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What are the three magma types? |
Basaltic - 50% silicon (hottest)
Andesitic - 60% silicon
Rhyolitic - 70% silicon (coolest) |
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What does Bowen's Reaction Series show? |
The relationship between temperature of magma and the rock thats formed. The less melted, the more mafic. |
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Igneous rock types |
Plutonic - Formed underground, tend to have large crystals
Volcanic - formed from magma, tend to have tiny crystals |
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What's viscosity? |
The resistance to flow (molasses-like) |
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Why are there explosive and non-explosive eruptions? |
Low viscosity means gas can escape magma easily, relieving pressure. High viscosity = vice versa |
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What comes out of volcanoes? |
Pyroclasts - rock fragments
Tephra - pyroclast deposits
Ash |
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Porphyritic
Aphenitic
Glassy |
- large grains set in fine grains
- small grains
- glassy texture |
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Crater vs Caldera |
Craters are smaller while calderas are often several km wide |
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What are the types of volcanoes? |
Shield - short and barely inclined
Tephra/cinder cone - cone-shaped
Stratacone - tall and steep |
