Main types of extrusive landforms Flashcards
Whats the pneumonic to remember main types of extrusive landforms?
act civilised contain (&) compress silly valorise compassion (for) liam payne don’t vail
What is a lava plateaux formed from?
fissure eruptions
What are the lava flows for a lava plateaux?
basaltic so travel far
What are the slopes of lava plateaux like?
flat and featureless
Where do lava plateaux occur?
at divergent margins
Whats an example of a lava plateaux?
Antrim lava plateaux, northern ireland
What type of lava are basic/shield volcanoes formed from?
free-flowing, basaltic lava
What type of slopes do basic/shield volcanoes have?
gentle sides that cover a large area
Where do basic/shield volcanoes occur?
divergent margins/hotspots
Whats an example of a basic/shield volcano?
Mauna Loa, Haiwaii
What are the sides and cone of acid/dome volcanoes like?
steep-sided convex cones
What lava do acid/dome volcanoes consist of?
rhyolitic lava, viscous
Where do acid/dome volcanoes usually occur?
convergent plate margins
Whats an example of an acid/dome volcano?
Puy region, france
What are ash and cinder cones formed from?
ash, cinders and volcanic bombs ejected from the crater
What are the sides of ash and cinder cones like?
steep-sided and symmetrical
Whats an example of an ash and cinder cone?
Paricutín, Mexico
What are the shape of composite cones?
classic pyramid shaped volcanoes
What do composite cones consist of?
layers of ash and lava that are usually andesitic
What are examples of composite cones?
Mount Etna, Mount Fuji (Japan)
How is a caldera formed?
when the build up of gases becomes extreme and a huge explosions removes the summit of the cone, leaving an opening several km in diameter
What might the caldera become flooded by?
the sea, or a lake might form within it
Where do calderas often occur?
at convergent margins
What lava do calderas produce?
rhyolitic and andesitic
Whats an example of a caldera?
Krakatoa (Indonesia) Santorini (Greece)
