Fourth Grade · Science · week 28

Weathering vs erosion vs deposition

Distinguish weathering, erosion, and deposition as three connected processes that break down, move, and deposit Earth materials.

Earth's surface is constantly changing through three connected processes. Weathering breaks rock into smaller pieces right where it is, using wind, water, ice, or even plant roots pushing into cracks. Erosion then picks up those broken pieces and carries them somewhere else, usually by wind, water, or ice.

Deposition is the final step: eventually the moving water, wind, or ice slows down or stops, and it drops, or deposits, the material it was carrying. A sandbar at a river bend, a delta where a river meets the ocean, and a pile of sand at the base of a windy dune are all places where deposition has happened.

📋 For the teacher
Teach it (10–15 min):
  • Look for a real example nearby: a cracked sidewalk, a dry creek bed, or a sandy area near moving water, and identify which process, weathering, erosion, or deposition, is most visible.
  • Use the phrase "break, move, drop" as a simple three-word memory hook for weathering, erosion, deposition, in order.
  • Ask your child to predict what would happen to a small pile of sand if you poured water over it slowly, connecting directly to next week's stream-table lab.
  • Avoid rushing through all three in one sentence; give each one its own clear moment and example.
Talk about it:
  • What is the difference between weathering and erosion?
  • Where have you seen evidence of deposition near your home or on a trip?
  • Why does deposition usually happen where moving water or wind slows down?

Mastery looks like: They can correctly sort real or described examples into weathering, erosion, or deposition and explain the "break, move, drop" order.

Common stumbles: Mixing up weathering (breaking in place) with erosion (moving material); assuming deposition can happen without erosion first carrying the material somewhere.

Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
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