Transcript The Theory of Plate Tectonics

The Theory of Plate Tectonics
• Page 97
• Lithosphere is broken
Theory of
up into tectonic
Plate Tectonics
plates.
• Plates move around
on top of the
asthenosphere.
• Plates are made of
Theory of
oceanic and
Plate Tectonics
continental
lithosphere.
In our model of
Pangaea, South
America and Africa fit
together… Where did
the lithosphere come
from between South
America and Africa?
• Used evidence from
Theory of
“Continental Drift”
Plate Tectonics
and Sea Floor
Spreading.”
• Tuzo Wilson
What makes the plates move??
Convection
Currents
• Arthur Holmes
(1930’s)
• heat transfer
inside the earth
causes mantle
material to move.
How do
Convection
Currents work?
• Heat rises, cool
sinks.
• As mantle material
heats up, it rises to
the surface.
• Near the surface, it
“cools,” sinking
back down,
creating a circular
movement.