processes along convergent boundary

1. Watch and Observe.

2. Processes and
Landforms Along with
Convergence of Plates
Activity 3: A,B & C

4. Convergent Boundary
•Continental Plate   Oceanic Plate
•Oceanic Plate   Oceanic Plate
•Continental Plate   Continental
Plate

5. Activity 1:
Head on collision
Part A: Converging
Continental Plate and
Oceanic Plate

6. Objective
•Explain the processes that
occur along convergent
boundaries.
•Determine the consequences
of colliding plates.

7. Procedure
Plate A Plate B

8. •Q1. What type of
plate is Plate A? How
about Plate B? Why
did you say so?

9. •Ans. Plate A is an
oceanic plate because it
is relatively thinner than
plate B. Plate B is a
continental plate
because it is thicker and
floats higher than plate A

10. •Q2. Describe what happens to
Plate A as it collides with Plate
B? Why?

11. •Ans. Plate A bends
downward because
Plate A is denser than
Plate B.

12. •Q3. What do you think
may happen to the
leading edge of Plate A as
it continues to move
downward? Why?

13. •Ans. The leading edge of
plate A will start to melt
because the temperature
beneath the crust is
higher.

14. •Q4. What do you call this
molten material?

15. Ans. Magma

16. •Q5. What is formed on top of
Plate B?
Plate B

17. Ans. Volcanoes or
Volcanic Arc
Plate B

18. •Q6. As the plates continue to grind
against each other, what other
geologic event could take place?

19. •Ans. Earthquakes
Earthquakes

20. Converging Oceanic Crust Leading Plate
and Continental Crust Leading Plate
•During the convergence of an
oceanic plate and a continental
plate, the denser oceanic plate
slides under the continental
plate. This process is called
subduction.

21. Converging Oceanic Crust Leading Plate
and Continental Crust Leading Plate
•The following will take place:
•Formation of a volcanic arc
•Formation of an oceanic
trench
•Occurrence of earthquakes

23. Activity 1:
Head on collision
Part B: Convergence of
Two Oceanic Plates

24. Oceanic Plate A
Ocean
Water
Figure11: Cross-sectional diagram of
converging oceanic plates
Oceanic Plate B

25. PLATE A
PLATE B

26. Q1. What are the
geologic
processes/events that
will occur because of
this plate movement?

27. •Ans. The following geologic
processes/events may happen:
•Plate B undergoes subduction or
sinking of plate towards the mantle.
•Earthquakes may happen
•Trenches will form
•Volcanoes will form at the surface of
Plate A

28. Q2. What geologic features
might form at the surface of
Plate A?
•Volcanoes will form on
the surface of Plate A.

29. Q3. If the edge of Plate A
suddenly flicks upward, a
large of amount of water
may be displaced. What
could be formed at the
surface of the sea?

30. •Ans. Tsunami is
formed at the
surface of the sea

31. PLATE A
PLATE B

33. Convergence of Oceanic Plates
•When two oceanic
plates converge, they will
undergo subduction
process

34. Convergence of Oceanic Plates
The following geologic events will take place:
•Formation of a volcanic island arc
•Formation of trench
•Generates shallow, intermediate and deep
earthquakes
•Tsunami may be produced from strong
earthquakes generated by the ocean floor.

35. Formation of the Philippine
Archipelago
•Many parts of the country
originated from oceanic-
oceanic convergence.

36. •Majority of the islands of the
Philippine archipelago are
considered part of the Philippine
Mobile Belt formed 65 million years
at the southern edge of the
Philippine Plate and are considered
as part of the island arcs

37. Eurasian
Plate
Figure 13: Sundaland block of Eurasian Plate which includes Palawan,Mindoro and Zamboanga.

38. Formation of the Philippine Archielago
•Other parts of the Philippines
such as Palawan, Mindoro, and
the Zamboanga peninsula are the
highland sections of the
Sundaland block of the Eurasian
plate

39. Formation of the Philippine Archielago
•The Philippine Mobile Belt
eventually collided with the
Sundaland block which explains
the presence of trenches such as
the Manila-Negros-Cotabato
Trench System and the Sulu
Trench.

41. East
Luzon
Trough
Philippine
Trench
Figure15: Subduction of Philippine Sea Plate

42. Formation of the Philippine Archielago
•Aside from the formation of
trenches and troughs, the
downward movement of oceanic
lithospheres underneath the
Philippine Archipelago creates
active volcanic chains.

43. Formation of the Philippine Archielago
•For example, the descent of the West
Philippine Sea oceanic lithosphere along
the Manila Trench created a volcanic
chain from Taiwan to Mindoro. Some of
the known active volcanoes in this chain
are Pinatubo in Central Luzon, and Taal in
Batangas.

44. Formation of the Philippine Archielago
•Also, the constant dipping movement
of slabs induces frequent moderate to
strong earthquakes at various depths,
gives rise to mountain ranges and
develops the geologic character of
the Philippine Archipelago.

45. Activity 1:
Head on collision
Part C: Two Continental Plates Converging

47. Convergence of Continental Plates
•When two continental plates
meet head-on, neither is
subducted. Instead the crust
tends to buckle and be
pushed upwards.

48. Convergence of Continental Plates
•No subduction means no trench, no
volcanoes, no volcanic island arc is
created instead a large group of tall
mountains called Mountain Ranges
form.
•Shallow earthquakes may also
happen

50. Collision of India and Asia

51. The Himalayas
•Earth’s highest mountain
range, the Himalayas, was
formed millions of years ago
when the Indo-Australian
Plate crashed into the
Eurasian Plate. Even today,
the Indo-Australian Plate
continues to push against the
Eurasian Plate at a rate of
about 5 cm a year!

52. Convergent Plate Boundaries
Oceanic -
Continental
• Subduction
occurs
• Volcanic arc
• Trench
• Earthquakes
Oceanic - Oceanic
• Subduction
occurs
• Volcanic Island
arc
• Trench
• Earthquakes
• Tsunami
• Continental -
Continental
• Mountain
Ranges
• Earthquakes
• No subduction
• No Volcanoes
• No Trench
• No Island Arcs