1. Land Form Patterns: Volcanic Mountains
Unit 1: Land & Water Forms
World Geography 3200/3202

2. Course Outcomes In this lesson you will:
1.1.8 Explain what causes a volcano to erupt. (k)
1.1.9 Describe the characteristics of an ash and-cinder cone, a shield cone, and acomposite cone. (k)
Conclude how the location of active volcanoes is related to places where plates meet. (a)

3. Terminology
Volcano: An opening in the Earth’s crust through which magma, gases, and ash erupt.
Magma: Molten or melted rock found below Earth’s crust. When magma cools to a solid it forms igneous rocks.
Lava: magma that flows at the Earth’s surface.
Ash : Small pieces of lava that are blasted into the air during volcanic eruptions.
Vent: The opening through which the volcanic material flows.

4. Types of Volcanoes
Ash & Cinder Cone
Shield Cone
Composite Cone

5. Ash & Cinder Cone The simplest type of volcano.
Symmetrical shape, steep sides, large crater. A single vent.
Very explosive. Lava is thick and slow flowing, often blocking the vent  Boom!

6. Shield Cone Shape is broad and flat.
The volcano is built of lava, which nearly always flows from the vent.
Eruptions are milder / the least explosive.

7. Composite Cone
Shape is similar to ash and cinder, except it is built of layers of ash, cinder, and lava.
A network of magma vents develop inside, forming mini-volcanoes.
Eruptions can be explosive, followed by periods of quiet activity.

8. Volcanoes: Review
Which type of volcano is most explosive? Ash & Cinder
Which type of volcano is least explosive? Shield
Which type of volcano is explosive at times and slow flowing lava at times? Composite

9. Volcanoes: Review
Which type of volcano has the thickest lava? Ash & Cinder
Which type of volcano has the thinnest, most liquid lava? Shield
Which type of volcano often has side vents? Composite
Which type of volcano has the gentlest slope? Shield

10. Volcanoes: Review Which type of volcano is steepest? Ash & Cinder
What term is given to the opening of a volcano? Crater
Liquid, fluid, melted rock below the earth's surface is known as: Magma
Liquid, fluid, melted rock that reaches the earth's surface is known as: Lava