Smooth River Rock and Compilation

Small rocks have been rounded as they were carried downstream and deposited in a low area within the stream.

Possible Guiding, Compelling and/or Anchoring Questions

• Why are the rocks smooth without jagged edges?
• Why is there a pile of rocks all in one place in the stream?

Classroom Suggestions

• Lead students to understand that the rocks are carried downstream by the energy of the water and that the jagged edges are worn off from tumbling along the bottom of the stream. When they reach a low spot in the riverbed, the rocks pile up in that place. Have some smooth river rocks and some jagged rocks from a quarry in the classroom for the students to determine which location they came from.

Related Resources

• Sciencing: Photos and description of weathering of rocks in rivers.
• Scientific American: Explanation of weathering in rocks in many environments.