Chapter 4 Vocab Flashcards
Lava having a surface of angular blocks associated with material having andesitic and rhyolitic compositions.
Block Lava
A type of lava flow that has a jagged, blocky surface.
Aa Flows
A large depression typically caused by collapse of the summit area of a colcannon following a violent eruption.
Caldera
A rather small volcano built primarily of pyro classics ejected from a single vent.
Cinder Cone/ Scoria Cone
A volcano composed of both lava flows and pyro clastic material.
Composite Cone/stratovolcanoes
A A pipe like opening through which magma moves towards Earth surface. It terminates at a surface opening called a vent.
Conduit
Mountains formed in part by Igneous activity associated with the seduction of oceanic lithosphere beneath the Continent. Examples include the Andes and the Cascades.
Continental volcanic arc
The depression at the summit of a volcano or that which is produced by a meteorite impact.
Crater
Buoyant plumes of hot ash laden gases that can extend thousands of meters into the atmosphere
Eruption columns
A crack in rock along which there is a distinct separation
Fissures
Any eruption in which lava is extruded from narrow fractures or cracks in the crust
Fissure eruptions.
Flows of basaltic lava that issue from numerous cracks or fissures and commonly cover extensive areas to thicknesses of hundreds of meters
Flood basalt
A vent in a volcanic area from which fumes or gases escape
Fumaroles
A proposed concentration of heat in the mantle capable of introducing magma that in turn extrudes on the earths surface. That intraplate volcanism that produced the Hawaiian Islands is one example
Hotspot
Igneous activity that occurs within a tectonic plate away from plate boundaries.
Intraplate volcanism
A chain of volcanic islands generally located a few hundred kilometers from a trench where there is active subduction of one oceanic plate beneath another
Island arcs/volcanic island arc
Mudflows on the slopes of volcanoes that result when unstable layers of ash and debris become saturated and flow downslope, usually following stream channels
Lahar
A bulbous mass associated with an old age volcano, produced when thick lava is slowly squeezed from the vent. Lava domes may act as plugs to the deflect subsequent gaseous eruptions
Lava dome
Tunnel in hardened lava that acts as a horizontal conduit from lave flowing from a volcanic vent. Lava tubes allow fluid lavas to advance great distances
Lava tubes
A mass of hotter than normal mantle material that ascends toward the surface, where it may lead to igneous activity. These plumes of solid yet mobile material may originate as deep as the core mantle boundary
Mantle Plume
Incandescent volcanic debris that is buoyed up by hot gases and moves downslope in an avalanche fashion
Nuée ardente
A lava flow with a smooth to ropy surface.
Pahoehoe Flows
A volcanic cone that forms on the flank of a larger volcano
Parasitic Cone
Ballistic lava that solidifies in an underwater environment and develops a structure that resembles a pile of pillows
Pillow lavas
Of vertical conduit through which magmatic materials have passed.
Pipe
A highly heated mixture, largely of ash and pumice fragments. Traveling down the flanks of volcano or along the surface of the ground
Pyroclastic flow
The volcanic rock ejected during an eruption. Pyroclastics include ash bombs and blocks
Pyroclastic material
Hardened lava that has retained the vesicles produced by escaping gases
Scoria
Abroad, gently sloping volcano built from fluid basaltic lava’s
Shield Volcanoes
A measure of a fluids resistance to flow
Viscosity
An isolated, steep sided, erosional remnant consisting of lava that once occupied the vent of a volcano
Volcanic neck
A mountain formed from lava and/or pyroclastic’s
Volcano
Gaseous components of magma dissolved in the melt. Volatiles will readily vaporize at surface pressures.
Volatiles
