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Location of Volcanism

Where are most active volcanoes found?
Other locations?

Typical Eruption Sequence

1.
2.
3.
4.
5.
6.
7.
8.

Volcano

Conical or dome-shapes landforms - built from eruption of lava flows and/or pyroclastic materials
Magma rises from a magma chamber through a conduit (vent)
Type of volcano depends on:
1.
2.

Spatter Cones

Small basalt cones - (only a few meters tall)
Built on top of active pahoehoe lava flows.
• Spatter Cone Example 1
• Spatter Cone Example 2

Cinder Cones (a.k.a. Scoria Cones)

Cone-shaped pile of loose cinders ((scoria) erupted from a central vent.
Eruption craters, Lava flows
• Cinder Cone Example 1
• Cinder Cone Example 2
• Cinder Cone Example 3
• Cinder Cone Example 4
• Cinder Cone Example 5
• Cinder Cone Example 6

Shield Volcanoes

Shallow slopes with relatively flat tops built from basalt, pahoehoe lava flows (look like a shield lying on ground)
Largest volcanoes in the world and Solar System
• Shield Volcano Example 1
• Shield Volcano Example 2
• Shield Volcano Example 3
• Shield Volcano Example 4

Stratovolcanoes (a.k.a. Composite Cones)

Conical volcano of andesite, dacite or rhyolite flows and pyroclastic deposits
Violent eruption - due to gas content and high viscosity magma
Ash deposits can be extensive
• Stratovolcano Example 1
• Stratovolcano Example 2
• Stratovolcano Example 3
• Stratovolcano Example 4
• Stratovolcano Example 5
• Stratovolcano Example 6
• Stratovolcano Example 7

Domes

Steep-sided domes/piles of andesite, dacite or rhyolite lava flows (viscous - low gas)
Endogenous domes - lava builds the dome from the inside
Exogenous domes - lava builds the dome by flows on the surface
• Dome Example 1
• Dome Example 2
• Dome Example 3
• Dome Example 4
• Dome Example 5
• Dome Example 6
• Dome Example 7

Other Volcanic Features

Flood Basalt – large volume fissure eruptions of basalt lava flows.
• Flood Basalt Example 1
• Flood Basalt Example 2
• Flood Basalt Example 3

Caldera – magma chamber collapse structures
• Caldera Example 1
• Caldera Example 2

Sea Floor Volcanism – mid-ocean ridge, seamounts, guyots

Hot Springs – magma heated water and geysers

 

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