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Date: _____________________
Period: _______
Diagram: Plate Tectonic Boundaries and Formations
Directions:
1. Label all plate boundaries below. (#1-4)
2. Label all features that plate boundaries form. (A-F)
3. Describe in detail what is occurring in order for lithospheric motion to occur. (#5-12)
A
F
1
D
E
2
4
3
1. convergent boundary
A. trench
2. divergent boundary
B. mountain range
3. convergent boundary
C. earthquake
4. transform boundary
C
B
D. mid-ocean ridge/seafloor spreading
E. rift valley
F. volcano
5. Describe the two different types of crust.
Continental crust is lithosphere that is dry land and is not as dense as oceanic crust located beneath Earth’s oceans.
6. Looking at plate boundary #1, describe each type of crust and the role they play at this boundary.
The oceanic crust is denser than the continental crust and is subducting under the continental crust. As a result of
subduction volcanic mountains are created on land.
7. Looking at plate boundary #2, describe each type of crust and the role they play at this boundary.
Oceanic crusts are moving apart at this divergent boundary. As they move apart a rift valley is formed between the two
plates. A mid-ocean ridge is created as volcanoes are formed along the ocean floor.
8. Looking at plate boundary #3, describe each type of crust and the role they play at this boundary.
Continental/continental convergent boundaries create mountain ranges. Neither plate is dense enough to sink below the
other; as a result they push one another upwards.
9. Describe the convection motion at plate boundary #1.
The convection of current of the oceanic plate is moving in a clockwise motion. The convection current of the
continental plate is moving in a counter clockwise motion. These movements bring the two plates together.
10. Describe the convection motion at plate boundary #2.
The convection current of the oceanic plate on the left has a counter clockwise motion and the convection
current of the oceanic plate on the right has a clockwise motion. As a result the two plates are moving apart creating a
rift valley and mid-ocean ridge.
11. Describe the convection motion at plate boundary #3.
The convection current under the continental crust on the left is moving clockwise and convection current on the right
is moving counter clockwise. The result is the two plates pushing each other with no subduction. Mountain ranges are
the result.
12. If new crust is made at divergent boundaries where sea floor spreading occurs, why is the Earth not getting bigger?
The Earth is not getting bigger because crust is being destroyed in subduction zones at convergent boundaries.