Volcanism
Unusually hot regions of Earth's mantle where high temperature plumes of magma rise to the surface
hot spots
Nonexplosive lava that comes out of ocean ridges
pillow lava
opening in which lava comes out of
vent
broad, gently sloping sides and circular base
shield volcanoes
large, irregularly shaped pluton
batholith
Most are underwater where plates move apart and new ocean floor is produced as magma rises to fill the gap
Divergent volcanoes
non-explosive lava with less than 50% silica
basaltic magma
bowl shaped depression around the vent
crater
formed when eruptions eject small pieces of lava into the air and it falls back to the Earth, forming piles around the vent
cinder cones
lens- shaped pluton with a round top and flat bottom
laccolith
Create subduction zones at oceanic-continental boundaries
convergent volcanism
intermediate explosive magma
andesitic magma
tube-like structure from which lava reaches the surface
conduit
formed by layers of ash and hardened chunks of lava from violent eruptions alternating with layers of lava
composite volcanoes
form when magma intrudes parallel to layers of rock
sills
hot spots beneath continental crust where a tremendous amount of basalt is released
flood basalts
most explosive magma with 60% or more silica content
rhyolithic magma
cracks that lava flows out of
fissures
formed by non-explosive eruptions
shield volcanoes
pluton that cuts across preexisting rocks (up & down)
dike
An example of these are the deccan traps in India
Flood basalts
rapidly moving clouds of tephra mixed with hot, suffocating gases
pyroclastic flows
large depression formed when magma chamber empties and the summit collapses
caldera
Hawaii is an example of these
hot spots
occurs when the magma in a volcano conduit solidifies