Definitions for test #3 Flashcards
Igneous
having solidified from lava or magma. (relating to or involving volcanic processes)
Intrusive
having been forced between preexisting rocks or rock layers while in a molten or plastic condition. noting or pertaining to plutonic rocks.
lithification
complex process whereby freshly deposited loose grains of sediment are converted into rock. The sediment may be compacted by rearrangement of grains under pressure, reducing pore space and driving out interstitial liquid.
rock texture
the size, shape, and arrangement of the grains
ash flow
An avalanche of volcanic ash, generally a highly heated mixture of volcanic gases and ash, traveling down the flanks of a volcano or along the surface of the ground.
tsunami
ocean waves triggered by: Large earthquakes that occur near or under the ocean.
shield volcano
a broad domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava.
batholith
a type of igneous rock that forms when magma rises into the earth’s crust, but does not erupt onto the surface.
laccolith
a type of igneous intrusion that has split apart two strata, resulting in a domelike structure; the floor of the structure is usually horizontal
sedimentary
that has formed from sediment deposited by water or air.
extrusive
relating to or denoting rock that has been extruded at the earth’s surface as lava or other volcanic deposits.
compaction
decrease of the volume of a fixed mass of sediment from any cause, commonly from continual sediment deposition at a particular site.
rock composition
refers to both the types of minerals within a rock and the overall chemical makeup of the rock
lahars
a hot or cold mixture of water and rock fragments that flow quickly down the slopes of a volcano.
pahoehoe lava
basaltic lava forming smooth undulating or ropy masses.
composite volcano
A volcano with a broad base, steep sides, and often a crater at the top. The volcano is composed of alternating layers of ash and lava flows.
dike
a large slab of rock that cuts through another type of rock.
metamorphic
etamorphic rocks are formed when igneous, sedimentary, or other metamorphic rocks undergo a physical change due to extreme heat and pressure.
erosion
the geological process in which earthen materials are worn away and transported by natural forces such as wind or water.
crystallization
he process in which crystals are formed either from something that has been melted or from a solution
ash fall
a rain of airborne ash resulting from a volcanic eruption.
volcanic gas
the fluid gas phase released by active volcanoes, both during eruption and quiescence. Compositionally, volcanic gases are molecular combinations of four major elements (H, C, O, and S)
aa lava
a more viscous flow whose surface is covered by thick, jumbled piles of loose, sharp blocks.
pluton
a body of intrusive igneous rock.
sill
a tabular sheet of igneous rock intruded between and parallel with the existing strata.
