- alluvial formation
- alluvial placer
- alluvial river
- alluvial valley
- alluvium period
- alluvium precipitability
- almoclastic rock
- alongshore
- aloxite closure
- alternate
- alternate irrigation
- alternating deposit
- alternating gradient
- alternating strain
- alternation
- alternative
- alternative project
- altimeter
- altimetric data
- altitude
- altitude effect
- altitude range
- aluminium rivet
- aluminium solder
- ambit
- amorphous rock
- amortization
- amphibious
- amphoric
- ample
- amygdaloid
- analysis certificate
- analyzer
- anchor bolt
- anchor mixer
- anchorage
- ancillary
- angle shears
- angle-cutter
- angled
- anglepoise lamp
- angular data
- angular grain
- angular slip
- angular strain
- angularity
- annealing point
- annual intensity
- annual output
- anomalousness