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4th grade · Science · Unit 8 of 8

Rock Layers & Erosion

Weathering, erosion and what rock layers tell us.

What your child practices

Practices how water, ice, wind and plants break down and move rock, and how patterns in rock layers and fossils show how a landscape changed over time.

Maine Learning Results learning standard: 4-ESS1-1; 4-ESS2-1 · rock layers and fossils show landscape change, and weathering and erosion shape the land

How we explain it

Children can open this short lesson before they practice.

  1. Weathering breaks rock. Erosion moves it. Running water moves the most.
  2. Glaciers scrape and carry rock. Roots growing in cracks can split rock.
  3. Over a very long time, erosion can carve deep canyons.
  4. Plants and their roots slow erosion on a hillside.

Example: Which hillside erodes faster in heavy rain: a bare one or a grassy one? Roots hold soil in place. A bare hill has nothing to hold the soil. Answer: the bare hillside

Rock Layers & Erosion in Maine

In the Maine Learning Results, this is unit 8 of 8 in 4th grade Science, after Waves & Codes.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Maine Department of Education

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Which moves rock and soil the most in a river valley?

    • Sound
    • Running water
    • Moonlight
    • Sunlight
  2. Question 2

    Moving bits of rock and soil to a new place is called…

    • weathering
    • freezing
    • eruption
    • erosion
  3. Question 3

    Which happens faster on a bare hill than on a grassy hill?

    • Fossil forming
    • Plant growth
    • Erosion
    • Rock building
  4. Question 4

    Which can cause weathering?

    • Water freezing in cracks
    • A shadow
    • Moonlight
    • A rainbow
  5. Question 5

    A river carved the Grand Canyon by…

    • one big flood in a day
    • wind only
    • an earthquake
    • erosion over a very long time
  6. Question 6

    Layers: sea fossils at the bottom, then river sand, then land plants on top. What changed?

    • Land became sea
    • The layers were glued
    • Nothing changed
    • A sea became land over time