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.
People who seriously study the Grand Canyon use a trick
to remember the rock layers. It is a memory game. By remembering the saying,
it reminds them of the layers.
Know the canyon's history,
study rocks made by time.
Bright Angel Shale
- Time Tapeats
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
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.
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!
- 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.