Beacon Lesson Plan Library

Edible Rock

Angie Worcester
Bay District Schools


Students experiment with gelatin Rock Strata to possibly discover fossils and identify the effects of erosion and weathering on the sedimentary rock. They illustrate and summarize their findings.


The student understands how processes of weathering and erosion constantly change the surface of the Earth.


-Gelatin Rock Strata (see associated file for recipe)
-Water (a fountain or a pitcher)
-One blow dryer
-Plastic plates (one per student or group)
-Plastic forks (one per student or group)
-White construction paper for illustrations (one per student)
-Copies of the rubric (see associated file)


1. Prepare the Rock Strata experiment. (May take 1-3 days to make.)
2. Collect supplies needed for the experiment and assessment activity.
3. Decide whether to complete the experiment as a whole group or in small groups.
3. Copy rubric for students or groups of students.


1. Introduce the lesson the day before by telling students that tomorrow an archaeologist will visit the classroom to share an edible geology experiment with them.

2. On the day of the experiment, dress as an archaeologist with boots, tools, and goggles in order to peak their attention. Bring in the Rock Strata experiment.

3. Review the three rock groups and how they formed.

4. Explain to students that today you will demonstrate erosion and weathering with a section of the sedimentary Rock Strata that you have prepared. Also discuss the possibility of locating fossils in the rock layers.

5.List vocabulary words (such as sedimentary, erosion, and weathering) on the board or overhead as they are used during the lesson. Have students copy them for later use.

6. Cut the Rock Strata into the appropriate number of pieces. Using one piece, identify the layers and discuss their relative age.

7. Using the blow dryer, blow wind onto the Rock Strata and discuss the results. Relate this to what occurs in nature as wind blows continually over time on rocks.

8. Next, pour water slowly and then quickly over the Rock Strata, observing and discussing what happens. Again, relate this to what occurs in nature as it rains or snows or sleets.

9. Pass out pieces of the Rock Strata to individual students or groups. Give students plastic forks to use as tools to dig for fossils.

10. Give students plenty of time to dig into their Rock Strata. They should be seated near other students if not working in groups so they can talk with each other as they work. Walk among students, listening and discussing with them their findings. Students should keep a record of what is found.

11.Allow students to eat their Rock Strata when they are finished experimenting. They should then clean up their dig area.

12. During the next class period, ask students to identify the number of fossils they discovered. Keep track of the total number of fossils found in this archaeological dig. Discuss why fossils are found only in sedimentary rocks and why some students may not have found fossils in their section. Relate their findings to what happens in nature.

13. Discuss the effects of weathering on the Rock Strata and on real rocks.

14. Pass out rubrics and construction paper. Discuss rubric and give directions for completing the illustrations and paragraphs.

15. Monitor and assist students as needed.

16. Collect illustrations and paragraphs.


Students demonstrate their understanding of the effects of weathering and erosion on the land by creating an illustration of the changes that occur to the strata. They also summarize in a paragraph how the processes constantly change the Earth. A rubric will be used to check the assessment. Students who do not demonstrate understanding should receive formative feedback from the teacher in order to adjust their assessments.

Attached Files

The rubric and a recipe for the Rock Strata     File Extension: pdf

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