Plate Tectonics

Plate Tectonics

  • Submitted By: isabelc
  • Date Submitted: 03/18/2009 4:02 AM
  • Category: Science
  • Words: 528
  • Page: 3
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Standard 2 Notes
Theory of Continental Drift:
Pangea was a supercontinent. All continents connected.
Pangea broke apart and drifted to their current positions.
The landmasses still move today
Wegner's original theory was wrong.
Continets are attatched to the crust
the whole plate moves
convection currents of magma moves plates
tectonic plates float of magma
fossils of the same plant and snimal species are found on continents that are on different sides of the atlantic ocean (like mesosaurus and glossopteris)
Pangea formed during the permian period
Plate Boundaries:
Convergent Boundary : collision of two plates.
continental-continental himalayas eurasian & indian plate
chile fault- formed by convergence of Nazca & South American plates.
Aleutian Trench north american plate and pacific plate
java trench indian & burma & sudan
Phillippine plate & pacific plate creates marianna trench
caribbean fault: caribbeans & american plates.
Divergent Boundary: plates move away
mid-atlantic ridge
south west indian ocean ridge
Transform Boundary
slide against each other
when stress builds and suddenly release, an earthquake may occur.
alpine fault pacific & indo-australian plate
divergent offspring & transform fault
Inside the Earth
Core
iron, nickel
no oxygen silicon alumnium magnesium
dense
33%
Mantle
thicker than crust
contains most of the Earth's mass
magma liquid rock
denser than crust less dense than core
more magnesium & less alumnium and silicon than crust
67%
Crust
outer-most layer
5-100 km thick
thinnest
less than 1%
-continental & oceanic crust made of oxygen, silicon, alumnium
Compounds are composed of 2 or more elements
Layers go from less dense (outer layer) to most dense (inner layer)
Physical Structure
Lithosphere
outer layer
crust & upper rigid part of mantle
tectonic plates
Asthenosphere
plastic layer of mantle
lithosphere moves on top
solid rock
moves slowly
Mesosphere
Strong lower part of the...

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