Solved Plate Tectonics - Review and Reinforce The Theory of ... - Free Printable

Let's go through the worksheet step by step and solve each part.

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Part 1: Label each figure by writing the type of plate boundary it shows.

We have three diagrams:

1. Figure 1: Two plates are moving away from each other, with new crust forming in the middle (like a rift valley or mid-ocean ridge).
- ✔ Answer: Divergent boundary

2. Figure 2: Two plates are colliding and pushing up mountains (one is continental, one might be oceanic or both continental). The diagram shows uplifted landforms.
- ✔ Answer: Convergent boundary (specifically continental-continental convergence, since there’s mountain building)

3. Figure 3: Two plates are sliding past each other horizontally with no significant uplift or subduction.
- ✔ Answer: Transform boundary

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Part 2: Answer the following questions on a separate sheet of paper.

#### 4. Describe what happens when:
a. Two plates carrying oceanic crust collide
→ One oceanic plate is forced beneath the other in a process called subduction, forming a deep ocean trench. The subducting plate melts as it goes into the mantle, which can cause volcanic activity on the overriding plate.

b. Two plates carrying continental crust collide
→ Neither plate subducts because continental crust is too buoyant. Instead, they crumple and fold, forming large mountain ranges like the Himalayas.

c. A plate carrying oceanic crust collides with a plate carrying continental crust
→ The denser oceanic plate subducts beneath the lighter continental plate, forming a deep ocean trench and often causing volcanic arcs (like the Andes) on the continental side.

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#### 5. Explain what force caused the movement of the continents from one supercontinent to their present positions.

→ The movement of continents is driven by convection currents in the Earth’s mantle. These currents slowly move the tectonic plates across the surface. Heat from the Earth’s core causes mantle material to rise, cool, and sink, creating circulation patterns that push and pull the plates. This process is known as plate tectonics.

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Part 3: Building Vocabulary – Fill in the blanks

6. A scientific theory is a well-tested concept that explains a wide range of observations.
✔ Answer: theory

7. Breaks in Earth’s crust where rocks have slipped past each other are called faults.
✔ Answer: faults

8. The lithosphere is broken into separate sections called tectonic plates.
✔ Answer: tectonic plates

9. A(n) rift valley is a deep valley on land that forms along a divergent boundary.
✔ Answer: rift valley

10. The geological theory that states that pieces of Earth’s crust are in constant, slow motion is called plate tectonics.
✔ Answer: plate tectonics

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✔ Final Answers Summary:

Figures:
1. Divergent boundary
2. Convergent boundary
3. Transform boundary

Questions:
4.
a. Oceanic-oceanic: Subduction, trench, volcanoes
b. Continental-continental: Mountain building
c. Oceanic-continental: Subduction, volcanoes, trench

5. Convection currents in the mantle drive plate movement.

Vocabulary:
6. theory
7. faults
8. tectonic plates
9. rift valley
10. plate tectonics

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