Science Lesson: Mountains are Mountains, Aren’t They?

Abstract
In this lesson, students will discuss mountains and volcanoes and explore connections between the different types of each.
Purpose – Engagement of students in discovering the different types of volcanoes and mountains and how they form.

Objectives
Students will be able to:
1. Identify mountains and volcanoes formed by collision boundaries on a plate boundary map.
2. Identify mountains and volcanoes that are likely formed by other processes.

National Science Education Standard:

CONTENT STANDARD D – Earth and Space Science
ENERGY IN THE EARTH SYSTEM
• Earth systems have internal and external sources of energy, both of which create heat. The sun is the major external source of energy. Two primary sources of internal energy are the decay of radioactive isotopes and the gravitational energy from the earth's original formation.
• The outward transfer of earth's internal heat drives convection circulation in the mantle that propels the plates comprising earth's surface across the face of the globe.

THE ORIGIN AND EVOLUTION OF THE EARTH SYSTEM
• Interactions among the solid earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the earth system. We can observe some changes such as earthquakes and volcanic eruptions on a human time scale, but many processes such as mountain building and plate movements take place over hundreds of millions of years.

Teacher Background
Earth Science is not always straightforward. Although most volcanoes are formed at subduction zones, with volcanic mountains forming on land and islands forming in the sea, this is not always the case. Nor do all volcanoes look alike. Some volcanoes are formed over “hot spots.” These are places where the magma in the mantle spurt upward, breaking through the crust. Volcanoes also vary their shape depending upon the material that is extruded from them. High viscosity magma, or ash eruptions, results in the formation of strato-volcanoes. Low viscosity magma that pours out of the volcano over a great area results in the formation of shield volcanoes.

Mountains also vary. Many very large, tall mountain ranges are the result of two continental plates colliding, However, there are other ranges that are the result of faulting in the earth. Parts of the plates are uplifted and form mountain ranges.

Image Courtesy of USGS - This Dynamic Earth: The Story of Plate Tectonics "The Himalayas: Two continents collide"

Activity

1. Review mountain and volcano formation with students. What plate boundary types form mountains and what boundary types form volcanoes?

2. Put the plate boundary overhead up for students to see. Ask them, based upon what you just told me, where would you expect to see mountains? What about volcanoes?

3. Now show students the World Map in relief. Ask students where they see mountains. Do they always match up with collision boundaries?

4. Where do they see volcanic mountains or islands? Do they always match up with subduction zones?

5. Have groups take plate boundary maps and color mountains ranges that are formed by collision boundaries one color, volcanoes that are formed at subduction zones another color, mountains that are not are not obviously associated with collision boundaries a third color, and volcanoes that are not obviously associated with subduction zones the forth color. Remind them their maps should have a key.

Closure
Have several students share their ideas with the class. Once several students have shared their ideas, leave students with the following questions: If not all mountains and volcanoes are associated with plate boundaries, what caused them? (You may have the students answer out loud, in their science notebooks or leave the question unanswered as “food for thought.”)

Embedded Assessment
Have students correctly identified the mountains and volcanoes that are formed by collision plate boundaries? Have students correctly identified mountains and volcanoes that do not appear to be formed by collision plate boundaries?

Homework
Write a 2-3 sentence conclusion in your science notebook. Conclusions should describe what you have learned and be thought provoking.

Embedded Assessment