"animal exclusion" theory - advance heading
- abate
- abatis
- abaxial
- Abbevillean
- Abbevillian
- abbreviation
- ABC method
- abdomen
- aber
- abernathyite
- aberrance
- aberration
- abichite
- abiding fish place
- abies
- abietene
- abime
- abiogenesis
- abioglyph
- abjunction
- ablate
- ablation
- ablation moraine
- ablatograph
- ablykite
- Abney level
- abnormal anticlinorium
- abnormal contact
- abnormal dip
- abnormal event
- abnormal pore pressure
- abnormal pressure
- abnormal rock
- abnormally high formation pressure
- abnormally high pore pressure
- aboral
- aboral surface
- aboriginal
- about 60% complete
- above flood-plain