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Mountain Building

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Mountain Building Folding Faulting Volcanoes Mountain Building Volcanoes What are Volcanoes? A volcano is most commonly a conical hill or mountain built around a vent ... – PowerPoint PPT presentation

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Title: Mountain Building


1
Mountain Building
  • Folding
  • Faulting
  • Volcanoes

2
Mountain Building
  • Volcanoes

3
What are Volcanoes?
  • A volcano is most commonly a conical hill or
    mountain
  • built around a vent
  • that connects with reservoirs of molten rock
    below the surface of the Earth.
  • Molten rock below the surface of the Earth that
    rises in volcanic vents is known as magma.
  • After it erupts from a volcano it is called lava.

4
3 types of volcanoes
  • Ash and cinder cone
  • Shield cone
  • Composite cone

5
1. Ash Cinder Cones
  • As the gas-charged lava is blown violently into
    the air, it breaks into small fragments that
    solidify and fall as cinders around the vent to
    form a circular or oval cone.
  • Most cinder cones have a bowl-shaped crater at
    the summit
  • They rarely rise more than a thousand feet or so
    above their surroundings.

6
1. Ash Cinder Cones
  • Cone shaped
  • Symmetrical
  • Steep sides
  • Violent eruptions
  • Layers of ash Cinder
  • Single central Vent
  • Crater at Summit

7
1. Ash Cinder Cones
8
2. Shield Cones
  • Shield volcanoes are built almost entirely of
    fluid lava flows.
  • Flow after flow pours out in all directions from
    a central summit vent, or group of vents,
  • building a broad, gently sloping cone of flat,
    domical shape, with a profile much like that of a
    warrior's shield.

9
2. Shield Cones
  • Shield shaped
  • Flat, Shallow sides
  • Non-Violent slow emissions of lava
  • Layers of lava
  • No one single vent
  • Covers Large area

10
2. Shield Cones
11
3. Composite Cones
  • Shape not as steep as ash cinder
  • Non-Violent slow emissions of lava one time and
    violent ash eruptions next time
  • Layers of alternating lava Ash/cinder
  • Weak sections may form in the side of the cone.
  • Lava flows out of these forming smaller cones

12
3. Composite Cones
13
Pacific Ring of Fire
  • Volcanoes occur all around the Pacific ocean.
  • At the tectonic plate boundaries.
  • Pattern known as the Pacific Ring of Fire

14
Pacific Ring of Fire
15
  • What type of volcano is illustrated below?
  • a. Ash and cinder c. Hot spot
  • b. Composite d. Shield

16
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