Snack Tectonics Lab Introduction: As you know, the three main types of plate boundaries are: Convergent Boundaries -- plates come together. Divergent Boundaries -- plates move apart from each other. Transform Boundaries --two plates slip sideways past each other headed in opposite directions. As you have also learned, there are two types of crust, the denser, younger, thinner oceanic crust and the older, less dense, thicker continental crust. Exactly what happens at each boundary is affected by the type of crust the plates in question are composed of. Purpose: In this lab, you will use edible materials to model several types of boundaries. The parts of the model represent the real world as follows: frosting = asthenosphere (the plastic, or moldable, layer on which Earth's plates ride) fruit roll up = thin, dense oceanic crust graham crackers - thick, less dense continental crust Materials: Two squares of graham cracker One fruit roll-up, cut in half Cup of water Frosting Sheet of waxed paper Plastic knife PROCEDURE: 1. Use the wax paper as a “place mat” to protect the table. 2. Break the cracker in half. 3. Unroll your fruit roll up and cut it into 2 small pieces about the same size as the cracker squares. 4. When you get your frosting, follow directions on the picture to the left. 1 Notice how the frosting is exposed and pushed up where the plates are separated? This represents magma coming to the surface where real plates are moving apart at divergent plate boundaries. Most divergent plate boundaries are located within oceanic crust, where the upwelling magma results in sea-floor spreading and forms a mid-ocean ridge. When plates begin to pull apart at continents, rift valleys are made, like the Great Rift Valley in Africa, which could become the bottom of the sea floor if the plates continue to pull apart. Draw and label a side view of your model in your Journal. 2 Draw and label a side view of this model in your Journal. 3 Notice how the wet edges crumple? This is how mountains are made at convergent plate boundaries! When continents move towards each other there is nowhere for the rock to go but up! Draw and label a side view of this model in your Journal. 4 Draw and label a side view of this model in your Journal. CLEAN UP: Throw away the wax paper and wash off your plastic knife and place it on the tray near the sink. Wipe up any mess on your table. Conclusion: Write a summary of the different types of tectonic plate boundaries in your Journal. Final step: As you write your conclusion, you may eat all remaining model materials