water from obliquely breaking
waves.
Beach face The wet, sloping
surface that extends from the berm
to the shoreline.
Beach nourishment Large
quantities of sand are added to the
beach system to offset losses caused
by wave erosion. By building
beaches seaward, beach quality and
storm protection are both improved.
Bed See Strata.
Bed load Sediment rolled along
the bottom of a stream by moving
water, or particles rubbed along the
ground surface by wind.
Bedding plane A nearly flat
surface separating two beds of
sedimentary rock. Each bedding
plane marks the end of one deposit
and the beginning of another having
different characteristics.
Bedrock A general term for the
rock that underlies soil or other
unconsolidated surface materials.
Belt of soil moisture A zone in
which water is held as a film on the
surface of soil particles and may be
used by plants or withdrawn by
evaporation. The uppermost
subdivision of the zone of aeration.
Berm The dry, gently sloping zone
on the backshore of a beach at the
foot of the coastal cliffs or dunes.
Biochemical Describing a type of
chemical sediment that forms when
material dissolved in water is
precipitated by water-dwelling
organisms. Shells are common
examples.
Biogenous sediment Seafloor
sediments consisting of material of
marine-organic origin.
Bituminous coal The most
common form of coal, often called
soft, black coal.
Block lava Lava having a surface
of angular blocks associated with
material having andesitic and
rhyolitic compositions.
Blowout (deflation hollow) A
depression excavated by wind in
easily eroded materials.
Body wave A seismic wave that
travels through Earth’ s interior.
Bottomset bed A layer of fine
sediment deposited beyond the
advancing edge of a delta and then
buried by continuous delta growth.
Bowen’s reaction series A
concept proposed by N. L. Bowen
that illustrates the relationship
between magma and the minerals
crystallizing from it during the
formation of igneous rock.
Braided stream A stream
consisting of numerous intertwining
channels.
Breakwater A structure
protecting a nearshore area from
breaking waves.
Breccia A sedimentary rock
composed of angular fragments that
were lithified.
Brittle deformation Deformation
that involves the fracturing of rock.
Associated with rocks near the
surface.
Burial metamorphism Lowgrade metamorphism that occurs in
the lowest layers of very thick
accumulations of sedimentary
strata.
Caldera A large depression
typically caused by collapse of the
summit area of a volcano following
a violent eruption.
Caliche A hard layer, rich in
calcium carbonate, that forms
beneath the B horizon in soils of arid
regions.
Calving Wastage of a glacier that
occurs when large pieces of ice
break off into water.
Cap rock A necessary part of
an oil trap, the cap rock is
impermeable and hence keeps
upwardly mobile oil and gas from
escaping at the surface.
Capacity The total amount of
sediment a stream is able to
transport.
Capillary fringe A relatively
narrow zone at the base of the zone
of aeration. Here water rises from
the water table in tiny threadlike
openings between grains of soil or
sediment.
Catastrophism The concept that
Earth was shaped by catastrophic
events of a short-term nature.
Cavern A naturally formed
underground chamber or series of
chambers most commonly
produced by solution activity in
limestone.
Cementation One way in which
sedimentary rocks are lithified. As
material precipitates from water that
percolates through the sediment,
open spaces are filled and particles
are joined into a solid mass.
Cenozoic era A time span on the
geologic time scale beginning about
65.5 million years ago following the
Mesozoic era.
Chemical bond A strong
attractive force that exists between
atoms in a substance. It involves the
transfer or sharing of electrons that
allows each atom to attain a full
valence shell.
Chemical compound A
substance formed by the chemical
combination of two or more
elements in definite proportions and
usually having properties different
from those of its constituent
elements.
Chemical sedimentary rock
Sedimentary rock consisting of
material that was precipitated from
water by either inorganic or organic
means.
Chemical weathering The
processes by which the internal
structure of a mineral is altered by
the removal and/or addition of
elements.
Cinder cone A rather small
volcano built primarily of pyroclastics
ejected from a single vent.
Cirque An amphitheater-shaped
basin at the head of a glaciated
valley produced by frost wedging
and plucking.
Clastic A sedimentary rock
texture consisting of broken
fragments of preexisting rock.
Cleavage The tendency of a
mineral to break along planes of
weak bonding.
Climate feedback mechanism
Because the atmosphere is a
complex interactive physical system,
several different outcomes may
result when one of the system’ s
elements is altered. These various
possibilities are called climatefeedback mechanisms.
Climate system The exchanges of
energy and moisture occurring
among the atmosphere,
hydrosphere, geosphere, biosphere,
and cryosphere.
Coarse-grained texture See
Phaneritic texture.
Coast A strip of land that
extends inland from the coastline
as far as ocean-related features can
be found.
Coastline The coast’ s seaward
edge; the landward limit of the effect
of the highest storm waves on the
shore.
Col A pass between mountain
valleys where the headwalls of two
cirques intersect.
Color A phenomenon of light by
which otherwise identical objects
may be differentiated.
Column A feature found in caves
that is formed when a stalactite and
stalagmite join.
Columnar joints A pattern of
cracks that forms during cooling of
molten rock to generate columns.
Compaction A type of
lithification in which the weight of
overlying material compresses more
deeply buried sediment. It is most
important in fine-grained
sedimentary rocks such as shale.
Competence A measure of the
largest particle a stream can transport;
a factor dependent on velocity.
Composite cone A volcano
composed of both lava flows and
pyroclastic material.
Compound See Chemical
compound.
Compressional mountains
Mountains in which great horizontal
forces have shortened and
thickened the crust. Most major
mountain belts are of this type.
Concordant A term used to
describe intrusive igneous masses
that form parallel to the bedding of
the surrounding rock.
Conduit A pipelike opening
through which magma moves
toward Earth’ s surface. It terminates
at a surface opening called a vent.
Confined aquifer An aquifer that
has impermeable layers (aquitards)
both above and below.
Cone of depression A coneshaped depression immediately
surrounding a well.
Conformable layers Rock layers
that were deposited without
interruption.
Conglomerate A sedimentary
rock consisting of rounded,
gravel-size particles.
GLOSSARY
534
waves.
Beach face The wet, sloping
surface that extends from the berm
to the shoreline.
Beach nourishment Large
quantities of sand are added to the
beach system to offset losses caused
by wave erosion. By building
beaches seaward, beach quality and
storm protection are both improved.
Bed See Strata.
Bed load Sediment rolled along
the bottom of a stream by moving
water, or particles rubbed along the
ground surface by wind.
Bedding plane A nearly flat
surface separating two beds of
sedimentary rock. Each bedding
plane marks the end of one deposit
and the beginning of another having
different characteristics.
Bedrock A general term for the
rock that underlies soil or other
unconsolidated surface materials.
Belt of soil moisture A zone in
which water is held as a film on the
surface of soil particles and may be
used by plants or withdrawn by
evaporation. The uppermost
subdivision of the zone of aeration.
Berm The dry, gently sloping zone
on the backshore of a beach at the
foot of the coastal cliffs or dunes.
Biochemical Describing a type of
chemical sediment that forms when
material dissolved in water is
precipitated by water-dwelling
organisms. Shells are common
examples.
Biogenous sediment Seafloor
sediments consisting of material of
marine-organic origin.
Bituminous coal The most
common form of coal, often called
soft, black coal.
Block lava Lava having a surface
of angular blocks associated with
material having andesitic and
rhyolitic compositions.
Blowout (deflation hollow) A
depression excavated by wind in
easily eroded materials.
Body wave A seismic wave that
travels through Earth’ s interior.
Bottomset bed A layer of fine
sediment deposited beyond the
advancing edge of a delta and then
buried by continuous delta growth.
Bowen’s reaction series A
concept proposed by N. L. Bowen
that illustrates the relationship
between magma and the minerals
crystallizing from it during the
formation of igneous rock.
Braided stream A stream
consisting of numerous intertwining
channels.
Breakwater A structure
protecting a nearshore area from
breaking waves.
Breccia A sedimentary rock
composed of angular fragments that
were lithified.
Brittle deformation Deformation
that involves the fracturing of rock.
Associated with rocks near the
surface.
Burial metamorphism Lowgrade metamorphism that occurs in
the lowest layers of very thick
accumulations of sedimentary
strata.
Caldera A large depression
typically caused by collapse of the
summit area of a volcano following
a violent eruption.
Caliche A hard layer, rich in
calcium carbonate, that forms
beneath the B horizon in soils of arid
regions.
Calving Wastage of a glacier that
occurs when large pieces of ice
break off into water.
Cap rock A necessary part of
an oil trap, the cap rock is
impermeable and hence keeps
upwardly mobile oil and gas from
escaping at the surface.
Capacity The total amount of
sediment a stream is able to
transport.
Capillary fringe A relatively
narrow zone at the base of the zone
of aeration. Here water rises from
the water table in tiny threadlike
openings between grains of soil or
sediment.
Catastrophism The concept that
Earth was shaped by catastrophic
events of a short-term nature.
Cavern A naturally formed
underground chamber or series of
chambers most commonly
produced by solution activity in
limestone.
Cementation One way in which
sedimentary rocks are lithified. As
material precipitates from water that
percolates through the sediment,
open spaces are filled and particles
are joined into a solid mass.
Cenozoic era A time span on the
geologic time scale beginning about
65.5 million years ago following the
Mesozoic era.
Chemical bond A strong
attractive force that exists between
atoms in a substance. It involves the
transfer or sharing of electrons that
allows each atom to attain a full
valence shell.
Chemical compound A
substance formed by the chemical
combination of two or more
elements in definite proportions and
usually having properties different
from those of its constituent
elements.
Chemical sedimentary rock
Sedimentary rock consisting of
material that was precipitated from
water by either inorganic or organic
means.
Chemical weathering The
processes by which the internal
structure of a mineral is altered by
the removal and/or addition of
elements.
Cinder cone A rather small
volcano built primarily of pyroclastics
ejected from a single vent.
Cirque An amphitheater-shaped
basin at the head of a glaciated
valley produced by frost wedging
and plucking.
Clastic A sedimentary rock
texture consisting of broken
fragments of preexisting rock.
Cleavage The tendency of a
mineral to break along planes of
weak bonding.
Climate feedback mechanism
Because the atmosphere is a
complex interactive physical system,
several different outcomes may
result when one of the system’ s
elements is altered. These various
possibilities are called climatefeedback mechanisms.
Climate system The exchanges of
energy and moisture occurring
among the atmosphere,
hydrosphere, geosphere, biosphere,
and cryosphere.
Coarse-grained texture See
Phaneritic texture.
Coast A strip of land that
extends inland from the coastline
as far as ocean-related features can
be found.
Coastline The coast’ s seaward
edge; the landward limit of the effect
of the highest storm waves on the
shore.
Col A pass between mountain
valleys where the headwalls of two
cirques intersect.
Color A phenomenon of light by
which otherwise identical objects
may be differentiated.
Column A feature found in caves
that is formed when a stalactite and
stalagmite join.
Columnar joints A pattern of
cracks that forms during cooling of
molten rock to generate columns.
Compaction A type of
lithification in which the weight of
overlying material compresses more
deeply buried sediment. It is most
important in fine-grained
sedimentary rocks such as shale.
Competence A measure of the
largest particle a stream can transport;
a factor dependent on velocity.
Composite cone A volcano
composed of both lava flows and
pyroclastic material.
Compound See Chemical
compound.
Compressional mountains
Mountains in which great horizontal
forces have shortened and
thickened the crust. Most major
mountain belts are of this type.
Concordant A term used to
describe intrusive igneous masses
that form parallel to the bedding of
the surrounding rock.
Conduit A pipelike opening
through which magma moves
toward Earth’ s surface. It terminates
at a surface opening called a vent.
Confined aquifer An aquifer that
has impermeable layers (aquitards)
both above and below.
Cone of depression A coneshaped depression immediately
surrounding a well.
Conformable layers Rock layers
that were deposited without
interruption.
Conglomerate A sedimentary
rock consisting of rounded,
gravel-size particles.
GLOSSARY
534