Beacon Lesson Plan Library

The Wedding of a Mountain

Cheryle Borsos
Santa Rosa District Schools


The wedding of a mountain takes place every day! That is right, W for weathering, E for erosion, and D for deposition. In this lesson, students learn the distinctions of the three processes of weathering, erosion, and deposition.


The student knows that mechanical and chemical activities shape and reshape the Earth's land surface by eroding rock and soil in some areas and depositing them in other areas, sometimes in seasonal layers.


- 4 pieces of white photocopy paper
- 4 pair of scissors
- 8 hand fans
- 8 hand shovels
- 4 long pieces of white or yellow chalk
- 4 wooden mallets
- 1 clay mountain model
- 1 pair of tweezers
- 1 Student Demonstration Plan (see Associated File) for each student
- 1 Observation Checklist (half-page size, see Associated File) for each student
- 1 Goal 3 Standards Checklist (quarter-page size, see Associated File) for each student


1. Photocopy a class set of the Student Demonstration Plan and the Observation Checklist (see Associated File). Photocopy enough Standards Checklists (see Associated File) to assess each student.
2. Gather materials and set up 8 lab stations; 4 stations should each have a piece of paper, scissors, a hand fan, and a hand shovel. The other 4 stations should each have a piece of chalk, wooden mallet, hand fan, and a hand shovel.
3. Make a mountain model out of clay.


1. Activate student interest by telling them that they are going to a W-E-D-ding in class today! Ask them if they think it is possible for a mountain to WED. (Many students will think that the question is ludicrous, but they will play along.)

2. Write the letters W.E.D. on the board so students can see the word wed. Then tell the students that mountains, like the rest of the Earth’s surface are constantly participating in a W-E-D-ding.

3. Explain that W stands for Weathering. Describe the process of weathering as the breaking down of particles into smaller pieces. Note: You will discuss causes of weathering later in the lesson. You are simply introducing and explaining the terms at this point.

4. Explain that E stands for Erosion. Describe erosion as the process of moving material from one place to another.

5. Explain that the D stands for Deposition. Deposition is the process of leaving material in a place different from where it originated. It is where the material is “deposited” or dropped off when it is being eroded.

6. Draw students’ attention to the clay mountain model. Ask them to think of ways nature might weather or break down the mountain into smaller pieces. Here is where you want to introduce elements of weathering. After students share their ideas, highlight and describe the elements of wind, rain, running water, ice-wedging, glacial movement, human and or animal activities as some potential elements of weathering. Note: You may want to stick with mechanical forms of weathering and explain chemical weathering in an extension lesson.

7. Ask students to think of ways that pieces of the mountain might be eroded or moved to another place. After students share their ideas, highlight the elements of wind, rain, running water, gravity, glacial movement, human and animal activity as potential agents of erosion. Explain that some of the agents can act as both a weathering agent and an erosion agent.

8. Clarify once more that if the agent is breaking the material into a smaller substance, weathering is taking place. If the agent is transporting material from one place to another, erosion is taking place.

9. The last process to discuss is deposition. Ask students to think about a likely place for deposition of material that is being weathered and eroded from a mountainside. Guide them to understand that much of the material is deposited at the foot of the mountain. That is why they can observe boulders and various sized rocks piled up along the base of the mountain.

10. Demonstrate the three processes using the clay mountain model. Take a pair of tweezers and pick little pieces of clay from the side of the mountain. Explain that this represents weathering. You are breaking the mountain into smaller pieces. As you pluck pieces from the mountain with the tweezers stick the pieces on the mountain in the same location. Ask students to observe what happens. In a moment or so, gravity will pull the pieces down off the mountain and deposit them at the base. Ask students to tell you what agent caused the erosion (gravity). Then ask them where the material was deposited.

11. Ask the students to write down their thoughts about what would happen to the material at the base of a mountain if a river passed over it. This is where you can make a formative assessment of student understanding. Students should infer that the river could do a number of things to the material deposited at the base of the mountain. The running force of the water could break down the rocks into smaller pieces (weathering). The water could transport some of the material down the river a little further (erosion). The river could deposit the material along the riverbank or at a distance down river (deposition).

12. Collect student explanations then invite them to share their ideas. This will allow you to address any misconceptions and provide unsure students with another opportunity to make sense of the three processes.

13. Instruct students that they will be going to their lab stations where they will find a variety of materials. Their task will be to use the materials to demonstrate the processes of weathering, erosion, and deposition. They will need to record how they will demonstrate each process on the Student Demonstration Plan (see Associated File).

14. Divide students into 8 lab groups; 4 groups will demonstrate the processes with paper and 4 groups will demonstrate with chalk. Explain to the students that they will be demonstrating the processes to another group with different materials in five minutes. Allow groups time to explore the materials, brainstorm, and develop and record their plan on the Student Demonstration Plan (see Associated File). Remind them NOT to do the demonstration until they perform it in front of the other group. They are to talk through and record the demonstration before actually performing it.

15. Inform students in advance that all members of the group must somehow participate in the demonstration, and that each member must complete a Student Demonstration Plan (see Associated File).

16. While students are working with their lab partners, circulate around to each group to ensure that they understand the activity. Inquire with the students about their plans to help ensure a successful demonstration. Complete the Goal 3 Standards Checklists (see Associated File) as you observe students.

17. Once all groups have completed the planning sheet, facilitate the demonstration by asking each paper group to observe one chalk group. Note: It is best to preplan which groups will observe whom so that there is an easy transition at this point. For example, you might say, Steven’s group will observe Sarah’s group; Rachel’s group will observe Ron’s group, etc.

18. Each observer must complete an Observation Checklist (see Associated File) to assess the performance of the group demonstration.

19. After the first round of demonstrations, ask students to switch roles so that the observers are now the demonstrators. Repeat step 18.

20. Bring closure to the lesson by inviting students back to their seats for a follow up discussion. Ask them to think about what agent the scissors could have been in nature (wind, rain, etc.). Ask them to think about what agent the shovel and the hand fans could have been (wind, a bulldozer, etc.).

21. End the lesson by saying, “Congratulations class. With this lesson, I thee WED!”


Students are formatively assessed by answering a question about a river's effect on a mountain and through a peer checklist (see Associated File). Students will also be evaluated on the standards through a checklist (see Associated File) completed by the teacher.


-This lesson is an introduction to the processes of weathering, erosion, and deposition. You may want to extend this lesson to differentiate between chemical and mechanical weathering.
-Another possible extension would be to have the students explore the potential dangers of these three processes and to have students develop potential methods for prevention.
-This lesson would also lend itself to further investigation on other features of the Earth’s surface. One example would be beach erosion.
-Students could research current articles pertaining to the destruction of these forces of nature.
-Another possible extension to this lesson is to take students outside to look for signs of weathering, erosion, and deposition. They can record their findings on a particular date and return to the site a few weeks later to observe any changes.
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