How do you think the Grand Canyon was formed? What about a mountain or a hill? It all comes back to layers and how they are compressed.
Our Earth is made of layers. It has, overall, four layers based on chemical variations: the solid crust on the outside, the mantle, the outer core and inner core. Another one our projects goes into more detail, but in this project, we are discussing the Earth’s crust and especially the sedimentary rocks found near the surface.
Sedimentary rocks are often found in layers. Think of the Grand Canyon, where the rock layers are exposed like a layer cake. Each layer is made of sediments that were laid down (or deposited) in a certain environment such as a sand dune or lakebed. Sediments are deposited horizontally; the lowest layers are the oldest and the highest layers are the youngest.
In this project, we will be learning about geological folds using playdough!
Compressive stress can make rocks form or crumple into folds. Folds are bends in the rock. We are going to make folds with playdough because as in layered sedimentary rocks, you can trace the folding of the layers with your eyes, just like we will see in the playdough!
Supplies:
● Playdough (can also be made using supplies below)
○ Flour
○ Water
○ Salt
○ Oil
○ Food Coloring
○ Mixing bowl
○ Measuring cups
● Rolling pin
● Knife
● Table covering/cutting board (to protect table)
● 2 blocks or items to push together.