Changing Earth's Surface - Lay It Down
You've learned how the layers of rock at the Grand Canyon were deposited. Remember the first layer was volcanic, then a series of oceans added layer upon layer of sediment. The whole process is called deposition. We use the Grand Canyon as an example. It is familiar to us and the layers of rock are easy to see. Deposition can be seen in many other locations. You can tell the difference between layers by color or texture changes.
Know the canyon's history, study rocks made by time.
- Know Kaibab Limestone
- The Toroweap Formation
- Canyon's Coconino Sandstone
- History Hermit Shale
- Study Supai Formation
- Rocks Redwall Limestone
- Made Muav Limestone
- By Bright Angel Shale
- Time Tapeats Sandstone
You don't have to learn the names of each layer, but it is interesting to see just how many there are.
Photo of layer model at Grand Canyon National Park visitor center.
Peanut Butter and Jelly Geology!
- Bread (if you have white, wheat, and pumpernickel it looks even better!)
- Crunchy peanut butter
- Gummy fish or worm candy
Make up a story as you assemble your sandwich. Your story can be different, but here is a sample.
- A volcanic eruption covers the ground with a lava flow. Put your pumpernickel bread or regular bread on a plate.
- An inland sea covers the area. Rivers bring sediment and deposit it over the lava flow. Spread butter on your bread.
- Mudslides, brought on by heavy rain, send sediment down the rivers and into the sea. Add honey.
- The sea recedes. A layer of sand is deposited by wave action. Add your white bread.
- A huge flash flood brings mud, small pebbles and rocks. Spread peanut butter on the white bread.
- The sea advances. Another layer of sediment is brought by tributary rivers. Add jelly.
- Animals die. Their bodies fall to the soft bottom of the sea to be trapped in sediment. Add gummy fish. (They become fossils)
- The sea recedes again. A volcanic blast covers the area with another lava flow. Add your last slice of bread.
Extension: If you have the time, and aren't too hungry - try these! Use your layer model to show uplift. Then cut it in half to create a fault. Move and slide the halves along the fault. Make the bottom layers metamorphic by squishing your sandwich. If you are ready, just eat it!