Plate Tectonics
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For many years it was believed by geologists that
the location of the continents was fixed. These scientists
believed that the locations of the continents were
determined many billions of years ago. It was believed
that the continents were simply areas where the crust was
too high for the oceans to cover them over.
Modern scientific discoveries have helped us
understand that this view of the Earth is inaccurate. We
have learned that the lithosphere (the crust and upper
layer of the mantle) float on top of the asthenosphere and
can move around. How does this happen?
At the bottom of the ocean, located almost exactly
halfway between the continents are under-water mountain
ranges. This is where hot magma escapes from the
Earth’s core, and spreads outward. As the seafloor spreads
outward, the continents are carried across the sea, riding
on top of the crust.
As new crust is created it forms what resemble
giant plates. One side of the plate is where new crust is
being made, while the other side is where older crust is
being destroyed. These plates are called tectonic plates
and move from 5-10 cm a year.
Materials: colored pencils, Plate Boundary Map
What To Do:
1. Don’t glue in the map.
2. Find all the arrows on the map (10) and color them orange.
3. Find the Nazca Plate and lightly color it blue.
4. Find the South American Plate and color the continent green
and the ocean blue.
5. Find the mid-Atlantic Ridge with the help of your teacher
and trace it in red.
6. Color the ocean on either side of the mid-Atlantic Ridge
blue.
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The Effects of Moving Plates
The earth’s crust is broken up into many pieces called
plates. These plates move along the top of the
asthenosphere. The plates move very
slowly-at rates of several centimeters
a year. The cracks between the plates
are called plate boundaries. Along
plate boundaries the plates slide past
each other, pull apart or move
together. The Theory of Plate
Tectonics explains all of this
movement. Plate tectonics is what causes major crustal
features such as mountains, volcanoes, fault lines and
ocean basins.
When the plates move toward each other the land
crumbles and form high mountain ranges. The
Himalayan Mountains were formed with the IndoAustralian plate slammed into the Eurasian plate. When
plates pull apart ocean basins are formed such as the
Atlantic Ocean. Volcanoes and earthquakes also occur
around many plate boundaries.
Watch the Plate Tectonics segment of TLC
Elementary School: Geological Processes from
www.discoveryeducation.com
Questions:
1. What was Pangea? _____________________
2. What two continents fit together like a puzzle?
________________________________________
3. What did Alfred Wegner call his theory?
___________________________________________
4. What theory do scientists use to explain the moving
continents? _________________________________
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Your teacher will show you a Power Point called Types of Plate
Boundaries.
Questions:
1. How do convergent boundaries move? _________________
2. How do transform boundaries move? __________________
3. How do divergent boundaries? _______________________
4. What type of Plate
Boundary is shown?
______________________
5. What type of effects does
this type of boundary have
on the area around it?
_______________________
_______________________
6. What type of Plate
Boundary is shown?
______________________
7. What type of effects does
this type of boundary have
on the area around it?
_______________________
_______________________
8. What type of Plate
Boundary is shown?
______________________
9. What type of effects does
this type of boundary have
on the area around it?
_______________________
_______________________
Name ____________________
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Period _____
EXIT TICKET
Plate Tectonics
1. Convergent plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Mountains
C. River Valleys
2. Divergent plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Mountains
C. River Valleys
3. Transform plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Volcanoes
C. Glaciers
4. The only place you can see the Mid-Atlantic Ridge on
land is
A. The Himalayan Mountains
B. The Andes Mountains
C. Iceland
5. The theory that explains all the movement along plate
boundaries is called –
A. Big Bang Theory
B. Conservation of Mass Theory
C. Theory of Plate Tectonics
Name ____________________
Period _____
EXIT TICKET
Plate Tectonics
1. The only place you can see the Mid-Atlantic Ridge on
land is
A. The Himalayan Mountains
B. The Andes Mountains
C. Iceland
2. The theory that explains all the movement along plate
boundaries is called –
A. Big Bang Theory
B. Conservation of Mass Theory
C. Theory of Plate Tectonics
3. Convergent plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Mountains
C. River Valleys
4. Divergent plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Mountains
C. River Valleys
5. Transform plate boundaries cause what type of crustal
feature?
A. Ocean basins
B. Volcanoes
C. Glaciers
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