Viewing All Flashcards for Dynamic Planet Vocab
A blocky and fragmented form of lava occurring in flows with fissured and
A great irregular mass of coarse-grained igneous
rock with an exposed surface of more than 100 square kilometers, which has
either intruded the country rock or been derived from it through metamorphism.
A structure formed when the crust is divided
into blocks of different elevation by a set of normal faults
A large, circular depression in a volcanic terrain, typically originating in
collapse, explosion, or erosion.
The largest vent of a volcano, situated at the
center of its cone.
A steep, conical hill built up about a volcanic vent and composed of coarse
pyroclasts expelled from the vent by escaping gases.
The mass per unit volume of a substance, commonly expressed in grams/ cubic
The violent oscillatory motion of the ground
caused by the passage of seismic waves radiating from a fault along which
sudden movement has taken place
A theory of fault movement and earthquake generation that holds that faults
remain locked while strain energy accumulates in the country rock, and then
suddenly slip and release this energy.
The point on the Earth's surface directly above the focus or hypocenter of
A planar or gently curved fracture in the Earth's crust across which there
has been relative displacement.
A mountain or range formed as a horst when it was elevated between parallel
The plane that best approximates the fracture
surface of a fault
A plateau basalt extending many kilometers in flat, layered flows
originating in fissure eruptions.
The point at which the rupture occurs; synonymous with hypocenter.
A planar feature, such as a bedding plane, that has been strongly warped,
presumably by deformation.
A small vent in the ground from which volcanic gases and heated groundwater
emerge, but not lava.
: The point below the epicenter at which an earthquake actually begins; the
A rock formed by congealing rapidly or slowly
from a molten state.
An igneous rock body that has forced its way in a molten state into
surrounding country rock.
Igneous rock that is interpreted as a former
intrusion from its cross-cutting contacts, chilled margins, or other field
The mechanism whereby areas of the crust rise or subside until the mass of
their topography is buoyantly supported or compensated by the thickness of
crust below, which "floats" on the denser mantle. The theory that
continents and mountains are supported by low-density crustal
A large and relatively planar fracture in a rock across which there is no
relative displacement of the two sides.
A sill-like igneous intrusion that forces apart
two strata and forms a round, lens-shaped body many times wider than it is
A mudflow of unconsolidated volcanic ash, dust, breccia, and boulders
mixed with rain or the water of a lake displaced by a lava flow.
Magma or molten rock that has reached the
A sinuous, hollow tunnel formed when the outside
of a lava flow cools and solidifies and the molten material passing through it
is drained away
A strike-slip fault on which the displacement of the far block is to the
left when viewed from either side.
The outer, rigid shell of the Earth, situated above the asthenosphere and
containing the crust, continents, and plates.
Molten rock material that forms igneous rocks
upon cooling. Magma that reaches the surface is referred to as lava
A magma-filled cavity within the lithosphere
A measure of earthquake size, determined by taking the common logarithm base
10) of the largest ground motion observed during the arrival of a P-wave or
seismic surface wave and applying a standard correction for distance to the
: The main bulk of the Earth, between the crust
and core, ranging from depths of about 40 to 3480 kilometers. It is composed of
dense mafic silicates and divided into concentric layers by phase changes that
are caused by the increase in pressure with depth.
The boundary between crust and mantle, marked by
a rapid increase in seismic wave velocity to more than 8 kilometers per second.
Depth: 5 to 45 kilometers. Abbreviated "Moho" or
The S-shaped fold connecting two horizontal
parts of the same stratum at different elevations. Its central limb is usually
A dip-slip fault in which the block above the fault has moved downward
relative to the block below.
A fault that combines some strike slip motion with some dip-slip motion.
The release of juvenile gases to the atmosphere
and oceans by volcanism
A basaltic lava flow with a glassy, smooth, and
undulating, or ropy, surface
The primary or fastest wave traveling away from
a seismic event through the solid rock, and consisting of a train of
compressions and dilations of the material
A strike-slip fault on which the displacement of the far block is to the
right when viewed from either side.
The mechanism by which new sea floor crust is created at ridges in
divergence zones and adjacent plates are moved apart to make room. This process
may continue at 0.5 to 10 centimeters/year through many geologic periods.
A mode of seismic prospecting in which the seismic profile is examined for
waves that have been refracted upward from seismic discontinuities below the
profile. Greater depths may be reached than through seismic reflection.
A seismic wave that follows the earth's surface only, with a speed less than
that of S-waves. There are Raleigh
waves (forward and vertical vibrations) and Love waves (transverse vibrations).
A volcanic cone consisting of both lava and pyroclastic rocks, often
A quantity describing the forces acting on each part of a body in units of
force per unit area
A fault whose relative displacement is purely
A dipping planar zone descending away from a trench and defined by high
seismicity, interpreted as the shear zone between a sinking oceanic plate and
an overriding plate.
The secondary seismic wave, traveling slower
than the P-wave, and consisting of elastic vibrations transverse to the
direction of travel. It cannot penetrate a liquid.
A large fold whose limbs are higher than its center; a fold with the
youngest strata in the center.
A dip-slip fault in which the upper block above
the fault plane moves up and over the lower block, so that older strata are
placed over younger
: A strike-slip fault connecting the ends of an
offset in a mid-ocean ridge. Some pairs of plates slide past each other along
Large destructive wave caused by sea-floor
movements in an earthquake.
A volcanic sediment of rock fragments, usually glass, less than 2
millimeters in diameter that is formed when escaping gases force out a fine
spray of magma.
A pyroclastic rock fragment ranging from about
fist- to car-sized.
A pyroclastic rock fragment that shows the
effects of cooling in flight in its streamlined or "bread-crust"
: The deposit of lava and pyroclastic materials that has settled close to
the volcano's central vent.
A rounded accumulation around a volcanic vent of
congealed lava too viscous to flow away quickly; hence usually rhyolite lava
: A collective term for all the pyroclastic rocks deposited around a
volcano, especially by a volcanic explosion.
Gases, especially steam, emitted from a vent
or released from lava.
Can refer to either Obsidian or Pumice
The vertical chamber along which magma and gas ascend to the surface; also,
a formation of igneous rock that cooled in a pipe and remains after the erosion
of the volcano.
Any opening through the crust that has allowed magma to reach the surface,
including the deposits immediately surrounding this vent.