Submitted by: Kate Selkirk
In this rock cycle lesson plan, which is adaptable for grades 6 through 8, students use BrainPOP resources to explore whether magma can turn directly into sedimentary rock. Students will review the processes in the rock cycle and model the rock cycle using crayon shavings.
- Explain whether magma can turn directly into sedimentary rock.
- Review processes in the rock cycle.
- Model rock cycle using crayon shavings.
- Computer and projector/SmartBoard for BrainPOP movie
- Ceramic mugs
- Hot plate and water
- Safety goggles
- Art supplies for sketching
- Small plastic knives
- Small individual cupcake tins
Preparation:Break students into groups prior to activity. Draw a blank rock cycle diagram on chart paper that includes a box or blank for each process and arrows between them to indicate the progression.
- Have students copy the blank rock cycle diagram from the chart into their notebooks or on loose-leaf paper.
- Show the BrainPOP Rock Cycle movie. Pause it to discuss at key points and provide students with time to fill in the rock cycle diagram. Guide them to determine each type of rock and label the arrows with the processes that turn one rock into another.
- After the movie has ended, allow students 2 minutes to independently finish their diagrams, review with a partner for 1 minute, and then share out for 2 minutes.
- Demonstrate the procedures for the rock model. Say to students, "We’re going to model the rock cycle today using crayons. We’re going to have to use our imaginations and pretend that each color crayon is a type of rock and we’re going to make it morph into the other kinds of rock."
- Divide students into teams of three and give each person a crayon and a plastic knife. Ask students, "If we were to call the crayon a rock, what kind of rock would it be?" (Igneous, uniform, glassy).
- Have students take turns within their groups to gently scrape the knife across the crayon, which creates shavings. Be sure they hold their crayons over the tin cup. Discuss what they just created (sediments). Ask student to predict what type of rock they will turn their sediments into (sedimentary rock).
- Continue the discussion by saying, "Now we want to turn these sediments into rock. What kind of rock do you think it will turn into? (sedimentary rock) What should we do? (apply pressure) How do we know this is sedimentary rock? (layers of different minerals or rock pieces)."
- Have students press the shavings together until they form a solid rock. Then say, "In the rock cycle, sedimentary rock can change into metamorphic rock. What do we have to do to turn this rock into metamorphic rock?" (Apply heat and pressure.)
- Students should place the tin cup over warm water using the mugs. Gently press down on the shavings with wax paper. If you see the crayon start to melt, remove the tin immediately. Ask students, "What has to happen in order for metamorphic rock to turn into igneous rock?" (Apply extreme heat, and rock needs to melt and then cool) "What is molten rock called?" (Might say magma or lava) "What is the difference between magma & lava?" (Magma is underground and intrusive, and lava is above ground and extrusive)
- Place the tin over hot water and watch the “metamorphic rock” turn into molten rock.
- Leave the tin on the table and wait for the liquid to cool.
- Have students do the following practice activities with their small groups. 1) Draw your own diagram of the “Crayon Rock Cycle” on chart paper. 2) Use captions to explain how the appearance of your rock changed. 3) Label the processes that changed the crayon rocks. 4) Write whether there are any other “pathways” were not addressed today.
- You might also choose to have students complete the Rock Cycle Quiz or examine the Rock Cycle Q&A together.
Extension Activity:Have students write a creative short story about a rock that goes through the rock cycle, perhaps even pretending to be the rock itself. The story should explain what experiences the rock undergoes to turn from one rock into another. Students may work with a partner to add detail and creativity to their stories.
Students can also try the BrainPOP rock cycle experiment.