Science Volcano Terms Flashcards
Shield Volcano
a wide, gently-sloping mountain made of layers of lava; formed by quiet eruptions
Volcanic Neck
hardened magma in a volcano’s pipe
Basin
a broad, bowl-shaped valley formed when the crust is bent forward
Cinder Cone
a steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs
Central Valley
the large basin in California between the Coast Ranges and the Sierra Nevada
Composite Volcano
a tall, cone-shaped mountain in which layers of lava and ash alternate
Geyser
a fountain of water and steam that builds up pressure underground and erupts at regular intervals
Extinct
a volcano that is no longer active and is unlikely to erupt again
Ring of Fire
volcano belt that rims the Pacific Ocean
Lava
liquid magma that reaches the surface; also, the rock formed when liquid lava hardens
Magma
the molten mixture of rock-forming substances, gases, and water form the mantle
Crater
a bowl-shaped area that forms around a volcano’s opening
Batholith
a mass of rock formed when a large body of magma cools inside the crust
Sill
a slab of volcanic rock formed when magma squeezes between layers of rock
Dike
a slab of volcanic rock formed when magma forces itself across rock layers
Caldera
the large hole formed at the top of a volcano formed when the roof of a magma chamber collapses
Volcano
a weak spot in the crust where magma has come to the surface
Lava Flow
area covered by lava from a volcano’s vent
Vent
opening through which magma leaves a volcano
Pipe
a long tube through which magma moves from the magma chamber to the surface
Magma Chamber
the pocket beneath a volcano where magma collects
Hot Spot
an area where magma from deep within the mantle melts through the crust above it
Island Arc
a string of islands found by volcanoes along a deep-ocean trench
Intrusion
an igneous rock layer formed when magma hardens beneath Earth’s surface
Dormant
a volcano not currently active, but may become active again in the future
Pyroclastic Flow
an explosive volcanic eruption of ash, cinders, bombs, and gases
Silica
a material found in magma that is formed from the elements oxygen and silicon
Dike
a slab of volcanic rock formed when magma forces itself across rock layers
