B

B horizon
The subsoil; the zone where iron oxides and clay minerals accumulate.
barometer
An instrument for measuring atmospheric pressure.
barrier island
Long, narrow island composed of sand; nature’s first line of defense against storms.
base level
Where a stream meets a large body of standing water, usually the ocean.
basin
A circular anticline; oldest rocks are in the center and the youngest are on the outside.
batholith
An enormous body of granitic rock.
bathymetric map
A topographic map that shows depth below sea level to indicate geographic features. These maps are created from the measurement of ocean depths using echo sounders.
beach
The sediments on a shore.
bed load
Sediments moved by rolling or bumping along the stream bed.
Big Bang Theory
The hypothesis that all matter and energy were at one time compresses into a very small volume; then there was an explosion that sent everything moving outward, causing the universe to expand.
binary star
A system of two stars that orbit a common center of mass.
bioaccumulation
The accumulation of toxic substances within organisms so that the concentrations increase up the food web.
biochemical sedimentary rocks
Rocks that form from materials created by living organisms removing ions from water and falling to the bottom to become sediments.
bioclastic
Sedimentary rock that forms from pieces of living organisms.
biodiversity
The number of species of plants, animals and other organisms within a particular habitat.
biofuel
A fuel made from living materials, usually crop plants.
biomass
The total mass of living organisms in a given region.
biome
The living organisms that are found within a climate zone that make that zone distinct.
biotic
Living features of an ecosystem include viruses, plants, animals, and bacteria.
biozone
A rock unit that is defined by a characteristic index fossil or fossil assemblage.
black hole
The super dense core left after a supergiant explodes as a supernova.
blizzard
A large snowstorm with high winds.
body fossil
The remains of an ancient organism. Examples include shells, bones, teeth, and leaves.
body waves
Seismic waves that travel through the body of a planet; e.g. primary or secondary waves.
bottom trawling
Fishing by dragging nets along the ocean floor.
Bowen’s Reaction Series
The order in which minerals undergo partial melting or fractional crystallization, which depends on temperature and the composition of the mineral.
brackish
Water that is a mixture of freshwater and saltwater.
breakwater
Structure built in the water parallel to the shore to protect from strong incoming waves.