Unit Plan 28 (Grade 4 Science): Rock Layers & Fossils

Focus: Use rock and fossil patterns to explain how Earth’s landscapes change over time.

Grade Level: 4

Subject Area: Science (Earth Science • Evidence & History of Earth)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students become “Earth detectives,” using rock layers and fossils as clues to how landscapes have changed over long periods of time. They examine diagrams, photographs, and simple rock/fossil models to notice patterns—such as where certain fossils appear, how rock layers are stacked, and where layers are broken or tilted. Students use these patterns as evidence to explain changes like rising and sinking land, erosion, and changes in environments (for example, an area that used to be under the ocean).

Essential Questions

• How can rock layers and fossils act like pages in a history book about Earth’s past?
• What patterns in rocks and fossils help us tell which layers are older or younger?
• How can we use evidence from fossils to explain how landscapes and environments have changed over time?
• Why do scientists say that evidence from rocks and fossils is important for understanding Earth’s history?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Observe and describe patterns in rock layers and fossil locations using diagrams, pictures, or models.
2. Use those patterns to order rock layers from older to younger in simple scenarios.
3. Explain how fossils in rock layers can show that environments have changed (e.g., ocean fossils found in rocks now on land).
4. Construct a written or oral explanation that uses evidence from rocks and fossils to describe landscape changes over time.
5. Create a simple “Rock & Fossil Story Panel” (diagram + explanation) that tells how a landscape changed using patterns in layers and fossils.

Standards Alignment — 4th Grade (NGSS-Aligned)

• 4-ESS1-1 — Identify evidence from patterns in rock formations and fossils in rock layers to support an explanation for changes in landscapes over time.
  • Example: Use a diagram of stacked rock layers with different fossils to explain that the area was once underwater and later became land.

Success Criteria — Student Language

• I can describe patterns I see in rock layers and fossils (what is on top, what is below, what repeats).
• I can tell which rock layers are older or younger in a simple rock column or diagram.
• I can explain how finding a certain fossil in a rock layer gives clues about past environments.
• I can write or tell a short “Earth story” about how a landscape changed, using evidence from rock and fossil patterns.