Chapter 6, Section 1 Igneous Rocks

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Chapter 6, Section 1Igneous Rocks

• Igneous Rock

• A rock that forms from the cooling and hardening
  of molten rock

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• Magma
• Lava

• Molten rock found under the Earths Surface
• Molten Rock found on the Earths surface

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• Felsic magma
• Mafic magma

• Light in color, very thick has a high silica
  content
• Dark in color and very thin low silica content

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• Intrusive igneous rocks

• Rocks that form underground from magma
• Take a long time to cool because underground
  (holds the heat in)

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• Extrusive igneous rock

• Forms on the Earths surface from lava
• Cools and hardens very quickly b/c on the Earths
  surface

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• Crystal size
• Porphyry

• Intrusive igneous rocks tend to have LARGE
  crystals
• The longer it takes the rock to cool, the larger
  the crystals will be
• VERY large crystals

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• Felsic magmas
• Granite
• Rhyolite
• Pumice
• Obsidian

• Granite family

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• Mafic magmas
• Gabbro
• Basalt
• Scoria
• Diabase

• Gabbro family

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• Diorite family

• Intermediate magma
• Diorite and andesite