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Deposition Builds New Landforms

Grade 4 Earth Science — Shaping Earth’s Surface | Unit 1, Lesson 3 of 6

📚 Grade: 4th Grade⏱️ Duration: 45–60 minutes🔬 Subject: Earth Science — Shaping Earth’s Surface

🏖️🌊🌀

When moving water or wind slows down, dropped sediment can build new landforms.

📋 NGSS Standard:
4-ESS2-1 — Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation. / 4-ESS2-2 — Analyze and interpret data from maps to describe patterns of Earth’s features.

🎯 Learning Objective

Students will explain how deposition happens and identify evidence that sediment was dropped and collected in a new place.

💡 The Big Idea

Deposition happens when moving water, wind, or ice drops the sediment it was carrying. This can build new landforms over time.

🔬 The Science

Science Snapshot

When transport energy drops, carried material can pile up and build new shapes.

What is happening?

Deposition happens when carried materials settle out and accumulate. This process can create sandbars, deltas, mudflats, alluvial fans, and other build-up landforms.

Why it works that way

A drop in speed or energy is usually the reason deposition begins. Coarse, heavy particles settle sooner, while fine particles can stay suspended longer and travel farther before being dropped.

Look for this in the lesson

Students should connect landform shape to the moment transport slowed down. That helps them explain not only that a deposit formed, but why it formed there.

Ask while you read: Where in the system would you expect the biggest particles to settle first?

📦 Materials

🏠 Household Items to Gather

Tray or clear container
Sand, soil, or cinnamon in water
Cup and spoon
Worksheet and pencil

📋 Printables

Student worksheet page from this lesson

🧪 Investigation

Step 1 — Mix sediment in water (8 min)
Stir a small amount of sediment into water and notice that it stays suspended for a while.

Step 2 — Let the water slow down (10 min)
Pour carefully into a tray or let the container rest and watch sediment settle.

Step 3 — Observe where material collects (10 min)
Notice thicker piles, layers, or new shapes where sediment was dropped.

Step 4 — Connect to real places (10 min)
Compare the model to river deltas, sandbars, beaches, and piles at the base of hills.

Step 5 — Explain the sequence (10 min)
Students describe weathering, erosion, and deposition in order using one example.

💬 Discussion Questions

What causes deposition to happen?The moving water, wind, or ice slows down and drops sediment.

How is deposition connected to erosion?Erosion carries material; deposition is where that carried material gets dropped.

What evidence shows deposition in your model?Students may mention piles, layers, or sediment settled at the bottom.

Can deposition build landforms?Yes. Repeated deposition can build deltas, beaches, and other features.

🚀 Extensions

Extension: Look at photos of river deltas or sandbars and compare them to your model.

👩‍🏫 Parent/Teacher Notes

Teaching move: Ask students to narrate the full sequence: break, move, settle.

Misconception to catch: Students may think sediment disappears when it leaves one place. Emphasize that it often collects somewhere else.

Student Worksheet

Name: ________________________ Date: ________________________

Explain how deposition works

Use the model and your observations to show where sediment settled and why.

Where was the sediment moving?	Where did it settle?	Why did it settle there?

2️⃣ Put the processes in order

🔑 PARENT ANSWER KEY — Detach before giving worksheet to students

Sample ideas

Sediment settles when moving water slows down. Students might say a river drops sediment where it meets slower water and forms a delta.

✅ What Success Looks Like

Student identifies deposition as dropped sediment.
Student connects deposition to slower movement or less energy.
Student places weathering, erosion, and deposition in a sensible order.