Volcanoes

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Volcanoes

• Volcanic Landforms

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• What landforms does lava create on Earths
  surface?
• How does magma that hardens beneath the surface
  create landforms?

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Landforms From Lava Ash
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Shield Volcano

• A wide, gently-sloping mountain made of layers of
  lava and formed by quiet eruptions
• Example The Hawaiian Islands

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Cinder Cone

• A steep, cone-shaped hill or mountain made of
  volcanic ash, cinders, and bombs piled of around
  a volcanos opening
• Example Sunset crater in Arizona

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Composite Volcano

• A tall, cone-shaped mountain in which layers of
  lava alternate with layers of ash and other
  volcanic materials
• Example Mount St. Helens in Washington and Mount
  Fuji in Japan

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Caldera

• The large hole at the top of a volcano formed
  when the volcanos magma chamber collapses

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What are the three types of volcanic mountains?

• The three types of volcanic mountains are
• Shield volcanoes
• Cinder cone volcanoes
• Composite volcanoes

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What landforms does lava create on Earths
surface? Explain how each landform is formed.

• Shield volcanoes
• Lava pours out of the volcanos vent and hardens
  creating new layers of rock
• Cinder cone volcanoes
• Ash, cinders, and bombs pile up around the
  volcano vent in a cone-shaped pile
• Composite volcanoes
• Quiet eruptions (lava flow) alternate with
  explosive eruptions (ash, cinders, and bombs)
  creating a tall cone-shaped mountain
• Lava plateaus
• Lava fills the cracks in Earth creating higher
  elevated, flat land

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Landforms From Magma
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Volcanic Neck

• A deposit of hardened magma in a volcanos pipe
• Looks like a giant tooth stuck in the ground

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Dike

• A slab of volcanic rock formed when magma hardens
  in a vertical crack

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Sill

• A slab of volcanic rock formed when magma hardens
  in a horizontal crack

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Compare and Contrast What is the difference
between a dike and a sill?

• Both a dike and a sill form when magma hardens in
  a crack
• A dike forms when magma hardens into a vertical
  crack
• A sill forms when magma hardens into a horizontal
  crack

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Batholith

• A mass of rock formed when a large body of magma
  cooled inside the crust

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How does magma that hardens beneath the surface
create landforms?

• Volcanic necks
• Magma hardens inside the volcanos pipe and the
  softer layer around the pipe wears away
• Dikes
• Magma forces its way into vertical cracks in the
  crust and hardens
• Sill
• Magma squeezes between horizontal layers of rock
  and hardens