Download The Plate Tectonics Theory

Plate Tectonics Theory Notes
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_________________________ =
o The crust & uppermost part of the mantle
o This layer is broken up into large plates called _____________
_______________ or _________________________________
_________________________ =
o Soft, bendable layer just below the lithosphere
o The plates float on top of the _______________________
Plate Tectonics Theory
states that pieces of Earth’s
____________________ are in constant, slow motion, driven by
___________________________________ in the mantle.
The lithosphere is broken into large, continent sized sections called
__________________________. There are about 30 tectonic plates on the
Earth’s surface
The plates of the lithosphere float on top of the liquid rock in the mantle
called the ________________________.
The tectonic plates move very slowly (about 1 to 8 cm per year). This is
close to how much your __________________ grow in one year.
Plate Tectonics: Boundary Types
• 3 types of plate boundary movements
 Convergent:
_________________________________________________________________
_________________________________________________________________
 Divergent:
_________________________________________________________________
_________________________________________________________________
 Transform:
_________________________________________________________________
_________________________________________________________________
Convergent Boundaries
There are 3 types of convergent boundaries.
1) Continental vs. Oceanic
o At this type of boundary, the denser oceanic plate dives under the less
dense continental plate.
o When 1 plate moves underneath another one, it’s called
_____________________ .
o This type of boundary forms ___________________________________
on the continent and ________________ under water.
o Example: Juan de Fuca dives under North American plate, forming the
____________________________________ in western North America.
2) Oceanic vs. Oceanic
o When two oceanic plates collide, the plate that is _____________,
therefore colder and denser, is the one that will sink
(_______________).
o _________________ form under water and curved ________________
__________________________ (aka island arcs) form above the water.
o ______________________________________ (Aleutian Islands) of
Alaska is an example.
3) Continental vs. Continental
o When two huge masses of continental plates meet head-on, neither
one will ____________ .
o This causes solid rock to undergo ___________________ (where rock
crumples and bends).
o Huge slivers of rock many kilometers wide are piled on top of one
another, forming __________________________________________.
o This is how the __________________________________________in
the world grow.
o Example: _________________________________________________
(Mt. Everest ~ 29,000 ft)
Divergent Boundaries
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Where 2 plates ____________________from one another.
Occur in the _____________ and on _____________.
When plates diverge _________________________, they create
__________________________________. Mid-ocean ridges are areas
where __________________________________ forms. Creating new
oceanic crust is called ____________________________________.
When plates diverge _______________, the plates spread apart and form a
deep valley called a _______________________.
Example: _______________________________in east Africa marks a deep
crack in the African continent that runs for ~3,000 km
Transform Boundaries
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At _____________________________________________, the plates grind
past each other side by side (called ________________ ).
This shearing creates ______________.
________________ can happen at transform boundary faults.
This type of boundary separates the North American plate from the Pacific
plate along the _________________________________, a famous
transform plate boundary that’s responsible for many of California’s
______________________.