demonstrations:sedimentary_rock_snacks
Sedimentary Rock Snacks
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Kitchen Chemistry, Rocks, Soil and Erosion
Alternative titles: Edible Sedimentary Rocks
Summary
Using rice krispies, marshmallows, chocolate chips, and candies, students create layered snack bars that model the formation of sedimentary rocks in the rock cycle.
Procedure
- Grease an 8×8 inch baking pan.
- In a microwave-safe bowl, heat marshmallows and butter for 1–2 minutes, then stir until smooth.
- Mix in rice krispies cereal gradually until well coated.
- Press half of the mixture into the bottom of the greased pan.
- Add a layer of chocolate chips on top.
- Cover with the remaining rice krispies mixture and press lightly.
- Sprinkle mini M&M’s on top and press gently so they stick.
- Allow the mixture to cool for about an hour, then cut into bars.
Links
How to Make Sedimentary Rocks - Rainy Day Mum:
Making Edible Rocks - Pinal Geology and Mineral Museum:
📄 Edible Rocks For Kids - Sarah McClelland: https://littlebinsforlittlehands.com/rock-cycle-for-kids/
Variations
- Use different candy pieces to represent various sediments.
- Add crushed cookies or pretzels for additional “rock fragments.”
- Create a three-layer version to show more complex sedimentary layering.
Safety Precautions
- Supervise children when using the microwave or handling hot marshmallow mixture.
- Allow the mixture to cool before eating.
- Be mindful of food allergies to chocolate, marshmallows, or candy ingredients.
Questions to Consider
- How does this snack model show the way sedimentary rocks are formed? (The different candy pieces represent sediments that are pressed together in layers.)
- What real-world processes are missing from this edible version of the rock cycle? (Long time scales, pressure, cementing minerals, and natural erosion.)
- How would metamorphic or igneous rocks be represented in a food-based model? (Metamorphic could be made by reheating and pressing ingredients, igneous by fully melting and letting them solidify again.)