Download Geo 1-2 Tectonic Plates Notes

The Theory of Tectonic Plates
Plate Tectonics
Plate Tectonics
• Theory that earth’s outer shell (crust) is not
one solid sheet of rock…more like a jigsaw
puzzle
• Each plate moves separately
– Movements can lead to earthquakes, volcanoes
and more
Plate Tectonics
Continental Drift Theory*
*Supported by looks
and by the fossil record
When plates move
• Seafloor spreading
– New earth forms where plates pull part
The Ring of Fire
Why do you
think that
there are so
many
volcanoes and
earthquakes
around the
Pacific Ocean?
• Together
When plates move
– Oceanic and Continental plate
– Oceanic under Continental (subduction)
• Melting crust causes mountains/volcanoes to form
– Like Cascade Mountains in the USA
When plates move
• Together
– Continental and Continental plate
– Mash together and up
• Mountains formed (like Himalayan Mountains)
When plates move
• Sliding/faulting
– Plates move grind past each
other
• Like San Andres fault
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Where would you see seafloor spreading?
Where are the Cascade Mountains?
Where are the Himilayan Mountains?
Where is the Ring of Fire?
Where is the San Andres Fault?