Weathering, Erosion, and Deposition

Active learning works for weathering, erosion, and deposition because these processes are dynamic and best understood through direct observation. Students need to see how rocks break down, move, and settle to truly grasp how landscapes change over time. Hands-on stations and simulations let them experience these processes at scale they can measure and discuss immediately.

• Grade 9
• Geography
• 4 activities
• 35 min–50 min

Learning Objectives

1. Compare and contrast the mechanisms of physical and chemical weathering, citing specific examples from Canadian geology.
2. Analyze the impact of human activities, such as deforestation and agriculture, on the rate and extent of soil erosion in Canada.
3. Predict the long-term geomorphological changes to a specific Canadian landscape, like the Canadian Shield or the Prairies, under different erosion scenarios.
4. Classify different types of erosional agents (water, wind, ice) based on the landforms they create in various Canadian environments.
5. Evaluate the effectiveness of different land management strategies in mitigating accelerated erosion.

Stations Rotation

⏱ 45 min·Small Groups

Stations Rotation: Weathering Types

Prepare four stations: physical abrasion (rocks in shaking tray with gravel), freeze-thaw (ice cubes in rock cracks), chemical dissolution (vinegar on chalk), and biological (moss on bricks). Small groups spend 10 minutes at each, sketching changes and noting conditions. Debrief with class predictions on rates.

Prepare & details

Differentiate between physical and chemical weathering processes.

Facilitation Tip: During Station Rotation, have students rotate only after they complete both observation and explanation tasks at each station, ensuring they connect weathering to erosion.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Experiential Learning

⏱ 50 min·Pairs

Stream Table Simulation: Erosion and Deposition

Provide trays with layered sand and soil. Pairs pour water at varying flows, observing channel formation, sediment transport, and delta building. Measure erosion width before/after, then adjust slope or vegetation to test variables. Record with photos and discuss human parallels.

Prepare & details

Analyze how human activities can accelerate erosion.

Facilitation Tip: Set up the Stream Table Simulation with clear flow rates and sediment sizes so groups can compare results directly and discuss variables like slope.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 40 min·Small Groups

Model Glacier: Erosion Paths

Use wooden blocks as 'glaciers' on flour-sugar 'landscapes' in trays. Small groups push blocks downhill, noting U-shaped valleys and moraines. Compare to photos of Canadian Rockies, then simulate meltwater deposition. Groups present findings.

Prepare & details

Predict the long-term impact of specific erosional processes on a given landscape.

Facilitation Tip: For the Model Glacier activity, use colored layers of clay or sand to make striations visible and have students trace erosion paths onto acetate sheets.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 35 min·Individual

Human Impact Mapping: Local Erosion

Distribute Ontario topo maps or Google Earth views. Individuals identify erosion sites like riverbanks or farms, annotate causes (e.g., logging), and predict 50-year changes. Share in whole-class gallery walk with sticky note questions.

Prepare & details

Differentiate between physical and chemical weathering processes.

Facilitation Tip: In Human Impact Mapping, provide topographic maps of Ontario with clear legend symbols so students can accurately mark erosion hotspots.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Teaching This Topic

Teach weathering, erosion, and deposition as a sequence students can manipulate and measure, not just memorize. Avoid starting with definitions—instead, let students observe processes first, then name them. Use Canadian examples daily to build relevance and connection to local landforms. Research shows that students grasp these concepts better when they manipulate models and revise ideas based on evidence rather than abstract explanations.

What to Expect

Successful learning looks like students clearly separating weathering, erosion, and deposition in discussions and diagrams. They should use evidence from activities to explain how each process transforms landscapes and connect these ideas to real Canadian environments. Group work should include precise vocabulary and accurate cause-and-effect reasoning.

Watch Out for These Misconceptions

Common Misconception

During Station Rotation: Weathering Types, watch for students using 'weathering' to describe any change in rock appearance, including movement.

What to Teach Instead

Have students repeat the weathering station without adding water or wind, then add agents only after they record initial breakdown. Ask them to describe differences in their lab sheets before moving to erosion stations.

Common Misconception

During Model Glacier: Erosion Paths, watch for students assuming glaciers only erode near their edges.

What to Teach Instead

Ask students to mark striations along the entire base of their glacier model and explain why the middle also erodes. Discuss how weight and pressure cause erosion throughout the glacier's path.

Common Misconception

During Stream Table Simulation: Erosion and Deposition, watch for students labeling all sediment movement as 'deposition'.

What to Teach Instead

Have students pause the simulation at set intervals to photograph and label where erosion (sediment removal) and deposition (sediment settling) occur. Require them to justify their labels with measurements of slope and flow speed.

Assessment Ideas

Quick Check

After Station Rotation: Weathering Types, present students with images of Canadian landforms and ask them to identify the dominant process at each stage. Have them use sticky notes to mark weathering, erosion, or deposition and justify their choices in two sentences.

Discussion Prompt

During Human Impact Mapping: Local Erosion, pose the question: 'How might building a new subdivision in the Oak Ridges Moraine affect erosion in local creeks?' Have students pair up to predict two specific consequences using their maps, then share findings with the class.

Exit Ticket

After Model Glacier: Erosion Paths, ask students to define 'deposition' in their own words and provide one Canadian example. Then have them explain, using their glacier model observations, how human activity like mining could disrupt deposition in that example.

Extensions & Scaffolding

• Challenge students to design a landform that demonstrates all three processes in one location, using only household materials and a written explanation of their choices.
• For students who struggle, provide partially completed diagrams of landforms with some labels missing, asking them to fill in processes and agents step by step.
• Deeper exploration: Have students research a Canadian landform (e.g., Niagara Escarpment, Athabasca Sand Dunes) and trace its formation through weathering, erosion, and deposition, citing scientific sources.

Key Vocabulary

Physical Weathering	The breakdown of rocks into smaller pieces without changing their chemical composition, often caused by mechanical forces like frost wedging or abrasion.
Chemical Weathering	The decomposition of rocks through chemical reactions, such as dissolution, oxidation, or hydrolysis, which alters the rock's mineral composition.
Erosion	The process by which natural forces, like wind, water, or ice, move weathered rock and soil from one place to another.
Deposition	The geological process in which sediments, soil, and rocks are added to a landform or landmass, typically occurring when an erosional agent loses its energy.
Mass Wasting	The downslope movement of soil, rock, and regolith under the direct influence of gravity, often triggered by saturation or seismic activity.