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A Cheap, Easy
Earth Science Demo

My Soil Has Layers!

From 101 Effective Earth Science Demonstrations Using Only One or Two Items, by William Johnston, with Mark Francek.

Source: E. Richard Churchill, Louis V. Loeschnig, Muriel Mandell, and Frances Zweifel: 365 Simple Science Experiments with Everyday Materials (1997), page 172.

Objective: To learn about properties of soils and how their contents relate to the principle of density and sedimentation.


About the Authors

Bill Johnston is a science teacher in southeastern Michigan. Mark Francek is an earth science educator at Central Michigan University.

Standards: Properties of Earth Materials (physical and chemical properties of rocks and soils; soil properties), Structure of the Earth System (layering and properties of earths internal structure; soil properties: biotic, physical, and chemical; biotic influence on rock formation and weathering), and Properties and Changes in Matter (substance density).

Materials: jars with lids, cup of each soil sample from different locations and depths (topsoil, upper soil, subsoil, or deeper soil), water.

Procedure:

  1. Fill each jar with cup of soil.
  2. Add water to each jar so that each jar is approximately three-quarters filled.
  3. Ensure that each lid is securely fastened and shake well.
  4. Repeat the above procedure with the desired amount of soil samples to be tested.
  5. Wait for the soil to fully settle. (It might take a few hours so youll want to prepare the samples at the beginning of the school day.)
  6. Observe each jar of soil and have students make illustrations with labels describing what they see.
Be sure you have permission to perform this demo from the custodians, principal, and teachers in classrooms near and below yours.

Science Behind It: As the soil samples settle, they form bands or layers depending on the content of each sample. In mostly all soil samples, the heavier, larger, and more dense particles settle to the bottom, while the lighter-colored and weighted particles tend to settle towards the top. From doing this simple test, it is easy to determine the texture and composition of various soils. This demo also relates to sedimentation and layering of sedimentary rocks. It would be a good idea for teachers to interrelate those concepts in order to help students relate their knowledge and gain a more thorough understanding.