A particle or block of solid volcanic ejecta is a ___?
Pyroclast
What major type of fault occurs when rocks on one side of the fault are shoved over the rocks on the other side.
Thrust fault
What is most likely to cause a volcanic eruption to be violent?
large amounts of dissolved gas
Consists primarily of erupted volcanic ash and rock fragments held loosely together
Cinder-Cone Volcano
Large, irregularly shaped lump made of lava that hardened before being thrown out of the volcano
Volcanic Block
What are large almond or teardrop shaped pieces of ejecta formed when lava solidifies after being thrown high in the air.
Volcanic Bomb
Lava in water solidifies almost instantly, forming rounded structures
Pillow lava
What is an underground channel that formed when surface lava hardened before the lava underneath it?
Lava tunnel
Volcano that probably will not erupt again
Extinct Volcano
Solid particles less than 2 mm in diameter
Volcanic Ash
The type of mountain that forms when molten rock erupts from a hole in the earth's crust.
Volcanic Mountain
Hardened lava that forms rough, jagged rocks with a crumbly texture
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The underground _______ is the actual source of a volcanic eruption.
Magma Chamber
Formed partly by explosive eruptions of ash and rock fragments and partly by mild lava flows
Composite Volcano
Solid ejecta larger than 2 mm but less that 64 mm in diameter
Lapilli
What is the channel in a volcano through which gases, ash, and molten rock are ejected from the earth's interior.
Vent
A mass of underground volcanic rock that is similar to a laccolith but much larger
Batholith
The molten rock beneath the surface of the earth.
Magma
Volcano that is inactive but can erupt again
Dormant volcano
Hardened lava with a surface that is either smooth or ropy
Pahoehoe
What is a bowl-shaped hollow formed by the collapse of an underground magma chamber?
Caldera
Volcano
The general name for a mass of underground volcanic rock.
Igneous Intrusion
Broad and gently sloping with mild eruptions
Shield Volcano
Superheated cloud of gas and small particles that travels as an avalanche
Pyroclastic flow