Unit Plan 14 (Grade 6 Science): Weathering & Erosion
Explain how weathering, erosion, and deposition shape landforms over different time and space scales through hands-on models and evidence-based learning.
Focus: Explain how physical and chemical weathering, erosion, and deposition work together as geoscience processes that shape landscapes at different spatial (local to global) and temporal (seconds to millions of years) scales.
Grade Level: 6
Subject Area: Science (Earth & Space Science — Earth’s Systems)
Total Unit Duration: 5 sessions (one week), 50–60 minutes per session
I. Introduction
In this unit, students explore how rocks break down and sediments move to continually reshape Earth’s surface. Through hands-on models, observations, and landform images, they distinguish between physical (mechanical) and chemical weathering, observe erosion by water and wind, and see how deposition builds new landforms like deltas and sand dunes. Students connect these processes to different spatial and temporal scales, explaining how both slow change (valley formation) and faster events (landslides, flash floods) are part of Earth’s evolving surface, aligned with MS-ESS2-2.
Essential Questions
- How do weathering, erosion, and deposition work together to change Earth’s surface?
- What is the difference between physical weathering and chemical weathering, and where do we see each in real landscapes?
- How do geoscience processes act over different spatial scales (from a single rock to whole mountain ranges) and time scales (from seconds to millions of years)?
- How can models, maps, and landform evidence help us construct explanations of how landscapes formed?
- In what ways do human activities speed up or slow down weathering and erosion?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Describe and give examples of physical weathering (ice wedging, abrasion, root wedging) and chemical weathering (rusting, dissolving, acid rain effects).
- Explain how erosion by water, wind, ice, and gravity moves weathered material and how deposition builds new landforms (deltas, alluvial fans, dunes).
- Use models, images, and maps to describe how landscapes such as canyons, valleys, and beaches form over long time scales, while some changes (e.g., landslides, flood erosion) can happen quickly.
- Identify and compare spatial and temporal scales of change in at least two landform examples (e.g., a cliff face vs. a river system).
- Construct an evidence-based explanation of how weathering, erosion, and deposition changed a specific landscape over time, aligned with MS-ESS2-2.
Standards Alignment — 6th Grade (NGSS-based custom)
- MS-ESS2-2 — Construct an explanation based on evidence for how geoscience processes have changed Earth’s surface at varied spatial and temporal scales.
- In this unit: students explain how weathering, erosion, and deposition shape landforms from small rock features to large river valleys, over short and long time periods.
Success Criteria — Student Language
- I can tell the difference between physical weathering and chemical weathering, and give a real-world example of each.
- I can explain how erosion moves sediments and how deposition builds new landforms.
- I can use models, photos, or maps to show how a landscape changed over time and space.
- I can describe whether a change is happening quickly (landslide, flood) or slowly (valley, canyon formation), and on a small or large scale.
- I can write or present an explanation that uses evidence to show how weathering, erosion, and deposition shaped a specific place.