Chapter 8
Plate Tectonics
• Plate tectonics
• Earth has
plates???
• The formation,
movement and
interactions of
earth’s plates
• Rigid moving pieces
of Earth’s crust,
called……….
• Lithosphere
• Rigid, moving pieces
of Earth’s crust and
upper mantle
• Asthenosphere • Partially melted layer
on top of which the
lithosphere moves
• Continental drift
• Theory proposed by
Alfred Wegener
stating that the
continents moved
or drifted from one
location to another
over a period of
time
• Evidence????
• Common fossils
on South America
and Africa
• MESOSAURUS
• Location of
Earthquakes and
Volcanoes….
• Located along plate
boundaries
• Ring of Fire….ring
of volcanoes &
earthquakes
around the Pacific
Ocean
Types of Plate Boundaries
• 4 types of plates
boundaries…
• Divergent
• Convergent/collisi
on
• Subduction
• Transform/sliding
• Divergent
• Feature formed?
• 2 plates are
moving apart
• Mid-ocean ridge
Example – Mid-Atlantic Ridge
• Convergent/colli
sion
• 2 plates slam
together
• Feature formed?
• Mountains and
mountain ranges
Example - Himalayas
• Subduction
• One plate moves
underneath
another plate
• Feature formed
• Trench
Example – Marianas Trench &
Peru-Chile Trench
• Ocean- ocean plate
• Ocean – continental
plate
• Which plate
subducts?
• What happens to it?
• The denser one (ocean)
• It melts!
• Transform/sliding
• 2 plates slide past
each other
• Feature formed?
• Fault, like San
Andreas
Example – San Andreas