Convergent Plates Lesson Plan:
Mountain Building and Subduction
The Convergent Plates Lesson Plan demonstrates what happens when tectonic plates are crashing into each other and explains Mountain Building and Subduction.
- To understand what happens
when tectonic plates converge
- To observe landforms that
have occurred from convergence
- For Telephone Book
Demonstration: Two phone books for each pair of students
- For Cookie Subduction Model:
Enough sandwich-style cookies to have one for each
Italicized words are suggestions for language to use during the
When the plates of the earth’
s surface collide two things can happen:
- The layers push against
each other. Folds occur or mountains rise up.
Place two phone books on
a table with pages facing
Push the phone books
Observe what happens to
Compare this to mountain
building at convergent boundaries.
One layer, the heavier of
the two, goes under the other. This is called subduction. The layer
that goes under gets very hot because it is closer to the hot center
of the earth. Pockets of magma may get pushed up and the hot magma
can have an effect on the rocks that are going under the top layer.
(Note: this could be
done in a separate lesson about subduction.)
Take apart a
sandwich-style cookie with a cream center.
Using the half that has
the cream on top, put the cookie just under your two front
teeth. Your front teeth
represent one tectonic plate and the cookie represents the
Slowly push the cookie
toward the inside of your mouth, while the cream filling is
jammed up against your front
Have a friend tell you
what is happening to the filling. (It is folding up against
your teeth while the cookie
is being subducted below.
Explanation for the
Teacher/Science behind the work:
When two plates crash together it
is called a convergent boundary. Because plates only move a few
centimeters each year, collisions are slow and last for millions of
Oceanic plates tend to be heavier
than continental plates. Therefore, when an oceanic plate converges
with a continental plate, the oceanic plate tends to be forced under
the continental plate, or subducted under the continental plate. When
a plate is subducted, a trench occurs as one plate dives below
another. The rock in this plate melts as it approaches the depths of
the mantle. Earthquakes occur. Volcanoes form to release the molten
rock to the surface.
plates converge, mountains and trenches form. Earthquakes occur in
these areas as the plates move together. Subducted plates melt and
the molten rock is released to the surface through volcanoes.