1. 6B21 Modeling Rock Layers

2. B21 Layers Background All types of rocks (sedimentary, metamorphic, and igneous) can be found in layers on Earth. In Unit A you learned soils are found in layers. Below these soil layers is bedrock. Bedrock can be made up of many rock layers. Here you will model the formation of layers that make up sedimentary rock. Challenge: Where are the oldest rock layers: on the top layer or on the bottom layer?

3. B21 Layers Procedure 1 1.Copy this data table into your lab book. 2.Use chips to represent sediments. Each person should use different color chips. 3.Use 1 hand to hold the graduated cylinder. Use your other hand to practice picking up 1 chip “sediment” at a time and placing it in the cylinder while your partner counts them. ROCK LAYERSTIMELAYER HEIGHT (cm) Rock Layer A15 seconds Rock Layer B15 seconds

4. B21 Layers Procedure 2 4. Switch roles and have your partner practice it. 5. Empty the cylinder. 6. The 1 st person placing sediments in the cylinder forms Rock Layer A. With your partner acting as timer, try to put as many sediments as you can into the cylinder in 15 seconds. Only pick up one sediment at a time and use only one hand to put the sediment in the cylinder. Use your other hand to hold base steady.

5. B21 Layers Procedure 3 7. Switch roles and have your partner complete Step 6. They will form Rock Layer B. 8. Use a metric ruler to measure the height of each “rock layer” in centimeters (cm). 9. Share your layer data with the teacher. 10. Record the class range of rock layer heights.

6. B21 Rock Layer Heights (cm) Hr 1 LayerHt cm A B

7. B21 Rock Layer Heights (cm) Hr 2 LayerHt cm A B

8. B21 Rock Layer Heights (cm) Hr 3 LayerHt cm A B

9. B21 Rock Layer Analysis: Date_______ Name______________________ Hr__ Copy and answer in 1 paragraph each 1.Were the rock layer heights always the same? 2.Which rock layer formed first: A or B? Why? 3.On a hillside you see a snake fossil above a fish fossil. Which is older, and why? 4.On the hillside you see a coal layer older than the fish fossil. Is it above or below? Why? 5.Sometimes old rocks are found on Earth’s surface. Explain how this could happen.