A’KF diagram Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A three-component triangular graph that is used to show how metamorphic *mineral assemblages vary as a function of rock composition within one ...
A-layer Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
The seismic layer corresponding to the *crust of the Earth. It varies in thickness from a few kilometres to 70–90 km. The base lies on the ...
A-subduction Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
The movement of one continental lithospheric *plate under another (*subduction) in a *collision zone, with the separation of part or all of the upper ...
A-train Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A series of Earth-observing satellites operated by NASA and other national space agencies. All the satellites are in *polar orbit...
aa Quick reference
A Dictionary of Environment and Conservation (3 ed.)
Volcanic **lava rock that is thick and porous and has a rough, jagged surface when it cools. It
Aalenian Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A *stage in the European Middle *Jurassic (175.6–171.6 Ma, Int. Commission on Stratigraphy, 2004). See also
abandoned channel Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A former stream channel through which water no longer flows (e.g. a *cut-off).
abandoned well Quick reference
A Dictionary of Environment and Conservation (3 ed.)
Any *well that has not been used for a long time and/or is not properly sealed, and is so
abandonment facies association Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A *facies association formed under conditions of rising sea level, when *clastic deposition has ceased and sediment is deposited very slowly....
abapical Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
A directional term meaning away from the shell *apex.
abaptation Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
The process by which an organism is fitted to its environment as a consequence of the characters it inherits, which have been filtered by ...
abatement Quick reference
A Dictionary of Environment and Conservation (3 ed.)
The elimination or reduction of emissions that create *pollution. Examples include smoke abatement and noise abatement.
abatement debris Quick reference
A Dictionary of Environment and Conservation (3 ed.)
Waste materials produced by *remediation activities.
Abbey, Edward (1927–89) Quick reference
A Dictionary of Environment and Conservation (3 ed.)
who wrote the book *Desert Solitaire and is remembered for his strong criticism of public land policies and his
abiogenesis Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
abiotic Quick reference
A Dictionary of Environment and Conservation (3 ed.)
Devoid of life, not *biotic, non‐biological. That part of a natural environment that comprises only chemical or physical
abiotic Quick reference
A Dictionary of Geography (5 ed.)
Not living, non-biological, usually describing factors in an ecosystem: atmospheric gases, humidity, salinity, soil mineral particles, water, and so on.
abiotic Quick reference
A Dictionary of Geology and Earth Sciences (4 ed.)
Non-living; devoid of life. Compare
ablation Quick reference
A Dictionary of Environment and Conservation (3 ed.)
1. The process by which *snow or *ice is lost from a *glacier or *ice cap
ablation Quick reference
A Dictionary of Geography (5 ed.)
Loss of snow and ice from a glacier by *sublimation, melting, and evaporation; and from the *calving
