Science 8 – Helgeson
A Model of the Rock Cycle
Name _________________________________ Period _______
Objectives:
1. To summarize the rock cycle
2. To analyze and predict the sequence of events in the rock cycle
Background Information:
The rock cycle is a model that shows how one kind of rock changes into another kind of rock. The
diagram of the rock cycle shows how the earth's rocks are changed again and again. The rock cycle has
no beginning and no end, rocks are continually changing from one form to another. The changes that
take place in the rock cycle never destroy or create matter. The elements are just distributed in other
forms.
Weathering is the breakdown of rocks and minerals at and just below the Earth’s surface
Sediment is soil, sand, and minerals that are transported and deposited by wind and water
Erosion is the movement (transport) of weathered particles by agents of erosion, such as wind, water,
ice, or gravity.
Deposition is the process of laying down of material that has been eroded and transported from another
location, generally in layers.
Compaction is when deposited particles are compressed into a smaller volume.
Cementation is when the deposited particles are “glued” together by a cementing agent or by pressure.
Lava is molten rock on the surface of the earth
Magma is molten rock beneath the surface of the earth
Igneous rocks are formed from the cooling and crystallization of molten rock
Sedimentary rocks are formed by the deposition of sediments
Metamorphic rocks result when a sedimentary or an igneous rock is changed by temperature and
pressure within the crust of the Earth
Materials:
Crayons
Candle
10cm x 10cm square of
aluminum foil
Goggles
Plastic knife
Test tube clamp
Procedure & Observations:
1. Each crayon represents an igneous rock.
2. Use the knife to shave off small pieces of two different crayon rocks.
What process does this represent? ________________________________________________________
What do the shavings represent? _________________________________________________________
3. Gently blow the shavings.
What process does this represent? ________________________________________________________
4. Drop the shavings onto the piece of foil.
What process does this represent? ________________________________________________________
5. Fold the foil over and press between your hands until the shavings stick together.
What process does this represent? ________________________________________________________
What type of rock does this process produce? _______________________________________________
6. PUT ON YOUR GOGGLES! Tie back long hair and loose clothing.
7. Make a small boat from your foil. Put the rock made in Step 5 and any shavings you have in the boat.
Use the test tube clamp to hold the boat over a candle flame.
8. Take the boat off the flame as soon as the crayon rocks begin to melt.
9. Let the crayon rock cool.
What process does this represent? ________________________________________________________
What type of rock does this process produce? _______________________________________________
10. Heat the crayon rock until it is completely melted and the colors have blended. Let the crayon rock
cool.
What process does this represent? ________________________________________________________
What type of rock does this process produce? _______________________________________________
Conclusion: Draw a diagram of the rock cycle below. Include the weathering, erosion, deposition,
compaction, heat, pressure, and all three classifications of rocks.