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  1. Why does Earth have transform faults (geometrically)?
    Transform faults are large and long vertical fractures found within the Earth's crust that are caused by both divergent zones and because of Earth's curvature as a sphere.
  2. What tectonic feature does a transform (fault) zone displace or offset?
    Movement along these faults is side to side, which offset divergent zones or spreading centers (because  Earth is a sphere and does not rip apart like a plane)
  3. Describe the movement of the adjacent plates of transform plate boundaries.
    Transform faults usually extend outwards for very long distances from the divergent zones.
  4. Name a famous American transform fault zone.
    San Andreas Fault
  5. Describe what happens at convergent plate boundaries.
    Different lithosphere plates meet or converge. This margin is the place where new larger continents may be combined by "collisions".
  6. What destructive forces are associated with convergent plate boundaries?
    These plate boundaries are directly associated with Earth's most destructive earthquakes, volcanoes and with the largest mountains on Earth's surface.
  7. What are the three types of convergent plate boundaries?
    Oceanic crust being subducted beneath oceanic crust (can create new continental crust).

    Oceanic crust being subducted beneath continental crust (can expand existing areas of continental crust).

    When both plates composed of continental crust collide (which can greatly increase the size of existing continents).
  8. What type of crusts are involved with the creation of island arcs?
    Oceanic crust is subducted beneath another oceanic crust which results in island arcs.
  9. Label components of oceanic crust-continental crust convergent zone.
    • Deep sea trenches found just offshore from the continents. 
    • Violent volcanoes and earthquakes are located above and within this subduction zone. 
    • Here continents can grow by acquiring "accreted terreains"
  10. What is an accreted terrain?
    Seafloor, island arcs and ocean sedement that is "scraped off" onto a continenst as the oceanic crust is being subucted into the mantle (This can make continents larger).
  11. What happens when two continental plates collide (i.e. are any of these plated subducted? Why?)
    When these crusts collide, one crust overrides another or "stacks up" to create enormous sized mountains.
  12. Name an European and an Asian mountain range caused by two continental plates colliding.
    Alps and the Himalayas.
  13. Why are metamorphic rocks most common at convergent zones?
    Because convergent zones involve compression.
  14. Describe the relative volocities of lithospheric plates.
    The most common reference for rates of plate motion is relative velocity or the movement of one plate relative to another plate.
  15. What is the basic premise of the Passive Plate theory?
    States the convection of heat from the core and mantle drives plate movement.
  16. What is the basic premise of the Slab Pull theory?
    States that oceanic slabs sink into the mantle under its own weight.
  17. What is meant by the super-continent cycle?Who came up with the name?
    Came up by J. Tuzo Wilson. States that approximately every 500 million years, most of the Earth's plates collide together to form a massive continent.