dike		Opening through which molten rock and gases leave a volcano.
compound		Bowl-shaped area around a volcano's central opening.
caldera		A deposit of hardened magma in a volcano's pipe.
aa		Slab of volcanic rock formed when magma squeezes between layers of rock.
element		Slab of volcanic rock formed when magma is forced across rock layers. Acts much like a levee.
silica		____ volcano - Steep cone-shaped volcano with alternating layers of ash and other volcanic materials.
hotspot		A major belt of volcanoes that rims the Pacific Ocean.
geyser		The area covered by lava as it pours out of a volcano's vent.
volcano		The expulsion of ash, cinders, bombs, and gases during an explosive eruption.
active		A volcano that is currently erupting or showing signs that it will erupt.
magmachamber		A material found in magma and made of silicon and oxygen.
pahoehoe		A volcano that no longer active and unlikely to erupt again.
viscosity		Two or more elements that are chemically combined.
physical		Fast-moving lava that hardens to form smooth, rope-like coils.
chemical		Long tube through which magma moves through a volcano.
pipe		A volcano that is not currently active, but will be active again.
dormant		Weak spot in the crust where magma has come to the surface.
islandarc		Liquid magma that reaches the surface.
pyroclasticflow		Pocket beneath a volcano where magma collects.
ringoffire		Fountain of water and steam that builds up underground and erupts at regular intervals.
magma		___ property - any characteristic of a substance that can be observed or measured without changing the composition of the substance.
lavaflow		____ property - any property of a substance that produces a change in the composition of the matter.
cindercone		Slow-moving lava that hardens to form rough chunks.
volcanicneck		A large hole formed when a volcano collapses.
sill		Area where magma melts through the Earth's crust.
batholith		Mass of rock formed when a large body of magma cools outside of the crust.
extinct		Wide, sloping mountain made of layers of lava and formed by quiet eruptions.
shieldvolcano		Molten mixture of rock-forming substances, gases, and water from the mantle.
lava		A substance that cannot be broken down into other substances.
veht		The resistance of a liquid to flowing.
crater		String of islands formed by volcanoes.