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24 terms

Volcanos

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a dry form of lava resembling clinkers
caldera
large, circular-shaped opening formed when the top of a volcano collapses
cinder cone
a steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening.
crater
a bowl-shaped opening at the top of a volcano
felsic lava
silica-rich lava
fissure
an opening, a groove, a split
hot spot
a volcanically active area of Earth's surface far from a tectonic plate boundary
lapilli
Tephra particles between 2mm and 64mm in diameter
lava
magma that reaches Earth's surface
mafic lava
dark-colored lava rich in magnesium and iron
magama
liquid rock material that has not reahed the earth's surface
pahoehoe
Solidified basaltic lava flow on land that has formed with smooth, ropelike surfaces
pillow lava
lava that flows out of fissures on the ocean floor and cools rapidly in rounded shapes
pyroclastic material
The volcanic rock ejected during an eruption, including ash, bombs, and blocks
shield cone
volcanic mountain with a broad base and gently sloping sides
stratovolcano
A composite volcanic cone built of interlayered lava flows and pyroclastic materials
tephra
Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground.
vent
a hole for the escape of gas or air
volcanic ash
rock particals more that 0.25mm but less than 5mm across that are blown into the air by a volcanic eruption
volcanic block
The largest tephra, formed from solid rock blasted from a fissure
volcanic bomb
large, spindle-shaped clot of lava thrown out of a volcano
volcanic dust
volcanic ash that is less than 0.25 mm in diameter
volcanism
any activity that includes the movement of magma toward or onto Earth's surface
volcano
a cone-shaped hill or mountain around this opening, built up of the material that is forced out