Новый большой англо-русский словарь. 2001.
Ahorizon — A horizon n. In ABC soil, the uppermost zone of soil, containing humus; topsoil. Also called zone of leaching. * * * … Universalium
B-horizon — Illuvial horizon in which soluble material from the overlying Ahorizon has been deposited [16] … Lexicon of Cave and Karst Terminology