Science chapter 18 Flashcards
Pluton that cuts across preexisting rocks and often forms when magma invaders crack in surrounding rock bodies
dike
Any activity that includes the movement of magma toward or onto Earth’s surface
Volcanism
An area where magma from deep within the mantle melts through the crust above it
hot spot
huge amounts of lava that erupt from fissures
flood basalt
A tubelike structure that allows lava to reach the surface
conduit
Opening in Earth’s crust through which lava erupts and flows out onto the surface
vent
A bowl-shaped area that forms around a volcano’s central opening
Crater
A long crack in Earth’s crust
fissure
Large craters up to 100 km in diameter can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption
Caldera
a broad, domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava.
shield volcano
Steep-sided, the generally small volcano that is built by the accumulation of tephra around the vent.
cinder cone
Generally cone-shaped with concave slopes, built by violent eruptions of volcanic fragments and lava that accumulate in alternating layers
composite volcano
resistance to flow
Viscosity
bits of rock dropped from the air from volcanoes
Tephra
Swift moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a violent eruption
pyroclastic flow
a body of intrusive igneous rock.
pluton
irregularly shaped pluton that is similar to a batholith but smaller, generally forms 5-30 km beneath Earth’s surface, and cuts across older rocks
stock
Relatively small, mushroom-shaped pluton that forms when magma intrudes into parallel rock layers close to Earth’s surface.
Laccolith
Pluton that forms when magma intrudes parallel rock layers
v
sill
coarse grained, irregularly shaped, igneous rock mass that covers at least 100 km(2), generated forms 10 - 30 km below Earth’s surface, and is common in the interior of major mountain chains
batholith
