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Fossil Fuels and the Carbon Cycle

Author(s): Nancy P. Moreno, PhD, Barbara Z. Tharp, MS, and Judith Dresden, MS.

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In this activity, students will learn about the layers of Earth’s crust by exploring a representative model. Each student will “drill” into his or her GeoMuffin and take core samples to identify what fossil fuels might be present. Students will learn that different fossil fuels are formed in different layers of Earth’s crust. 

  1. Lead a class discussion of how fossil fuels were formed under the ground, how they are mined and how they are used. Then, show the GeoMuffins to the class. Point out that all of the muffins look the same on the surface. Tell students that the muffins have layers similar to those visible in a cross-section of Earth’s crust. Explain that each student will explore a muffin to discover whether or not it holds petroleum deposits, and where those deposits might be located.

  2. Give a GeoMuffin and a copy of the student page to each student or team of students. Ask, What do you think the inside of the muffin looks like? (The colored layers in the GeoMuffins represent the following: red = oil; green = predicting layer for oil; yellow = soil or rock layer; brown = soil or rock layer.)

  3. Instruct students to draw their predictions on their student sheets without touching or removing the baking cup. Students also should predict whether or not they will find oil.

  4. Have students insert a toothpick near the edge of their muffins to represent “North.” Based on what they can observe on the top surface of the muffin, have students select and mark six places on the muffin to “drill.” Demonstrate how to take a core sample by gently twisting a section of plastic drinking straw into a muffin and then pulling it back out.

  5. Use a cotton swab to dislodge to the core by inserting it into the top of the straw and pushing the core out the bottom. Encourage students to take at least six samples, recording each sample’s location on their worksheets, and then drawing and coloring the samples in order.

  6. When students have finished sampling, recording and coloring, they should evaluate their information, looking for a pattern. Based on their cores, students should draw an estimated side view of their GeoMuffins, showing all the layers. Next, have students cut through the center of their muffins and compare the actual appearance of the muffins to their predictions. 

  7. Ask, Did the core samples provide helpful information? Why or why not? Did you find anything to predict the presence of oil? Mention that geologists frequently look for certain patterns of the layers in cores. Certain patterns can predict or suggest the presence of oil.


Funded by the following grant(s)

National Institute of Environmental Health Sciences, NIH

National Institute of Environmental Health Sciences, NIH

My Health My World: National Dissemination
Grant Number: 5R25ES009259
The Environment as a Context for Opportunities in Schools
Grant Number: 5R25ES010698, R25ES06932

Houston Endowment Inc.

Foundations for the Future: Capitalizing on Technology to Promote Equity, Access and Quality in Elementary Science Education