Volcanoes Flashcards
Volcanic activity can be intrusive and extrusive. What does this mean?
Intrusive: below earths surface
Extrusive: on earths surface
5 main types of volcano…
Dome Composite cone Shield Caldera Fissure
Lava eruptions are extrusive, and the formation of large magma chambers (batholiths) is intrusive. Name other intrusive features…
Dyke
Sill
Batholith
Laccolith
Lava eruptions are extrusive.
What are the 3 main types of lava?
Basaltic
Andesitic
Rhyolitic
At which plate margin would you find basaltic lava?
Constructive
At which plate margin would you find andesitic lava?
Destructive
At which plate margin would you find rhyolitic lava?
Destructive
What is the silica content of the 3 lava types (low, medium and high)?
Basaltic: LOW
Andesitic: MEDIUM
Rhyolitic: HIGH
Where do dome volcanoes occur?
At destructive margins
Where do caldera volcanoes occur?
Destructive margins
Where do shield volcanoes occur?
Constructive margins
Where do fissure volcanoes occur?
Constructive margins
What type of lava do dome volcanoes eject?
Rhyolitic or Andesitic
What type of lava do caldera volcanoes eject?
Andesitic or rhyolitic
What type of lava do shield volcanoes eject?
Basaltic
What type of lava do fissure volcanoes eject?
Basaltic
What are hot springs?
Springs are places where groundwater emerges at the surface of the crust. If these areas are close to recent intrusive volcanic activity, the water is heated, resulting in a HOT SPRING.
Hot springs and geysers are NOT the same.
What is a geezer?
A cool dude in London.
No seriously, what is a geyser?
Where the groundwater is heated to boiling point and ejected with more force due to increased pressure.
What is a hotspot?
A volcano that occurs away from a plate margin.
What causes a hotspot to occur?
Magma plume rises from mantle. This stays stationary and the ground above moves upwards over time. Over time this creates a dormant volcano, as the crust will continue to move over the hotspot, eventually creating a chain of dormant volcanoes.
