Rock Layer Folding Experiment

Although the land you stand on seems like it is firmly in place, it is actually moving. The Earth’s crust is divided up into pieces that are called “plates.” These plates are slowly moving around the Earth. While they are moving they sometimes bump into one another which causes the rocks on the plates to fold and push their way into mountains. All rock layers are originally created horizontally. This is a simple experiment that is great for showing the possible effects when pressure is applied to horizontal rock layers.

You Will Need:

Clay Rock Experiment Mini Me Geology
  • Clay, several colors
  • Rolling pin or can of soda

Step 1: Form several different colors of softened modeling clay into even layers and stack them one on top of the other. You can make the layers as thick or thin as you like using the rolling pin or soda can.

Step 2: Using your hands, push the ends of the “rock layers” together to see what happens. Depending on the amount of pressure you apply and the direction that you hold your hands, the clay will form either a syncline or an anticline.

Folded Syncline

Synclines form when the ends of the rock layers turn up and the layers form a “U” shape.

Anticlines form when the ends of the rock layers turn down and the layers form an “∩” shape.


  • Try forming some layers that are thick and some that are thin to see if there is a different in the effects of the pressure.
  • Rock layers which are very long may form both synclines and anticlines in a line, like a wave. Perform the experiment with different lengths of “rock layers” to see if both shapes will form.

You can find more great activities like these in our Rock Cycle Kit and Rock Detectives Kits!

3 Responses to “Rock Layer Folding Experiment”

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  2. lol! thanks for this great post. We absolutely enjoyed it so much!

  3. Lot of smarts in that positng!

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