Presentation on the Convergence of Continental Plates

Lecture Notes

2. Part C: Two Continental Plates Converging
Materials:
• modeling clay
• 2 blocks of wood
• paper
Procedure:
1. On a piece of paper, flatten the modeling clay with the palm of your
hand.
2. Cut the clay into four strips; each strip should be 0.5 cm thick, 4 cm
wide, and 12 cm long.
3. Put 4 strips one on top of the other.
4. Place a block of wood at each end of the clay strips and slowly push
the two blocks together. Observe what happens to the clay.

3. 1. What happened to the strips of clay as they were
pushed from opposite ends?
2. If the strips of clay represent the Earth’s
lithosphere, what do you think is formed in the
lithosphere?
3. What other geologic event could take place with
this type of plate movement aside from your
answer in 2?
4. In terms of the consequences on the Earth’s
lithosphere, how will you differentiate this type of
convergent plate boundary with the other two?

5. Unlike the
other two
types of
convergent
boundaries,
subduction
ceases for this
particular
type of
convergence.
The forces in the lower
mantle that drive the
movements of the
lithospheric plates are
too great to be
changed by this
collision. The
continents cannot be
sucked into the trench
because their granite
rocks are too buoyant
to be subducted.
Therefore, the two
continents collide!

6. No trench, no volcano, and definitely no island arc are created during this process.
Instead, what is created is a large group of tall mountains called mountain range.

7. The collision of the Nazca and
South American Plates has
deformed and pushed up the
land to form the high peaks of
the Andes Mountains. This
photograph is of the
Pachapaquimining area in
Peru.

8. The Himalayan Mountains are
the result of the slow but powerful
collision between India on the
Indo-Australian Plate and the
China on the Eurasian Plate.

9. The strips of clay buckled upward.

10. Mountains are formed in the
lithosphere.

11. Earthquakes will occur due to the collision of
the two plates. (Since there is no subduction,
only shallow earthquakes will happen)

12. Since the two plates involved are both
continental plates there is no subduction
process (because both plates are low in
density). As a result, mountains are formed
instead of volcanoes.