Chapter 18 Vocabulary Flashcards
Describes all the processes associated with the discharge of magma, hot water, and steam
Volcanism
Unusually hot area in earth’s mantle where high-temperature plumes if magma rise toward the surface
Hot Spot
Huge amounts of lava that erupt from fissures
Flood basalt
A long crack in earth’s crust
Fissure
A tube-like 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
Bowl-shaped depression that forms around the central vent at the summit of a volcano
Crater
Large crater that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption
Caldera
Broad volcanoes with gently sloping slopes
Shield volcanoes
Steed-sided, generally small volcano that is built by the accumulation of tephra around the vent
Cinder cones
Generally cone-shaped with concave slopes
Composite Volcanoes
Magma that flows onto earth’s surface
Lava
Describes magma or igneous rock that is rich in magnesium and iron that is generally dark in color
Mafic
Describes magma or igneous rock that is rich in feldspar and silica and that is generally light in color
Felsic
Describes a material’s resistance to flow
Viscosity
Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground
Tephra
Swift-moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a volcanic eruption
Pyroclastic flow
