Sediment Fossil Surprise Activity

Transcription

1 Sediment Fossil Surprise Activity Name: 4th grade PSI Science Activity Question How are fossils deposited in sediment layers? Before You Begin Do you think that all sediment layers contain fossils? Why or why not? Why do you think fossils may be different in different layers of sediment?

2 Purpose During this experiment, you will construct a model of fossils found in sediment layers. Models help us to visualize more clearly Earth processes that can be difficult to see, especially on a very large scale, such as with rock layers. In nature, fossils are deposited in sediment layers over a long period of time; it is a process that happens over hundreds of thousands to millions of years. In this experiment, you will simulate what is left behind after many years of fossils being deposited into sediment layers. (Remember to answer Lab Questions during class while you are engaged in the activity. Conclusion Questions can be answered after class.) Materials (enough for each student to make a model) Clear cup or bowl Variety of baking ingredients Variety of snack foods Blank sheets of paper Pencils, Markers Scissors (for preparing ingredients as fossils) Spoons (for creating model)

3 Procedure 1. Watch A Fossil Forms slides with the class and discuss. 2. Discuss with your group: What do you think the relationship is between the age of this animals bones and the age of the sediment it gets buried in? How might fossils of other organisms be similar to how this one formed? How might fossils of other organisms be different to how this one formed? 3. On your piece of paper, sketch the outline of your cup or bowl. This will be the area where you plan your model of fossils in rock layers. Label the bottom of your cup oldest and the top of your cup newest.

4 4. Starting from the bottom, draw one sediment layer and its fossils at a time. You will have to decide what kind of environment your sediment layers formed in. Think about questions such as: Will the layers contain fossils of fish because it was a water environment, or will there be plants or land animals in the layers? How will the fossils change in each new layer? Label the fossils you put in your layers of sediment. 5. After completing your drawing, choose the ingredients that you will use to represent the sediment layers and fossils you included in your drawing. 6. If you want, prepare your fossils - make your ingredients look more like the organism they will represent. 7. Using your drawing as a guide, build your model. Think about what you will need to deposit first, how and when your organisms will be deposited, whether or not they will be buried by sediment these questions should be running through your head as you are depositing your sediment and fossils. 8. Share your model and drawing with a partner. Also have them share their model with you. Observe what they did closely and how their model is both similar and different from yours.

5 Lab Questions 1. As you drew your model, how did you decide how thick or thin sediment layers were? How did you decide how many fossils were in a layer and where to put them? 2. In nature, what do you think determines the thickness of sediment layers? 3. In nature, what do you think causes more or less fossils to exist in a sediment layer?

6 4. Did your partner s model form in a different kind of environment than yours? If yes, did you notice any differences because of the environment the rocks formed in? If no, how do you think the environment a rock forms in affects how it forms? Conclusion Questions 1. How is this model of fossils in sediment layers similar to the fossils found in sediment layers in nature? 2. How is it different?

7 TEACHER NOTES This lesson is taken from: This activity has been adapted from its original form to get students thinking more deeply about questions related to the models they create. (The original lesson plan written by National Geographic is available on the page linked above.) This website will be used in the beginning of the lesson to show the slides A Fossil Forms. If possible, these films should be shown on a projector. Watching these slides and having a brief discussion with the class about them should get students thinking about how fossils are formed and how they will build a model of fossils. The lesson plan also includes specific questions to ask after looking a these slides, which students should discuss in their groups. (The slides are found by clicking here on the linked page.) The materials students use to create their models are up to you, dependent on what is available and what you think will work well. Here are a few suggestions for materials students can use to create models: Edible baking ingredients: coconut flakes, whipped cream, pudding, crushed graham crackers Edible snack foods: raisins, candies, vanilla wafers, nuts Remind students that lab questions should be answered while they are doing the activity, not afterwards.

8 Answer Key Answers to the Lab Questions: 1. As you drew your model, how did you decide how thick or thin sediment layers were? How did you decide how many fossils were in a layer and where to put them? answers will vary 2. In nature, what do you think determines the thickness of sediment layers? The amount of time that sediments are deposited over, the amount of erosion that occurs, the amount that a sediment compacts, the amount of sediment in the environment that is deposited 3. In nature, what do you think causes more or less fossils to exist in a sediment layer? The strength of fossils over time (some organisms will decay and not many fossils will be left), the amount of organisms that lived in the given area 4. Did your partner s model form in a different kind of environment than yours? If yes, did you notice any differences because of the environment the rocks formed in? If no, how do you think the environment a rock forms in affects how it forms? answers will vary The environment will affect the types of fossils and sediment that are found there, the environment will also affect how layers are eroded Answers to the Conclusion Questions: 1. How is this model of fossils in sediment layers similar to the fossils found in sediment layers in nature? Different types of sediment exist in different layers, different fossils are found in different layers, the oldest layer is on the bottom and the newest on top 2. How is it different? The sediments are not cemented, the sediments and fossils were deposited very quickly, the sediments and fossils are different materials than those found in nature