What is stratigraphy? Stratigraphy is the study of strata – or layers. When we look at things that have been layered, such as the stories of a building, which layer had to be built first? Was it the top floor or the basement? The same is true for soil layers!
How does Sand Art demonstrate stratigraphy?
- Colored chalk
- Table salt
- Plastic bag
- Clear bottle or jar
- Funnel or rolled piece of paper
What to Do
- Place colored chalk and some table salt into a plastic bag.
- Use the salt to crush the chalk – this will color the salt
- Once you have made all your colors, carefully funnel them into the clear jar one at a time. If you tilt the jar while you add the sand, you can make really neat layers!
- Once your jar is full, close the top and display your stratigraphy sand art.
What is Happening?
This activity demonstrates the layering of soil on our Earth’s surface. The oldest layer is at the bottom and the youngest layer is at the top. In many places, like the Grand Canyon, exposed layers of rock can be seen because after the rock layers formed in these locations, something (like water in this case) came through and carved out chasms exposing the rock layers.