1. Chapter 13
Volcanoes

2. Volcanoes
Volcanoes – places where magma breaks through onto the surface of the earth
Common along plate boundaries

3. Building a Volcano
1. Magma collected in chambers below earth’s surface
2. Pressure build and is pushed through a vent
3. Rock and ash fall around opening
4. Over time a cone is built

4. Many located along subduction zones

6. Island Arcs
Island Arcs – string of volcanic islands

9. Types of Volcanoes Tall and pointy Small and long Sticky lava
Not sticky lava

10. Types of Volcanoes Composite – tall and pointy Sticky lava
Formed by alternating quiet and explosive eruptions

11. Felsic Lava Rich in light colored silicate material
Cooler and stickier
Gases cannot escape

13. Pyroclastic Material Fragments of rock from an eruption Volcanic Ash
Lapilli – “Little stones”
Volcanic Bombs
Volcanic Blocks

20. Types of Volcanoes Shield – long sloping layers Quiet eruptions
Fluid lava

21. Mafic Lava Rich in magnesium and iron Dark Gases are able to escape
Quiet eruptions