Name______#______Date______Hour______

Center #2: Snack Tectonics

Materials Needed for this Activity:

  • A small baggie for each group member that contains two graham cracker pieces, two fruit strip pieces, and a sheet of wax paper
  • A can of frosting and a spoon
  • This lab sheet
  • Pencil

Part I Read the Background Information and Make Predictions Directions: Read the background information and fill in any blanks below:

The main force that helps shape the surface of the Earth is plate tectonics. The rigid outer layer of the Earth, called the ______, is broken up into the ______that fit together like a jigsaw puzzle. These plates are made of rock, but the rock is generally lightweight compared to the denser rock beneath it. This allows the plate to float on top of the denser material. This dense, fluid-like material that the plates float upon is located in the ______. Not all tectonic plates are the same. Plates made of continental crust are thicker but less dense than the plates made up of oceanic crust. In this activity, you will use scientific models to represent the interaction between continental plates, oceanic plates, and the asthenosphere.

Make predictions:

The frosting is a scientific model of ______.

The graham crackers are a scientific model of ______.

The fruit strip pieces are a scientific model of ______.

Part II Create the Scientific Models Directions: You will create several scientific models of tectonic plate boundaries in this part of the activity. It is important that you follow step-by–step instructions without skipping anything.

Model #1:

  • Take the wax paper out of the bag and spread it out in front of you.
  • Call the teacher over.
  • Once the teacher has spread the frosting out on your wax paper, place the two fruit strips on the frosting next to each other; the short ends should be facing.
  • Gently push down on the fruit strips as you pull them away from each other.

1. If you modeled this correctly, you should see that some of the frosting has been pushed up as the fruit strips were pulled apart. What type of plate boundary does this represent? Explain why you think it is that type of plate boundary based on your scientific model:

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Model #2:

  • Remove one of the fruit strips from Model #1. You may eat it or throw it away.
  • Place one of the graham crackers on the frosting next to the remaining fruit strip; the short ends of each piece should be facing one another.
  • Slowly and gently push the graham cracker towards the fruit strip.

2. If you modeled this correctly, the fruit strip and the graham cracker should be overlapped with the graham cracker partly on top of the fruit strip. What type of plate boundary does this represent? Explain why you think it is that type of plate boundary based on your scientific model:

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Model #3:

  • Remove the fruit strip from Model #2. You may eat it or throw it away.
  • Take the small cup to the teacher and ask for milk. There will be one cup for the entire table to use.
  • Remove the graham cracker from model #2 and dip the short edge in milk. Place it back on top of the frosting.
  • Dip the other graham cracker edge in milk and place it in the frosting facing the other graham cracker.
  • Make sure both dipped edges are facing each other.
  • Slowly and gently push the graham crackers together.

3. If you modeled this correctly, the graham crackers should be smooshed together with a small mound of cracker pushed up between the two pieces. What type of plate boundary does this represent? Explain why you think it is that type of plate boundary based on your scientific model:

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Model #4:

  • Turn the graham crackers around so that the dry edges are facing each other, still on top of the frosting.
  • Slide the crackers back and forth while pushing them against each other.

4. If you modeled this correctly, the graham crackers should appear broken down as crumbs have rubbed off. What type of plate boundary does this represent? Explain why you think it is that type of plate boundary based on your scientific model:

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  • You may eat any of the remaining food from your models or throw it away.
  • Call the teacher over to discuss and check your answers.
  • Make any corrections if necessary.
  • Clean up any remaining materials before moving on to Part III.

Part III Analysis and Conclusion Directions: Think about what you already know, and reference Part I and Part II of this activity to answer the questions below.

1. Do you want to change any of these answers from Part I?

The frosting is a scientific model of ______.

The graham crackers are a scientific model of ______.

The fruit strip pieces are a scientific model of ______.

2. Which is denser, continental or oceanic crust? ______

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3. Provide evidence from today’s activity to support your answer to questions #2: ______

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4. Which of your scientific models from Part II of this activity shows subduction? Explain how this model shows subduction:

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5. Which of your scientific models from Part II of this activity shows sea-floor spreading? Explain how this model shows sea-floor spreading:

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6. Which of your scientific models from Part II of this activity shows mountain building? Explain how this model shows mountain building:

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