Chapter 9 Vocab - Volcanoes

a type of lava flow that has a jagged, blocky surface

a large mass of igneous rock that formed when magma was emplaced at depth, crystallize, and subsequently exposed by erosion

a large depression typically caused by collapse or ejection of the summit area of a volcano

a rather small volcano built primarily of pyroclastic ejected from a single vent

a pattern of cracks that form during cooling of molten rock to generate columns that are generally six sided

a volcano composed of both lava flows and pyroclastic material

a pipeline opening through which magma moves toward earth’s surface. it terminates at the vent

mountains formed in part by igneous activity associated with the subduction of oceanic lithosphere beneath a continent

the depression at the summit of a volcano, or that which is produced by a meteorite impact

melting that occurs as rock ascends due to a drop in confining pressure

a tabular shaped intrusive igneous feature that cuts through the surrounding rock

buoyant plumes that extend thousands of meters into the atmosphere

an eruption into which lava is extruded from narrow fractures or cracks in the crust

flows of basaltic lava that issue from numerous cracks or fissures and commonly cover extensive areas to thicknesses of hundreds of meters

a vent into a volcanic area from which fumes or gases escape

natural steam used for power generation

a concentration of heat into the mantle capable of producing magma, which in turn exudes onto earth’s surface

igneous activity that occurs within a tectonic plates away from plate boundaries

a chain of volcanic islands generally located a few hundred kilometers from a trench where active subduction of one oceanic slab beneath another is occurring

a massive igneous body intruded between preexisting strata

mudflows on the slopes of volcanoes that result when unstable layers of ash and debris become saturated and flow downslope, usually following stream channels

tunnel hardened lava that acts as a horizontal conduit for lava flowing from a volcanic vent.

a mass of hotter than normal mantle material that ascends toward the surface, where it may lead to igneous activity

incandescent volcanic debris buoyed up by hot gases that moves downslope in an avalanche fashion