Volcanoes

Science

batholith

a large rock mass that forms when magma cools inside Earth’s crust

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caldera

a large, circular hole that forms when the top of a volcano collapses

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cinder cone volcano

a steep, cone-shaped volcano, it is made of ash and cinders

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composite volcano

a tall, cone-shaped volcano, it is made of alternating layers of lava and ash

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crater

a cup-like shape that forms at the vent of a volcano

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dike

a slab of volcanic rock formed when magma hardens across layers of rock

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fault-block mountain

mountains formed as blocks of rock move up or down along faults

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geyser

a hot spring that periodically shoots water and steam into the air

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hot spot

an area where magma melts through the crust above it

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lava

molten rock that reaches the Earth's surface

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magma

molten rock beneath the Earth's surface

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magma chamber

a large pocket of molten rock under a volcano

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mountain

a tall landform that rises to a peak

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pyroclastic flow

the fast-moving hot gases, ash, and cinders expelled from a volcano

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shield volcano

a wide, gently sloping mountain formed by lava from quiet eruptions

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sill

igneous rock feature formed when magma squeezes between layers of rock

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vent

an opening in the ocean floor where water heated by magma below rises up through cracks

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viscosity

a fluid's resistance to flowing

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volcanic neck

hardened magma in a volcano’s pipe

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volcano

a mountain through which lava flows to Earth’s surface

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