ESC 1000
Earth Science Name: __Answers___
Chapter 9: Volcanoes and Other
Igneous Activity
Part K Chapter 9 Key Terms 40 Points
Fill in the blanks with the word or words that best fit the definition:
1.
AA flow A type of lava flow that has a jagged blocky surface.
2.
Batholith A large mass of igneous rock that formed when magma was emplaced at depth,
crystallized, and subsequently exposed by erosion.
3.
Caldera A large depression
typically caused by collapse or ejection of the summit area of a volcano.
4.
Cinder Cone A rather small
volcano built primarily of pyroclastics ejected from
a single vent.
5.
Columnar Joint A pattern of cracks
that form during cooling of molten rock to generate columns that are generally
six-sided.
6.
Composite Cone A volcano composed of
both lava flows and pyroclastic materials.
7.
Conduit A pipelike
opening through which magma moves toward Earths surface. It terminates at a
surface opening called a vent.
8.
Continental Volcanic
Arc Mountains formed in
part by igneous activity associated with the seduction of oceanic lithosphere
beneath a continent.
9.
Crater The depression at the
summit of a volcano, or that which is produced by a meteorite impact.
10.
Decompression
Melting Melting that occurs
as rock ascends due to a drop in confining pressure.
11.
Dike - A tabular shaped intrusive igneous feature that is cuts through the
surrounding rock.
12.
Fissure A crack in the crust
which allows Volcano activity to frequently begin if magma can move forcefully
toward the surface..
13.
Fissure eruption An eruption in which lava is extruded from narrow fractures or cracks
in the crust.
14.
Flood basalt Flows of basaltic lava that issue from numerous cracks or fissures and
commonly cover extensive areas to thickness of thousands of meters.
15.
Furmarole A vent in a
volcanic area from which fumes or gases escape.
16.
Geothermal Gradient
The gradual increase in temperature with depth in the
crust. The average is 30ΊC per kilometer in the upper crust.
17.
Hot Spot A concentration of
heat in the mantle capable of producing magma, which in turn extrudes onto
Earths surface. The intraplate volcanism that
produced the
18.
Intraplate Volcanism Igneous activity that occurs within a tectonic plate away from
boundaries.
19.
Island Arc 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. Same as volcanic island arc.
20.
Laccolith A massive igneous
body intruded between preexisting strata.
21.
Lahar Mudflows on the slopes of volcanoes that result when unstable layers
of ash and debris become saturated.
22.
Mantle Plume 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.
23.
Muee Ardente
Destructive fiery flows, capable of racing down steep
volcanic slopes at speeds that can approach 200 kilometers (125) per hour.
24.
Pahoehoe Flow A lava flow with a smooth-to-ropey surface.
25.
Parasitic Cone
A volcanic cone that forms on the flank of a larger
volcano.
26.
Partial Melting
The process by which most igneous rocks melt. Since individual
minerals have different melting points, most igneous rocks melt over a
temperature range of a few hundred degrees. If the liquid is squeezed out after
some melting has occurred, a melt with a higher silica content results.
27.
Pipe A vertical conduit
through which magmatic materials have passed.
28.
Pluton A structure that results from the emplacement and crystallization of
magma beneath the surface of Earth.
29.
Pyroclastic Flow A highly heated
mixture, largely of ash and pumice fragments, traveling down the flanks of a
volcano or along the surface of the ground.
30.
Pyroclastic Material The volcanic rock
ejected during an eruption, including ash, bombs, and blocks.
31.
Scoria Cone Same as cinder cone: A
rather small volcano built primarily of pyroclastics
ejected from a single vent.
32.
Shield Volcano A broad, gently
sloping volcano built from fluid basaltic lavas.
33.
Sill A tabular igneous
body that was intruded parallel to the layering of preexisting rock.
34.
Strato volcanoes Same as composite cone: A volcano composed of both lava flows
and pyroclastic materials.
35.
Vent surface opening
36.
Viscosity A measure of a
fluids resistance to flow.
37.
Volatiles Gaseous components of
magma dissolved in the melt. Volatiles will readily vaporize (form a gas) at
surface pressures.
38.
39.
Volcanic Neck An isolated, steep-sided, erosional remnant
consisting of lava that once occupied the vent of a volcano.
40.
Volcano A mountain formed of
lava and/or pyroclastics.