Kaboom!
When a common type of basaltic lava hardens, it forms a____________ .
a rough, jagged surface
The particles produced in volcanic eruptions are called what?
pyroclastic materials
Magma forms when solid rock in the crust and upper mantle
partially melts
A large depression in a volcano is called a what?
caldera
At divergent plate boundaries in the ocean, _____________ and melts because of a decrease in pressure.
magma rises
What forms when fluid basaltic lava flows out of fissures?
lava palteaus
Most islands have grown from the ocean floor from what type of volcano?
shield volcanoes
Structures that form from the cooling and hardening of magma beneath Earth’s surface are called what?
plutons
Which type of landform develops at plate boundaries where one oceanic plate descends beneath another?
trench
What happens to viscosity as the temperature of lava increases?
its viscosity decreases
What forms where slabs of oceanic lithosphere are subducted under continental lithosphere?
continental volcanic arc
What type of volcano is fairly symmetrical and has both layers of lava and pyroclastic deposits?
a composite cone volcano
The lens-shaped pluton that has pushed overlying rock layers upward is called what?
lacolith
What are the landforms at divergent ocean plate boundaries?
mid-ocean ridges
What plays a major part in determining the form of a volcano?
magma composition
A particle larger than 64 mm in size ejected as glowing lava is called what?
volcanic bomb
Most intraplate volcanic activity occurs where ______________________ toward the surface within a plate
mantle plumes rise
A body of intrusive igneous rock that has surface exposure of more than 100 square kilometers is called what?
batholith
A pluton that forms where magma flows between parallel layers of sedimentary rock is called what?
sill
Which of the following is similar to a batholith but has less than 100 square kilometers exposed?
stock
The most explosive volcanic eruptions come from what type of volcano?
composite cones
Which type of intrusive feature forms when magma is injected into fractures cutting across rock layers?
a dike
The broad, slightly dome-shaped volcanoes of Hawaii are what type of volcano?
shield volcanoes
A landform made of magma that hardened in a volcano's conduit and was later exposed by erosion is called what?
volcanic neck
What two things determine the viscosity of magma?
temperature and chemical composition